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{{Short description|Failed Moon landing mission in the Apollo program}}
{{About|the 1970 spaceflight|the film based upon it|Apollo 13 (film){{!}}''Apollo 13'' (film)||Apollo 13 (disambiguation)}}
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{{featured article}}
{{Use American English|date=January 2014}}
{{Use mdy dates|date=November 2019}}
{{Infobox spaceflight
| name               = Apollo 13
| image              = File:Apollo 13 Service Module (lossless crop).jpg
| image_caption     = ''Odyssey''{{'}}s damaged [[Apollo command and service module#Service module (SM)|service module]], as seen from the [[Apollo Lunar Module]] ''Aquarius'', hours before reentry
| image_alt          = 

| mission_type       = Crewed lunar landing attempt ([[List of Apollo missions#Alphabetical mission types|H]])
| operator           = [[NASA]]
| COSPAR_ID          = {{Unbulleted list|CSM: 1970-029A|LM: 1970-029C}}
| SATCAT             = 4371<ref>{{cite web|url=https://www.n2yo.com/satellite/?s=4371|title=Apollo 13 CM|website=N2YO.com|access-date=August 18, 2019}}</ref>
| mission_duration   = 5&nbsp;days, 22&nbsp;hours, 54&nbsp;minutes, 41&nbsp;seconds{{sfn|Orloff|2000|p=309}}

| spacecraft         = {{Unbulleted list|[[Apollo command and service module|Apollo CSM]]-109 |[[Apollo Lunar Module|Apollo LM]]-7}}
| manufacturer       = {{Unbulleted list|CSM: [[North American Rockwell]]|LM: [[Grumman]]}}
| launch_mass        = 44,069 kg (CSM: 28,881 kg;<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-029A |title=Apollo 13 Command and Service Module (CSM) |publisher=[[NASA Space Science Data Coordinated Archive]] |access-date=January 9, 2023}}</ref> LM: 15,188 kg)<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-029C |title=Apollo 13 Lunar Module / EASEP |publisher=[[NASA Space Science Data Coordinated Archive]] |access-date=January 9, 2023}}</ref>
| landing_mass       = {{convert|11133|lb|kg|order=flip}}{{sfn|Orloff|2000|p=307}}
| crew_size          = 3
| crew_members       = {{Unbulleted list|[[Jim Lovell|James A. Lovell Jr.]]|[[Jack Swigert|John L. Swigert Jr.]]|[[Fred Haise|Fred W. Haise Jr.]]}}
| crew_callsign         = {{Unbulleted list  |CSM: ''Odyssey''  |LM: ''Aquarius''}}

| launch_date        = {{start date text|April 11, 1970, 19:13:00|timezone=yes}}&nbsp;UTC<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-029A |title=Apollo 13 |publisher=[[NASA Space Science Data Coordinated Archive]] |access-date=January 9, 2023}}</ref> 
| launch_rocket      = [[Saturn V]] SA-508
| launch_site        = [[Kennedy Space Center Launch Complex 39A|Kennedy LC-39A]]

| landing_date       = {{end date text|April 17, 1970, 18:07:41|timezone=yes}}&nbsp;UTC 
| landing_site       = South Pacific Ocean<br />{{Coord|21|38|24|S|165|21|42|W|type:event|name=Apollo 13 splashdown}}
| recovery_by        = {{USS|Iwo Jima|LPH-2|6}}

| interplanetary     = {{Infobox spaceflight/IP
  | type             = flyby
  | note             = orbit and landing aborted
  | object           = Moon
  | distance         = {{convert|137|nmi|km|order=flip|sp=us}}
  | arrival_date     = April 15, 1970, 00:21:00&nbsp;UTC
  }}

| docking            = {{Infobox spaceflight/Dock
  | docking_target   = LM
  | docking_type     = dock
  | docking_date     = April 11, 1970, 22:32:08&nbsp;UTC
  | undocking_date   = April 17, 1970, 16:43:00&nbsp;UTC
  | time_docked      = 
  }}

| insignia           = Apollo 13-insignia.png
| insignia_alt       = Apollo 13 logo
| crew_photo         = Apollo 13 Prime Crew.jpg
| crew_photo_caption = [[Jim Lovell]], [[Jack Swigert]], [[Fred Haise]]
| crew_photo_alt     = Three astronauts posing behind a lunar globe

| programme          = [[Apollo program]]
| previous_mission   = [[Apollo 12]]
| next_mission       = [[Apollo 14]]
}}

'''Apollo 13''' (April 11{{endash}}17, 1970) was the seventh crewed mission in the [[Apollo program|Apollo space program]] and would have been the third [[Moon landing]]. The craft was launched from [[Kennedy Space Center]] on April 11, 1970, but the landing was aborted after an oxygen tank in the [[Apollo command and service module#Service module (SM)|service module]] (SM) exploded two days into the mission, disabling its electrical and [[life-support system]]. The crew, supported by backup systems on the [[Apollo Lunar Module|lunar module]] (LM), instead looped around the Moon in a [[circumlunar trajectory]] and returned safely to Earth on April 17. The mission was commanded by [[Jim Lovell]], with [[Jack Swigert]] as [[Apollo command and service module#Command module (CM)|command module]] (CM) pilot and [[Fred Haise]] as [[Apollo Lunar Module|Lunar Module]] (LM) pilot. Swigert was a late replacement for [[Ken Mattingly]], who was grounded after exposure to [[rubella]].

