<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2023 Workiva-->
<!--r:97f9ad13-1084-4bc3-a4fd-cb5025b2563d,g:d52dff2e-9b5b-414b-87a5-3eda20fb928a-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://intuitivemachines.com/role/Cover" xlink:type="simple" xlink:href="lunr-20230630.xsd#Cover"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_2a383e76-f0c7-47c4-9d3c-29fcbf354a7f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentType_2a383e76-f0c7-47c4-9d3c-29fcbf354a7f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_cab9ee37-a56d-4db4-b140-3331253624f8" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentQuarterlyReport_cab9ee37-a56d-4db4-b140-3331253624f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_138fb5b8-76a7-4690-92e6-0682ba94883f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentPeriodEndDate_138fb5b8-76a7-4690-92e6-0682ba94883f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_440aec4e-38af-4254-a76f-fd821f5f0aeb" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentTransitionReport_440aec4e-38af-4254-a76f-fd821f5f0aeb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_4e908abb-5c00-4f63-ae6b-31dc1f2383da" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityFileNumber_4e908abb-5c00-4f63-ae6b-31dc1f2383da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_fda76c96-5678-41d4-8395-914477f93886" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityRegistrantName_fda76c96-5678-41d4-8395-914477f93886" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_eefc5eaa-5ba7-41ce-8fa3-35689eb71294" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityIncorporationStateCountryCode_eefc5eaa-5ba7-41ce-8fa3-35689eb71294" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_8d010aad-4f7e-474d-845a-f747b4b29f28" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityTaxIdentificationNumber_8d010aad-4f7e-474d-845a-f747b4b29f28" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_e60f9861-110f-4441-9ccd-83f714183576" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityAddressAddressLine1_e60f9861-110f-4441-9ccd-83f714183576" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_79689eaf-7474-4772-9e3f-c5791ca704ba" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityAddressCityOrTown_79689eaf-7474-4772-9e3f-c5791ca704ba" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_df7178ca-3854-4c9a-9fe3-9251912c10fa" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityAddressStateOrProvince_df7178ca-3854-4c9a-9fe3-9251912c10fa" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_7c62582c-f8cf-4d2a-a73f-7a0d5956a3f5" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityAddressPostalZipCode_7c62582c-f8cf-4d2a-a73f-7a0d5956a3f5" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_82235e7a-eeff-451d-9648-41e684edff00" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_CityAreaCode_82235e7a-eeff-451d-9648-41e684edff00" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_83929871-3e88-47e4-bf60-341a30591867" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_LocalPhoneNumber_83929871-3e88-47e4-bf60-341a30591867" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_a7977848-d16b-4186-adee-4e698b2b9a71" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_Security12bTitle_a7977848-d16b-4186-adee-4e698b2b9a71" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_8ea9ec8b-3841-4e5b-a468-8463482ab58c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_TradingSymbol_8ea9ec8b-3841-4e5b-a468-8463482ab58c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_7ca05ee6-ee2b-4683-956a-f624d83634ba" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_SecurityExchangeName_7ca05ee6-ee2b-4683-956a-f624d83634ba" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_5399d156-be81-4012-b99d-ae424e9eec93" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityCurrentReportingStatus_5399d156-be81-4012-b99d-ae424e9eec93" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_848cd911-a0f7-45b4-9c0a-1112cbe2c89f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityInteractiveDataCurrent_848cd911-a0f7-45b4-9c0a-1112cbe2c89f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_27f7c086-cbb2-4660-906c-72e8fc00c48a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityFilerCategory_27f7c086-cbb2-4660-906c-72e8fc00c48a" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_d2c01b14-f2fa-4e17-b9a9-dc150d313bcd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntitySmallBusiness_d2c01b14-f2fa-4e17-b9a9-dc150d313bcd" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_3fdf0deb-aa65-4468-acb5-7b46a433d9bf" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityEmergingGrowthCompany_3fdf0deb-aa65-4468-acb5-7b46a433d9bf" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityExTransitionPeriod_547401a0-c546-46f2-b954-fc98e312f96f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityExTransitionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityExTransitionPeriod_547401a0-c546-46f2-b954-fc98e312f96f" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_6d3acd48-707f-4477-9ee6-b7b9c3bd786a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityShellCompany_6d3acd48-707f-4477-9ee6-b7b9c3bd786a" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_8ed7c4d5-907e-49c1-b94f-eecad0829c7f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityCentralIndexKey_8ed7c4d5-907e-49c1-b94f-eecad0829c7f" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_109d8cc2-1a0e-4ca0-8267-79b8301734dc" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_109d8cc2-1a0e-4ca0-8267-79b8301734dc" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_4807bd88-2a79-42a8-9b21-5fa136b70dbf" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_CurrentFiscalYearEndDate_4807bd88-2a79-42a8-9b21-5fa136b70dbf" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_392359ac-091d-4861-bb35-6344e3e17021" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentFiscalYearFocus_392359ac-091d-4861-bb35-6344e3e17021" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_ee9ab309-97f8-4741-a609-6f24fe3321b6" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentFiscalPeriodFocus_ee9ab309-97f8-4741-a609-6f24fe3321b6" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_ae053f78-2257-43ab-9b4c-0eeb4f7bbb53" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_AmendmentFlag_ae053f78-2257-43ab-9b4c-0eeb4f7bbb53" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_77d419c9-a745-430b-b46e-992d6392359b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_e73a170b-5ada-489c-b38d-063ec089acb3" xlink:to="loc_dei_DocumentInformationTable_77d419c9-a745-430b-b46e-992d6392359b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_0b14f4fa-b50a-4d75-a365-deec9efb7898" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_77d419c9-a745-430b-b46e-992d6392359b" xlink:to="loc_us-gaap_StatementClassOfStockAxis_0b14f4fa-b50a-4d75-a365-deec9efb7898" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_0b14f4fa-b50a-4d75-a365-deec9efb7898_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_0b14f4fa-b50a-4d75-a365-deec9efb7898" xlink:to="loc_us-gaap_ClassOfStockDomain_0b14f4fa-b50a-4d75-a365-deec9efb7898_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_63bfa276-5d13-4dba-aaea-a16e43940097" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_0b14f4fa-b50a-4d75-a365-deec9efb7898" xlink:to="loc_us-gaap_ClassOfStockDomain_63bfa276-5d13-4dba-aaea-a16e43940097" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_bad43a98-2c0e-499b-bda1-d64bee21a77a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63bfa276-5d13-4dba-aaea-a16e43940097" xlink:to="loc_us-gaap_CommonClassAMember_bad43a98-2c0e-499b-bda1-d64bee21a77a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_cc2d5030-6200-433b-9589-223cbb7c506a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63bfa276-5d13-4dba-aaea-a16e43940097" xlink:to="loc_us-gaap_CommonClassBMember_cc2d5030-6200-433b-9589-223cbb7c506a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_8776b042-8443-4a2e-9ad7-a697bb0beb0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63bfa276-5d13-4dba-aaea-a16e43940097" xlink:to="loc_us-gaap_CommonClassCMember_8776b042-8443-4a2e-9ad7-a697bb0beb0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_b7d62151-2bbd-4043-a0ba-9ac841969567" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_77d419c9-a745-430b-b46e-992d6392359b" xlink:to="loc_us-gaap_DebtInstrumentAxis_b7d62151-2bbd-4043-a0ba-9ac841969567" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b7d62151-2bbd-4043-a0ba-9ac841969567_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_b7d62151-2bbd-4043-a0ba-9ac841969567" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b7d62151-2bbd-4043-a0ba-9ac841969567_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_f1ebd0ea-e9e0-4499-8b6c-a27a1fe0360a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_b7d62151-2bbd-4043-a0ba-9ac841969567" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_f1ebd0ea-e9e0-4499-8b6c-a27a1fe0360a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_353436fb-dd74-4ae9-9221-c19ea5a94f7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_f1ebd0ea-e9e0-4499-8b6c-a27a1fe0360a" xlink:to="loc_us-gaap_WarrantMember_353436fb-dd74-4ae9-9221-c19ea5a94f7e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="lunr-20230630.xsd#CondensedConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_2fa40f76-73b0-49aa-a509-7fc678b2135f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2fa40f76-73b0-49aa-a509-7fc678b2135f" xlink:to="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:to="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c24adafb-9bb8-4b8b-b436-4742faeac365" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c24adafb-9bb8-4b8b-b436-4742faeac365" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashCurrent_9f35a1d2-ccfa-4dfc-9f30-5f74a69f6a69" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedCashCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_RestrictedCashCurrent_9f35a1d2-ccfa-4dfc-9f30-5f74a69f6a69" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_1790c34b-0ea3-4da6-b87b-df3b3e3dd53f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_1790c34b-0ea3-4da6-b87b-df3b3e3dd53f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNetCurrent_58ae85c2-63e4-46c5-9e45-d1568982d44c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerAssetNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_ContractWithCustomerAssetNetCurrent_58ae85c2-63e4-46c5-9e45-d1568982d44c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_9ba5863b-7a0d-4999-a54e-5b7aea894323" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_9ba5863b-7a0d-4999-a54e-5b7aea894323" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_8ebfd33b-cbaf-4d86-ba91-66a881491395" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_b390cee8-c57c-429a-a795-2bcf9d890a07" xlink:to="loc_us-gaap_AssetsCurrent_8ebfd33b-cbaf-4d86-ba91-66a881491395" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_2159752c-c4c7-462e-847e-b56b67550aad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_2159752c-c4c7-462e-847e-b56b67550aad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_1e6b19a0-c0e2-477b-9cb7-cc80fbec4d20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_1e6b19a0-c0e2-477b-9cb7-cc80fbec4d20" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_fa3f94c5-e142-47f0-b7c8-69374909dffa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_fa3f94c5-e142-47f0-b7c8-69374909dffa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_df18f03c-4092-484e-b771-c4a396db2902" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_fc326b3e-ad22-48a1-8edb-ead60518304e" xlink:to="loc_us-gaap_Assets_df18f03c-4092-484e-b771-c4a396db2902" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2fa40f76-73b0-49aa-a509-7fc678b2135f" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_c6835d9e-f3e9-4da7-9b42-739d8dfb17b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_AccountsPayableCurrent_c6835d9e-f3e9-4da7-9b42-739d8dfb17b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_12cf20cc-1bd4-4fd6-a328-8a62a9656b7d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_LongTermDebtCurrent_12cf20cc-1bd4-4fd6-a328-8a62a9656b7d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_ebd236d8-5986-48ac-b481-ad4af38ed651" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_ebd236d8-5986-48ac-b481-ad4af38ed651" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_3c5ce2c3-feb3-4aed-acda-43e69c2a0247" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_3c5ce2c3-feb3-4aed-acda-43e69c2a0247" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_d8b5ccda-9db4-48f2-a5e7-e52319a1b226" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_d8b5ccda-9db4-48f2-a5e7-e52319a1b226" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_e2e5b072-bd41-4f3b-8dec-8bd1f29ad173" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_e2328756-374f-443b-a0d4-c9974d289697" xlink:to="loc_us-gaap_LiabilitiesCurrent_e2e5b072-bd41-4f3b-8dec-8bd1f29ad173" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_56e37042-a4a4-421a-b45a-d11085d1c18b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_56e37042-a4a4-421a-b45a-d11085d1c18b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_e634c02e-4a2b-4a26-a5c2-9046efb9b6f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_e634c02e-4a2b-4a26-a5c2-9046efb9b6f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_7c1db31e-81a6-45a9-b7f1-595edde531c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_7c1db31e-81a6-45a9-b7f1-595edde531c7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SimpleAgreementsForFutureEquityLiability_e92cc6d3-4a70-4630-a8ce-8f32f409d8cc" xlink:href="lunr-20230630.xsd#lunr_SimpleAgreementsForFutureEquityLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_lunr_SimpleAgreementsForFutureEquityLiability_e92cc6d3-4a70-4630-a8ce-8f32f409d8cc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_c94d2d29-c6fd-45ee-9291-fd697312d14c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_c94d2d29-c6fd-45ee-9291-fd697312d14c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_661fafe4-8683-4046-8d5b-e357c7fda0f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_661fafe4-8683-4046-8d5b-e357c7fda0f5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_6c556d7b-f072-4ea3-a81c-970c7d471626" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_Liabilities_6c556d7b-f072-4ea3-a81c-970c7d471626" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_dea91390-cfd1-42f8-bbac-1c73cb3bf15d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_CommitmentsAndContingencies_dea91390-cfd1-42f8-bbac-1c73cb3bf15d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAbstract_027ef558-edaf-4c90-be44-fd2c177b006f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_TemporaryEquityAbstract_027ef558-edaf-4c90-be44-fd2c177b006f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_a41411b2-5f08-4171-aac8-88cb4ced8501" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityAbstract_027ef558-edaf-4c90-be44-fd2c177b006f" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_a41411b2-5f08-4171-aac8-88cb4ced8501" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_d6b5dc08-73cd-43fd-b2e7-a7a32010ca6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TemporaryEquityAbstract_027ef558-edaf-4c90-be44-fd2c177b006f" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_d6b5dc08-73cd-43fd-b2e7-a7a32010ca6f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommonUnitsValueIssued_2385bf8c-769a-48a5-8141-2098af45a7e6" xlink:href="lunr-20230630.xsd#lunr_CommonUnitsValueIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_lunr_CommonUnitsValueIssued_2385bf8c-769a-48a5-8141-2098af45a7e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_53c2ca09-4149-403f-82c0-834505196717" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_us-gaap_CommonStockValue_53c2ca09-4149-403f-82c0-834505196717" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_82d269a1-88ec-49fc-afd6-bfab298420a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_us-gaap_TreasuryStockCommonValue_82d269a1-88ec-49fc-afd6-bfab298420a4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_a8eed154-f62f-4fe9-b42a-a87ddd61c9b8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_us-gaap_AdditionalPaidInCapital_a8eed154-f62f-4fe9-b42a-a87ddd61c9b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_79a6fc49-6e55-48d5-a639-59c72fd59db6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_79a6fc49-6e55-48d5-a639-59c72fd59db6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_9faff744-98f3-46ce-9f6e-25eb7bd6f90c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e234a3a-ed2d-4629-803d-6f036792a867" xlink:to="loc_us-gaap_StockholdersEquity_9faff744-98f3-46ce-9f6e-25eb7bd6f90c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_f3bf8dd7-25a9-4d9d-819f-42b97236d3d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_9dfd2a61-50e0-415d-9da4-2430953afa5b" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_f3bf8dd7-25a9-4d9d-819f-42b97236d3d6" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_2994488b-bdcf-4ad0-888a-78cb7b65a31e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2fa40f76-73b0-49aa-a509-7fc678b2135f" xlink:to="loc_us-gaap_StatementTable_2994488b-bdcf-4ad0-888a-78cb7b65a31e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2f4fe380-28ec-4622-ae67-47808e432f71" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2994488b-bdcf-4ad0-888a-78cb7b65a31e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2f4fe380-28ec-4622-ae67-47808e432f71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2f4fe380-28ec-4622-ae67-47808e432f71_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2f4fe380-28ec-4622-ae67-47808e432f71" xlink:to="loc_us-gaap_ClassOfStockDomain_2f4fe380-28ec-4622-ae67-47808e432f71_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d6a25b80-9678-4ab1-8de6-07507847ece2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2f4fe380-28ec-4622-ae67-47808e432f71" xlink:to="loc_us-gaap_ClassOfStockDomain_d6a25b80-9678-4ab1-8de6-07507847ece2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_8732fe13-e5b9-47da-9b2d-bb8b3110db27" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_d6a25b80-9678-4ab1-8de6-07507847ece2" xlink:to="loc_us-gaap_CommonClassAMember_8732fe13-e5b9-47da-9b2d-bb8b3110db27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_92e3d1e0-2d43-404c-8300-f3bd3cf84208" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_d6a25b80-9678-4ab1-8de6-07507847ece2" xlink:to="loc_us-gaap_CommonClassBMember_92e3d1e0-2d43-404c-8300-f3bd3cf84208" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_4243afdc-a059-4b23-8363-911fb057ca8a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_d6a25b80-9678-4ab1-8de6-07507847ece2" xlink:to="loc_us-gaap_CommonClassCMember_4243afdc-a059-4b23-8363-911fb057ca8a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4d3362a9-fbe2-4c41-b678-8548cae6bf03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2994488b-bdcf-4ad0-888a-78cb7b65a31e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4d3362a9-fbe2-4c41-b678-8548cae6bf03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_4d3362a9-fbe2-4c41-b678-8548cae6bf03_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4d3362a9-fbe2-4c41-b678-8548cae6bf03" xlink:to="loc_us-gaap_RelatedPartyDomain_4d3362a9-fbe2-4c41-b678-8548cae6bf03_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_e8318400-a13d-48e2-9821-d1363a10176a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4d3362a9-fbe2-4c41-b678-8548cae6bf03" xlink:to="loc_us-gaap_RelatedPartyDomain_e8318400-a13d-48e2-9821-d1363a10176a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_61bfc7f4-322b-4afe-9df0-c4074097b833" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_e8318400-a13d-48e2-9821-d1363a10176a" xlink:to="loc_us-gaap_RelatedPartyMember_61bfc7f4-322b-4afe-9df0-c4074097b833" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_3fd9591f-9f20-4a70-b66f-13ab5cdee47e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_e8318400-a13d-48e2-9821-d1363a10176a" xlink:to="loc_us-gaap_NonrelatedPartyMember_3fd9591f-9f20-4a70-b66f-13ab5cdee47e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="lunr-20230630.xsd#CondensedConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_e1cbdcfb-12d3-427c-981a-e05c97e60df4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_e1cbdcfb-12d3-427c-981a-e05c97e60df4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_a917884d-0af3-4f1b-9763-2e8ecc190809" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_a917884d-0af3-4f1b-9763-2e8ecc190809" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesAuthorized_2bc63feb-15a6-4fca-96cb-22ff985e6f01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_TemporaryEquitySharesAuthorized_2bc63feb-15a6-4fca-96cb-22ff985e6f01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued_0da6f6ba-3ead-42ab-8b19-3f66ae331547" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_TemporaryEquitySharesIssued_0da6f6ba-3ead-42ab-8b19-3f66ae331547" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_6d700b2d-fd1d-48ae-881c-264dfecec836" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_TemporaryEquitySharesOutstanding_6d700b2d-fd1d-48ae-881c-264dfecec836" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_ba51a95b-ce53-48a0-9f29-876045f0d4a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_ba51a95b-ce53-48a0-9f29-876045f0d4a8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_42e232b5-e4f9-4776-bc0b-4163a9c93415" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_42e232b5-e4f9-4776-bc0b-4163a9c93415" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_0bf81916-bdd4-47d2-a0cf-1641af2b1447" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_CommonStockSharesIssued_0bf81916-bdd4-47d2-a0cf-1641af2b1447" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c3f06e69-ccc5-43df-b29c-8f50a592b98b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_c3f06e69-ccc5-43df-b29c-8f50a592b98b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_b26da823-b2a8-4abd-a540-792d9777e59b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_TreasuryStockCommonShares_b26da823-b2a8-4abd-a540-792d9777e59b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_b4b4e121-84b0-42bb-97e4-02a7be1bcdfc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_71aaad8d-40e8-4aa5-aeea-815666256a60" xlink:to="loc_us-gaap_StatementTable_b4b4e121-84b0-42bb-97e4-02a7be1bcdfc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_97cdd037-0762-4400-bade-a06e30b15751" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_b4b4e121-84b0-42bb-97e4-02a7be1bcdfc" xlink:to="loc_us-gaap_StatementClassOfStockAxis_97cdd037-0762-4400-bade-a06e30b15751" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_97cdd037-0762-4400-bade-a06e30b15751_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_97cdd037-0762-4400-bade-a06e30b15751" xlink:to="loc_us-gaap_ClassOfStockDomain_97cdd037-0762-4400-bade-a06e30b15751_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_aa6022a1-e60e-4f2a-bd73-52763c27720c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_97cdd037-0762-4400-bade-a06e30b15751" xlink:to="loc_us-gaap_ClassOfStockDomain_aa6022a1-e60e-4f2a-bd73-52763c27720c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_2ebdf2b8-049d-400f-ba07-5a949c0e5421" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_aa6022a1-e60e-4f2a-bd73-52763c27720c" xlink:to="loc_us-gaap_CommonClassAMember_2ebdf2b8-049d-400f-ba07-5a949c0e5421" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_08c3e7ef-e98e-4687-9227-6b56bc838680" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_aa6022a1-e60e-4f2a-bd73-52763c27720c" xlink:to="loc_us-gaap_CommonClassBMember_08c3e7ef-e98e-4687-9227-6b56bc838680" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_257f55f7-5f49-43eb-9dfd-43b5881ea8c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_aa6022a1-e60e-4f2a-bd73-52763c27720c" xlink:to="loc_us-gaap_CommonClassCMember_257f55f7-5f49-43eb-9dfd-43b5881ea8c7" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/CondensedConsolidatedStatementsofMezzanineDeficitandShareholdersDeficit" xlink:type="simple" xlink:href="lunr-20230630.xsd#CondensedConsolidatedStatementsofMezzanineDeficitandShareholdersDeficit"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/CondensedConsolidatedStatementsofMezzanineDeficitandShareholdersDeficit" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b64e9a06-1098-4653-a3f7-93864632c896" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b64e9a06-1098-4653-a3f7-93864632c896" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_e96a96c7-3e94-48ea-8663-f0fdbbaf9a4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_TemporaryEquitySharesOutstanding_e96a96c7-3e94-48ea-8663-f0fdbbaf9a4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_211aacb5-3a16-44f5-bb43-feb2064cdd07" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_211aacb5-3a16-44f5-bb43-feb2064cdd07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_9dbdc4d5-65d3-46ec-97a0-ec2fbca43504" xlink:href="lunr-20230630.xsd#lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_9dbdc4d5-65d3-46ec-97a0-ec2fbca43504" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_435f6b6b-3e8f-4de7-8d89-4abc1a1627b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues_435f6b6b-3e8f-4de7-8d89-4abc1a1627b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAccretionOfDividends_da0a0bdb-f76e-4f10-8d66-5226e02504b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityAccretionOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