Editing Apollo 13 (section)

== Space vehicle ==
[[File:Apollo 13 CSM (Ap13-69-H-1791).jpg|thumb|left|upright=0.68|CSM-109 ''Odyssey'' in the [[Operations and Checkout Building]]]]
The Saturn V rocket used to carry Apollo&nbsp;13 to the Moon was numbered SA-508, and was almost identical to those used on Apollo{{nbsp}}8 through 12.{{sfn|Apollo 13 Press Kit|1970|p=74}} Including the spacecraft, the rocket weighed in at {{convert|6501733|lb|order=flip}}.{{sfn|Orloff|2000|p=284}} The [[S-IC]] first stage's engines were rated to generate {{convert|100000|lbf|N|order=flip|-4}} less total thrust than Apollo 12's, though they remained within specifications.<ref name = "journal launch" /> To keep its [[liquid hydrogen]] propellent cold, the [[S-II]] second stage's cryogenic tanks were insulated; on earlier Apollo missions this came in the form of panels that were affixed, but beginning with Apollo&nbsp;13, insulation was sprayed onto the exterior of the tanks.<ref name = "ten launch">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap10fj/as10-day1-pt1.html|title=Apollo 10: Day 1, part 1: Countdown, launch and climb to orbit|date=February 6, 2022|access-date=April 15, 2022}}</ref> Extra propellant was carried as a test, since future [[List of Apollo missions#Alphabetical mission types|J missions]] to the Moon would require more propellant for their heavier payloads. This made the vehicle the heaviest yet flown by NASA, and Apollo&nbsp;13 was visibly slower to clear the launch tower than earlier missions.<ref name = "journal launch">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/02earth_orbit_tli.html|title=Day 1: Earth orbit and translunar injection|date=February 17, 2017|access-date=July 28, 2019}}</ref>

The Apollo&nbsp;13 spacecraft consisted of Command Module&nbsp;109 and Service Module&nbsp;109 (together CSM-109), called ''Odyssey'', and Lunar Module{{nbsp}}7 (LM-7), called ''Aquarius''. Also considered part of the spacecraft was the [[launch escape system]], which would propel the command module (CM) to safety in the event of a problem during liftoff, and the Spacecraft–LM Adapter, numbered as SLA-16, which housed the lunar module (LM) during the first hours of the mission.{{sfn|Orloff & Harland|2006|p=364}}{{sfn|Apollo 13 Press Kit|1970|pp=78, 81}}

The LM stages, CM and service module (SM) were received at [[Kennedy Space Center]] (KSC) in June 1969; the portions of the Saturn&nbsp;V were received in June and July. Thereafter, testing and assembly proceeded, culminating with the rollout of the launch vehicle, with the spacecraft atop it, on December 15, 1969.{{sfn|Orloff & Harland|2006|p=364}} Apollo&nbsp;13 was originally scheduled for launch on March 12, 1970, but that January NASA announced the mission would be postponed until April 11, both to allow more time for planning and to spread the Apollo missions over a longer period.<ref name = "postpone">{{cite press release|title=MSC 70–9|publisher=[[NASA]]|date=January 8, 1970|url=https://www.nasa.gov/centers/johnson/pdf/83122main_1970.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.nasa.gov/centers/johnson/pdf/83122main_1970.pdf |archive-date=2022-10-09 |url-status=live | access-date = July 27, 2019}}</ref> The plan was to have two Apollo flights per year and was in response to budgetary constraints<ref>{{cite news|title=Apollo's Schedule Shifted by NASA|date=January 9, 1970|newspaper=[[The New York Times]]|page=17|url=https://www.nytimes.com/1970/01/09/archives/apollos-schedule-shifted-by-nasa-next-flight-in-april.html}}</ref> that had recently seen the cancellation of Apollo 20.<ref>{{cite news|title=Apollo 13 and 14 may be set back|date=January 6, 1970|newspaper=[[The New York Times]]|page=26|url=https://www.nytimes.com/1970/01/06/archives/apollo-13-and-14-may-be-set-back.html|agency=UPI}}</ref>