A routine stir of an oxygen tank ignited damaged wire insulation inside it, causing an explosion that vented the contents of both of the SM's oxygen tanks to space.{{NoteTag|The event is described as an explosion in modern NASA histories and accounts by the crew.<ref>{{cite web|title=The Apollo 13 accident|author=Williams, David|url=https://nssdc.gsfc.nasa.gov/planetary/lunar/ap13acc.html|publisher=NASA|quote=The Apollo 13 malfunction was caused by an explosion and rupture of oxygen tank no. 2 in the service module.}}</ref><ref>{{harvnb|Cortright|1975|pp=248–249}}: "I did, of course, occasionally think of the possibility that the spacecraft explosion might maroon us... Thirteen minutes after the explosion, I happened to look out of the left-hand
window, and saw the final evidence pointing toward potential catastrophe. "</ref> However, the formal accident report avoids the use of the term.{{sfn|Accident report|p=143}} NASA engineers at the time preferred "tank failure", both because it was more accurate and to avoid the negative connotations around the word "explosion".<ref>{{harvnb|Cooper|2013|page=21}}: "Later, in describing what happened, NASA engineers avoided using the word "explosion;" they preferred the more delicate and less dramatic term "tank failure," and in a sense it ''was'' the more accurate expression, inasmuch as the tank did not explode in the way a bomb does but broke open under pressure."</ref>}} Without oxygen, needed for breathing and for generating electric power, the SM's propulsion and life support systems could not operate. The CM's systems had to be shut down to conserve its remaining resources for reentry, forcing the crew to transfer to the LM as a lifeboat. With the lunar landing canceled, mission controllers worked to bring the crew home alive.

Although the LM was designed to support two men on the lunar surface for two days, [[Christopher C. Kraft Jr. Mission Control Center|Mission Control]] in Houston improvised new procedures so it could support three men for four days. The crew experienced great hardship, caused by limited power, a chilly and wet cabin and a shortage of [[potable water]]. There was a critical need to adapt the CM's cartridges for the [[carbon dioxide scrubber]] system to work in the LM; the crew and mission controllers were successful in improvising a solution. The astronauts' peril briefly renewed public interest in the Apollo program; tens of millions watched the [[splashdown]] in the [[South Pacific Ocean]] on television.

An investigative review board found fault with preflight testing of the oxygen tank and [[Teflon]] being placed inside it. The board recommended changes, including minimizing the use of potentially combustible items inside the tank; this was done for [[Apollo 14]]. The story of Apollo&nbsp;13 has been dramatized several times, most notably in the 1995 film ''[[Apollo&nbsp;13 (film)|Apollo&nbsp;13]]'' based on ''[[Lost Moon]]'', the 1994 memoir co-authored by Lovell – and an episode of the 1998 miniseries ''[[From the Earth to the Moon (miniseries)|From the Earth to the Moon]]''.

{{toc limit|3}}

== Background ==
In 1961, U.S. President [[John F. Kennedy]] challenged his nation to land an astronaut on the [[Moon]] by the end of the decade, with a safe return to Earth.<ref name = "mission overview" /> [[NASA]] worked towards this goal incrementally, sending astronauts into space during [[Project Mercury]] and [[Project Gemini]], leading up to the [[Apollo program]].{{sfn|Hacker & Grimwood|2010|p=382}} The goal was achieved with [[Apollo 11]], which landed on the Moon on July&nbsp;20, 1969. [[Neil Armstrong]] and [[Buzz Aldrin]] walked on the lunar surface while [[Michael Collins (astronaut)|Michael Collins]] orbited the Moon in [[Command module Columbia|Command Module ''Columbia'']]. The mission returned to Earth on July&nbsp;24, 1969, fulfilling Kennedy's challenge.<ref name = "mission overview">{{cite web|title=Apollo 11 Mission Overview|url=https://www.nasa.gov/mission_pages/apollo/missions/apollo11.html|date=December 21, 2017|access-date=February 14, 2019|publisher=[[NASA]]}}</ref>

NASA had contracted for fifteen [[Saturn&nbsp;V]] rockets to achieve the goal; at the time no one knew how many missions this would require.{{sfn|Chaikin|1995|pp=232–233}} Since success was obtained in 1969 with the sixth Saturn{{nbsp}}V on Apollo&nbsp;11, nine rockets remained available for a hoped-for [[Canceled Apollo missions#Follow-on lunar missions|total of ten landings]]. After the excitement of Apollo&nbsp;11, the general public grew apathetic towards the space program and Congress continued to cut NASA's budget; [[Apollo 20]] was canceled.{{sfn|Chaikin|1995|p=285}} Despite the successful lunar landing, the missions were considered so risky that astronauts could not afford life insurance to provide for their families if they died in space.{{NoteTag|No Apollo astronaut flew without life insurance, but the policies were paid for by private third parties whose involvement was not publicized.<ref name = "weinberger" />}}<ref name="weinberger">{{cite web|last=Weinberger|first=Howard C.|title=Apollo Insurance Covers|publisher=Space Flown Artifacts (Chris Spain)|url=http://www.spaceflownartifacts.com/flown_apollo_insurance_covers.html|access-date=December 11, 2019}}</ref>