_TemporaryEquityAccretionOfDividends_da0a0bdb-f76e-4f10-8d66-5226e02504b0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockAccretionOfRedemptionDiscount_3a8c2a6f-351a-4cdf-8a2b-94cee66dc234" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockAccretionOfRedemptionDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_PreferredStockAccretionOfRedemptionDiscount_3a8c2a6f-351a-4cdf-8a2b-94cee66dc234" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NoncontrollingInterestIncreaseFromEstablishment_253e4cce-23ed-4d4b-b19e-255a73f7bd8f" xlink:href="lunr-20230630.xsd#lunr_NoncontrollingInterestIncreaseFromEstablishment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_lunr_NoncontrollingInterestIncreaseFromEstablishment_253e4cce-23ed-4d4b-b19e-255a73f7bd8f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NoncontrollingInterestTemporaryEquityRemeasurement_2404e9d9-ffaa-4aea-a475-ec95ae4e90ba" xlink:href="lunr-20230630.xsd#lunr_NoncontrollingInterestTemporaryEquityRemeasurement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_lunr_NoncontrollingInterestTemporaryEquityRemeasurement_2404e9d9-ffaa-4aea-a475-ec95ae4e90ba" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_c9ed8e21-3c22-42a2-aa47-3fd080510fce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_83047433-74c9-4266-8dfa-c57efe9367e1" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_c9ed8e21-3c22-42a2-aa47-3fd080510fce" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_683a2626-a38d-4245-bbf7-56751e539945" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_29415571-942e-4c26-9491-a138f1a7e137" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b64e9a06-1098-4653-a3f7-93864632c896" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MembersUnitsSharesOutstanding_403a3e46-e196-47cd-910f-5793941dc944" xlink:href="lunr-20230630.xsd#lunr_MembersUnitsSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_MembersUnitsSharesOutstanding_403a3e46-e196-47cd-910f-5793941dc944" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_f44e5a1f-347c-47e3-9e14-e1e1fe9ea222" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_f44e5a1f-347c-47e3-9e14-e1e1fe9ea222" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MembersUnitsCarryingAmountAttributableToParent_ea9c2178-cbfb-4418-84f5-19cd81f0b983" xlink:href="lunr-20230630.xsd#lunr_MembersUnitsCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_MembersUnitsCarryingAmountAttributableToParent_ea9c2178-cbfb-4418-84f5-19cd81f0b983" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_96462afa-f222-4b95-9891-c7716c45b276" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_StockholdersEquity_96462afa-f222-4b95-9891-c7716c45b276" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_bd30b1aa-4846-431d-bcc8-e37f56fbd7d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_bd30b1aa-4846-431d-bcc8-e37f56fbd7d4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Dividends_21fd8877-1033-4c81-8dee-766a86e9a386" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Dividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_Dividends_21fd8877-1033-4c81-8dee-766a86e9a386" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockAccretionOfRedemptionDiscount_42cd2e01-1a12-4b58-8e94-83e80fa3e88f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockAccretionOfRedemptionDiscount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_4169c29b-730a-40b9-84e8-9a6b3fda84dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_NetIncomeLoss_4169c29b-730a-40b9-84e8-9a6b3fda84dc" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_RecapitalizationShares_5b3ca5de-0f33-4889-a27c-e3c199e7e691" xlink:href="lunr-20230630.xsd#lunr_RecapitalizationShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_RecapitalizationShares_5b3ca5de-0f33-4889-a27c-e3c199e7e691" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_RecapitalizationValue_0a00b39b-f01c-40a0-bcf0-d578bdc87a3c" xlink:href="lunr-20230630.xsd#lunr_RecapitalizationValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_RecapitalizationValue_0a00b39b-f01c-40a0-bcf0-d578bdc87a3c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NetIncomeLossAttributableToParentPreBusinessCombination_a69e1b8f-feea-401d-843b-922684625f7c" xlink:href="lunr-20230630.xsd#lunr_NetIncomeLossAttributableToParentPreBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_NetIncomeLossAttributableToParentPreBusinessCombination_a69e1b8f-feea-401d-843b-922684625f7c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_0d9f66bd-a635-46e4-90f3-d29892897ef2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_0d9f66bd-a635-46e4-90f3-d29892897ef2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_530ca29d-b62c-4219-b23a-2d961e79af53" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_530ca29d-b62c-4219-b23a-2d961e79af53" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_a6d31663-e38a-43a6-9937-70f3aff2ffb2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_a6d31663-e38a-43a6-9937-70f3aff2ffb2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AdjustmentsToAdditionalPaidInCapitalEstablishmentOfEarnOutLiabilities_d64cb3d5-448a-4551-9d0f-596f80307c0b" xlink:href="lunr-20230630.xsd#lunr_AdjustmentsToAdditionalPaidInCapitalEstablishmentOfEarnOutLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_AdjustmentsToAdditionalPaidInCapitalEstablishmentOfEarnOutLiabilities_d64cb3d5-448a-4551-9d0f-596f80307c0b" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NoncontrollingInterestIncreaseFromEstablishment_6c1ea352-c423-4988-8ad8-9e6208acba90" xlink:href="lunr-20230630.xsd#lunr_NoncontrollingInterestIncreaseFromEstablishment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ConversionOfSAFEAgreementsSharesIssued_8d39a49b-8e41-4d97-af57-38ea130cdbfc" xlink:href="lunr-20230630.xsd#lunr_ConversionOfSAFEAgreementsSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_ConversionOfSAFEAgreementsSharesIssued_8d39a49b-8e41-4d97-af57-38ea130cdbfc" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ConversionOfSAFEAgreementsValue_bd39863c-9fed-40e9-8a45-a9383c0eb3e0" xlink:href="lunr-20230630.xsd#lunr_ConversionOfSAFEAgreementsValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_ConversionOfSAFEAgreementsValue_bd39863c-9fed-40e9-8a45-a9383c0eb3e0" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_WarrantsIssuedDuringPeriodValueNewIssues_232d1713-ab82-45fb-a094-02c075954c0f" xlink:href="lunr-20230630.xsd#lunr_WarrantsIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_WarrantsIssuedDuringPeriodValueNewIssues_232d1713-ab82-45fb-a094-02c075954c0f" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_a35963eb-742f-4010-80f5-d10e79951d16" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_DividendsPreferredStock_a35963eb-742f-4010-80f5-d10e79951d16" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_bfd421d2-f901-483d-bca8-9ae4d25fe97d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_bfd421d2-f901-483d-bca8-9ae4d25fe97d" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockIssuedDuringPeriodSharesWarrantsExercised_090da38f-40f7-46b3-8c10-338467ccb5b6" xlink:href="lunr-20230630.xsd#lunr_StockIssuedDuringPeriodSharesWarrantsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_StockIssuedDuringPeriodSharesWarrantsExercised_090da38f-40f7-46b3-8c10-338467ccb5b6" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockIssuedDuringPeriodValueWarrantsExercised_bf4e5205-d903-41f7-a762-a5dee39bd2fc" xlink:href="lunr-20230630.xsd#lunr_StockIssuedDuringPeriodValueWarrantsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_StockIssuedDuringPeriodValueWarrantsExercised_bf4e5205-d903-41f7-a762-a5dee39bd2fc" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment_077a8347-70e1-4151-af00-8241e95dafe5" xlink:href="lunr-20230630.xsd#lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment_077a8347-70e1-4151-af00-8241e95dafe5" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NoncontrollingInterestRemeasurement_d466b5c4-a2f0-4f0f-a2f6-adea99d37422" xlink:href="lunr-20230630.xsd#lunr_NoncontrollingInterestRemeasurement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_lunr_NoncontrollingInterestRemeasurement_d466b5c4-a2f0-4f0f-a2f6-adea99d37422" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_314a33bc-c2ad-4781-9d06-68c60e793605" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_9340046b-3a6a-4beb-a205-5a8b46d931de" xlink:to="loc_us-gaap_StockholdersEquityOther_314a33bc-c2ad-4781-9d06-68c60e793605" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MembersUnitsSharesOutstanding_1b763f37-8f46-4bf4-8a88-8f759b1afe2a" xlink:href="lunr-20230630.xsd#lunr_MembersUnitsSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_cfd55f9e-928a-46a0-b2b8-aa05fc1ffd5f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MembersUnitsCarryingAmountAttributableToParent_5a271293-63db-4b6b-b292-8af5c9a6f96d" xlink:href="lunr-20230630.xsd#lunr_MembersUnitsCarryingAmountAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_29aecc87-da10-46d7-a118-d9b57147a62d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_8a39cb8e-a2d3-4c63-90e9-474683b123bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b64e9a06-1098-4653-a3f7-93864632c896" xlink:to="loc_us-gaap_StatementTable_8a39cb8e-a2d3-4c63-90e9-474683b123bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_8a39cb8e-a2d3-4c63-90e9-474683b123bc" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7" xlink:to="loc_us-gaap_EquityComponentDomain_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5463e87c-a0c1-4fe9-9c5c-75571a0ebab7" xlink:to="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_07a2f39e-6d84-4bc0-96f3-a6e9ccd2a348" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:to="loc_us-gaap_CommonStockMember_07a2f39e-6d84-4bc0-96f3-a6e9ccd2a348" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_f2586364-3c9e-4fcc-8a36-df3377b5bb08" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:to="loc_us-gaap_TreasuryStockCommonMember_f2586364-3c9e-4fcc-8a36-df3377b5bb08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_92b07784-8a7a-4c3d-a753-709c72a3f816" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_92b07784-8a7a-4c3d-a753-709c72a3f816" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_939da88b-fc15-4775-8408-15dbdde66402" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_39adee6e-afb0-4e81-8b05-fbede4b5e07a" xlink:to="loc_us-gaap_RetainedEarningsMember_939da88b-fc15-4775-8408-15dbdde66402" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_3875e41b-0538-48fe-88ea-88debd7cad0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_8a39cb8e-a2d3-4c63-90e9-474683b123bc" xlink:to="loc_us-gaap_StatementClassOfStockAxis_3875e41b-0538-48fe-88ea-88debd7cad0e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3875e41b-0538-48fe-88ea-88debd7cad0e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3875e41b-0538-48fe-88ea-88debd7cad0e" xlink:to="loc_us-gaap_ClassOfStockDomain_3875e41b-0538-48fe-88ea-88debd7cad0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3875e41b-0538-48fe-88ea-88debd7cad0e" xlink:to="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MembersUnitsMember_842dedb2-bd86-44ca-8d7e-936bb1582e0c" xlink:href="lunr-20230630.xsd#lunr_MembersUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_lunr_MembersUnitsMember_842dedb2-bd86-44ca-8d7e-936bb1582e0c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_ef2f8280-b049-4a9b-9d33-8c06c9cf6b82" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_us-gaap_CommonClassAMember_ef2f8280-b049-4a9b-9d33-8c06c9cf6b82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8a936d59-286d-4028-b9c1-fec27395cfa4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_us-gaap_CommonClassBMember_8a936d59-286d-4028-b9c1-fec27395cfa4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_52352521-42c1-46fb-9883-3c72a58cd65a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_us-gaap_CommonClassCMember_52352521-42c1-46fb-9883-3c72a58cd65a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_85abac8b-6238-4e34-a2b9-4d0751493806" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_85abac8b-6238-4e34-a2b9-4d0751493806" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommitmentSharesMember_10bcf0c3-6adb-4882-ab05-2cb9c60dd9be" xlink:href="lunr-20230630.xsd#lunr_CommitmentSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c794be05-81a1-457a-b069-fa3c34eec732" xlink:to="loc_lunr_CommitmentSharesMember_10bcf0c3-6adb-4882-ab05-2cb9c60dd9be" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/CondensedConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="lunr-20230630.xsd#CondensedConsolidatedStatementsofCashFlows"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/CondensedConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_b71e44a1-9fc8-45bb-819c-4832edfd8217" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:to="loc_us-gaap_ProfitLoss_b71e44a1-9fc8-45bb-819c-4832edfd8217" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_1831967b-bb51-4dd5-89f0-b9dfcab58aee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_1831967b-bb51-4dd5-89f0-b9dfcab58aee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_2db68970-83a2-4ee0-b8ee-5dbba4a100dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_2db68970-83a2-4ee0-b8ee-5dbba4a100dc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_0ab48549-3132-4092-98ef-e921ab58a442" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_0ab48549-3132-4092-98ef-e921ab58a442" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_59045dec-728a-4c9b-8eda-4c465f13cf5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_ShareBasedCompensation_59045dec-728a-4c9b-8eda-4c465f13cf5c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ChangeInFairValueOfSAFEAgreement_b4dd5f96-7a29-44fe-b5cc-51cf57aa1b89" xlink:href="lunr-20230630.xsd#lunr_ChangeInFairValueOfSAFEAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_lunr_ChangeInFairValueOfSAFEAgreement_b4dd5f96-7a29-44fe-b5cc-51cf57aa1b89" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_8bff8eaa-6e9d-46e1-a5da-d0bba5445494" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_8bff8eaa-6e9d-46e1-a5da-d0bba5445494" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_f6c80ccf-dd83-4fd7-8f2c-ef04bbdc2130" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2d5d5502-ea58-4e30-ab3e-37befa8658f7" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_f6c80ccf-dd83-4fd7-8f2c-ef04bbdc2130" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_fada61d6-ff15-44a5-80cb-e7d719bee6d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_fada61d6-ff15-44a5-80cb-e7d719bee6d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_525b50bd-d354-4d4a-bb15-307f18482768" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_525b50bd-d354-4d4a-bb15-307f18482768" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidExpense_8fbfadbb-7d3a-4a5e-8d4f-19378f82465a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidExpense_8fbfadbb-7d3a-4a5e-8d4f-19378f82465a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_fda7c009-84d3-4e73-8a32-41553acc60e6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_fda7c009-84d3-4e73-8a32-41553acc60e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_431c917a-1880-4078-9051-1cb321a50dd6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_431c917a-1880-4078-9051-1cb321a50dd6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDueToAffiliates_98462991-e85f-455f-bf5b-7321cba22b69" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInDueToAffiliates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInDueToAffiliates_98462991-e85f-455f-bf5b-7321cba22b69" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_156e4f41-2a16-445a-91a0-a0fdf94a6426" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_156e4f41-2a16-445a-91a0-a0fdf94a6426" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_f3fefdc6-5750-483d-8b89-8fd6c273116d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_18df23c7-b0cb-40c1-a8aa-493f7d7c1cab" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_f3fefdc6-5750-483d-8b89-8fd6c273116d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_14582064-82f4-48b0-ac42-333306d47bef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_f2d5c130-1e05-40ea-9609-5dd497b214b3" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_14582064-82f4-48b0-ac42-333306d47bef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_cd01a7a9-840f-467f-82ae-d9dba80ef734" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_cd01a7a9-840f-467f-82ae-d9dba80ef734" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_3c2fa750-5cde-44ab-be9b-4ef77107164f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_cd01a7a9-840f-467f-82ae-d9dba80ef734" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_3c2fa750-5cde-44ab-be9b-4ef77107164f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_d815e479-edda-492a-8484-8ac069d2171c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_cd01a7a9-840f-467f-82ae-d9dba80ef734" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_d815e479-edda-492a-8484-8ac069d2171c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ProceedsFromBusinessCombination_3eda19bd-6d7b-412b-9796-35c4027c1c82" xlink:href="lunr-20230630.xsd#lunr_ProceedsFromBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_lunr_ProceedsFromBusinessCombination_3eda19bd-6d7b-412b-9796-35c4027c1c82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_91186830-dbdf-4e3e-be4d-453fa64311fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_91186830-dbdf-4e3e-be4d-453fa64311fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfMergerRelatedCostsFinancingActivities_c02e47c6-07ce-4aba-85de-54d0b2e32b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfMergerRelatedCostsFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_PaymentsOfMergerRelatedCostsFinancingActivities_c02e47c6-07ce-4aba-85de-54d0b2e32b3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_e1e7ee56-0400-4945-9a14-6e04ff6d04f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_e1e7ee56-0400-4945-9a14-6e04ff6d04f9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_876ae1fe-1604-4645-a92c-e78c5dbf341c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_RepaymentsOfDebt_876ae1fe-1604-4645-a92c-e78c5dbf341c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_b1f9c908-9843-48a7-afa8-0803984d2233" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_PaymentsOfDividends_b1f9c908-9843-48a7-afa8-0803984d2233" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ProceedsFromIssuanceOfCommonUnits_3dd04524-2d2b-4fb6-a2e9-4e1e8ec45306" xlink:href="lunr-20230630.xsd#lunr_ProceedsFromIssuanceOfCommonUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_lunr_ProceedsFromIssuanceOfCommonUnits_3dd04524-2d2b-4fb6-a2e9-4e1e8ec45306" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_826c3fe7-70ed-4bae-b9d5-7df7a8910858" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_826c3fe7-70ed-4bae-b9d5-7df7a8910858" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromWarrantExercises_f715b5a3-fb7a-4c8a-9b42-745d9a1445d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromWarrantExercises"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_ProceedsFromWarrantExercises_f715b5a3-fb7a-4c8a-9b42-745d9a1445d6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ProceedsFromSAFEAgreements_165a4488-ccc9-4c96-9a90-bc56dadc6518" xlink:href="lunr-20230630.xsd#lunr_ProceedsFromSAFEAgreements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_lunr_ProceedsFromSAFEAgreements_165a4488-ccc9-4c96-9a90-bc56dadc6518" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_930ea1a6-2e06-478b-a91f-2f8345f99b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_930ea1a6-2e06-478b-a91f-2f8345f99b7a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_20723895-11a7-4cca-b9f6-488823ce4f87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_20723895-11a7-4cca-b9f6-488823ce4f87" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_3bc10e4f-10e0-482c-8eba-78d7c93b013e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_3bc10e4f-10e0-482c-8eba-78d7c93b013e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_8e1063cb-2d85-403c-83d8-ee0cf5e976b5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_8069b0d4-d660-4207-888e-466f805b350c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_RestrictedCash_8069b0d4-d660-4207-888e-466f805b350c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c1766805-4b59-4043-89e1-daffd3c1d1e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_e7efabd4-d810-486e-9a5f-88dbfb8f2208" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c1766805-4b59-4043-89e1-daffd3c1d1e8" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_73b19da4-371c-4a5c-9b11-223ef59b4903" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_73b19da4-371c-4a5c-9b11-223ef59b4903" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_d56a2a7a-fcc9-4aff-90af-d105f8b40b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_73b19da4-371c-4a5c-9b11-223ef59b4903" xlink:to="loc_us-gaap_InterestPaidNet_d56a2a7a-fcc9-4aff-90af-d105f8b40b2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaid_f732bb75-f720-42ae-84dc-c9709d29c8b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxesPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_73b19da4-371c-4a5c-9b11-223ef59b4903" xlink:to="loc_us-gaap_IncomeTaxesPaid_f732bb75-f720-42ae-84dc-c9709d29c8b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_948a6d46-f0e0-481d-9aca-416408ff19bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:to="loc_us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_948a6d46-f0e0-481d-9aca-416408ff19bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ConversionOfSimpleAgreementsForFutureEquityIntoCommonStock_b0a903a3-1387-41b8-93c3-29772c3cf211" xlink:href="lunr-20230630.xsd#lunr_ConversionOfSimpleAgreementsForFutureEquityIntoCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:to="loc_lunr_ConversionOfSimpleAgreementsForFutureEquityIntoCommonStock_b0a903a3-1387-41b8-93c3-29772c3cf211" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_f1766e0d-a71e-48b5-b209-6de1b61b3be4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_f1766e0d-a71e-48b5-b209-6de1b61b3be4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_11a64649-b706-4fc6-98f0-a9105a6d2967" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_15c55f29-5561-4f99-8ea6-0ed45e6d8333" xlink:to="loc_us-gaap_DividendsPreferredStock_11a64649-b706-4fc6-98f0-a9105a6d2967" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_57ae80c3-f5a8-495c-b1fb-5b34399cc605" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_335f55d7-3847-4999-8376-727d93f1efd7" xlink:to="loc_us-gaap_StatementTable_57ae80c3-f5a8-495c-b1fb-5b34399cc605" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_faf27118-d2fd-4baa-afde-23ec6a7d8b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_57ae80c3-f5a8-495c-b1fb-5b34399cc605" xlink:to="loc_us-gaap_StatementClassOfStockAxis_faf27118-d2fd-4baa-afde-23ec6a7d8b6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_faf27118-d2fd-4baa-afde-23ec6a7d8b6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_faf27118-d2fd-4baa-afde-23ec6a7d8b6f" xlink:to="loc_us-gaap_ClassOfStockDomain_faf27118-d2fd-4baa-afde-23ec6a7d8b6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_681635f7-e397-4de9-91be-02ee873426f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_faf27118-d2fd-4baa-afde-23ec6a7d8b6f" xlink:to="loc_us-gaap_ClassOfStockDomain_681635f7-e397-4de9-91be-02ee873426f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommitmentSharesMember_2f26cdc4-912f-4b2f-b92e-aae14cc040fb" xlink:href="lunr-20230630.xsd#lunr_CommitmentSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_681635f7-e397-4de9-91be-02ee873426f6" xlink:to="loc_lunr_CommitmentSharesMember_2f26cdc4-912f-4b2f-b92e-aae14cc040fb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/BusinessDescriptionDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#BusinessDescriptionDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/BusinessDescriptionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:href="lunr-20230630.xsd#lunr_BusinessDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare_ce1defad-cb14-41fa-8529-2a55ff86983a" xlink:href="lunr-20230630.xsd#lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare_ce1defad-cb14-41fa-8529-2a55ff86983a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CashHeldInTrustAvailableForUse_c37e7d43-677d-47f2-bb42-9b2d8afa8eb5" xlink:href="lunr-20230630.xsd#lunr_CashHeldInTrustAvailableForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_lunr_CashHeldInTrustAvailableForUse_c37e7d43-677d-47f2-bb42-9b2d8afa8eb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_98a208e7-7929-4323-84ca-1b7a00a109dc" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementValueSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_98a208e7-7929-4323-84ca-1b7a00a109dc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_1f837c9a-993a-4784-91c3-34d732cabc00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_1f837c9a-993a-4784-91c3-34d732cabc00" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_a03e6d74-28a6-4782-9cb2-6466b68ed6de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_a03e6d74-28a6-4782-9cb2-6466b68ed6de" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:href="lunr-20230630.xsd#lunr_BusinessDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_lunr_BusinessDescriptionLineItems_d3ed4903-a06f-499e-bec3-e5b6b5686cb3" xlink:to="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_c8b63e3a-b6ee-4527-8e