[[File:1970 Mission Control Apollo 13.jpg|thumb|left|alt=see caption|Mission Operations Control Room during the TV broadcast just before the Apollo&nbsp;13 accident. Astronaut [[Fred Haise]] is shown on the screen.]]
Even before the first U.S. astronaut entered space in 1961, planning for a centralized facility to communicate with the spacecraft and monitor its performance had begun, for the most part the brainchild of [[Christopher C. Kraft Jr.]], who became NASA's first [[Flight controller#Flight director|flight director]]. During [[John Glenn]]'s Mercury ''[[Friendship 7]]'' flight in February 1962 (the first crewed orbital flight by the U.S.), one of Kraft's decisions was overruled by NASA managers. He was vindicated by post-mission analysis and implemented a rule that, during the mission, the flight director's word was absolute<ref name = "mission control history">{{cite web|last=Neufeld|first=Michael J.|author-link=Michael J. Neufeld|title=Remembering Chris Kraft: Pioneer of Mission Control|url=https://airandspace.si.edu/stories/editorial/remembering-chris-kraft-pioneer-mission-control|publisher=[[Smithsonian Air and Space Museum]]|date=July 24, 2019|access-date=December 8, 2019}}</ref> – to overrule him, NASA would have to fire him on the spot.<ref name = "Cass 1" /> Flight directors during Apollo had a one-sentence job description, "The flight director may take any actions necessary for crew safety and mission success."<ref>{{cite news|title=A legendary tale, well-told|access-date=October 5, 2019|last=Williams|first=Mike|url=https://news.rice.edu/2012/09/13/a-legendary-tale-well-told/|publisher=Rice University Office of Public Affairs|date=September 13, 2012|archive-date=August 17, 2020|archive-url=https://web.archive.org/web/20200817125432/https://news.rice.edu/2012/09/13/a-legendary-tale-well-told/|url-status=dead}}</ref>

Houston's [[Christopher C. Kraft Jr. Mission Control Center|Mission Control Center]] was opened in 1965. It was in part designed by Kraft and now named for him.<ref name = "mission control history" />  In Mission Control, each flight controller, in addition to monitoring [[telemetry]] from the spacecraft, was in communication via voice loop to specialists in a Staff Support Room (or "back room"), who focused on specific spacecraft systems.<ref name = "Cass 1" />

Apollo&nbsp;13 was to be the second [[List of Apollo missions#Alphabetical mission types|H mission]], meant to demonstrate precision lunar landings and explore specific sites on the Moon.{{sfn|Apollo Program Summary Report|1975|p=B-2}} With Kennedy's goal accomplished by Apollo&nbsp;11, and [[Apollo 12]] demonstrating that the astronauts could perform a precision landing, mission planners were able to focus on more than just landing safely and having astronauts minimally trained in geology gather lunar samples to take home to Earth. There was a greater role for science on Apollo&nbsp;13, especially for geology, something emphasized by the mission's motto, ''Ex luna, scientia'' (From the Moon, knowledge).{{sfn|Launius|2019|p=186}}

== Astronauts and key Mission Control personnel ==
[[File:Apollo 13 Crew before launch - S70-34767.jpg|alt=see caption|thumb|Swigert, Lovell and Haise the day before launch]]
{{Spaceflight crew
|terminology = Astronaut
|position1 = Commander (CDR)
|crew1_up = [[Jim Lovell|James A. Lovell Jr.]]
|flights1_up = Fourth and last
|position2 = Command Module Pilot (CMP)
|crew2_up = [[Jack Swigert|John "Jack" L. Swigert Jr.]]
|flights2_up = Only
|position3 = Lunar Module Pilot (LMP)
|crew3_up = [[Fred Haise|Fred W. Haise Jr.]]
|flights3_up = Only
}}
Apollo&nbsp;13's mission commander, [[Jim Lovell]], was 42 years old at the time of the spaceflight. He was a graduate of the [[United States Naval Academy]] and had been a naval aviator and [[test pilot]] before being selected for the [[NASA Astronaut Group 2|second group of astronauts]] in 1962; he flew with [[Frank Borman]] in [[Gemini&nbsp;7]] in 1965 and Buzz Aldrin in [[Gemini&nbsp;12]] the following year before flying in [[Apollo 8]] in 1968, the first spacecraft to orbit the Moon.{{sfn|Apollo 13 Press Kit|1970|pp=108–109}} At the time of Apollo 13, Lovell was the NASA astronaut with the most time in space, with 572 hours over the three missions.<ref name = "experience" >{{cite web|title=Apollo 13: The moon-mission that dodged disaster|first1=Elizabeth|last1=Howell|first2=Kimberly|last2=Hickok|url=https://www.space.com/17250-apollo-13-facts.html|website=Space.com|publisher=Future US|date=March 31, 2020|access-date=April 1, 2020}}</ref>