87-7690ad6b9752" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_c8b63e3a-b6ee-4527-8e87-7690ad6b9752" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c8b63e3a-b6ee-4527-8e87-7690ad6b9752_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c8b63e3a-b6ee-4527-8e87-7690ad6b9752" xlink:to="loc_us-gaap_ClassOfStockDomain_c8b63e3a-b6ee-4527-8e87-7690ad6b9752_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c42c0f33-be62-4430-b9b8-a6bdfb85faa3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c8b63e3a-b6ee-4527-8e87-7690ad6b9752" xlink:to="loc_us-gaap_ClassOfStockDomain_c42c0f33-be62-4430-b9b8-a6bdfb85faa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_0ec44bca-d9b8-40bf-a8dc-acc9eeaa683b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c42c0f33-be62-4430-b9b8-a6bdfb85faa3" xlink:to="loc_us-gaap_CommonClassAMember_0ec44bca-d9b8-40bf-a8dc-acc9eeaa683b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_9181c268-3a58-48ba-80f0-9438c61e6d91" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_9181c268-3a58-48ba-80f0-9438c61e6d91" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_9181c268-3a58-48ba-80f0-9438c61e6d91_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_9181c268-3a58-48ba-80f0-9438c61e6d91" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_9181c268-3a58-48ba-80f0-9438c61e6d91_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_f5d017a3-bc75-4f8b-bc6e-8fd09a0fe4b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_9181c268-3a58-48ba-80f0-9438c61e6d91" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_f5d017a3-bc75-4f8b-bc6e-8fd09a0fe4b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PublicWarrantsMember_062a9e33-b399-448d-86f9-947ea0cc4e93" xlink:href="lunr-20230630.xsd#lunr_PublicWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_f5d017a3-bc75-4f8b-bc6e-8fd09a0fe4b2" xlink:to="loc_lunr_PublicWarrantsMember_062a9e33-b399-448d-86f9-947ea0cc4e93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_7a31754c-d32e-4442-91f8-a1f5edcaf0b1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_7a31754c-d32e-4442-91f8-a1f5edcaf0b1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_7a31754c-d32e-4442-91f8-a1f5edcaf0b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_7a31754c-d32e-4442-91f8-a1f5edcaf0b1" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_7a31754c-d32e-4442-91f8-a1f5edcaf0b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_3f3f936a-288d-40e9-ae10-5fa2246e3d5e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_7a31754c-d32e-4442-91f8-a1f5edcaf0b1" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_3f3f936a-288d-40e9-ae10-5fa2246e3d5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommitmentSharesMember_1993e688-aa5f-47aa-a40d-383c4e902d63" xlink:href="lunr-20230630.xsd#lunr_CommitmentSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_3f3f936a-288d-40e9-ae10-5fa2246e3d5e" xlink:to="loc_lunr_CommitmentSharesMember_1993e688-aa5f-47aa-a40d-383c4e902d63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_79f9181b-2e4e-40ab-acd2-0cbb11965834" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_BusinessDescriptionTable_579fac62-a500-4dad-8d30-769fce02cfdb" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_79f9181b-2e4e-40ab-acd2-0cbb11965834" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_79f9181b-2e4e-40ab-acd2-0cbb11965834_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_79f9181b-2e4e-40ab-acd2-0cbb11965834" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_79f9181b-2e4e-40ab-acd2-0cbb11965834_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fef3bb8d-90ed-4dff-8902-3e18c1329066" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_79f9181b-2e4e-40ab-acd2-0cbb11965834" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fef3bb8d-90ed-4dff-8902-3e18c1329066" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CantorStockPurchaseAgreementMember_90e1037b-5586-47d3-8529-476b46bea59c" xlink:href="lunr-20230630.xsd#lunr_CantorStockPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fef3bb8d-90ed-4dff-8902-3e18c1329066" xlink:to="loc_lunr_CantorStockPurchaseAgreementMember_90e1037b-5586-47d3-8529-476b46bea59c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#SummaryofSignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:href="lunr-20230630.xsd#lunr_AccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_a734c613-5b5f-48ba-91e3-7b43489be895" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_NumberOfOperatingSegments_a734c613-5b5f-48ba-91e3-7b43489be895" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_76529132-676d-4af3-8fe6-f9cdff1b76ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_NumberOfReportableSegments_76529132-676d-4af3-8fe6-f9cdff1b76ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_1a91e028-78f5-46a7-8806-6480faeaf604" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_1a91e028-78f5-46a7-8806-6480faeaf604" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_ef514050-cf7a-425f-9e69-430e781f96e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_ef514050-cf7a-425f-9e69-430e781f96e3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_3834a93d-b47b-446d-81ce-7a742dce84a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_3834a93d-b47b-446d-81ce-7a742dce84a2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_007a07b2-2ed0-4d73-b26a-a48b36c6503a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_007a07b2-2ed0-4d73-b26a-a48b36c6503a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_03ca9008-ecbb-4db3-ae82-00c8b1e60636" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_03ca9008-ecbb-4db3-ae82-00c8b1e60636" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_6fcc84b9-e9c4-488f-819e-14f9e0682777" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_6fcc84b9-e9c4-488f-819e-14f9e0682777" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_73f0782a-d015-4bf8-b95a-e8c52bd266f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_73f0782a-d015-4bf8-b95a-e8c52bd266f0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_WorkingCapitalSurplusDeficit_8eb7723b-b59c-446d-924e-4af95947b5d7" xlink:href="lunr-20230630.xsd#lunr_WorkingCapitalSurplusDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_WorkingCapitalSurplusDeficit_8eb7723b-b59c-446d-924e-4af95947b5d7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ProceedsFromAcquisitionOfBusiness_e599e119-9719-4778-a817-e1abc9a1b437" xlink:href="lunr-20230630.xsd#lunr_ProceedsFromAcquisitionOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_ProceedsFromAcquisitionOfBusiness_e599e119-9719-4778-a817-e1abc9a1b437" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_db9915ff-cd65-42c3-b6e9-8b80db7dfa0f" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementValueSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_db9915ff-cd65-42c3-b6e9-8b80db7dfa0f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_56778c8f-33eb-4d0a-b5ba-208acd9a5d54" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_56778c8f-33eb-4d0a-b5ba-208acd9a5d54" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromWarrantExercises_ae0dbf93-64a3-4833-aa8a-604f5eed7760" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromWarrantExercises"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_ProceedsFromWarrantExercises_ae0dbf93-64a3-4833-aa8a-604f5eed7760" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PrepaidExpenseCapitalizedBusinessAcquisitionCosts_a42b818a-0520-4b2c-a183-16e912478430" xlink:href="lunr-20230630.xsd#lunr_PrepaidExpenseCapitalizedBusinessAcquisitionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_PrepaidExpenseCapitalizedBusinessAcquisitionCosts_a42b818a-0520-4b2c-a183-16e912478430" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_e56fe53e-aef3-414d-b032-718aa73cba33" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_e56fe53e-aef3-414d-b032-718aa73cba33" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PaymentOfAcquisitionRelatedCosts_53e9cd5c-8d2e-46bb-9f7e-117836031fc2" xlink:href="lunr-20230630.xsd#lunr_PaymentOfAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_PaymentOfAcquisitionRelatedCosts_53e9cd5c-8d2e-46bb-9f7e-117836031fc2" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_7bdebb53-8062-4c8a-93f0-346f02a1d8a3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_CommonStockSharesIssued_7bdebb53-8062-4c8a-93f0-346f02a1d8a3" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_f3f78160-58d6-4f98-b411-e114777e59cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_f3f78160-58d6-4f98-b411-e114777e59cd" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_9ca9ff85-f9e9-415f-9975-ec1b15aab1fa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_9ca9ff85-f9e9-415f-9975-ec1b15aab1fa" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid_350dea57-176d-4d6a-a33e-13b86f66ac1d" xlink:href="lunr-20230630.xsd#lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid_350dea57-176d-4d6a-a33e-13b86f66ac1d" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_bb590832-3c92-46b2-b8d0-2dee29ceadd2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_bb590832-3c92-46b2-b8d0-2dee29ceadd2" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommonStockVotingRightsNumberOfVotesPerShare_73e56788-9635-47d0-8c25-b4ac5b8fb537" xlink:href="lunr-20230630.xsd#lunr_CommonStockVotingRightsNumberOfVotesPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_CommonStockVotingRightsNumberOfVotesPerShare_73e56788-9635-47d0-8c25-b4ac5b8fb537" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_410aa527-3d8e-49aa-a004-ccf5b5501b8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_410aa527-3d8e-49aa-a004-ccf5b5501b8c" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:href="lunr-20230630.xsd#lunr_AccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_lunr_AccountingPoliciesLineItems_d63e7353-fbc6-4bc4-8380-611738d63310" xlink:to="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_c3a3b281-be2a-4124-9457-059a77677708" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_c3a3b281-be2a-4124-9457-059a77677708" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_c3a3b281-be2a-4124-9457-059a77677708_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_c3a3b281-be2a-4124-9457-059a77677708" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_c3a3b281-be2a-4124-9457-059a77677708_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_e5a1a9a1-9ea6-488d-ad32-c015267ccfd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_c3a3b281-be2a-4124-9457-059a77677708" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_e5a1a9a1-9ea6-488d-ad32-c015267ccfd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_867b7f7b-2463-447c-9070-9ca7b4c59ed1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_e5a1a9a1-9ea6-488d-ad32-c015267ccfd3" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_867b7f7b-2463-447c-9070-9ca7b4c59ed1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierConcentrationRiskMember_86aa9890-fb93-461d-b65b-0917c2acfa7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplierConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_e5a1a9a1-9ea6-488d-ad32-c015267ccfd3" xlink:to="loc_us-gaap_SupplierConcentrationRiskMember_86aa9890-fb93-461d-b65b-0917c2acfa7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_442f3c00-94bd-4445-bd3f-c40090626002" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_442f3c00-94bd-4445-bd3f-c40090626002" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_442f3c00-94bd-4445-bd3f-c40090626002_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_442f3c00-94bd-4445-bd3f-c40090626002" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_442f3c00-94bd-4445-bd3f-c40090626002_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_442f3c00-94bd-4445-bd3f-c40090626002" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_d2b58f20-ea9d-4137-9d43-20531d52bc49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_d2b58f20-ea9d-4137-9d43-20531d52bc49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_b016c4a0-d99f-4488-a4d3-cffa0bbb754a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:to="loc_us-gaap_AccountsReceivableMember_b016c4a0-d99f-4488-a4d3-cffa0bbb754a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsTotalMember_89d95158-da67-4820-a41e-106afe04ce9c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfGoodsTotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:to="loc_us-gaap_CostOfGoodsTotalMember_89d95158-da67-4820-a41e-106afe04ce9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AccountsPayableBenchmarkMember_5dbc8650-1e32-4c13-902d-f2f4f036965f" xlink:href="lunr-20230630.xsd#lunr_AccountsPayableBenchmarkMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9334f506-20e7-4bcf-ac95-21f1a3198273" xlink:to="loc_lunr_AccountsPayableBenchmarkMember_5dbc8650-1e32-4c13-902d-f2f4f036965f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_101be25a-5c28-47db-b08c-78c576810ecc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_101be25a-5c28-47db-b08c-78c576810ecc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_101be25a-5c28-47db-b08c-78c576810ecc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_101be25a-5c28-47db-b08c-78c576810ecc" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_101be25a-5c28-47db-b08c-78c576810ecc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4d02fa38-5d13-4156-9f5b-9a7993897c22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_101be25a-5c28-47db-b08c-78c576810ecc" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4d02fa38-5d13-4156-9f5b-9a7993897c22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementMember_8aff5500-f64a-498b-b538-8c3e00146437" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4d02fa38-5d13-4156-9f5b-9a7993897c22" xlink:to="loc_lunr_StockPurchaseAgreementMember_8aff5500-f64a-498b-b538-8c3e00146437" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ForwardPurchaseAgreementMember_b7122cb0-8a6c-4bad-873b-25f9d875760d" xlink:href="lunr-20230630.xsd#lunr_ForwardPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4d02fa38-5d13-4156-9f5b-9a7993897c22" xlink:to="loc_lunr_ForwardPurchaseAgreementMember_b7122cb0-8a6c-4bad-873b-25f9d875760d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_a50a72e9-a5d6-4237-ab0d-ef7187389437" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_srt_MajorCustomersAxis_a50a72e9-a5d6-4237-ab0d-ef7187389437" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_a50a72e9-a5d6-4237-ab0d-ef7187389437_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_a50a72e9-a5d6-4237-ab0d-ef7187389437" xlink:to="loc_srt_NameOfMajorCustomerDomain_a50a72e9-a5d6-4237-ab0d-ef7187389437_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_a50a72e9-a5d6-4237-ab0d-ef7187389437" xlink:to="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CustomerOneMember_e2c6165a-9183-459c-8b91-910e0e76626d" xlink:href="lunr-20230630.xsd#lunr_CustomerOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_CustomerOneMember_e2c6165a-9183-459c-8b91-910e0e76626d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CustomerTwoMember_9ab8e472-d0ea-434d-9a2b-ae26ac768434" xlink:href="lunr-20230630.xsd#lunr_CustomerTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_CustomerTwoMember_9ab8e472-d0ea-434d-9a2b-ae26ac768434" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CustomerThreeMember_1bf8e41a-cce2-4ed3-9cc8-a55442a2afae" xlink:href="lunr-20230630.xsd#lunr_CustomerThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_CustomerThreeMember_1bf8e41a-cce2-4ed3-9cc8-a55442a2afae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CustomerFourMember_67980152-f927-450c-a4ba-8fdb295906b3" xlink:href="lunr-20230630.xsd#lunr_CustomerFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_CustomerFourMember_67980152-f927-450c-a4ba-8fdb295906b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CustomerFiveMember_04601f6d-961a-4681-8b7b-26a4fe542eba" xlink:href="lunr-20230630.xsd#lunr_CustomerFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_CustomerFiveMember_04601f6d-961a-4681-8b7b-26a4fe542eba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LargestCustomerMember_fdca2197-3aee-4398-a848-6b47be112f55" xlink:href="lunr-20230630.xsd#lunr_LargestCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d496e9cf-6b8f-4e72-a078-398ecd00b4fc" xlink:to="loc_lunr_LargestCustomerMember_fdca2197-3aee-4398-a848-6b47be112f55" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_b8796fd0-e221-4147-91b4-6ee1e4f8ed75" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_b8796fd0-e221-4147-91b4-6ee1e4f8ed75" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_b8796fd0-e221-4147-91b4-6ee1e4f8ed75_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_b8796fd0-e221-4147-91b4-6ee1e4f8ed75" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_b8796fd0-e221-4147-91b4-6ee1e4f8ed75_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_68396896-c21a-4744-8f77-627c93add2a6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionBySupplierAxis_b8796fd0-e221-4147-91b4-6ee1e4f8ed75" xlink:to="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_68396896-c21a-4744-8f77-627c93add2a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SupplierOneMember_2d9d3156-c599-493e-bfae-2eaa9dec6c3d" xlink:href="lunr-20230630.xsd#lunr_SupplierOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionSupplierDomain_68396896-c21a-4744-8f77-627c93add2a6" xlink:to="loc_lunr_SupplierOneMember_2d9d3156-c599-493e-bfae-2eaa9dec6c3d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_c269b344-3a3a-41df-b98a-538c08eb2daa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_us-gaap_StatementClassOfStockAxis_c269b344-3a3a-41df-b98a-538c08eb2daa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c269b344-3a3a-41df-b98a-538c08eb2daa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c269b344-3a3a-41df-b98a-538c08eb2daa" xlink:to="loc_us-gaap_ClassOfStockDomain_c269b344-3a3a-41df-b98a-538c08eb2daa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c269b344-3a3a-41df-b98a-538c08eb2daa" xlink:to="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassABCommonUnitsMember_23db6125-c4a7-425f-8c6e-a27a1bebba0f" xlink:href="lunr-20230630.xsd#lunr_ClassABCommonUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:to="loc_lunr_ClassABCommonUnitsMember_23db6125-c4a7-425f-8c6e-a27a1bebba0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_1337a694-9466-4582-9b69-d48ce8014b94" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:to="loc_us-gaap_CommonClassAMember_1337a694-9466-4582-9b69-d48ce8014b94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_876672bd-7e01-4263-aa2d-ae54425268cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:to="loc_us-gaap_CommonClassBMember_876672bd-7e01-4263-aa2d-ae54425268cf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_5c99da9c-f238-41b4-b4fe-9d94de5c9016" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_04d47189-33e2-481a-99c0-06066b03b0be" xlink:to="loc_us-gaap_CommonClassCMember_5c99da9c-f238-41b4-b4fe-9d94de5c9016" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_srt_OwnershipAxis_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4" xlink:to="loc_srt_OwnershipDomain_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_e0b64892-c673-47f7-ab6d-b37ef938decb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_5f1c34c1-758d-44cd-b01d-9eb7c0fe38c4" xlink:to="loc_srt_OwnershipDomain_e0b64892-c673-47f7-ab6d-b37ef938decb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCMember_4597a177-43c5-42db-90e9-6abccefc7e57" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_e0b64892-c673-47f7-ab6d-b37ef938decb" xlink:to="loc_lunr_IntuitiveMachinesLLCMember_4597a177-43c5-42db-90e9-6abccefc7e57" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_d22968ed-7d4a-4329-9c51-2f99af63505e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_dei_LegalEntityAxis_d22968ed-7d4a-4329-9c51-2f99af63505e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_d22968ed-7d4a-4329-9c51-2f99af63505e_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_d22968ed-7d4a-4329-9c51-2f99af63505e" xlink:to="loc_dei_EntityDomain_d22968ed-7d4a-4329-9c51-2f99af63505e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_73341db3-32ae-4c05-8590-8e7d18d25fae" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_d22968ed-7d4a-4329-9c51-2f99af63505e" xlink:to="loc_dei_EntityDomain_73341db3-32ae-4c05-8590-8e7d18d25fae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCMember_71d9fbda-7f18-492c-b8f6-a53191e1c588" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_73341db3-32ae-4c05-8590-8e7d18d25fae" xlink:to="loc_lunr_IntuitiveMachinesLLCMember_71d9fbda-7f18-492c-b8f6-a53191e1c588" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCPriorInvestorsMember_7ea8ddcd-fe63-4f15-a1bf-83b510060fdb" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCPriorInvestorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_73341db3-32ae-4c05-8590-8e7d18d25fae" xlink:to="loc_lunr_IntuitiveMachinesLLCPriorInvestorsMember_7ea8ddcd-fe63-4f15-a1bf-83b510060fdb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_708ff388-a3ec-440d-b0b3-040c7247e2a0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_lunr_AccountingPoliciesTable_e55d67ed-319e-4196-8341-c15b1d0deb87" xlink:to="loc_srt_CounterpartyNameAxis_708ff388-a3ec-440d-b0b3-040c7247e2a0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_708ff388-a3ec-440d-b0b3-040c7247e2a0_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_708ff388-a3ec-440d-b0b3-040c7247e2a0" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_708ff388-a3ec-440d-b0b3-040c7247e2a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15de9fd8-f162-4f72-898c-9f0af69047f2" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_708ff388-a3ec-440d-b0b3-040c7247e2a0" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15de9fd8-f162-4f72-898c-9f0af69047f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_FormerMembersOfAcquireeMember_822db011-5184-4173-a020-873252890e7b" xlink:href="lunr-20230630.xsd#lunr_FormerMembersOfAcquireeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15de9fd8-f162-4f72-898c-9f0af69047f2" xlink:to="loc_lunr_FormerMembersOfAcquireeMember_822db011-5184-4173-a020-873252890e7b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/SummaryofSignificantAccountingPoliciesPropertyandEquipmentUsefulLifeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#SummaryofSignificantAccountingPoliciesPropertyandEquipmentUsefulLifeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/SummaryofSignificantAccountingPoliciesPropertyandEquipmentUsefulLifeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_fc5a3915-ddce-42ea-91f4-35111adc1eec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_681ef816-202d-4461-bcc9-82910dab3db6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_fc5a3915-ddce-42ea-91f4-35111adc1eec" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_681ef816-202d-4461-bcc9-82910dab3db6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea3e8a7e-702e-41bf-949b-d7927f97c2a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_fc5a3915-ddce-42ea-91f4-35111adc1eec" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea3e8a7e-702e-41bf-949b-d7927f97c2a7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea3e8a7e-702e-41bf-949b-d7927f97c2a7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6842b04b-1cf1-4ba0-a9dd-65cc8d50a733" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_940374e8-489f-4e88-b08c-dac64bad5ab9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_940374e8-489f-4e88-b08c-dac64bad5ab9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_bb5ad534-1dd9-40a6-abc1-c521910e9ef8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:to="loc_us-gaap_VehiclesMember_bb5ad534-1dd9-40a6-abc1-c521910e9ef8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ComputersAndSoftwareMember_d00e792c-b057-486e-8bf2-2de5e7810ba4" xlink:href="lunr-20230630.xsd#lunr_ComputersAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:to="loc_lunr_ComputersAndSoftwareMember_d00e792c-b057-486e-8bf2-2de5e7810ba4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_6e318164-d0d6-45ee-ad26-72ecf74d7bb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_6e318164-d0d6-45ee-ad26-72ecf74d7bb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_ca40047e-c96c-4123-95b6-c9663ec8e645" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_93c1789c-1d01-4d3d-b340-85938c542dba" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_ca40047e-c96c-4123-95b6-c9663ec8e645" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_c1c2205f-e5b8-4100-b5ce-984f229dce92" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea3e8a7e-702e-41bf-949b-d7927f97c2a7" xlink:to="loc_srt_RangeAxis_c1c2205f-e5b8-4100-b5ce-984f229dce92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c1c2205f-e5b8-4100-b5ce-984f229dce92_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_c1c2205f-e5b8-4100-b5ce-984f229dce92" xlink:to="loc_srt_RangeMember_c1c2205f-e5b8-4100-b5ce-984f229dce92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7492feb8-8918-450b-9ca4-7dbcba3282d6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_c1c2205f-e5b8-4100-b5ce-984f229dce92" xlink:to="loc_srt_RangeMember_7492feb8-8918-450b-9ca4-7dbcba3282d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_ae17eac5-9652-462f-8915-4ca01b1f7c6f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7492feb8-8918-450b-9ca4-7dbcba3282d6" xlink:to="loc_srt_MinimumMember_ae17eac5-9652-462f-8915-4ca01b1f7c6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_db476e29-de1c-4655-a507-258f590c193c