[[Jack Swigert]], the command module pilot (CMP), was 38&nbsp;years old and held a [[Bachelor of Science|B.S.]] in mechanical engineering and an [[Master of Science|M.S.]] in aerospace science; he had served in the Air Force and in state [[Air National Guard]]s and was an engineering test pilot before being selected for the [[NASA Astronaut Group 5|fifth group of astronauts]] in 1966.<ref name = "swigert bio" /> [[Fred Haise]], the Lunar Module pilot (LMP), was 36 years old. He held a B.S. in aeronautical engineering, had been a [[United States Marine Corps|Marine Corps]] fighter pilot, and was a civilian research pilot for NASA when he was selected as a Group{{nbsp}}5 astronaut.{{sfn|Apollo 13 Press Kit|1970|pp=111–112}}{{sfn|Chaikin|1995|pp=589–593}}

According to the standard Apollo crew rotation, the prime crew for Apollo&nbsp;13 would have been the backup crew{{NoteTag|The role of the backup crew was to train and be prepared to fly in the event something happened to the prime crew.<ref>{{cite web|publisher=NASA|access-date=December 5, 2019|title=50 years ago: NASA names Apollo 11 crew|url=https://www.nasa.gov/feature/50-years-ago-nasa-names-apollo-11-crew|date=January 30, 2019}}</ref> Backup crews, according to the rotation, were assigned as the prime crew three missions after their assignment as backups.{{sfn|Slayton & Cassutt|1994|p=137}}}} for [[Apollo 10]], with Mercury and Gemini veteran [[Gordon Cooper]] in command, [[Donn F. Eisele]] as CMP and [[Edgar Mitchell]] as LMP. [[Deke Slayton]], NASA's Director of Flight Crew Operations, never intended to rotate Cooper and Eisele to a prime crew assignment, as both were out of favor{{snd}}Cooper for his lax attitude towards training, and Eisele for incidents aboard [[Apollo 7|Apollo{{nbsp}}7]] and an extramarital affair. He assigned them to the backup crew because no other veteran astronauts were available.{{sfn|Slayton & Cassutt|1994|p=236}} Slayton's original choices for Apollo&nbsp;13 were [[Alan Shepard]] as commander, [[Stuart Roosa]] as CMP, and Mitchell as LMP. However, management felt Shepard needed more training time, as he had only recently resumed active status after surgery for an [[Ménière's disease|inner ear disorder]] and had not flown since 1961. Thus, Lovell's crew (himself, Haise and [[Ken Mattingly]]), having all backed up Apollo 11 and being slated for [[Apollo 14]], was swapped with Shepard's.{{sfn|Slayton & Cassutt|1994|p=236}}

Swigert was originally CMP of Apollo&nbsp;13's backup crew, with [[John Young (astronaut)|John Young]] as commander and [[Charles Duke]] as lunar module pilot.<ref name="backup">{{cite web|url=https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/landing-missions/apollo13-crew.cfm|title=Apollo 13 Crew|website=Smithsonian National Air and Space Museum|access-date=January 6, 2018|archive-date=October 24, 2020|archive-url=https://web.archive.org/web/20201024155252/https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/landing-missions/apollo13-crew.cfm|url-status=dead}}</ref> Seven days before launch, Duke contracted [[rubella]] from his son's friend.<ref name="Oral">{{cite web |title=Charles M. Duke, Jr. Oral History  |publisher= NASA |url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/DukeCM/DukeCM_3-12-99.htm |access-date=December 17, 2019}}</ref> This exposed both the prime and backup crews, who trained together. Of the five, only Mattingly was not immune through prior exposure. Normally, if any member of the prime crew had to be grounded, the remaining crew would be replaced as well, and the backup crew substituted, but Duke's illness ruled this out,{{sfn|NASA 1970|p=6}} so two days before launch, Mattingly was replaced by Swigert.<ref name = "swigert bio">{{cite web|url=http://www.jsc.nasa.gov/Bios/htmlbios/swigert-jl.html|access-date=August 21, 2009|title=Astronaut Bio: John L. Swigert|date=January 1983|publisher=NASA|archive-url=https://web.archive.org/web/20090731012402/http://www.jsc.nasa.gov/Bios/htmlbios/swigert-jl.html|archive-date=July 31, 2009| url-status=dead}}</ref> Mattingly never developed rubella and later flew on [[Apollo 16]].<ref>{{cite journal|url=https://www.universetoday.com/62576/13-things-that-saved-apollo-13-part-3-charlie-dukes-measles/|last=Atkinson|first=Nancy|title=13 things that saved Apollo 13, Part 3: Charlie Duke's measles|date=April 12, 2010|access-date=November 13, 2019|journal=[[Universe Today]]}}</ref>

For Apollo, a third crew of astronauts, known as the support crew, was designated in addition to the prime and backup crews used on projects Mercury and Gemini. Slayton created the support crews because [[James McDivitt]], who would command [[Apollo 9]], believed that, with preparation going on in facilities across the US, meetings that needed a member of the flight crew would be missed. Support crew members were to assist as directed by the mission commander.{{sfn|Slayton & Cassutt|1994|p=184}} Usually low in seniority, they assembled the mission's rules, [[flight plan]], and checklists, and kept them updated;<ref>{{cite journal|last=Hersch|first=Matthew|date=July 19, 2009|title=The fourth crewmember|journal=[[Air & Space/Smithsonian]]|access-date=October 4, 2019|url=https://www.airspacemag.com/space/the-fourth-crewmember-37046329/}}</ref>{{sfn|Brooks, Grimwood, & Swenson|1979|p=261}} for Apollo&nbsp;13, they were [[Vance D. Brand]], [[Jack Lousma]] and either [[William Pogue]] or [[Joseph P. Kerwin|Joseph Kerwin]].{{NoteTag|Some sources list Kerwin{{sfn|Slayton & Cassutt|1994|p=251}} and others list Pogue as the third member{{sfn|Brooks, Grimwood, & Swenson|1979|p=378}}{{sfn|Orloff|2000|p=137}}<ref>{{cite interview|url=https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/PogueWR/WRP_7-17-2000.pdf|interviewer=Kevin M. Rusnak|date=July 17, 2000|location=Houston, Texas|title=Oral History Transcript|archive-url=https://web.archive.org/web/20190501104039/https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/PogueWR/WRP_7-17-2000.pdf|archive-date=May 1, 2019|url-status=dead|publisher=NASA|pages=12-25-12-26|series=Johnson Space Center Oral History Project}}</ref>}}<ref name = "support crew">{{cite press release|title=MSC 69–56|publisher=[[NASA]]|date=August 6, 1969|url=https://www.nasa.gov/centers/johnson/pdf/83121main_1969.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.nasa.gov/centers/johnson/pdf/83121main_1969.pdf |archive-date=2022-10-09 |url-status=live | access-date = July 27, 2019|location=Houston, Texas}}</ref>

For Apollo&nbsp;13, flight directors were [[Gene Kranz]], White team{{sfn|Mission Operations Report 1970|p=I-1}} (the lead flight director);{{sfn|Kranz|2000|p=307}}{{sfn|Lovell & Kluger|2000|p=79}} [[Glynn Lunney]], Black team; [[Milton Windler]], Maroon team and [[Gerald D. Griffin|Gerry Griffin]], Gold team.{{sfn|Mission Operations Report 1970|p=I-1}} The [[Flight controller#CAPCOM|CAPCOMs]] (the person in Mission Control, during the Apollo program an astronaut, who was responsible for voice communications with the crew){{sfn|Morgan|2001|p=48}} for Apollo&nbsp;13 were Kerwin, Brand, Lousma, Young and Mattingly.{{sfn|Orloff & Harland|2006|p=362}}

== Mission insignia and call signs ==
[[File:Apollo 13 Flown Silver Robbins Medallion (SN-354).jpg|thumb|alt=see caption|Apollo 13 flown silver [[NASA space-flown Gemini and Apollo medallions|Robbins medallion]]]]

The Apollo&nbsp;13 mission insignia depicts the Greek god of the Sun, [[Apollo]], with three horses pulling his chariot across the face of the Moon, and the Earth seen in the distance. This is meant to symbolize the Apollo flights bringing the light of knowledge to all people. The mission motto, ''Ex luna, scientia'' ("From the Moon, knowledge"), appears. In choosing it, Lovell adapted the motto of his alma mater, the Naval Academy, ''Ex scientia, tridens'' ("From knowledge, sea power").{{sfn|Lovell & Kluger|2000|p=81}}{{sfn|Orloff|2000|p=283}}

On the patch, the mission number appeared in [[Roman numerals]] as Apollo XIII. It did not have to be modified after Swigert replaced Mattingly, as it is one of only two Apollo mission insignia{{snd}}the other being Apollo 11{{snd}}not to include the names of the crew. It was designed by artist [[Lumen Martin Winter]], who based it on a mural he had painted for the [[St. Regis New York|St. Regis Hotel]] in New York City.<ref>{{cite news|url=https://www.newspapers.com/clip/36238158/daily_news/|title=Astros Wear Badge of Apollo|last1=Crafton|first1=Jean|date=April 12, 1970|page=105|newspaper=Daily News|location=New York City|via=Newspapers.com}}</ref> The mural was later purchased by actor [[Tom Hanks]],<ref>{{cite news|url=https://www.chicagotribune.com/suburbs/lake-county-news-sun/ct-lns-moran-lovell-stories-st-1003-20151002-story.html|title=Apollo 13 astronaut Jim Lovell shares stories about Tom Hanks, Ron Howard|last1=Moran|first1=Dan|date=October 2, 2015|newspaper=Chicago Tribune|access-date=April 11, 2020}}</ref> who portrayed Lovell in the movie ''[[Apollo&nbsp;13 (film)|Apollo&nbsp;13]]'', and it is now in the [[Captain James A. Lovell Federal Health Care Center]] in Illinois.<ref>{{cite news|url=https://chicagotribune.newspapers.com/clip/36239172/chicago_tribune/|title=Namesake Brings Personal Touch to Lovell Center Fete|last1=Moran|first1=Dan|newspaper=Chicago Tribune|date=October 2, 2015|page=1|via=Newspapers.com}}</ref>