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7492feb8-8918-450b-9ca4-7dbcba3282d6" xlink:to="loc_srt_MaximumMember_db476e29-de1c-4655-a507-258f590c193c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/BusinessCombinationandRelatedTransactionsDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#BusinessCombinationandRelatedTransactionsDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/BusinessCombinationandRelatedTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_5f26cf6d-626c-4bc8-a5ea-bb5485054fc5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_5f26cf6d-626c-4bc8-a5ea-bb5485054fc5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_e4e76ca0-61a4-4730-8f75-9139e1dff8c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_e4e76ca0-61a4-4730-8f75-9139e1dff8c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfVotesForEachShare_3c6a8b4e-9666-449c-bf72-c5e7075b8610" xlink:href="lunr-20230630.xsd#lunr_NumberOfVotesForEachShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_NumberOfVotesForEachShare_3c6a8b4e-9666-449c-bf72-c5e7075b8610" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_82c8915b-8326-4985-b792-5306ec9bba68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_82c8915b-8326-4985-b792-5306ec9bba68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_16f72a29-4ce2-4a25-8c7f-04a42786cca1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_16f72a29-4ce2-4a25-8c7f-04a42786cca1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_720583ef-1be5-45a4-802d-75312b9c1726" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_720583ef-1be5-45a4-802d-75312b9c1726" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_273458c1-ac77-4967-ad0f-b9ec5e9583f3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_273458c1-ac77-4967-ad0f-b9ec5e9583f3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares_06cae081-abc5-41a0-a648-36a1a4b4ef73" xlink:href="lunr-20230630.xsd#lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares_06cae081-abc5-41a0-a648-36a1a4b4ef73" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_ddf3a57c-cf1d-48e1-b845-48af910f8777" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_ddf3a57c-cf1d-48e1-b845-48af910f8777" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_EarnOutUnitsAmountVestedIfMilestoneAchieved_6767865d-9474-404e-b5be-f572c6f15449" xlink:href="lunr-20230630.xsd#lunr_EarnOutUnitsAmountVestedIfMilestoneAchieved"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_EarnOutUnitsAmountVestedIfMilestoneAchieved_6767865d-9474-404e-b5be-f572c6f15449" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_941d6ae3-84a9-4e2a-9857-6052d2db7443" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_941d6ae3-84a9-4e2a-9857-6052d2db7443" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfDaysFollowingClosingDate_451be173-58a8-468d-a9b4-a4b8f39855a4" xlink:href="lunr-20230630.xsd#lunr_NumberOfDaysFollowingClosingDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_NumberOfDaysFollowingClosingDate_451be173-58a8-468d-a9b4-a4b8f39855a4" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfYearsAfterClosingDate_99c3f6ea-f340-4435-8945-685b59ac4510" xlink:href="lunr-20230630.xsd#lunr_NumberOfYearsAfterClosingDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_NumberOfYearsAfterClosingDate_99c3f6ea-f340-4435-8945-685b59ac4510" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessCombinationExchangeRatio_7ddc3ad0-8085-4d34-92f9-cfebace820f7" xlink:href="lunr-20230630.xsd#lunr_BusinessCombinationExchangeRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_BusinessCombinationExchangeRatio_7ddc3ad0-8085-4d34-92f9-cfebace820f7" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementSharesSharesAuthorized_1bf9cf0d-1f2e-419f-9581-2f961bdb078c" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementSharesSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementSharesSharesAuthorized_1bf9cf0d-1f2e-419f-9581-2f961bdb078c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_3f025015-0394-4d67-83d9-b1dfb0e75341" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_3f025015-0394-4d67-83d9-b1dfb0e75341" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_8479a51d-8cde-4ae6-8af6-ea937873dc86" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_8479a51d-8cde-4ae6-8af6-ea937873dc86" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockPreferenceStockAndWarrants_c11bd726-8ff6-4f4a-803a-482784c0c31a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockPreferenceStockAndWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockPreferenceStockAndWarrants_c11bd726-8ff6-4f4a-803a-482784c0c31a" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued_bcd42231-0df1-47bf-b1c8-0743e835cbdc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_TemporaryEquitySharesIssued_bcd42231-0df1-47bf-b1c8-0743e835cbdc" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_1294450b-2db6-4ff8-84ca-20e18dea5956" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_1294450b-2db6-4ff8-84ca-20e18dea5956" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid_a76aa66c-20f9-46aa-b0a5-fd5f821b8d3a" xlink:href="lunr-20230630.xsd#lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_TaxReceivableAgreementPercentOfCashTaxSavingsRequiredToBePaid_a76aa66c-20f9-46aa-b0a5-fd5f821b8d3a" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TaxReceivableAgreementEligibilityMinimumPercentOfCommonUnitsExchanged_9ea08a9e-3a03-4db7-841b-1832967f094f" xlink:href="lunr-20230630.xsd#lunr_TaxReceivableAgreementEligibilityMinimumPercentOfCommonUnitsExchanged"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_TaxReceivableAgreementEligibilityMinimumPercentOfCommonUnitsExchanged_9ea08a9e-3a03-4db7-841b-1832967f094f" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementPeriodAfterCommencementDate_245393cb-fcc6-4bb2-bbc9-8f912eac1801" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementPeriodAfterCommencementDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementPeriodAfterCommencementDate_245393cb-fcc6-4bb2-bbc9-8f912eac1801" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_4eb2bb01-6b15-4564-b481-55a6fdc16891" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementValueSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementValueSharesAuthorized_4eb2bb01-6b15-4564-b481-55a6fdc16891" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment_7f2831b7-359f-4809-acc2-0848387a31a7" xlink:href="lunr-20230630.xsd#lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_AdjustmentsToAdditionalPaidInCapitalRecapitalizationAdjustment_7f2831b7-359f-4809-acc2-0848387a31a7" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementSharesIssued_d19ae6ff-3fca-4814-a8c6-5f6baa6bb90d" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementSharesIssued_d19ae6ff-3fca-4814-a8c6-5f6baa6bb90d" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementResaleOfCommitmentSharesLessThan_2eaf08b0-d99b-4ad3-8ab7-159b6cbceae0" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementResaleOfCommitmentSharesLessThan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementResaleOfCommitmentSharesLessThan_2eaf08b0-d99b-4ad3-8ab7-159b6cbceae0" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementLiability_61dfd816-c7e1-4c31-a151-1c4bc3919946" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementLiability_61dfd816-c7e1-4c31-a151-1c4bc3919946" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfCounterparties_3eb36f2e-7a44-4d3c-8d96-f32a43203e60" xlink:href="lunr-20230630.xsd#lunr_NumberOfCounterparties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_NumberOfCounterparties_3eb36f2e-7a44-4d3c-8d96-f32a43203e60" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementRedemptionPrice_d93e7363-0a6e-4dba-9cc6-32e00e01576b" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementRedemptionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementRedemptionPrice_d93e7363-0a6e-4dba-9cc6-32e00e01576b" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementAmountPrepaidForRepurchaseObligation_b369b497-44fa-4413-9fb6-c769f53558de" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementAmountPrepaidForRepurchaseObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementAmountPrepaidForRepurchaseObligation_b369b497-44fa-4413-9fb6-c769f53558de" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementSharesToBeRepurchased_81ecfb96-e680-45c2-ad69-42594b9a03df" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementSharesToBeRepurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementSharesToBeRepurchased_81ecfb96-e680-45c2-ad69-42594b9a03df" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementTransactionFeesPaid_8b5adbfc-1200-4137-880e-1f876fee0349" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementTransactionFeesPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementTransactionFeesPaid_8b5adbfc-1200-4137-880e-1f876fee0349" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementSharesAuthorizedButNotPurchasedDueToEarlyTermination_47cbe497-1df1-4600-b7c3-2c37a56211c8" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementSharesAuthorizedButNotPurchasedDueToEarlyTermination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementSharesAuthorizedButNotPurchasedDueToEarlyTermination_47cbe497-1df1-4600-b7c3-2c37a56211c8" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementCashReturnedToCompanyUponTermination_3c2fe530-9ecf-48c2-906e-bd9c4a9b7a1f" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementCashReturnedToCompanyUponTermination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementCashReturnedToCompanyUponTermination_3c2fe530-9ecf-48c2-906e-bd9c4a9b7a1f" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockPurchaseAgreementGainLossOnAgreementSettlement_e3f7369d-eb17-49a0-a6c3-9c87f8c81ec1" xlink:href="lunr-20230630.xsd#lunr_StockPurchaseAgreementGainLossOnAgreementSettlement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_lunr_StockPurchaseAgreementGainLossOnAgreementSettlement_e3f7369d-eb17-49a0-a6c3-9c87f8c81ec1" xlink:type="arc" order="35"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_de382a91-9747-4470-94ea-ae3f42b5260a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_de382a91-9747-4470-94ea-ae3f42b5260a" xlink:type="arc" order="36"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_fba289a6-4d33-44d2-9e8e-02d37f5c4bee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_fba289a6-4d33-44d2-9e8e-02d37f5c4bee" xlink:type="arc" order="37"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5fbdfbf3-2b69-4017-a97b-48fc493a43bb" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_49783ad0-73cd-4bae-828e-8acef589f2e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_us-gaap_StatementClassOfStockAxis_49783ad0-73cd-4bae-828e-8acef589f2e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_49783ad0-73cd-4bae-828e-8acef589f2e7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_49783ad0-73cd-4bae-828e-8acef589f2e7" xlink:to="loc_us-gaap_ClassOfStockDomain_49783ad0-73cd-4bae-828e-8acef589f2e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_49783ad0-73cd-4bae-828e-8acef589f2e7" xlink:to="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_ebb1eacf-2134-44d7-9a55-d85c27f7bccc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:to="loc_us-gaap_CommonClassBMember_ebb1eacf-2134-44d7-9a55-d85c27f7bccc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_116c21ed-9295-4fb0-93bb-4f35c4b22f38" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:to="loc_us-gaap_CommonClassCMember_116c21ed-9295-4fb0-93bb-4f35c4b22f38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_0f8482de-50a1-4763-8d30-f3bfdb07a014" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_0f8482de-50a1-4763-8d30-f3bfdb07a014" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_a49f5ed1-aeae-4bbe-bc4b-2039b814d872" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:to="loc_us-gaap_CommonClassAMember_a49f5ed1-aeae-4bbe-bc4b-2039b814d872" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CertainLLCCommonUnitsMember_e5e4543f-b536-4fcd-8213-da6f7a83d6a0" xlink:href="lunr-20230630.xsd#lunr_CertainLLCCommonUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_fd7bba0d-8c0e-45ab-b3f4-e2515b58530a" xlink:to="loc_lunr_CertainLLCCommonUnitsMember_e5e4543f-b536-4fcd-8213-da6f7a83d6a0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_b5b2aaa4-8efc-40c3-b6b5-a78141adc717" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_b5b2aaa4-8efc-40c3-b6b5-a78141adc717" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b5b2aaa4-8efc-40c3-b6b5-a78141adc717_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b5b2aaa4-8efc-40c3-b6b5-a78141adc717" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b5b2aaa4-8efc-40c3-b6b5-a78141adc717_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_aeb92148-be35-4ae1-89cb-8b564f638480" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b5b2aaa4-8efc-40c3-b6b5-a78141adc717" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_aeb92148-be35-4ae1-89cb-8b564f638480" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCMember_e3d6a912-ca46-43c1-8b7b-7c157dee7dbf" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_aeb92148-be35-4ae1-89cb-8b564f638480" xlink:to="loc_lunr_IntuitiveMachinesLLCMember_e3d6a912-ca46-43c1-8b7b-7c157dee7dbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_23dcb1bf-0efd-470c-911e-1e3198b0920e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_23dcb1bf-0efd-470c-911e-1e3198b0920e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_23dcb1bf-0efd-470c-911e-1e3198b0920e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_23dcb1bf-0efd-470c-911e-1e3198b0920e" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_23dcb1bf-0efd-470c-911e-1e3198b0920e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_23dcb1bf-0efd-470c-911e-1e3198b0920e" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommonUnitsMember_1ae3d7ef-90b9-4dc2-b87d-c6b81baa1c48" xlink:href="lunr-20230630.xsd#lunr_CommonUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:to="loc_lunr_CommonUnitsMember_1ae3d7ef-90b9-4dc2-b87d-c6b81baa1c48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_2fc5ad78-46fd-4177-b13d-f92bff92503f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:to="loc_us-gaap_CommonStockMember_2fc5ad78-46fd-4177-b13d-f92bff92503f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommitmentSharesMember_63fa5bdc-9901-4335-9b8b-8c9b557fca6a" xlink:href="lunr-20230630.xsd#lunr_CommitmentSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:to="loc_lunr_CommitmentSharesMember_63fa5bdc-9901-4335-9b8b-8c9b557fca6a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_EarnoutUnitsMember_563eee0c-a285-46a5-82ed-f73fdacacc59" xlink:href="lunr-20230630.xsd#lunr_EarnoutUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_8ba15924-2768-4e61-866c-821ffae0ac59" xlink:to="loc_lunr_EarnoutUnitsMember_563eee0c-a285-46a5-82ed-f73fdacacc59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_e03ec00f-2bbd-4bf8-a349-e43efe53f195" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_d79ba9cb-3b20-4cd5-82e7-2fc237f2a744" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_e03ec00f-2bbd-4bf8-a349-e43efe53f195" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PreferredInvestorWarrantsMember_0a989d33-ae1f-493a-93fb-43557af1ad42" xlink:href="lunr-20230630.xsd#lunr_PreferredInvestorWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_e03ec00f-2bbd-4bf8-a349-e43efe53f195" xlink:to="loc_lunr_PreferredInvestorWarrantsMember_0a989d33-ae1f-493a-93fb-43557af1ad42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_bff21493-3d4f-463d-93c2-2f4f54352605" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_bff21493-3d4f-463d-93c2-2f4f54352605" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bff21493-3d4f-463d-93c2-2f4f54352605_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_bff21493-3d4f-463d-93c2-2f4f54352605" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bff21493-3d4f-463d-93c2-2f4f54352605_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_32c4922e-85f9-4d3b-a255-27f4c8feae97" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_bff21493-3d4f-463d-93c2-2f4f54352605" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_32c4922e-85f9-4d3b-a255-27f4c8feae97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SeriesAPurchaseAgreementMember_4ed1cfa2-5cf9-4733-b2aa-0bf0bec2073f" xlink:href="lunr-20230630.xsd#lunr_SeriesAPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_32c4922e-85f9-4d3b-a255-27f4c8feae97" xlink:to="loc_lunr_SeriesAPurchaseAgreementMember_4ed1cfa2-5cf9-4733-b2aa-0bf0bec2073f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ForwardPurchaseAgreementMember_111a1487-e0ba-429c-98f7-1e2c23f784eb" xlink:href="lunr-20230630.xsd#lunr_ForwardPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_32c4922e-85f9-4d3b-a255-27f4c8feae97" xlink:to="loc_lunr_ForwardPurchaseAgreementMember_111a1487-e0ba-429c-98f7-1e2c23f784eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CantorStockPurchaseAgreementMember_d702030c-01d3-433b-8ac6-292ecc25afc7" xlink:href="lunr-20230630.xsd#lunr_CantorStockPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_32c4922e-85f9-4d3b-a255-27f4c8feae97" xlink:to="loc_lunr_CantorStockPurchaseAgreementMember_d702030c-01d3-433b-8ac6-292ecc25afc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MilestoneAxis_884bc52c-bd59-488d-8291-e981a9ec4c03" xlink:href="lunr-20230630.xsd#lunr_MilestoneAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_lunr_MilestoneAxis_884bc52c-bd59-488d-8291-e981a9ec4c03" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MilestoneDomain_884bc52c-bd59-488d-8291-e981a9ec4c03_default" xlink:href="lunr-20230630.xsd#lunr_MilestoneDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lunr_MilestoneAxis_884bc52c-bd59-488d-8291-e981a9ec4c03" xlink:to="loc_lunr_MilestoneDomain_884bc52c-bd59-488d-8291-e981a9ec4c03_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:href="lunr-20230630.xsd#lunr_MilestoneDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lunr_MilestoneAxis_884bc52c-bd59-488d-8291-e981a9ec4c03" xlink:to="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IfTriggeringEventIOccursMember_c3a16df3-c300-41ef-b839-61fd7cfeb2fb" xlink:href="lunr-20230630.xsd#lunr_IfTriggeringEventIOccursMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_IfTriggeringEventIOccursMember_c3a16df3-c300-41ef-b839-61fd7cfeb2fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IfTriggeringEventsIAndIIAOccurMember_fe8cdf27-2e93-426d-86c0-63df74c38924" xlink:href="lunr-20230630.xsd#lunr_IfTriggeringEventsIAndIIAOccurMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_IfTriggeringEventsIAndIIAOccurMember_fe8cdf27-2e93-426d-86c0-63df74c38924" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TriggeringEventIIAMember_a1a23c8e-48f0-4afc-9124-2abbbe9a321b" xlink:href="lunr-20230630.xsd#lunr_TriggeringEventIIAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_TriggeringEventIIAMember_a1a23c8e-48f0-4afc-9124-2abbbe9a321b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IfTriggeringEventIIBOccursAndTriggeringEventIDoesNotMember_df666782-30b5-4a88-9fb1-aa92e100e690" xlink:href="lunr-20230630.xsd#lunr_IfTriggeringEventIIBOccursAndTriggeringEventIDoesNotMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_IfTriggeringEventIIBOccursAndTriggeringEventIDoesNotMember_df666782-30b5-4a88-9fb1-aa92e100e690" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TriggeringEventIIBMember_6336775f-d361-471d-bf01-36ce6e96bfa9" xlink:href="lunr-20230630.xsd#lunr_TriggeringEventIIBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_TriggeringEventIIBMember_6336775f-d361-471d-bf01-36ce6e96bfa9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IfTriggeringEventIIIOccursAndTriggeringEventsIIAAndIIBDoNotMember_bdb326a0-b165-4357-bfcd-297d00943c73" xlink:href="lunr-20230630.xsd#lunr_IfTriggeringEventIIIOccursAndTriggeringEventsIIAAndIIBDoNotMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_IfTriggeringEventIIIOccursAndTriggeringEventsIIAAndIIBDoNotMember_bdb326a0-b165-4357-bfcd-297d00943c73" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TriggeringEventIIIMember_1b1e917f-05b4-4c23-beff-08cc7cde1aec" xlink:href="lunr-20230630.xsd#lunr_TriggeringEventIIIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_MilestoneDomain_2550809d-6f50-4c7c-920b-52f9c326db6a" xlink:to="loc_lunr_TriggeringEventIIIMember_1b1e917f-05b4-4c23-beff-08cc7cde1aec" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d39ac266-3c4a-46bf-8f90-457f41d8749a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_srt_RangeAxis_d39ac266-3c4a-46bf-8f90-457f41d8749a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d39ac266-3c4a-46bf-8f90-457f41d8749a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d39ac266-3c4a-46bf-8f90-457f41d8749a" xlink:to="loc_srt_RangeMember_d39ac266-3c4a-46bf-8f90-457f41d8749a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9a6717b3-e251-4d35-97d7-3dfe7d510f5c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d39ac266-3c4a-46bf-8f90-457f41d8749a" xlink:to="loc_srt_RangeMember_9a6717b3-e251-4d35-97d7-3dfe7d510f5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_a6ff63a0-6eda-4b98-a165-af2629297596" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_9a6717b3-e251-4d35-97d7-3dfe7d510f5c" xlink:to="loc_srt_MinimumMember_a6ff63a0-6eda-4b98-a165-af2629297596" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_033865d4-72ca-4d14-aefe-3a725e92898e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_9a6717b3-e251-4d35-97d7-3dfe7d510f5c" xlink:to="loc_srt_MaximumMember_033865d4-72ca-4d14-aefe-3a725e92898e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_b1d3fe8b-6f9d-48df-9e61-3f20c2656345" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6aeba549-8c25-4e39-9c80-99eaaf0dbd1f" xlink:to="loc_srt_CounterpartyNameAxis_b1d3fe8b-6f9d-48df-9e61-3f20c2656345" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b1d3fe8b-6f9d-48df-9e61-3f20c2656345_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_b1d3fe8b-6f9d-48df-9e61-3f20c2656345" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b1d3fe8b-6f9d-48df-9e61-3f20c2656345_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b21c79a2-f6a7-4ba1-addd-39b649267c9a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_b1d3fe8b-6f9d-48df-9e61-3f20c2656345" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b21c79a2-f6a7-4ba1-addd-39b649267c9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_FormerMembersOfAcquireeMember_f5e4590c-07b0-4094-a98a-ff18fc1a5a1b" xlink:href="lunr-20230630.xsd#lunr_FormerMembersOfAcquireeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b21c79a2-f6a7-4ba1-addd-39b649267c9a" xlink:to="loc_lunr_FormerMembersOfAcquireeMember_f5e4590c-07b0-4094-a98a-ff18fc1a5a1b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#RevenueDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_c62634f7-4034-4154-91b8-76fa05b44491" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a893844d-a9cc-44d7-a546-4c8ddc9e71b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_c62634f7-4034-4154-91b8-76fa05b44491" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a893844d-a9cc-44d7-a546-4c8ddc9e71b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_056e7263-f71e-4bee-95c8-2d58a6f1ab5f" xlink:href="lunr-20230630.xsd#lunr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_c62634f7-4034-4154-91b8-76fa05b44491" xlink:to="loc_lunr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_056e7263-f71e-4bee-95c8-2d58a6f1ab5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_8e2643b0-467d-4d12-a657-d2e62ae51d73" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_c62634f7-4034-4154-91b8-76fa05b44491" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_8e2643b0-467d-4d12-a657-d2e62ae51d73" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_3da1adaf-4fed-438e-bd21-7e65b8e4de0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerBasisOfPricingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_8e2643b0-467d-4d12-a657-d2e62ae51d73" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_3da1adaf-4fed-438e-bd21-7e65b8e4de0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_3da1adaf-4fed-438e-bd21-7e65b8e4de0e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_3da1adaf-4fed-438e-bd21-7e65b8e4de0e" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_3da1adaf-4fed-438e-bd21-7e65b8e4de0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_f0044f63-8ac4-4e38-be88-26acade4c365" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_3da1adaf-4fed-438e-bd21-7e65b8e4de0e" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_f0044f63-8ac4-4e38-be88-26acade4c365" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedPriceContractMember_0a37e6e9-2652-4f7c-837f-be1c907c2a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FixedPriceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_f0044f63-8ac4-4e38-be88-26acade4c365" xlink:to="loc_us-gaap_FixedPriceContractMember_0a37e6e9-2652-4f7c-837f-be1c907c2a9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeAndMaterialsContractMember_2c7a9d2d-5112-49e1-ad22-fe6447cf446f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TimeAndMaterialsContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_f0044f63-8ac4-4e38-be88-26acade4c365" xlink:to="loc_us-gaap_TimeAndMaterialsContractMember_2c7a9d2d-5112-49e1-ad22-fe6447cf446f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/RevenueNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#RevenueNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/RevenueNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDeferredCharges_89481d5f-e294-48d5-9fd5-6c20760e209a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfDeferredCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_AmortizationOfDeferredCharges_89481d5f-e294-48d5-9fd5-6c20760e209a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_fe8165fa-9b10-467a-99fc-8ccf4fa524c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_fe8165fa-9b10-467a-99fc-8ccf4fa524c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract_4ac8ccd7-0260-4100-bbbd-84a9ae9f40ad" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract_4ac8ccd7-0260-4100-bbbd-84a9ae9f40ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossOnContracts_0685d8b5-4a49-4d86-89f1-3283269f92a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossOnContracts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_LossOnContracts_0685d8b5-4a49-4d86-89f1-3283269f92a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractsVariableConsiderationConstrainedAmount_9efcf46f-b7ea-4947-8ce4-e47a5a14149b" xlink:href="lunr-20230630.xsd#lunr_ContractsVariableConsiderationConstrainedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractsVariableConsiderationConstrainedAmount_9efcf46f-b7ea-4947-8ce4-e47a5a14149b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractsVariableConsiderationMaximum_f842eb6b-f849-4bc9-b707-89b95c25f892" xlink:href="lunr-20230630.xsd#lunr_ContractsVariableConsiderationMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractsVariableConsiderationMaximum_f842eb6b-f849-4bc9-b707-89b95c25f892" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LongTermContractPercentComplete_d61a8511-f949-413a-92c3-9c3f3e48afbd" xlink:href="lunr-20230630.xsd#lunr_LongTermContractPercentComplete"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_LongTermContractPercentComplete_d61a8511-f949-413a-92c3-9c3f3e48afbd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent_e08b704b-e610-48af-9ed3-275c1c20248c" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent_e08b704b-e610-48af-9ed3-275c1c20248c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent_6c01e8b1-508a-4886-bf54-54b9fe2a6d3c" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent_6c01e8b1-508a-4886-bf54-54b9fe2a6d3c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_ea4a73e8-67b0-43a7-b0fc-60e12255997a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_ea4a73e8-67b0-43a7-b0fc-60e12255997a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_ea8dc581-c183-465d-baa9-5a59acda1a30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_ea8dc581-c183-465d-baa9-5a59acda1a30" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_7e09aec7-f8ae-4577-9ca6-92ebd66ba859" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_7e09aec7-f8ae-4577-9ca6-92ebd66ba859" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:href="lunr-20230630.xsd#lunr_ContractAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractDomain_61a21b23-e0e6-4da1-a1fb-2e9a217493c2_default" xlink:href="lunr-20230630.xsd#lunr_ContractDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:to="loc_lunr_ContractDomain_61a21b23-e0e6-4da1-a1fb-2e9a217493c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:href="lunr-20230630.xsd#lunr_ContractDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:to="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractOneMember_4300dc76-4ce7-443d-85db-b001539b647a" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractOneMember_4300dc76-4ce7-443d-85db-b001539b647a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractTwoMember_4ee44caf-7cfa-4a67-b895-f35fd2d4a110" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractTwoMember_4ee44caf-7cfa-4a67-b895-f35fd2d4a110" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractThreeMember_defda339-fdcb-4d0f-bdf4-830861f5f112" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractThreeMember_defda339-fdcb-4d0f-bdf4-830861f5f112" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_1ce93143-ccd4-4938-ac78-28e517041b76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_1ce93143-ccd4-4938-ac78-28e517041b76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4f4f3b91-3f63-4852-b4df-11f357e6f90b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:to="loc_srt_RangeMember_4f4f3b91-3f63-4852-b4df-11f357e6f90b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:to="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_7961c8d2-6df9-4210-8d1b-f1dae3ecfbbb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:to="loc_srt_MinimumMember_7961c8d2-6df9-4210-8d1b-f1dae3ecfbbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_cfc5d739-e3d5-434f-825f-b45648515d63" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:to="loc_srt_MaximumMember_cfc5d739-e3d5-434f-825f-b45648515d63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_2fb8750a-caec-4426-b6ab-a2c224f53a07_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:to="loc_srt_ScenarioUnspecifiedDomain_2fb8750a-caec-4426-b6ab-a2c224f53a07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:to="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_d3f377ff-1d21-460a-8e5c-3ddbe1b689cb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:to="loc_srt_ScenarioForecastMember_d3f377ff-1d21-460a-8e5c-3ddbe1b689cb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/RevenueNarrativeDetails_1" xlink:type="simple" xlink:href="lunr-20230630.xsd#RevenueNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/RevenueNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDeferredCharges_89481d5f-e294-48d5-9fd5-6c20760e209a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfDeferredCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_AmortizationOfDeferredCharges_89481d5f-e294-48d5-9fd5-6c20760e209a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_fe8165fa-9b10-467a-99fc-8ccf4fa524c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_fe8165fa-9b10-467a-99fc-8ccf4fa524c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract_4ac8ccd7-0260-4100-bbbd-84a9ae9f40ad" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityIncreaseFromEstimatedLossOnContract_4ac8ccd7-0260-4100-bbbd-84a9ae9f40ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossOnContracts_0685d8b5-4a49-4d86-89f1-3283269f92a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossOnContracts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_LossOnContracts_0685d8b5-4a49-4d86-89f1-3283269f92a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractsVariableConsiderationConstrainedAmount_9efcf46f-b7ea-4947-8ce4-e47a5a14149b" xlink:href="lunr-20230630.xsd#lunr_ContractsVariableConsiderationConstrainedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractsVariableConsiderationConstrainedAmount_9efcf46f-b7ea-4947-8ce4-e47a5a14149b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractsVariableConsiderationMaximum_f842eb6b-f849-4bc9-b707-89b95c25f892" xlink:href="lunr-20230630.xsd#lunr_ContractsVariableConsiderationMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractsVariableConsiderationMaximum_f842eb6b-f849-4bc9-b707-89b95c25f892" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LongTermContractPercentComplete_d61a8511-f949-413a-92c3-9c3f3e48afbd" xlink:href="lunr-20230630.xsd#lunr_LongTermContractPercentComplete"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_LongTermContractPercentComplete_d61a8511-f949-413a-92c3-9c3f3e48afbd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent_e08b704b-e610-48af-9ed3-275c1c20248c" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionCurrent_e08b704b-e610-48af-9ed3-275c1c20248c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent_6c01e8b1-508a-4886-bf54-54b9fe2a6d3c" xlink:href="lunr-20230630.xsd#lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_lunr_ContractWithCustomerLiabilityContractLossProvisionNoncurrent_6c01e8b1-508a-4886-bf54-54b9fe2a6d3c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_ea4a73e8-67b0-43a7-b0fc-60e12255997a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_ea4a73e8-67b0-43a7-b0fc-60e12255997a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_ea8dc581-c183-465d-baa9-5a59acda1a30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_ea8dc581-c183-465d-baa9-5a59acda1a30" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_7e09aec7-f8ae-4577-9ca6-92ebd66ba859" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_7e09aec7-f8ae-4577-9ca6-92ebd66ba859" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_4d1a772c-3b86-4680-b6e8-f0625c443354" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:href="lunr-20230630.xsd#lunr_ContractAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractDomain_61a21b23-e0e6-4da1-a1fb-2e9a217493c2_default" xlink:href="lunr-20230630.xsd#lunr_ContractDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:to="loc_lunr_ContractDomain_61a21b23-e0e6-4da1-a1fb-2e9a217493c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:href="lunr-20230630.xsd#lunr_ContractDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lunr_ContractAxis_61a21b23-e0e6-4da1-a1fb-2e9a217493c2" xlink:to="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractOneMember_4300dc76-4ce7-443d-85db-b001539b647a" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractOneMember_4300dc76-4ce7-443d-85db-b001539b647a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractTwoMember_4ee44caf-7cfa-4a67-b895-f35fd2d4a110" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractTwoMember_4ee44caf-7cfa-4a67-b895-f35fd2d4a110" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommercialLunarPayloadServicesContractThreeMember_defda339-fdcb-4d0f-bdf4-830861f5f112" xlink:href="lunr-20230630.xsd#lunr_CommercialLunarPayloadServicesContractThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_ContractDomain_ac8c3c26-359a-4405-a7d1-3b13793bfab3" xlink:to="loc_lunr_CommercialLunarPayloadServicesContractThreeMember_defda339-fdcb-4d0f-bdf4-830861f5f112" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4f4f3b91-3f63-4852-b4df-11f357e6f90b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:to="loc_srt_RangeMember_4f4f3b91-3f63-4852-b4df-11f357e6f90b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_4f4f3b91-3f63-4852-b4df-11f357e6f90b" xlink:to="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_7961c8d2-6df9-4210-8d1b-f1dae3ecfbbb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:to="loc_srt_MinimumMember_7961c8d2-6df9-4210-8d1b-f1dae3ecfbbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_cfc5d739-e3d5-434f-825f-b45648515d63" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_abfcf115-7d6c-4da0-94b0-2b43034dfc2e" xlink:to="loc_srt_MaximumMember_cfc5d739-e3d5-434f-825f-b45648515d63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_545e73be-2e9f-4c53-b00c-986e1ab75952" xlink:to="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_2fb8750a-caec-4426-b6ab-a2c224f53a07_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:to="loc_srt_ScenarioUnspecifiedDomain_2fb8750a-caec-4426-b6ab-a2c224f53a07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_2fb8750a-caec-4426-b6ab-a2c224f53a07" xlink:to="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_d3f377ff-1d21-460a-8e5c-3ddbe1b689cb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_0af6efa0-9e6e-4485-977b-59a6aa7424b8" xlink:to="loc_srt_ScenarioForecastMember_d3f377ff-1d21-460a-8e5c-3ddbe1b689cb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/PropertyandEquipmentNetScheduleofPropertyandEquipmentDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#PropertyandEquipmentNetScheduleofPropertyandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/PropertyandEquipmentNetScheduleofPropertyandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5c6991ff-1b0b-4641-8168-fe32033508cb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_3e1c967a-b0cc-48c0-8edb-c2e37f59b45a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5c6991ff-1b0b-4641-8168-fe32033508cb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_3e1c967a-b0cc-48c0-8edb-c2e37f59b45a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_02c31ba3-f480-4648-9762-0f8399396148" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5c6991ff-1b0b-4641-8168-fe32033508cb" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_02c31ba3-f480-4648-9762-0f8399396148" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_87e935a4-5083-4551-bfa7-b89bd6c58951" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5c6991ff-1b0b-4641-8168-fe32033508cb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_87e935a4-5083-4551-bfa7-b89bd6c58951" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d5d0811d-c221-4714-b473-6b29924daf97" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5c6991ff-1b0b-4641-8168-fe32033508cb" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d5d0811d-c221-4714-b473-6b29924daf97" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6a7d721d-cec6-4062-b0ae-d6781ebb28c5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d5d0811d-c221-4714-b473-6b29924daf97" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6a7d721d-cec6-4062-b0ae-d6781ebb28c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6a7d721d-cec6-4062-b0ae-d6781ebb28c5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6a7d721d-cec6-4062-b0ae-d6781ebb28c5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6a7d721d-cec6-4062-b0ae-d6781ebb28c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6a7d721d-cec6-4062-b0ae-d6781ebb28c5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_dd7e2254-2afa-453f-9248-e103df245a22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_dd7e2254-2afa-453f-9248-e103df245a22" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_f154d458-e4a7-4656-8cf8-d426a2756e7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_us-gaap_VehiclesMember_f154d458-e4a7-4656-8cf8-d426a2756e7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ComputersAndSoftwareMember_863fee67-676f-48b1-b365-0b740931cd1c" xlink:href="lunr-20230630.xsd#lunr_ComputersAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_lunr_ComputersAndSoftwareMember_863fee67-676f-48b1-b365-0b740931cd1c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_5bde8e17-149a-4d7e-a439-f24b48a6b4b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_5bde8e17-149a-4d7e-a439-f24b48a6b4b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_947bf2f7-7c3f-4c64-8c44-4743f449ef1b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_947bf2f7-7c3f-4c64-8c44-4743f449ef1b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_9a873182-5e4e-4237-85c2-2dc6e7f1b45c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9ed42ab6-47fb-4f0c-bc52-a94102172ea5" xlink:to="loc_us-gaap_ConstructionInProgressMember_9a873182-5e4e-4237-85c2-2dc6e7f1b45c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/PropertyandEquipmentNetNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#PropertyandEquipmentNetNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/PropertyandEquipmentNetNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_1e8677a3-ef5a-484d-a1c2-4edfc7c8aa5f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:to="loc_us-gaap_Depreciation_1e8677a3-ef5a-484d-a1c2-4edfc7c8aa5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_b071e03e-5873-4780-9ff0-36ae2e880fa1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_b071e03e-5873-4780-9ff0-36ae2e880fa1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressGross_ba8c4e80-cd69-49fb-af21-4a4d7c133942" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:to="loc_us-gaap_ConstructionInProgressGross_ba8c4e80-cd69-49fb-af21-4a4d7c133942" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsCapitalized_09aee61b-bb6a-418b-bc80-4408ef7abb0f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestCostsCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:to="loc_us-gaap_InterestCostsCapitalized_09aee61b-bb6a-418b-bc80-4408ef7abb0f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cd88816d-40b8-4ec3-acae-4e2b7729b710" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_3bf79987-b9b0-40ba-83f4-df3805e74cf8" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cd88816d-40b8-4ec3-acae-4e2b7729b710" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NatureOfExpenseAxis_39ba2019-b070-4f49-aee7-045c17ba9016" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NatureOfExpenseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cd88816d-40b8-4ec3-acae-4e2b7729b710" xlink:to="loc_us-gaap_NatureOfExpenseAxis_39ba2019-b070-4f49-aee7-045c17ba9016" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_39ba2019-b070-4f49-aee7-045c17ba9016_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterimPeriodCostsNotAllocableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NatureOfExpenseAxis_39ba2019-b070-4f49-aee7-045c17ba9016" xlink:to="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_39ba2019-b070-4f49-aee7-045c17ba9016_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_466cd99e-9dce-48bd-88d0-ffec77a93357" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterimPeriodCostsNotAllocableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NatureOfExpenseAxis_39ba2019-b070-4f49-aee7-045c17ba9016" xlink:to="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_466cd99e-9dce-48bd-88d0-ffec77a93357" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ConstructionCostsForLunarOperationsCenterMember_aadc66c9-4a7d-4e75-a675-7e3affe29c3f" xlink:href="lunr-20230630.xsd#lunr_ConstructionCostsForLunarOperationsCenterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_466cd99e-9dce-48bd-88d0-ffec77a93357" xlink:to="loc_lunr_ConstructionCostsForLunarOperationsCenterMember_aadc66c9-4a7d-4e75-a675-7e3affe29c3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_FabricationOfCommercialCommunicationsSatelliteMember_66c4c670-87e6-4549-ab39-b217c4276c48" xlink:href="lunr-20230630.xsd#lunr_FabricationOfCommercialCommunicationsSatelliteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_466cd99e-9dce-48bd-88d0-ffec77a93357" xlink:to="loc_lunr_FabricationOfCommercialCommunicationsSatelliteMember_66c4c670-87e6-4549-ab39-b217c4276c48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusAxis_de716e56-b4c9-4a18-bcb3-696780806f35" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgedStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cd88816d-40b8-4ec3-acae-4e2b7729b710" xlink:to="loc_us-gaap_PledgedStatusAxis_de716e56-b4c9-4a18-bcb3-696780806f35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusDomain_de716e56-b4c9-4a18-bcb3-696780806f35_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgedStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PledgedStatusAxis_de716e56-b4c9-4a18-bcb3-696780806f35" xlink:to="loc_us-gaap_PledgedStatusDomain_de716e56-b4c9-4a18-bcb3-696780806f35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgedStatusDomain_fe193ed3-3fef-4150-b5d0-016d907d82e9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgedStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PledgedStatusAxis_de716e56-b4c9-4a18-bcb3-696780806f35" xlink:to="loc_us-gaap_PledgedStatusDomain_fe193ed3-3fef-4150-b5d0-016d907d82e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetPledgedAsCollateralMember_5fc5fac5-5c19-480d-ad83-87bbb152c927" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetPledgedAsCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PledgedStatusDomain_fe193ed3-3fef-4150-b5d0-016d907d82e9" xlink:to="loc_us-gaap_AssetPledgedAsCollateralMember_5fc5fac5-5c19-480d-ad83-87bbb152c927" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a76fa950-c371-42dd-b5b3-9a46f365f4a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cd88816d-40b8-4ec3-acae-4e2b7729b710" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a76fa950-c371-42dd-b5b3-9a46f365f4a4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_a76fa950-c371-42dd-b5b3-9a46f365f4a4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a76fa950-c371-42dd-b5b3-9a46f365f4a4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_a76fa950-c371-42dd-b5b3-9a46f365f4a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_75af329e-d2b8-41f0-bd7f-55e6cd89fc2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_a76fa950-c371-42dd-b5b3-9a46f365f4a4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_75af329e-d2b8-41f0-bd7f-55e6cd89fc2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_e30a27da-9ad2-4075-b0f5-574bb5efb220" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_75af329e-d2b8-41f0-bd7f-55e6cd89fc2d" xlink:to="loc_us-gaap_ConstructionInProgressMember_e30a27da-9ad2-4075-b0f5-574bb5efb220" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/LeasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfFinanceLeases_5ada0eae-4898-4e5b-9ac3-9518cb12483d" xlink:href="lunr-20230630.xsd#lunr_NumberOfFinanceLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_NumberOfFinanceLeases_5ada0eae-4898-4e5b-9ac3-9518cb12483d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfRealEstateLeases_82790a6b-a4da-4664-b94b-bd12ec74a25b" xlink:href="lunr-20230630.xsd#lunr_NumberOfRealEstateLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_NumberOfRealEstateLeases_82790a6b-a4da-4664-b94b-bd12ec74a25b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_6d30b8ec-102f-4b1e-a41b-a996ae56bee2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_6d30b8ec-102f-4b1e-a41b-a996ae56bee2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_OperatingLeaseAmountOfLeaseCostsAbleToBeReimbursed_2c39a205-dc64-45a6-b722-ca3bdd214c33" xlink:href="lunr-20230630.xsd#lunr_OperatingLeaseAmountOfLeaseCostsAbleToBeReimbursed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_OperatingLeaseAmountOfLeaseCostsAbleToBeReimbursed_2c39a205-dc64-45a6-b722-ca3bdd214c33" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_25fd6c65-f195-46ee-9830-bed8ae263f2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_25fd6c65-f195-46ee-9830-bed8ae263f2f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_6bb0fb85-2e38-4909-8824-e5fb0efc4de2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_LongTermDebt_6bb0fb85-2e38-4909-8824-e5fb0efc4de2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LesseeGroundLeaseTermOfContract_ca870c34-e90c-44f8-bba8-a5c3465b2da9" xlink:href="lunr-20230630.xsd#lunr_LesseeGroundLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_LesseeGroundLeaseTermOfContract_ca870c34-e90c-44f8-bba8-a5c3465b2da9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LesseeGroundLeaseNumberOfOptionalRenewalPeriods_de5b80ad-337e-4958-95da-36266ae9948d" xlink:href="lunr-20230630.xsd#lunr_LesseeGroundLeaseNumberOfOptionalRenewalPeriods"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_LesseeGroundLeaseNumberOfOptionalRenewalPeriods_de5b80ad-337e-4958-95da-36266ae9948d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LesseeGroundLeaseTermOfRenewalPeriod_64dbfdc7-4e8d-4f18-941f-10481dfb6418" xlink:href="lunr-20230630.xsd#lunr_LesseeGroundLeaseTermOfRenewalPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_lunr_LesseeGroundLeaseTermOfRenewalPeriod_64dbfdc7-4e8d-4f18-941f-10481dfb6418" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleAndLeasebackTransactionGainLossNet_ac1e704b-03cb-4668-aefa-510367aef230" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleAndLeasebackTransactionGainLossNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_SaleAndLeasebackTransactionGainLossNet_ac1e704b-03cb-4668-aefa-510367aef230" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_0ebd6309-0839-4f34-963e-98de2fbe6739" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_0ebd6309-0839-4f34-963e-98de2fbe6739" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_4d13e3b9-e21a-4988-933d-7831a13dbf78" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_OperatingLeaseLiability_4d13e3b9-e21a-4988-933d-7831a13dbf78" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_4a15fe1d-10fe-4825-994b-b429a6c83523" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_181ba0a9-752f-40b6-8100-6ca047979c7c" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_4a15fe1d-10fe-4825-994b-b429a6c83523" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_e566886e-a067-489c-a9ec-7ba9259edaab" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_4a15fe1d-10fe-4825-994b-b429a6c83523" xlink:to="loc_srt_RangeAxis_e566886e-a067-489c-a9ec-7ba9259edaab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e566886e-a067-489c-a9ec-7ba9259edaab_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_e566886e-a067-489c-a9ec-7ba9259edaab" xlink:to="loc_srt_RangeMember_e566886e-a067-489c-a9ec-7ba9259edaab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e42d4305-2254-4e1e-a1f3-96ab3e550611" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_e566886e-a067-489c-a9ec-7ba9259edaab" xlink:to="loc_srt_RangeMember_e42d4305-2254-4e1e-a1f3-96ab3e550611" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_f26eaec4-7cf1-4d57-8121-9c69db272f4a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e42d4305-2254-4e1e-a1f3-96ab3e550611" xlink:to="loc_srt_MinimumMember_f26eaec4-7cf1-4d57-8121-9c69db272f4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_74e55b19-54bd-4c36-8e65-3aef4d5a32f9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e42d4305-2254-4e1e-a1f3-96ab3e550611" xlink:to="loc_srt_MaximumMember_74e55b19-54bd-4c36-8e65-3aef4d5a32f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_30225106-82a8-4f3a-a443-d71ea1c9ebaf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_4a15fe1d-10fe-4825-994b-b429a6c83523" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_30225106-82a8-4f3a-a443-d