The mission's motto was in Lovell's mind when he chose the call sign ''Aquarius'' for the lunar module, taken from [[Aquarius (constellation)|Aquarius]], the bringer of water.{{sfn|Chaikin|1995|p=291}}{{sfn|Lovell & Kluger|2000|p=87}} Some in the media erroneously reported that the call sign was taken from [[Aquarius/Let the Sunshine In|a song by that name]] from the musical ''[[Hair (musical)|Hair]]''.{{sfn|Lovell & Kluger|2000|p=87}}{{sfn|Lattimer|1988|p=77}} The command module's call sign, ''Odyssey'', was chosen not only for its [[Odyssey|Homeric association]] but to refer to the recent film, ''[[2001: A Space Odyssey]]'', based on [[The Sentinel (short story)|a short story]] by [[science fiction]] author [[Arthur C. Clarke]].{{sfn|Chaikin|1995|p=291}} In his book, Lovell indicated he chose the name ''Odyssey'' because he liked the word and its definition: a long voyage with many changes of fortune.{{sfn|Lovell & Kluger|2000|p=87}}

Due to the accident and the last minute crew change of Jack Swigert replacing Ken Mattingly three days prior to launch, the Apollo 13 [[Robbins medallions]] flown aboard the mission were melted down and reminted after the mission to reflect the correct crew, and the absence of a lunar landing date.<ref>{{Cite web |title=Medal, Robbins, Commemorative, Apollo 13 {{!}} National Air and Space Museum |url=https://airandspace.si.edu/collection-objects/medal-robbins-commemorative-apollo-13/nasm_A19850166000 |access-date=2024-06-15 |website=airandspace.si.edu |language=en}}</ref>

== 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>

== Training and preparation ==
[[File:Lovell deploying the flag.jpg|thumb|upright|Lovell practices deploying the flag]]

The Apollo&nbsp;13 prime crew undertook over 1,000 hours of mission-specific training, more than five hours for every hour of the mission's ten-day planned duration. Each member of the prime crew spent over 400 hours in simulators of the CM and (for Lovell and Haise) of the LM at KSC and at Houston, some of which involved the flight controllers at Mission Control.{{sfn|Apollo 13 Press Kit|1970|p=104}} Flight controllers participated in many simulations of problems with the spacecraft in flight, which taught them how to react in an emergency.<ref name = "Cass 1" />  Specialized simulators at other locations were also used by the crew members.{{sfn|Apollo 13 Press Kit|1970|p=104}}

The astronauts of Apollo 11 had minimal time for geology training, with only six months between crew assignment and launch; higher priorities took much of their time.{{sfn|Phinney|2015|p=100}} Apollo 12 saw more such training, including practice in the field, using a CAPCOM and a simulated backroom of scientists, to whom the astronauts had to describe what they saw.{{sfn|Phinney|2015|pp=103–104}} Scientist-astronaut [[Harrison Schmitt]] saw that there was limited enthusiasm for geology field trips. Believing an inspirational teacher was needed, Schmitt arranged for Lovell and Haise to meet his old professor, [[California Institute of Technology|Caltech]]'s [[Leon Silver|Lee Silver]]. The two astronauts, and backups Young and Duke, went on a field trip with Silver at their own time and expense. At the end of their week together, Lovell made Silver their geology mentor, who would be extensively involved in the geology planning for Apollo&nbsp;13.{{sfn|Phinney|2015|pp=107–111}} [[Farouk El-Baz]] oversaw the training of Mattingly and his backup, Swigert, which involved describing and photographing simulated lunar landmarks from airplanes.{{sfn|Phinney|2015|p=134}} El-Baz had all three prime crew astronauts describe geologic features they saw during their flights between Houston and KSC; Mattingly's enthusiasm caused other astronauts, such as Apollo 14's CMP, Roosa, to seek out El-Baz as a teacher.{{sfn|Phinney|2015|pp=141–142}}

Concerned about how close Apollo 11's LM, ''Eagle'', had come to running out of propellant during its lunar descent, mission planners decided that beginning with Apollo&nbsp;13, the CSM would bring the LM to the low orbit from which the landing attempt would commence. This was a change from Apollo 11 and 12, on which the LM made the burn to bring it to the lower orbit. The change was part of an effort to increase the amount of hover time available to the astronauts as the missions headed into rougher terrain.{{sfn|Harland|1999|p=53}}

The plan was to devote the first of the two four-hour lunar surface [[extravehicular activity|extravehicular activities]] (EVAs) to setting up the [[Apollo Lunar Surface Experiments Package]] (ALSEP) group of scientific instruments; during the second, Lovell and Haise would investigate [[Cone (crater)|Cone crater]], near the planned landing site.{{sfn|Orloff & Harland|2006|p=363}} The two astronauts wore their spacesuits for some 20 walk-throughs of EVA procedures, including sample gathering and use of tools and other equipment. They flew in the "[[Reduced-gravity aircraft|Vomit Comet]]" in simulated microgravity or lunar gravity, including practice in donning and doffing spacesuits. To prepare for the descent to the Moon's surface, Lovell flew the [[Lunar Landing Research Vehicle|Lunar Landing Training Vehicle]] (LLTV) after receiving helicopter training.{{sfn|Apollo 13 Press Kit|1970|p=105}} Despite the crashes of one LLTV and one similar Lunar Landing Research Vehicle (LLRV) prior to Apollo 13, mission commanders considered flying them invaluable experience and so prevailed on reluctant NASA management to retain them.<ref>{{cite web|last=Jones|first=Eric M.|title=Lunar Landing Training Vehicle NASA 952|date=April 29, 2006|access-date=January 4, 2021|url=https://history.nasa.gov/alsj/LLTV-952.html|publisher=[[NASA]]|work=Apollo Lunar Surface Journal}}</ref>