71ea1c9ebaf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_30225106-82a8-4f3a-a443-d71ea1c9ebaf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_30225106-82a8-4f3a-a443-d71ea1c9ebaf" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_30225106-82a8-4f3a-a443-d71ea1c9ebaf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3964a0a7-0561-4cb5-abb0-d5905fa7d90b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_30225106-82a8-4f3a-a443-d71ea1c9ebaf" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3964a0a7-0561-4cb5-abb0-d5905fa7d90b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_e83cb49d-d814-4524-934c-5a81a7f8d1f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3964a0a7-0561-4cb5-abb0-d5905fa7d90b" xlink:to="loc_us-gaap_ConstructionInProgressMember_e83cb49d-d814-4524-934c-5a81a7f8d1f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OfficeBuildingMember_57f6799c-a2a5-4657-8dbc-8184026d5a29" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OfficeBuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3964a0a7-0561-4cb5-abb0-d5905fa7d90b" xlink:to="loc_srt_OfficeBuildingMember_57f6799c-a2a5-4657-8dbc-8184026d5a29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ReimbursableLeaseholdImprovementCostsMember_f8614124-c4cc-47f0-9a8b-32dff1bc4810" xlink:href="lunr-20230630.xsd#lunr_ReimbursableLeaseholdImprovementCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3964a0a7-0561-4cb5-abb0-d5905fa7d90b" xlink:to="loc_lunr_ReimbursableLeaseholdImprovementCostsMember_f8614124-c4cc-47f0-9a8b-32dff1bc4810" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_79b3d583-b087-40f2-9167-3bd3312d3977" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_4a15fe1d-10fe-4825-994b-b429a6c83523" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_79b3d583-b087-40f2-9167-3bd3312d3977" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_79b3d583-b087-40f2-9167-3bd3312d3977_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_79b3d583-b087-40f2-9167-3bd3312d3977" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_79b3d583-b087-40f2-9167-3bd3312d3977_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_5d86b380-ee30-4b45-9f7c-410e005c1922" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_79b3d583-b087-40f2-9167-3bd3312d3977" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_5d86b380-ee30-4b45-9f7c-410e005c1922" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LunarOperationsCenterMember_9e045742-ffdc-4333-baba-795556d701ff" xlink:href="lunr-20230630.xsd#lunr_LunarOperationsCenterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_5d86b380-ee30-4b45-9f7c-410e005c1922" xlink:to="loc_lunr_LunarOperationsCenterMember_9e045742-ffdc-4333-baba-795556d701ff" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_42044158-7154-4382-b053-164969afe640" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_42044158-7154-4382-b053-164969afe640" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_2b55ea0b-0fd3-44d9-a5d8-ae03dbc0f932" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_2b55ea0b-0fd3-44d9-a5d8-ae03dbc0f932" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7a73a44a-319c-4a38-8b0f-fbb0d88b2b03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7a73a44a-319c-4a38-8b0f-fbb0d88b2b03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_264e89bc-4aed-453a-9120-827fd7be03ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_264e89bc-4aed-453a-9120-827fd7be03ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_1704dc25-e744-4eea-8caa-1ed0a08540e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_LineOfCredit_1704dc25-e744-4eea-8caa-1ed0a08540e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_d3a5c1a6-cf7b-4091-9ecc-1d38bdb4d119" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_d3a5c1a6-cf7b-4091-9ecc-1d38bdb4d119" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_b1859031-cdeb-4ffb-af60-9856abf01cc1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_LongTermDebt_b1859031-cdeb-4ffb-af60-9856abf01cc1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ddbbafac-3e9e-470d-9b2e-1ae8a449de2e" xlink:to="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_fea44ea4-5c7f-4115-ba3b-1477c0ec3004" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_us-gaap_DebtInstrumentAxis_fea44ea4-5c7f-4115-ba3b-1477c0ec3004" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_fea44ea4-5c7f-4115-ba3b-1477c0ec3004_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_fea44ea4-5c7f-4115-ba3b-1477c0ec3004" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_fea44ea4-5c7f-4115-ba3b-1477c0ec3004_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_74725573-08be-4a2d-978e-2d5090a52f90" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_fea44ea4-5c7f-4115-ba3b-1477c0ec3004" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_74725573-08be-4a2d-978e-2d5090a52f90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LiveOakLoanAgreementMember_1a0c8373-c831-424e-b2d9-f3f12223cc2f" xlink:href="lunr-20230630.xsd#lunr_LiveOakLoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_74725573-08be-4a2d-978e-2d5090a52f90" xlink:to="loc_lunr_LiveOakLoanAgreementMember_1a0c8373-c831-424e-b2d9-f3f12223cc2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementMember_4fcfdbad-94c3-44e2-bafe-2f65fc23573e" xlink:href="lunr-20230630.xsd#lunr_LiveOakSecondAmendedAndRestatedLoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_74725573-08be-4a2d-978e-2d5090a52f90" xlink:to="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementMember_4fcfdbad-94c3-44e2-bafe-2f65fc23573e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityOneMember_c4211f68-ea2f-41f4-a2e2-94cee2b89042" xlink:href="lunr-20230630.xsd#lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementMember_4fcfdbad-94c3-44e2-bafe-2f65fc23573e" xlink:to="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityOneMember_c4211f68-ea2f-41f4-a2e2-94cee2b89042" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityTwoMember_e4bd8f59-4a30-43a1-8a1d-37f11619b3c8" xlink:href="lunr-20230630.xsd#lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementMember_4fcfdbad-94c3-44e2-bafe-2f65fc23573e" xlink:to="loc_lunr_LiveOakSecondAmendedAndRestatedLoanAgreementFacilityTwoMember_e4bd8f59-4a30-43a1-8a1d-37f11619b3c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_0a72c226-860f-4017-b0d3-4120b0cd1e47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_0a72c226-860f-4017-b0d3-4120b0cd1e47" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_0a72c226-860f-4017-b0d3-4120b0cd1e47_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0a72c226-860f-4017-b0d3-4120b0cd1e47" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_0a72c226-860f-4017-b0d3-4120b0cd1e47_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_0eda5362-7f78-47b2-a14a-1253e39242db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0a72c226-860f-4017-b0d3-4120b0cd1e47" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_0eda5362-7f78-47b2-a14a-1253e39242db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_b5c988d2-e43f-4377-8cb8-f2d0796e700e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_0eda5362-7f78-47b2-a14a-1253e39242db" xlink:to="loc_us-gaap_LineOfCreditMember_b5c988d2-e43f-4377-8cb8-f2d0796e700e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_f52d5698-1885-4747-9386-3d71c6760de6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_srt_StatementScenarioAxis_f52d5698-1885-4747-9386-3d71c6760de6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_f52d5698-1885-4747-9386-3d71c6760de6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_f52d5698-1885-4747-9386-3d71c6760de6" xlink:to="loc_srt_ScenarioUnspecifiedDomain_f52d5698-1885-4747-9386-3d71c6760de6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_edd447b2-7bfc-4b71-ba18-711fa71314fd" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_f52d5698-1885-4747-9386-3d71c6760de6" xlink:to="loc_srt_ScenarioUnspecifiedDomain_edd447b2-7bfc-4b71-ba18-711fa71314fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_4938c36d-ad76-4587-9b59-55fe0a53a7e6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_edd447b2-7bfc-4b71-ba18-711fa71314fd" xlink:to="loc_srt_ScenarioForecastMember_4938c36d-ad76-4587-9b59-55fe0a53a7e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_1a361833-daab-448f-9d17-9648800d7eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_us-gaap_VariableRateAxis_1a361833-daab-448f-9d17-9648800d7eb7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_1a361833-daab-448f-9d17-9648800d7eb7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_1a361833-daab-448f-9d17-9648800d7eb7" xlink:to="loc_us-gaap_VariableRateDomain_1a361833-daab-448f-9d17-9648800d7eb7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_b339dc56-7c2c-46da-b768-ed0516054bff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_1a361833-daab-448f-9d17-9648800d7eb7" xlink:to="loc_us-gaap_VariableRateDomain_b339dc56-7c2c-46da-b768-ed0516054bff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrimeRateMember_e0e38fda-7a3a-447d-bb0c-78c5303a3d9e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrimeRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_b339dc56-7c2c-46da-b768-ed0516054bff" xlink:to="loc_us-gaap_PrimeRateMember_e0e38fda-7a3a-447d-bb0c-78c5303a3d9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_591dc4de-9ced-44df-935b-ef15f55ec16a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_srt_RangeAxis_591dc4de-9ced-44df-935b-ef15f55ec16a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_591dc4de-9ced-44df-935b-ef15f55ec16a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_591dc4de-9ced-44df-935b-ef15f55ec16a" xlink:to="loc_srt_RangeMember_591dc4de-9ced-44df-935b-ef15f55ec16a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_370725f4-35cd-49bb-9b71-a7546c9e6f8f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_591dc4de-9ced-44df-935b-ef15f55ec16a" xlink:to="loc_srt_RangeMember_370725f4-35cd-49bb-9b71-a7546c9e6f8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_9f370573-9723-4a43-9956-52abec780d56" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_370725f4-35cd-49bb-9b71-a7546c9e6f8f" xlink:to="loc_srt_MinimumMember_9f370573-9723-4a43-9956-52abec780d56" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_c30a62e4-b035-4774-b72e-24590702e3fa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a219e6d-a5d3-4149-94c1-64c79cbbd454" xlink:to="loc_us-gaap_CreditFacilityAxis_c30a62e4-b035-4774-b72e-24590702e3fa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_c30a62e4-b035-4774-b72e-24590702e3fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_c30a62e4-b035-4774-b72e-24590702e3fa" xlink:to="loc_us-gaap_CreditFacilityDomain_c30a62e4-b035-4774-b72e-24590702e3fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_f5a9e015-d2ea-4407-8037-c2e45546bbd5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_c30a62e4-b035-4774-b72e-24590702e3fa" xlink:to="loc_us-gaap_CreditFacilityDomain_f5a9e015-d2ea-4407-8037-c2e45546bbd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_52415f86-c570-49a3-8c44-46f620318828" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_f5a9e015-d2ea-4407-8037-c2e45546bbd5" xlink:to="loc_us-gaap_SecuredDebtMember_52415f86-c570-49a3-8c44-46f620318828" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_c9c90a6a-8c1f-4fa5-8b52-b112ebfe7a3c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_f5a9e015-d2ea-4407-8037-c2e45546bbd5" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_c9c90a6a-8c1f-4fa5-8b52-b112ebfe7a3c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/MezzanineEquityandEquityNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#MezzanineEquityandEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/MezzanineEquityandEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_15403806-a0fc-4e0a-8f3f-286e7e146c75" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_15403806-a0fc-4e0a-8f3f-286e7e146c75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_4483f3bd-a831-4e87-9fab-cf0c6ad6bf23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_4483f3bd-a831-4e87-9fab-cf0c6ad6bf23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement_d56e5b79-26c4-4ff6-abd5-5a239160e4c4" xlink:href="lunr-20230630.xsd#lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement_d56e5b79-26c4-4ff6-abd5-5a239160e4c4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_54618030-878f-40b5-afee-224a44d1b6d8" xlink:href="lunr-20230630.xsd#lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_lunr_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues_54618030-878f-40b5-afee-224a44d1b6d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares_440bfa88-7eda-4f2f-af39-bcda1db0a120" xlink:href="lunr-20230630.xsd#lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_lunr_BusinessCombinationEarnOutUnitsIssuedOrIssuableNumberOfShares_440bfa88-7eda-4f2f-af39-bcda1db0a120" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfVotesForEachShare_c9cd969b-09f6-4c59-aa00-cede6690b518" xlink:href="lunr-20230630.xsd#lunr_NumberOfVotesForEachShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_lunr_NumberOfVotesForEachShare_c9cd969b-09f6-4c59-aa00-cede6690b518" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockConvertibleConversionPrice_5c30177e-7510-4891-8217-49b1e19070f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockConvertibleConversionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_PreferredStockConvertibleConversionPrice_5c30177e-7510-4891-8217-49b1e19070f5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_c87a515a-b57d-465e-94d8-18016f2e87f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_c87a515a-b57d-465e-94d8-18016f2e87f0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PreferredStockConvertibleConversionPricePercentage_b22043a5-0777-4502-b254-e476df0d7826" xlink:href="lunr-20230630.xsd#lunr_PreferredStockConvertibleConversionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_lunr_PreferredStockConvertibleConversionPricePercentage_b22043a5-0777-4502-b254-e476df0d7826" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_e6c11a06-b39a-49d7-9e8e-fb4623259dab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_e6c11a06-b39a-49d7-9e8e-fb4623259dab" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_1f99cb77-930c-4eb0-a71e-a35f2b2e7675" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_d4405b4e-c245-4f2a-9773-b777163124bd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:to="loc_us-gaap_StatementClassOfStockAxis_d4405b4e-c245-4f2a-9773-b777163124bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d4405b4e-c245-4f2a-9773-b777163124bd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d4405b4e-c245-4f2a-9773-b777163124bd" xlink:to="loc_us-gaap_ClassOfStockDomain_d4405b4e-c245-4f2a-9773-b777163124bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d4405b4e-c245-4f2a-9773-b777163124bd" xlink:to="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_24a26d7b-4ac8-459d-ba7a-b5f11fa26457" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:to="loc_us-gaap_CommonClassAMember_24a26d7b-4ac8-459d-ba7a-b5f11fa26457" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8bf54be2-e9da-4c6e-9e6c-9333923c52ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:to="loc_us-gaap_CommonClassBMember_8bf54be2-e9da-4c6e-9e6c-9333923c52ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_e939d437-d398-42b4-8eef-0ebf4a121f1a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:to="loc_us-gaap_CommonClassCMember_e939d437-d398-42b4-8eef-0ebf4a121f1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_88e48ac2-35da-41c2-a1ba-509f9967adf6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8bc6133f-2d35-4eef-bd1a-c945d3b034db" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_88e48ac2-35da-41c2-a1ba-509f9967adf6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_a3f0e52b-67fc-4f2f-92de-c36be3f1475f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:to="loc_srt_OwnershipAxis_a3f0e52b-67fc-4f2f-92de-c36be3f1475f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_a3f0e52b-67fc-4f2f-92de-c36be3f1475f_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_a3f0e52b-67fc-4f2f-92de-c36be3f1475f" xlink:to="loc_srt_OwnershipDomain_a3f0e52b-67fc-4f2f-92de-c36be3f1475f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_f405bbf0-3a95-408a-a417-5e358614bc23" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_a3f0e52b-67fc-4f2f-92de-c36be3f1475f" xlink:to="loc_srt_OwnershipDomain_f405bbf0-3a95-408a-a417-5e358614bc23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCMember_8b2f245e-39bf-4988-addb-51f3fe88b775" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_f405bbf0-3a95-408a-a417-5e358614bc23" xlink:to="loc_lunr_IntuitiveMachinesLLCMember_8b2f245e-39bf-4988-addb-51f3fe88b775" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_203b81b3-065e-4cfc-a576-d468f978208a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:to="loc_dei_LegalEntityAxis_203b81b3-065e-4cfc-a576-d468f978208a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_203b81b3-065e-4cfc-a576-d468f978208a_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_203b81b3-065e-4cfc-a576-d468f978208a" xlink:to="loc_dei_EntityDomain_203b81b3-065e-4cfc-a576-d468f978208a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_9c006b8f-3818-4ab7-961f-209cfcdd4a9e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_203b81b3-065e-4cfc-a576-d468f978208a" xlink:to="loc_dei_EntityDomain_9c006b8f-3818-4ab7-961f-209cfcdd4a9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCPriorInvestorsMember_bc5e0dbb-6432-4d13-8d39-6db27190dec3" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCPriorInvestorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_9c006b8f-3818-4ab7-961f-209cfcdd4a9e" xlink:to="loc_lunr_IntuitiveMachinesLLCPriorInvestorsMember_bc5e0dbb-6432-4d13-8d39-6db27190dec3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_c53e8433-e237-4360-bae2-5e26819a7e66" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockByUniqueDescriptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_49c57d03-391b-4bf0-a6cb-a70484a89764" xlink:to="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_c53e8433-e237-4360-bae2-5e26819a7e66" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_c53e8433-e237-4360-bae2-5e26819a7e66_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_c53e8433-e237-4360-bae2-5e26819a7e66" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_c53e8433-e237-4360-bae2-5e26819a7e66_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_9e1a47ca-db0f-483d-8e31-e1dfbd392132" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_c53e8433-e237-4360-bae2-5e26819a7e66" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_9e1a47ca-db0f-483d-8e31-e1dfbd392132" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AfterYearThreePostClosingMember_750649b0-8486-49b9-b877-4430b444fd70" xlink:href="lunr-20230630.xsd#lunr_AfterYearThreePostClosingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_9e1a47ca-db0f-483d-8e31-e1dfbd392132" xlink:to="loc_lunr_AfterYearThreePostClosingMember_750649b0-8486-49b9-b877-4430b444fd70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AfterYearFourPostClosingMember_2b7bd029-fb72-4623-a964-cb0897aed514" xlink:href="lunr-20230630.xsd#lunr_AfterYearFourPostClosingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_9e1a47ca-db0f-483d-8e31-e1dfbd392132" xlink:to="loc_lunr_AfterYearFourPostClosingMember_2b7bd029-fb72-4623-a964-cb0897aed514" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AfterYearFivePostClosingMember_88647f07-8d1b-4b3e-a154-7a38ba666a50" xlink:href="lunr-20230630.xsd#lunr_AfterYearFivePostClosingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_9e1a47ca-db0f-483d-8e31-e1dfbd392132" xlink:to="loc_lunr_AfterYearFivePostClosingMember_88647f07-8d1b-4b3e-a154-7a38ba666a50" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/MezzanineEquityandEquityCapitalStockDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#MezzanineEquityandEquityCapitalStockDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/MezzanineEquityandEquityCapitalStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_098557b9-0815-4577-be0a-55ac1c78586e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_098557b9-0815-4577-be0a-55ac1c78586e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_0754e439-3c60-42f9-b4a2-c9bf2dc84876" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_0754e439-3c60-42f9-b4a2-c9bf2dc84876" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_bbc7f9f4-c371-45d3-87a9-50d675de3299" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_bbc7f9f4-c371-45d3-87a9-50d675de3299" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesAuthorized_438bbd96-7240-46d0-8aa1-3f251a0e8471" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_TemporaryEquitySharesAuthorized_438bbd96-7240-46d0-8aa1-3f251a0e8471" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_cdad7e1e-b4ae-4920-8c55-c0af866bd6c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_CommonStockSharesIssued_cdad7e1e-b4ae-4920-8c55-c0af866bd6c2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued_378f9f66-c188-4761-9b72-bcba31dfb9ed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_TemporaryEquitySharesIssued_378f9f66-c188-4761-9b72-bcba31dfb9ed" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_3566a04f-58a6-4f85-834a-6c80ab2dfb26" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_TreasuryStockCommonShares_3566a04f-58a6-4f85-834a-6c80ab2dfb26" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_6b97d2fe-84af-40d0-b8c0-399cc1617bb6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_6b97d2fe-84af-40d0-b8c0-399cc1617bb6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_ae970682-8fa2-4da7-b4cc-efc98014b2fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_TemporaryEquitySharesOutstanding_ae970682-8fa2-4da7-b4cc-efc98014b2fd" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TotalSharesOutstanding_71933b44-6099-4d7a-841e-89700b86a75b" xlink:href="lunr-20230630.xsd#lunr_TotalSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_lunr_TotalSharesOutstanding_71933b44-6099-4d7a-841e-89700b86a75b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TotalSharesIssued_2c0e8f9c-da1f-4309-88f8-1cd55e829078" xlink:href="lunr-20230630.xsd#lunr_TotalSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_lunr_TotalSharesIssued_2c0e8f9c-da1f-4309-88f8-1cd55e829078" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_TotalSharesAuthorized_9185e4aa-abd5-40fd-a934-340656f3c775" xlink:href="lunr-20230630.xsd#lunr_TotalSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_lunr_TotalSharesAuthorized_9185e4aa-abd5-40fd-a934-340656f3c775" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_b65c688d-1588-45b9-a95f-0b94588fbf90" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_abc0cc8a-a3c0-4293-8982-4ac503db883b" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_b65c688d-1588-45b9-a95f-0b94588fbf90" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_4b7c86d3-e29a-4121-bb90-c9a0c7289cea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_b65c688d-1588-45b9-a95f-0b94588fbf90" xlink:to="loc_us-gaap_StatementClassOfStockAxis_4b7c86d3-e29a-4121-bb90-c9a0c7289cea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_4b7c86d3-e29a-4121-bb90-c9a0c7289cea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4b7c86d3-e29a-4121-bb90-c9a0c7289cea" xlink:to="loc_us-gaap_ClassOfStockDomain_4b7c86d3-e29a-4121-bb90-c9a0c7289cea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4b7c86d3-e29a-4121-bb90-c9a0c7289cea" xlink:to="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_c6529a9e-22dd-4ed5-90b5-39f0741a5539" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:to="loc_us-gaap_CommonClassAMember_c6529a9e-22dd-4ed5-90b5-39f0741a5539" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_7bd922fa-d490-4132-a7f4-f9ce877f8e37" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:to="loc_us-gaap_CommonClassBMember_7bd922fa-d490-4132-a7f4-f9ce877f8e37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_04993c38-c87b-4f04-8da3-4288d49ae968" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:to="loc_us-gaap_CommonClassCMember_04993c38-c87b-4f04-8da3-4288d49ae968" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_c51c9b18-6cf2-4655-a73a-fdb2a2bbfbb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1663febe-2e60-4fee-b392-448030c95dd2" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_c51c9b18-6cf2-4655-a73a-fdb2a2bbfbb7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_fac6c26c-d37d-406d-a689-9d711c7b0863" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_b65c688d-1588-45b9-a95f-0b94588fbf90" xlink:to="loc_srt_CounterpartyNameAxis_fac6c26c-d37d-406d-a689-9d711c7b0863" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fac6c26c-d37d-406d-a689-9d711c7b0863_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_fac6c26c-d37d-406d-a689-9d711c7b0863" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_fac6c26c-d37d-406d-a689-9d711c7b0863_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_52947606-6f1a-43c9-a2c7-48a6a13c6534" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_fac6c26c-d37d-406d-a689-9d711c7b0863" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_52947606-6f1a-43c9-a2c7-48a6a13c6534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IPAXSponsorMember_8c414b8d-7609-47b3-9ff4-414464d09057" xlink:href="lunr-20230630.xsd#lunr_IPAXSponsorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_52947606-6f1a-43c9-a2c7-48a6a13c6534" xlink:to="loc_lunr_IPAXSponsorMember_8c414b8