== Experiments and scientific objectives ==
[[File:Lovell and Haise geology training (S70-20253).jpg|thumb|right|upright|Lovell (left) and Haise during geology training in Hawaii, January 1970]]

Apollo&nbsp;13's designated landing site was near [[Fra Mauro (crater)|Fra Mauro crater]]; the [[Fra Mauro formation]] was believed to contain much material spattered by the impact that had filled the [[Imbrium basin]] early in the Moon's history. Dating it would provide information not only about the Moon, but about the Earth's early history. Such material was likely to be available at Cone crater, a site where an impact was believed to have drilled deep into the lunar [[regolith]].{{sfn|Harland|1999|pp=51–53}}

Apollo 11 had left a [[seismometer]] on the Moon, but the solar-powered unit did not survive its first two-week-long lunar night. The Apollo 12 astronauts [[Apollo 12 Passive Seismic Experiment|also left one]] as part of its ALSEP, which was nuclear-powered.{{sfn|Harland|1999|pp=38–39}} Apollo&nbsp;13 also carried a seismometer (known as the Passive Seismic Experiment, or PSE), similar to Apollo 12's, as part of its ALSEP,  to be left on the Moon by the astronauts.{{sfn|Apollo 13 Press Kit|1970|p=29}} That seismometer was to be calibrated by the impact, after jettison, of the ascent stage of Apollo&nbsp;13's LM, an object of known mass and velocity impacting at a known location.{{sfn|Apollo 13 Press Kit|1970|p=42}}

Other ALSEP experiments on Apollo&nbsp;13 included a [[Heat Flow Experiment]] (HFE), which would involve drilling two holes {{convert|10|ft|order=flip}} deep.{{sfn|Apollo 13 Press Kit|1970|p=33}} This was Haise's responsibility; he was also to drill a third hole of that depth for a core sample.{{sfn|''Science News'' 1970-04-04|p=354}} A Charged Particle Lunar Environment Experiment (CPLEE) measured the protons and electrons of solar origin reaching the Moon.{{sfn|Apollo 13 Press Kit|1970|p=49}} The package also included a Lunar Atmosphere Detector (LAD){{sfn|Apollo 13 Press Kit|1970|p=51}} and a Dust Detector, to measure the accumulation of debris.{{sfn|Apollo 13 Press Kit|1970|p=62}} The Heat Flow Experiment and the CPLEE were flown for the first time on Apollo&nbsp;13; the other experiments had been flown before.{{sfn|''Science News'' 1970-04-04|p=354}}

[[File:Haise RTG (Ap13-70-H-103).jpg|thumb|left|Haise practices removing the fuel capsule from its transport cask mounted on the LM. The real cask sank unopened into the Pacific Ocean with its radioactive contents.]]
To power the ALSEP, the [[Systems for Nuclear Auxiliary Power#SNAP-27|SNAP-27]] radioisotope thermoelectric generator (RTG) was flown. Developed by the [[United States Atomic Energy Commission|U.S. Atomic Energy Commission]], SNAP-27 was first flown on Apollo 12. The fuel capsule contained about {{convert|8.36|lb|order=flip}} of [[Plutonium(IV) oxide|plutonium oxide]]. The cask placed around the capsule for transport to the Moon was built with heat shields of graphite and of beryllium, and with structural parts of titanium and of [[Inconel]] materials. Thus, it was built to withstand the heat of reentry into the Earth's atmosphere rather than pollute the air with plutonium in the event of an aborted mission.{{sfn|Apollo 13 Press Kit|1970|p=65}}

A United States flag was also taken, to be erected on the Moon's surface.{{sfn|Apollo 13 Press Kit|1970|pp=33, 65}} For Apollo 11 and 12, the flag had been placed in a heat-resistant tube on the front landing leg; it was moved for Apollo&nbsp;13 to the Modularized Equipment Stowage Assembly (MESA) in the LM descent stage. [[Lunar Flag Assembly|The structure to fly the flag]] on the airless Moon was improved from Apollo 12's.{{sfn|Apollo 13 Press Kit|1970|p=73}}

For the first time, red stripes were placed on the helmet, arms and legs of the commander's [[Apollo/Skylab A7L|A7L]] spacesuit. This was done as, after Apollo 11, those reviewing the images taken had trouble distinguishing Armstrong from Aldrin, but the change was approved too late for Apollo 12.<ref name = "red stripe">{{cite web|title=Commander's stripes|website=Apollo Lunar Surface Journal|publisher=[[NASA]]|access-date=July 20, 2019|url=https://www.hq.nasa.gov/alsj/alsj-CDRStripes.html|last=Jones|first=Eric M.|date=February 20, 2006}}</ref> New drink bags that attached inside the helmets and were to be sipped from as the astronauts walked on the Moon were demonstrated by Haise during Apollo&nbsp;13's final television broadcast before the accident.{{sfn|Turnill|2003|p=316}}<ref>{{cite web|url=https://www.hq.nasa.gov/alsj/alsj-DrinkFood.html|title=Water Gun, Helmet Feedport, In-Suit Drink Bag, and Food Stick|last1=Jones|first1=Eric M.|date=March 3, 2010|website=Apollo Lunar Surface Journal|publisher=NASA|access-date=November 15, 2019}}</ref>