d-7609-47b3-9ff4-414464d09057" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/WarrantsandSAFEAgreementsDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#WarrantsandSAFEAgreementsDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/WarrantsandSAFEAgreementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessAcquisitionWarrantsAssumed_d1407851-cfea-4360-a366-24a4dcd4cd55" xlink:href="lunr-20230630.xsd#lunr_BusinessAcquisitionWarrantsAssumed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_BusinessAcquisitionWarrantsAssumed_d1407851-cfea-4360-a366-24a4dcd4cd55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_c8a441b0-3c12-4038-be37-0de8bf77d510" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_c8a441b0-3c12-4038-be37-0de8bf77d510" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_457c7868-27c3-4a83-a473-e34f7b7174f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_457c7868-27c3-4a83-a473-e34f7b7174f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_10527457-c81f-4b86-9a24-35b3fd338f66" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_10527457-c81f-4b86-9a24-35b3fd338f66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsBecomeExercisable_e1352c7e-6dff-4257-b887-987952ee577c" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsBecomeExercisable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsBecomeExercisable_e1352c7e-6dff-4257-b887-987952ee577c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_1a016703-4fc9-449b-8873-3b8720ebfd2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_1a016703-4fc9-449b-8873-3b8720ebfd2a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsCanBeTransferredOrSold_98507c40-e55f-4554-8361-32f7b574604e" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsCanBeTransferredOrSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsCanBeTransferredOrSold_98507c40-e55f-4554-8361-32f7b574604e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightRedemptionPrice_da9b3046-32d2-472d-86d6-4eaece2309b1" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightRedemptionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightRedemptionPrice_da9b3046-32d2-472d-86d6-4eaece2309b1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightPeriodForPriorWrittenNoticeBeforeRedemption_b29f29c9-e6a3-4405-91b6-082d69bfcbc3" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightPeriodForPriorWrittenNoticeBeforeRedemption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightPeriodForPriorWrittenNoticeBeforeRedemption_b29f29c9-e6a3-4405-91b6-082d69bfcbc3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightClosingPriceRequiredToRedeemWarrants_d275d839-09d9-406a-b351-9a5fb0f92a80" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightClosingPriceRequiredToRedeemWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightClosingPriceRequiredToRedeemWarrants_d275d839-09d9-406a-b351-9a5fb0f92a80" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightPeriodInWhichStockMustReachMandatoryClosingPrice_2b09ccd0-5465-42df-88ae-2dbf2f1a0dd0" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightPeriodInWhichStockMustReachMandatoryClosingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightPeriodInWhichStockMustReachMandatoryClosingPrice_2b09ccd0-5465-42df-88ae-2dbf2f1a0dd0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightMaximumPeriodInWhichStockCanReachMandatoryClosingPrice_31f0003b-fbc6-4f36-b661-ccf7967cf743" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightMaximumPeriodInWhichStockCanReachMandatoryClosingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightMaximumPeriodInWhichStockCanReachMandatoryClosingPrice_31f0003b-fbc6-4f36-b661-ccf7967cf743" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightNumberOfBusinessDaysNoticePriorToNoticeBeingSent_f3df5477-fe7d-4fa6-bc8f-4da52f77dc8e" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightNumberOfBusinessDaysNoticePriorToNoticeBeingSent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightNumberOfBusinessDaysNoticePriorToNoticeBeingSent_f3df5477-fe7d-4fa6-bc8f-4da52f77dc8e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightWarrantsExercised_cfc63736-2cb8-4305-8463-b3024fd440b0" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightWarrantsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightWarrantsExercised_cfc63736-2cb8-4305-8463-b3024fd440b0" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromWarrantExercises_c6724adc-cd2b-44b5-b61c-79ae92ed4f5a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromWarrantExercises"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_ProceedsFromWarrantExercises_c6724adc-cd2b-44b5-b61c-79ae92ed4f5a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsMayBeExercised_1fdb5a83-d548-4172-89d8-44cd9918914c" xlink:href="lunr-20230630.xsd#lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsMayBeExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ClassOfWarrantOrRightPeriodBeforeWarrantsMayBeExercised_1fdb5a83-d548-4172-89d8-44cd9918914c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_NumberOfSAFEAgreements_25ffae27-9e03-4fb8-b32f-9fd211de2c5f" xlink:href="lunr-20230630.xsd#lunr_NumberOfSAFEAgreements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_NumberOfSAFEAgreements_25ffae27-9e03-4fb8-b32f-9fd211de2c5f" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SimpleAgreementsForFutureEquityLiability_557aac21-b3f6-4c90-8750-35084751e9de" xlink:href="lunr-20230630.xsd#lunr_SimpleAgreementsForFutureEquityLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_SimpleAgreementsForFutureEquityLiability_557aac21-b3f6-4c90-8750-35084751e9de" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ConversionOfSAFEAgreementsSharesIssued_d78b4c28-e6a7-46be-95e6-1bdfb0207640" xlink:href="lunr-20230630.xsd#lunr_ConversionOfSAFEAgreementsSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ConversionOfSAFEAgreementsSharesIssued_d78b4c28-e6a7-46be-95e6-1bdfb0207640" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ChangeInFairValueOfSAFEAgreement_63583ee1-d3e1-4f72-af6d-542cfdf384b6" xlink:href="lunr-20230630.xsd#lunr_ChangeInFairValueOfSAFEAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_lunr_ChangeInFairValueOfSAFEAgreement_63583ee1-d3e1-4f72-af6d-542cfdf384b6" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightTable_e0e880cc-a9da-43f3-b8d2-2c292c3f755a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems_77bb8a18-6889-4e82-a33c-16fd7e6784a9" xlink:to="loc_us-gaap_ClassOfWarrantOrRightTable_e0e880cc-a9da-43f3-b8d2-2c292c3f755a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_f6450c03-79d6-4f1d-8979-3261077f4469" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfWarrantOrRightTable_e0e880cc-a9da-43f3-b8d2-2c292c3f755a" xlink:to="loc_us-gaap_StatementClassOfStockAxis_f6450c03-79d6-4f1d-8979-3261077f4469" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f6450c03-79d6-4f1d-8979-3261077f4469_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f6450c03-79d6-4f1d-8979-3261077f4469" xlink:to="loc_us-gaap_ClassOfStockDomain_f6450c03-79d6-4f1d-8979-3261077f4469_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a08e49ca-041d-4e20-bd2d-e0f8681f044e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f6450c03-79d6-4f1d-8979-3261077f4469" xlink:to="loc_us-gaap_ClassOfStockDomain_a08e49ca-041d-4e20-bd2d-e0f8681f044e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_750fbbf6-8ce6-45b0-a8a0-6e317fc491dc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_a08e49ca-041d-4e20-bd2d-e0f8681f044e" xlink:to="loc_us-gaap_CommonClassAMember_750fbbf6-8ce6-45b0-a8a0-6e317fc491dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_4ff79722-d3c5-494b-b001-2bbde1f50267" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfWarrantOrRightTable_e0e880cc-a9da-43f3-b8d2-2c292c3f755a" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_4ff79722-d3c5-494b-b001-2bbde1f50267" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_4ff79722-d3c5-494b-b001-2bbde1f50267_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_4ff79722-d3c5-494b-b001-2bbde1f50267" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_4ff79722-d3c5-494b-b001-2bbde1f50267_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_ec34a804-3239-4efd-853b-17c6a935f381" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_4ff79722-d3c5-494b-b001-2bbde1f50267" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_ec34a804-3239-4efd-853b-17c6a935f381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PublicWarrantsMember_950f3471-8f53-4a73-99d6-7b155f7d5fa3" xlink:href="lunr-20230630.xsd#lunr_PublicWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_ec34a804-3239-4efd-853b-17c6a935f381" xlink:to="loc_lunr_PublicWarrantsMember_950f3471-8f53-4a73-99d6-7b155f7d5fa3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PrivateWarrantsMember_cf658f93-0609-4164-ab37-93c210591bda" xlink:href="lunr-20230630.xsd#lunr_PrivateWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_ec34a804-3239-4efd-853b-17c6a935f381" xlink:to="loc_lunr_PrivateWarrantsMember_cf658f93-0609-4164-ab37-93c210591bda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SeriesAPreferredWarrantsMember_41d3b181-e509-4754-889d-1020a22378d2" xlink:href="lunr-20230630.xsd#lunr_SeriesAPreferredWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_ec34a804-3239-4efd-853b-17c6a935f381" xlink:to="loc_lunr_SeriesAPreferredWarrantsMember_41d3b181-e509-4754-889d-1020a22378d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_362bda94-85a1-4880-b228-9a8f3ecfaf2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfWarrantOrRightTable_e0e880cc-a9da-43f3-b8d2-2c292c3f755a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_362bda94-85a1-4880-b228-9a8f3ecfaf2f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_362bda94-85a1-4880-b228-9a8f3ecfaf2f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_362bda94-85a1-4880-b228-9a8f3ecfaf2f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_362bda94-85a1-4880-b228-9a8f3ecfaf2f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8767accf-bd7a-4aaa-afc2-c9ef197066a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_362bda94-85a1-4880-b228-9a8f3ecfaf2f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8767accf-bd7a-4aaa-afc2-c9ef197066a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IntuitiveMachinesLLCMember_28ea2956-f0eb-4ed3-8114-04c8821fae56" xlink:href="lunr-20230630.xsd#lunr_IntuitiveMachinesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8767accf-bd7a-4aaa-afc2-c9ef197066a5" xlink:to="loc_lunr_IntuitiveMachinesLLCMember_28ea2956-f0eb-4ed3-8114-04c8821fae56" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#ShareBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_3757b4f0-fc29-4f33-ae18-9ce985a707af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_3757b4f0-fc29-4f33-ae18-9ce985a707af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare_b66cc418-a89d-4c70-bd1e-8fd75ba30a4b" xlink:href="lunr-20230630.xsd#lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_lunr_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare_b66cc418-a89d-4c70-bd1e-8fd75ba30a4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_0122a6ee-d97c-44fb-8bb2-df2e9505a1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_0122a6ee-d97c-44fb-8bb2-df2e9505a1ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_a347da46-c418-4e2b-b032-611cb85726f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_a347da46-c418-4e2b-b032-611cb85726f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_50881af1-6b8e-44d8-babb-b172aaddf98d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_50881af1-6b8e-44d8-babb-b172aaddf98d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_a4f84677-2a02-4281-aa7a-e06889cd11f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_a4f84677-2a02-4281-aa7a-e06889cd11f1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_c1750a19-d7e5-4c87-ab64-66302d2f156c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_c1750a19-d7e5-4c87-ab64-66302d2f156c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_47f625dc-ee5e-4214-9eda-a0f4b6cfb0ec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_47f625dc-ee5e-4214-9eda-a0f4b6cfb0ec" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_05b903e1-3c54-4120-89f3-37ebc6ce03f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_05b903e1-3c54-4120-89f3-37ebc6ce03f9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e7271161-c452-4940-8410-552abc801a7e" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_941de0a8-1ceb-4693-b0cd-2cf915900fd8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:to="loc_us-gaap_AwardTypeAxis_941de0a8-1ceb-4693-b0cd-2cf915900fd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_941de0a8-1ceb-4693-b0cd-2cf915900fd8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_941de0a8-1ceb-4693-b0cd-2cf915900fd8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_941de0a8-1ceb-4693-b0cd-2cf915900fd8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0e530039-cfe4-4f9d-ab37-0f80147ddd90" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_941de0a8-1ceb-4693-b0cd-2cf915900fd8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0e530039-cfe4-4f9d-ab37-0f80147ddd90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_9328cd85-24ee-41f7-af20-921c32a0fcd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0e530039-cfe4-4f9d-ab37-0f80147ddd90" xlink:to="loc_us-gaap_EmployeeStockOptionMember_9328cd85-24ee-41f7-af20-921c32a0fcd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_4b3c3216-fbb2-41f2-aca4-8f40f3074302" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0e530039-cfe4-4f9d-ab37-0f80147ddd90" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_4b3c3216-fbb2-41f2-aca4-8f40f3074302" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:to="loc_us-gaap_StatementClassOfStockAxis_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e" xlink:to="loc_us-gaap_ClassOfStockDomain_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ce1d57c5-c84c-4e6d-824e-f3fdeea55b1c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_79e6e4d2-c20a-4c49-b363-1fe6c4a71c9e" xlink:to="loc_us-gaap_ClassOfStockDomain_ce1d57c5-c84c-4e6d-824e-f3fdeea55b1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_da1cd9b4-b89e-4c7f-a967-3633398c1b5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ce1d57c5-c84c-4e6d-824e-f3fdeea55b1c" xlink:to="loc_us-gaap_CommonClassAMember_da1cd9b4-b89e-4c7f-a967-3633398c1b5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_f312655b-7438-42ee-a2ff-9f7e3415c521" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ce1d57c5-c84c-4e6d-824e-f3fdeea55b1c" xlink:to="loc_us-gaap_CommonClassBMember_f312655b-7438-42ee-a2ff-9f7e3415c521" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_6631d2aa-8088-4f19-ac12-d1e7bcb84762" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:to="loc_us-gaap_PlanNameAxis_6631d2aa-8088-4f19-ac12-d1e7bcb84762" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_6631d2aa-8088-4f19-ac12-d1e7bcb84762_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_6631d2aa-8088-4f19-ac12-d1e7bcb84762" xlink:to="loc_us-gaap_PlanNameDomain_6631d2aa-8088-4f19-ac12-d1e7bcb84762_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_f74e5a18-86a0-442b-9730-4921d3d7897a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_6631d2aa-8088-4f19-ac12-d1e7bcb84762" xlink:to="loc_us-gaap_PlanNameDomain_f74e5a18-86a0-442b-9730-4921d3d7897a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_A2021UnitOptionPlanMember_ff121efa-940e-499a-a8d2-d91ed1b47d91" xlink:href="lunr-20230630.xsd#lunr_A2021UnitOptionPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_f74e5a18-86a0-442b-9730-4921d3d7897a" xlink:to="loc_lunr_A2021UnitOptionPlanMember_ff121efa-940e-499a-a8d2-d91ed1b47d91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_OmnibusIncentive2023PlanMember_17bbeb58-f5b3-4464-bde7-8bd34815b4fd" xlink:href="lunr-20230630.xsd#lunr_OmnibusIncentive2023PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_f74e5a18-86a0-442b-9730-4921d3d7897a" xlink:to="loc_lunr_OmnibusIncentive2023PlanMember_17bbeb58-f5b3-4464-bde7-8bd34815b4fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_71486f2f-de8e-4bf1-9fe0-d86d98c6af22" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_c9a496af-4c9d-4543-b684-2c6a7a3bc299" xlink:to="loc_srt_RangeAxis_71486f2f-de8e-4bf1-9fe0-d86d98c6af22" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_71486f2f-de8e-4bf1-9fe0-d86d98c6af22_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_71486f2f-de8e-4bf1-9fe0-d86d98c6af22" xlink:to="loc_srt_RangeMember_71486f2f-de8e-4bf1-9fe0-d86d98c6af22_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e1f5a770-1d07-4ebc-9cb4-53cd69ab71ba" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_71486f2f-de8e-4bf1-9fe0-d86d98c6af22" xlink:to="loc_srt_RangeMember_e1f5a770-1d07-4ebc-9cb4-53cd69ab71ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_e81f0aae-c586-43f0-a371-26a82a3f7b67" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e1f5a770-1d07-4ebc-9cb4-53cd69ab71ba" xlink:to="loc_srt_MinimumMember_e81f0aae-c586-43f0-a371-26a82a3f7b67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_e9c64ac7-324c-4618-9b3e-fe0bdfb163d9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e1f5a770-1d07-4ebc-9cb4-53cd69ab71ba" xlink:to="loc_srt_MaximumMember_e9c64ac7-324c-4618-9b3e-fe0bdfb163d9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/ShareBasedCompensationRestrictedStockunitActivityDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#ShareBasedCompensationRestrictedStockunitActivityDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/ShareBasedCompensationRestrictedStockunitActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0a49d7d8-2b61-4064-928a-71cf76015812" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0a49d7d8-2b61-4064-928a-71cf76015812" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_deb64f22-0782-40b9-aeea-3030c402212f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_deb64f22-0782-40b9-aeea-3030c402212f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_08e4e8fe-8204-48a1-bb23-d53e2685cc3b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_08e4e8fe-8204-48a1-bb23-d53e2685cc3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_16a74b4a-4819-416f-a6a2-a216a68cfeba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_16a74b4a-4819-416f-a6a2-a216a68cfeba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_9786baba-67ab-4722-9c87-3ca36b82d2ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_ac1b2ea0-77d9-4b3a-8d29-7a137bedb2cc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_9786baba-67ab-4722-9c87-3ca36b82d2ee" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2de091d5-3e1b-4c1c-8e79-712b330fb6a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0a49d7d8-2b61-4064-928a-71cf76015812" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_3716971e-3e08-4951-b90a-da02aa43e007" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_3716971e-3e08-4951-b90a-da02aa43e007" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_da5293f7-f91a-43ca-88ca-060d13c7a787" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_da5293f7-f91a-43ca-88ca-060d13c7a787" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_50f3a21c-ac6d-43b1-bdaf-3a70039f8518" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_50f3a21c-ac6d-43b1-bdaf-3a70039f8518" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_bb0ba4cf-1f72-442c-8889-41788b850768" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_b02ddae1-b9b7-4d2e-8be4-b7f5083ac3e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_bb0ba4cf-1f72-442c-8889-41788b850768" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_9cbeca5f-d50e-483d-a346-3dda0a74537d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_29766db5-dc56-44e6-9978-85bcdc9a6f4d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0a49d7d8-2b61-4064-928a-71cf76015812" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_29766db5-dc56-44e6-9978-85bcdc9a6f4d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_29766db5-dc56-44e6-9978-85bcdc9a6f4d" xlink:to="loc_us-gaap_AwardTypeAxis_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b7514d9e-855f-4a0b-ab70-52a1c9ffb547" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_efeb3a6e-30cf-4b7b-91ef-8b63f55f996c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b7514d9e-855f-4a0b-ab70-52a1c9ffb547" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_d1f8a011-69c9-4885-9ce9-bac8c4c49880" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b7514d9e-855f-4a0b-ab70-52a1c9ffb547" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_d1f8a011-69c9-4885-9ce9-bac8c4c49880" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/FairValueMeasurementsFairValueofAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#FairValueMeasurementsFairValueofAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/FairValueMeasurementsFairValueofAssetsandLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_f77358d1-18b9-4311-a810-eac292ceffe7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_8492dd84-8b70-42eb-b298-e5b23108d9f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_f77358d1-18b9-4311-a810-eac292ceffe7" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_8492dd84-8b70-42eb-b298-e5b23108d9f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SimpleAgreementsForFutureEquityLiability_88f1488b-f927-478f-b14e-b22200da4c12" xlink:href="lunr-20230630.xsd#lunr_SimpleAgreementsForFutureEquityLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_f77358d1-18b9-4311-a810-eac292ceffe7" xlink:to="loc_lunr_SimpleAgreementsForFutureEquityLiability_88f1488b-f927-478f-b14e-b22200da4c12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_d9a65f9c-a532-4d78-8201-fde3a594ce4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_f77358d1-18b9-4311-a810-eac292ceffe7" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_d9a65f9c-a532-4d78-8201-fde3a594ce4a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3fc55f85-daa5-4b36-a011-95f5a4a727ca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_f77358d1-18b9-4311-a810-eac292ceffe7" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3fc55f85-daa5-4b36-a011-95f5a4a727ca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_b20c6866-4cb5-4978-9cf9-ccc84308e351" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3fc55f85-daa5-4b36-a011-95f5a4a727ca" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_b20c6866-4cb5-4978-9cf9-ccc84308e351" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_b20c6866-4cb5-4978-9cf9-ccc84308e351_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_b20c6866-4cb5-4978-9cf9-ccc84308e351" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_b20c6866-4cb5-4978-9cf9-ccc84308e351_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_bc79f18c-2aa4-4d5b-b851-6407ea1bbbed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_b20c6866-4cb5-4978-9cf9-ccc84308e351" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_bc79f18c-2aa4-4d5b-b851-6407ea1bbbed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_201140ee-91c9-4b3b-b38c-9c345c6a9fdf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_bc79f18c-2aa4-4d5b-b851-6407ea1bbbed" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_201140ee-91c9-4b3b-b38c-9c345c6a9fdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ea122d16-1b88-48ae-ad5c-99338175c939" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3fc55f85-daa5-4b36-a011-95f5a4a727ca" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ea122d16-1b88-48ae-ad5c-99338175c939" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ea122d16-1b88-48ae-ad5c-99338175c939_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ea122d16-1b88-48ae-ad5c-99338175c939" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ea122d16-1b88-48ae-ad5c-99338175c939_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6764ff-f975-49ff-b22a-b28b3071b675" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ea122d16-1b88-48ae-ad5c-99338175c939" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6764ff-f975-49ff-b22a-b28b3071b675" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_7b4415ec-8fb5-4277-9c46-eeabd514d258" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6764ff-f975-49ff-b22a-b28b3071b675" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_7b4415ec-8fb5-4277-9c46-eeabd514d258" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_92b3c813-a6b1-4607-a915-87a47538efb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6764ff-f975-49ff-b22a-b28b3071b675" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_92b3c813-a6b1-4607-a915-87a47538efb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_3126fd70-34ca-4829-9bd6-4c8b2f7bc488" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6764ff-f975-49ff-b22a-b28b3071b675" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_3126fd70-34ca-4829-9bd6-4c8b2f7bc488" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/FairValueMeasurementsChangeinFairValueofEarnoutLiabilitiesandSAFEAgreementsDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#FairValueMeasurementsChangeinFairValueofEarnoutLiabilitiesandSAFEAgreementsDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/FairValueMeasurementsChangeinFairValueofEarnoutLiabilitiesandSAFEAgreementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_b4d4f266-8185-4dc4-be98-f7c08347159c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_b4d4f266-8185-4dc4-be98-f7c08347159c" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_5458d315-2dc3-4fce-96ec-071f73a746aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_5458d315-2dc3-4fce-96ec-071f73a746aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_296a888b-91e8-4ee1-bfc0-b91ac570435c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_296a888b-91e8-4ee1-bfc0-b91ac570435c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_0c322b57-51a3-4132-893f-4827c11f0930" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_0c322b57-51a3-4132-893f-4827c11f0930" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityReclassifiedToEquity_a62dd81a-9d76-47ac-9f88-c07384678c87" xlink:href="lunr-20230630.xsd#lunr_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityReclassifiedToEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_3272f321-259c-4c74-ad7d-0691661386af" xlink:to="loc_lunr_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityReclassifiedToEquity_a62dd81a-9d76-47ac-9f88-c07384678c87" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_c0df1a63-5ba3-46e3-b9aa-7db3c57848da" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_abd5afa4-866b-434b-a35b-2e8ea8f6f319" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_b4d4f266-8185-4dc4-be98-f7c08347159c" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_abd5afa4-866b-434b-a35b-2e8ea8f6f319" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_f6951cca-867c-4bfe-9093-92ff44f56e12" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_abd5afa4-866b-434b-a35b-2e8ea8f6f319" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_f6951cca-867c-4bfe-9093-92ff44f56e12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_f6951cca-867c-4bfe-9093-92ff44f56e12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_f6951cca-867c-4bfe-9093-92ff44f56e12" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_f6951cca-867c-4bfe-9093-92ff44f56e12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47649a45-cfd5-4b7b-96c8-a058320341da" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_f6951cca-867c-4bfe-9093-92ff44f56e12" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47649a45-cfd5-4b7b-96c8-a058320341da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_ContingentConsiderationLiabilityMember_af112f45-4018-456b-aa59-ea3cd464842e" xlink:href="lunr-20230630.xsd#lunr_ContingentConsiderationLiabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47649a45-cfd5-4b7b-96c8-a058320341da" xlink:to="loc_lunr_ContingentConsiderationLiabilityMember_af112f45-4018-456b-aa59-ea3cd464842e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SAFEAgreementLiabilityMember_ab10ef6e-caa2-4c9c-bd71-73a5df115292" xlink:href="lunr-20230630.xsd#lunr_SAFEAgreementLiabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47649a45-cfd5-4b7b-96c8-a058320341da" xlink:to="loc_lunr_SAFEAgreementLiabilityMember_ab10ef6e-caa2-4c9c-bd71-73a5df115292" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#FairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_04e631b3-9f12-400d-b02f-ecada85092a0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_04e631b3-9f12-400d-b02f-ecada85092a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_EarnOutLiabilityMeasurementInput_94f6b4d8-cb47-4443-829f-644cc43a1465" xlink:href="lunr-20230630.xsd#lunr_EarnOutLiabilityMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_lunr_EarnOutLiabilityMeasurementInput_94f6b4d8-cb47-4443-829f-644cc43a1465" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SAFEAgreementLiabilityMeasurementInput_7f79090c-d91b-443d-91bd-63a05df753df" xlink:href="lunr-20230630.xsd#lunr_SAFEAgreementLiabilityMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_lunr_SAFEAgreementLiabilityMeasurementInput_7f79090c-d91b-443d-91bd-63a05df753df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement_9e60d1db-7519-4200-9ed1-22d230eade9f" xlink:href="lunr-20230630.xsd#lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_lunr_StockIssuedDuringPeriodSharesConversionOfSAFEAgreement_9e60d1db-7519-4200-9ed1-22d230eade9f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_bceed1cd-abcc-4671-b8ca-f2317703fda2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_bceed1cd-abcc-4671-b8ca-f2317703fda2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_bcd443a9-7efe-45ee-8f60-4cdea16bc79f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_40933968-55ba-445a-a7b2-6a2423b94556" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_bcd443a9-7efe-45ee-8f60-4cdea16bc79f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_c7914a68-423e-430a-9bb0-834c595170e9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_bcd443a9-7efe-45ee-8f60-4cdea16bc79f" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_c7914a68-423e-430a-9bb0-834c595170e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_c7914a68-423e-430a-9bb0-834c595170e9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_c7914a68-423e-430a-9bb0-834c595170e9" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_c7914a68-423e-430a-9bb0-834c595170e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_c7914a68-423e-430a-9bb0-834c595170e9" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputSharePriceMember_f3396dc9-33df-4ed4-9e30-0c1e62123b9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputSharePriceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_us-gaap_MeasurementInputSharePriceMember_f3396dc9-33df-4ed4-9e30-0c1e62123b9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputDividendYieldMember_b4c374d8-fb91-457b-bcce-9cf1355a20aa" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputDividendYieldMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputDividendYieldMember_b4c374d8-fb91-457b-bcce-9cf1355a20aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_ffe6bd08-dbbb-4d65-85d4-da960392af2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_ffe6bd08-dbbb-4d65-85d4-da960392af2d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputVolatilityMember_6819d26c-6d66-4a49-8818-e2490ef7f628" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputVolatilityMember_6819d26c-6d66-4a49-8818-e2490ef7f628" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputProbabilityOfContractBeingAwardedMember_8828e0fe-f490-4948-8e3a-a87b82439d76" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputProbabilityOfContractBeingAwardedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputProbabilityOfContractBeingAwardedMember_8828e0fe-f490-4948-8e3a-a87b82439d76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputProbabilityOfEquityFinancingMember_3905d104-1630-4146-95b1-1984d9b933e1" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputProbabilityOfEquityFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputProbabilityOfEquityFinancingMember_3905d104-1630-4146-95b1-1984d9b933e1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputProbabilityOfLiquidityEventMember_04ef3978-df65-4ad9-910d-f35f3a6b3e67" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputProbabilityOfLiquidityEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputProbabilityOfLiquidityEventMember_04ef3978-df65-4ad9-910d-f35f3a6b3e67" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputProbabilityOfDissolutionEventMember_105f55cf-3ca3-485c-8394-ef4278cf8de0" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputProbabilityOfDissolutionEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputProbabilityOfDissolutionEventMember_105f55cf-3ca3-485c-8394-ef4278cf8de0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_691d1828-5d8d-41de-bda8-d5f6df55d1d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_691d1828-5d8d-41de-bda8-d5f6df55d1d3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputExpectedTermEquityFinancingMember_946f8599-0888-4de5-9cd2-8d99cb4d00cd" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputExpectedTermEquityFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputExpectedTermEquityFinancingMember_946f8599-0888-4de5-9cd2-8d99cb4d00cd" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputExpectedTermLiquidityEventMember_a84c7dad-54f3-4ec1-a726-9ff33edfd133" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputExpectedTermLiquidityEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputExpectedTermLiquidityEventMember_a84c7dad-54f3-4ec1-a726-9ff33edfd133" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_MeasurementInputExpectedTermDissolutionEventMember_8ff61b94-969d-41df-9353-a670e7dc2f55" xlink:href="lunr-20230630.xsd#lunr_MeasurementInputExpectedTermDissolutionEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_58ad366d-d8ee-4199-9210-c60272fd9eb6" xlink:to="loc_lunr_MeasurementInputExpectedTermDissolutionEventMember_8ff61b94-969d-41df-9353-a670e7dc2f55" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_9cac3280-20fd-48e0-9dea-edef17711e09" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_bcd443a9-7efe-45ee-8f60-4cdea16bc79f" xlink:to="loc_us-gaap_StatementClassOfStockAxis_9cac3280-20fd-48e0-9dea-edef17711e09" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_9cac3280-20fd-48e0-9dea-edef17711e09_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9cac3280-20fd-48e0-9dea-edef17711e09" xlink:to="loc_us-gaap_ClassOfStockDomain_9cac3280-20fd-48e0-9dea-edef17711e09_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_47a15d03-69e9-49c9-867a-83dcc21f777e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9cac3280-20fd-48e0-9dea-edef17711e09" xlink:to="loc_us-gaap_ClassOfStockDomain_47a15d03-69e9-49c9-867a-83dcc21f777e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_c6c58403-84ca-4663-a7da-46569aaf5c70" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_47a15d03-69e9-49c9-867a-83dcc21f777e" xlink:to="loc_us-gaap_CommonClassAMember_c6c58403-84ca-4663-a7da-46569aaf5c70" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/NetIncomePerShareNarrativeDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#NetIncomePerShareNarrativeDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/NetIncomePerShareNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_069c5f84-f412-42b5-b688-776d2a5052d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_CommonStockVotingRightsNumberOfVotesPerShare_f6e0a791-1de4-40e2-8be4-28e1ebf4e881" xlink:href="lunr-20230630.xsd#lunr_CommonStockVotingRightsNumberOfVotesPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_069c5f84-f412-42b5-b688-776d2a5052d9" xlink:to="loc_lunr_CommonStockVotingRightsNumberOfVotesPerShare_f6e0a791-1de4-40e2-8be4-28e1ebf4e881" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_043825d8-0da3-4ea1-b4b8-8e644bec880b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_069c5f84-f412-42b5-b688-776d2a5052d9" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_043825d8-0da3-4ea1-b4b8-8e644bec880b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_8a688c7c-da99-46bf-bf06-725f2e647e1e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_069c5f84-f412-42b5-b688-776d2a5052d9" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_8a688c7c-da99-46bf-bf06-725f2e647e1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_c595e652-57db-41e7-b69d-3a503f1d8ec8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_8a688c7c-da99-46bf-bf06-725f2e647e1e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_c595e652-57db-41e7-b69d-3a503f1d8ec8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c595e652-57db-41e7-b69d-3a503f1d8ec8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c595e652-57db-41e7-b69d-3a503f1d8ec8" xlink:to="loc_us-gaap_ClassOfStockDomain_c595e652-57db-41e7-b69d-3a503f1d8ec8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_22977b28-98d7-4e65-b56e-fbb80a8d5edc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_c595e652-57db-41e7-b69d-3a503f1d8ec8" xlink:to="loc_us-gaap_ClassOfStockDomain_22977b28-98d7-4e65-b56e-fbb80a8d5edc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_8b435f77-8152-4bf4-a152-c2d688a599de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_22977b28-98d7-4e65-b56e-fbb80a8d5edc" xlink:to="loc_us-gaap_CommonClassAMember_8b435f77-8152-4bf4-a152-c2d688a599de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_e98df436-ff09-4c21-a125-39b914ec9803" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_22977b28-98d7-4e65-b56e-fbb80a8d5edc" xlink:to="loc_us-gaap_CommonClassBMember_e98df436-ff09-4c21-a125-39b914ec9803" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember_98eca73d-0522-4515-8773-7979f3f0e823" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_22977b28-98d7-4e65-b56e-fbb80a8d5edc" xlink:to="loc_us-gaap_CommonClassCMember_98eca73d-0522-4515-8773-7979f3f0e823" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_22547860-60ab-4785-ad6a-46670fc92805" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_8a688c7c-da99-46bf-bf06-725f2e647e1e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_22547860-60ab-4785-ad6a-46670fc92805" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_22547860-60ab-4785-ad6a-46670fc92805_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_22547860-60ab-4785-ad6a-46670fc92805" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_22547860-60ab-4785-ad6a-46670fc92805_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e1a006b-a02d-4eab-a570-6873fb1b2bbf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_22547860-60ab-4785-ad6a-46670fc92805" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e1a006b-a02d-4eab-a570-6873fb1b2bbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_c8da776d-678f-4b68-ae25-e8f587d1fb9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e1a006b-a02d-4eab-a570-6873fb1b2bbf" xlink:to="loc_us-gaap_WarrantMember_c8da776d-678f-4b68-ae25-e8f587d1fb9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_EarnoutUnitsMember_2d257d13-0e7e-4fdb-a621-24e4b997ab88" xlink:href="lunr-20230630.xsd#lunr_EarnoutUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4e1a006b-a02d-4eab-a570-6873fb1b2bbf" xlink:to="loc_lunr_EarnoutUnitsMember_2d257d13-0e7e-4fdb-a621-24e4b997ab88" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/RelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#RelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_329b80fb-44ba-40a3-a073-e70842107af3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_329b80fb-44ba-40a3-a073-e70842107af3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNet_9f777788-c8a9-4f86-ab2c-52dbb68ed4d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_AccountsReceivableNet_9f777788-c8a9-4f86-ab2c-52dbb68ed4d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeeExpense_783fc6d7-66ed-4c6e-9879-76cba2c27191" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ManagementFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_ManagementFeeExpense_783fc6d7-66ed-4c6e-9879-76cba2c27191" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_dc4943c5-78c1-4895-b23b-057bd293611d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_dc4943c5-78c1-4895-b23b-057bd293611d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityOwnershipPercentageExcludingConsolidatedEntityAndEquityMethodInvestee_3cdb7d42-7885-423b-8159-8c527dac0a4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityOwnershipPercentageExcludingConsolidatedEntityAndEquityMethodInvestee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_EquityOwnershipPercentageExcludingConsolidatedEntityAndEquityMethodInvestee_3cdb7d42-7885-423b-8159-8c527dac0a4a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LicenseFeeExpense_43abf45f-d150-4b52-8f13-85faf9aaa823" xlink:href="lunr-20230630.xsd#lunr_LicenseFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_lunr_LicenseFeeExpense_43abf45f-d150-4b52-8f13-85faf9aaa823" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_5a5404da-b6e4-4637-a84d-def87e475666" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_fcb8c280-8832-4bd6-befa-2e3329e4ec27" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_fcb8c280-8832-4bd6-befa-2e3329e4ec27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_fcb8c280-8832-4bd6-befa-2e3329e4ec27_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_fcb8c280-8832-4bd6-befa-2e3329e4ec27" xlink:to="loc_us-gaap_RelatedPartyDomain_fcb8c280-8832-4bd6-befa-2e3329e4ec27_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_d346e9a5-a6d4-4b3d-9eee-1f04596b52c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_fcb8c280-8832-4bd6-befa-2e3329e4ec27" xlink:to="loc_us-gaap_RelatedPartyDomain_d346e9a5-a6d4-4b3d-9eee-1f04596b52c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_71c3a5d1-8989-4930-b2f5-a41078e56577" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_d346e9a5-a6d4-4b3d-9eee-1f04596b52c7" xlink:to="loc_us-gaap_RelatedPartyMember_71c3a5d1-8989-4930-b2f5-a41078e56577" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_2e32af6f-1243-43f9-817e-35c2daebfba6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:to="loc_srt_CounterpartyNameAxis_2e32af6f-1243-43f9-817e-35c2daebfba6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2e32af6f-1243-43f9-817e-35c2daebfba6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_2e32af6f-1243-43f9-817e-35c2daebfba6" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2e32af6f-1243-43f9-817e-35c2daebfba6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_2e32af6f-1243-43f9-817e-35c2daebfba6" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_AxiomSpaceIncMember_76342df6-7d6b-4fcc-9a91-494b08dbe498" xlink:href="lunr-20230630.xsd#lunr_AxiomSpaceIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:to="loc_lunr_AxiomSpaceIncMember_76342df6-7d6b-4fcc-9a91-494b08dbe498" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IBXLLCMember_afb0746a-0243-4d9e-b096-d28cb6f18bc6" xlink:href="lunr-20230630.xsd#lunr_IBXLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:to="loc_lunr_IBXLLCMember_afb0746a-0243-4d9e-b096-d28cb6f18bc6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_KBRIncMember_52d9e0c9-ca0b-4d11-818c-89841943ee19" xlink:href="lunr-20230630.xsd#lunr_KBRIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:to="loc_lunr_KBRIncMember_52d9e0c9-ca0b-4d11-818c-89841943ee19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_XEnergyLLCMember_ebc75a87-4a6f-4099-9b77-7da1b7e7319e" xlink:href="lunr-20230630.xsd#lunr_XEnergyLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:to="loc_lunr_XEnergyLLCMember_ebc75a87-4a6f-4099-9b77-7da1b7e7319e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_PenumbraLLCMember_36fa2cc4-f9f6-4518-be1a-2e6eb3867a66" xlink:href="lunr-20230630.xsd#lunr_PenumbraLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_15877b96-1803-4d1b-919a-a356fab72332" xlink:to="loc_lunr_PenumbraLLCMember_36fa2cc4-f9f6-4518-be1a-2e6eb3867a66" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_beb0623d-dbd8-43e5-8c23-407fe929ceab" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:to="loc_dei_LegalEntityAxis_beb0623d-dbd8-43e5-8c23-407fe929ceab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_beb0623d-dbd8-43e5-8c23-407fe929ceab_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_beb0623d-dbd8-43e5-8c23-407fe929ceab" xlink:to="loc_dei_EntityDomain_beb0623d-dbd8-43e5-8c23-407fe929ceab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_14b54ef3-5ad7-4d37-89f6-68b0755b9b42" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_beb0623d-dbd8-43e5-8c23-407fe929ceab" xlink:to="loc_dei_EntityDomain_14b54ef3-5ad7-4d37-89f6-68b0755b9b42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_KBRIncMember_8c501b9c-9374-4007-ba3b-934e5cc0d197" xlink:href="lunr-20230630.xsd#lunr_KBRIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_14b54ef3-5ad7-4d37-89f6-68b0755b9b42" xlink:to="loc_lunr_KBRIncMember_8c501b9c-9374-4007-ba3b-934e5cc0d197" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_6705d93e-62e8-46db-8548-d4e4fabec65b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_d7b487a2-a070-4d76-a2f5-9e004bcf84bf" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_6705d93e-62e8-46db-8548-d4e4fabec65b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_6705d93e-62e8-46db-8548-d4e4fabec65b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_6705d93e-62e8-46db-8548-d4e4fabec65b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_6705d93e-62e8-46db-8548-d4e4fabec65b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_9675271a-dbf2-436f-a633-3182842aa020" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_6705d93e-62e8-46db-8548-d4e4fabec65b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_9675271a-dbf2-436f-a633-3182842aa020" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SNSMember_3b610941-bfc7-4c8c-97d8-8a7483ea40c1" xlink:href="lunr-20230630.xsd#lunr_SNSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_9675271a-dbf2-436f-a633-3182842aa020" xlink:to="loc_lunr_SNSMember_3b610941-bfc7-4c8c-97d8-8a7483ea40c1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://intuitivemachines.com/role/VariableInterestEntitiesDetails" xlink:type="simple" xlink:href="lunr-20230630.xsd#VariableInterestEntitiesDetails"/>
  <link:definitionLink xlink:role="http://intuitivemachines.com/role/VariableInterestEntitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage_97c94a32-c5ec-48d8-90b5-1e612e97462a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableInterestEntityOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:to="loc_us-gaap_VariableInterestEntityOwnershipPercentage_97c94a32-c5ec-48d8-90b5-1e612e97462a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_6f2c5d3c-6085-49fc-bca6-9f90e7ca077a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:to="loc_us-gaap_Assets_6f2c5d3c-6085-49fc-bca6-9f90e7ca077a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_c9ebb545-4d11-457d-84c0-3f8e8a9d88b8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:to="loc_us-gaap_Liabilities_c9ebb545-4d11-457d-84c0-3f8e8a9d88b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_VariableInterestEntityProfitsInterestPercent_8bbd250e-b8fc-4dc5-8a29-8296c6d8d57c" xlink:href="lunr-20230630.xsd#lunr_VariableInterestEntityProfitsInterestPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:to="loc_lunr_VariableInterestEntityProfitsInterestPercent_8bbd250e-b8fc-4dc5-8a29-8296c6d8d57c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_e2b4102f-e9f7-460a-a1bb-4c22b7620e65" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_d5b78c24-2caf-4c91-9888-e5387e79fcd5" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_e2b4102f-e9f7-460a-a1bb-4c22b7620e65" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_6fd32334-d63e-442d-92a4-5f8f28eb5af5" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_e2b4102f-e9f7-460a-a1bb-4c22b7620e65" xlink:to="loc_dei_LegalEntityAxis_6fd32334-d63e-442d-92a4-5f8f28eb5af5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_6fd32334-d63e-442d-92a4-5f8f28eb5af5_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_6fd32334-d63e-442d-92a4-5f8f28eb5af5" xlink:to="loc_dei_EntityDomain_6fd32334-d63e-442d-92a4-5f8f28eb5af5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_6fd32334-d63e-442d-92a4-5f8f28eb5af5" xlink:to="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_XEnergyMember_63014c3c-a38f-4f16-86e9-bf78ec162a37" xlink:href="lunr-20230630.xsd#lunr_XEnergyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:to="loc_lunr_XEnergyMember_63014c3c-a38f-4f16-86e9-bf78ec162a37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IXLLCJVMember_ceb864ef-b8cd-4cff-9440-6079f9fe2210" xlink:href="lunr-20230630.xsd#lunr_IXLLCJVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:to="loc_lunr_IXLLCJVMember_ceb864ef-b8cd-4cff-9440-6079f9fe2210" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_LLCKBRMember_7fbe2738-0a09-4961-910f-e00d66459935" xlink:href="lunr-20230630.xsd#lunr_LLCKBRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:to="loc_lunr_LLCKBRMember_7fbe2738-0a09-4961-910f-e00d66459935" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_KBRIncMember_64ce9152-0269-4474-b684-6c240e7b1373" xlink:href="lunr-20230630.xsd#lunr_KBRIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_f88c1c6a-2883-4ad8-8ea4-8b1c61892661" xlink:to="loc_lunr_KBRIncMember_64ce9152-0269-4474-b684-6c240e7b1373" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_59faae61-e06f-4313-8c9c-798c59e3feb7" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_e2b4102f-e9f7-460a-a1bb-4c22b7620e65" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_59faae61-e06f-4313-8c9c-798c59e3feb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_59faae61-e06f-4313-8c9c-798c59e3feb7_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_59faae61-e06f-4313-8c9c-798c59e3feb7" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_59faae61-e06f-4313-8c9c-798c59e3feb7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_acc9e216-8440-48a3-8533-9721b97dadcc" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_59faae61-e06f-4313-8c9c-798c59e3feb7" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_acc9e216-8440-48a3-8533-9721b97dadcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_IXLLCJVMember_db1e9f5f-dceb-4c03-846e-dfec3f2d78dc" xlink:href="lunr-20230630.xsd#lunr_IXLLCJVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_acc9e216-8440-48a3-8533-9721b97dadcc" xlink:to="loc_lunr_IXLLCJVMember_db1e9f5f-dceb-4c03-846e-dfec3f2d78dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lunr_SNSMember_25f6e715-3d91-470c-ac46-b05456f54343" xlink:href="lunr-20230630.xsd#lunr_SNSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_acc9e216-8440-48a3-8533-9721b97dadcc" xlink:to="loc_lunr_SNSMember_25f6e715-3d91-470c-ac46-b05456f54343" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#AwardTypeOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:type="arc" order="4"/>
  </link:definitionLink>
</link:linkbase>