Apollo&nbsp;13's primary mission objectives were to: "Perform selenological inspection, survey, and sampling of materials in a preselected region of the Fra Mauro Formation. Deploy and activate an Apollo Lunar Surface Experiments Package. Develop man's capability to work in the lunar environment. Obtain photographs of candidate exploration sites."{{sfn|Accident report|p=3-26}} The astronauts were also to accomplish other photographic objectives, including of the [[Gegenschein]] from lunar orbit, and of the Moon itself on the journey back to Earth. Some of this photography was to be performed by Swigert as Lovell and Haise walked on the Moon.{{sfn|Orloff & Harland|2006|p=385}} Swigert was also to take photographs of the [[Lagrangian point]]s of the Earth-Moon system. Apollo&nbsp;13 had twelve cameras on board, including those for television and moving pictures.{{sfn|''Science News'' 1970-04-04|p=354}} The crew was also to downlink [[bistatic radar]] observations of the Moon. None of these was attempted because of the accident.{{sfn|Orloff & Harland|2006|p=385}}

== Flight of Apollo 13 ==
[[File:Apollo 13 timeline.svg|center|framed|alt= Apollo 13's circumlunar flight trajectory, showing its distance to the Moon when the accident occurred|The [[circumlunar trajectory]] followed by Apollo&nbsp;13, drawn to scale. The accident occurred about 56 hours into the mission.]]

===Launch and translunar injection===
[[File:Apollo 13 launch (S70-34852).jpg|thumb|upright|Apollo&nbsp;13 launches from Kennedy Space Center, April 11, 1970]]
[[File:Apolo-1. CSM&LM diagram.svg|thumb|Apollo 13 spacecraft configuration during most of the journey: Click on image for key to numbered components.]]
The mission was launched at the planned time, 2:13:00&nbsp;pm [[Eastern Time Zone|EST]] (19:13:00&nbsp;UTC) on April 11. An anomaly occurred when the second-stage, center (inboard) engine shut down about two minutes early.<ref name="lver">{{cite book |author= |url=https://archive.org/details/nasa_techdoc_19900066486 |title=Saturn 5 Launch Vehicle Flight Evaluation Report: AS-508 Apollo 13 Mission |date=June 20, 1970 |publisher=[[NASA]] |publication-place=[[Marshall Space Flight Center|George C. Marshall Space Flight Center]], Huntsville, Alabama |id=MPR-SAT-FE-70-2 |access-date=May 30, 2017}}</ref>{{sfn|Benson & Faherty|1979|pp=494–499}} This was caused by severe [[pogo oscillation]]s. Starting with Apollo 10, the vehicle's guidance system was designed to shut the engine down in response to chamber pressure excursions.{{sfn|Larsen|2008|p=5-13}} Pogo oscillations had occurred on [[Titan (rocket family)|Titan rockets]] (used during the [[Project Gemini|Gemini program]]) and on previous Apollo missions,<ref>{{cite journal|last=Fenwick |first=Jim |date=Spring 1992 |title=Pogo |url=http://www.engineeringatboeing.com/articles/pogo.htm |journal=Threshold |publisher=[[Pratt & Whitney Rocketdyne]] |access-date=July 3, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20071213010936/http://www.engineeringatboeing.com/articles/pogo.htm |archive-date=December 13, 2007 }}</ref>{{sfn|Larsen|2008|pp=5-7–5-12}} but on Apollo&nbsp;13 they were amplified by an interaction with turbopump [[cavitation]].<ref>{{cite journal |last=Dotson |first=Kirk |date=Winter 2003–2004 |title=Mitigating Pogo on Liquid-Fueled Rockets |journal=Crosslink |volume=5 |issue=1 |pages=26–29 |location=El Segundo, California|publisher=[[The Aerospace Corporation]] |access-date=July 3, 2013 |url=http://aerospace.wpengine.netdna-cdn.com/wp-content/uploads/crosslink/V5N1.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://aerospace.wpengine.netdna-cdn.com/wp-content/uploads/crosslink/V5N1.pdf |archive-date=2022-10-09 |url-status=live}}</ref><ref name=launch>{{cite web |url=https://history.nasa.gov/afj/ap13fj/01launch_ascent.html |title=Launch and Reaching Earth Orbit |year=2016 |editor-last=Woods |editor-first=W. David |editor-last2=Turhanov|editor-first2=Alexandr|editor-last3=Waugh|editor-first3=Lennox J. |work=Apollo 13 Flight Journal |publisher=NASA |access-date=August 5, 2019}}</ref> A fix to prevent pogo was ready for the mission, but schedule pressure did not permit the hardware's integration into the Apollo&nbsp;13 vehicle.{{sfn|Larsen|2008|p=5-13}}<ref>{{cite journal|url=https://www.universetoday.com/62672/13-things-that-saved-apollo-13-part-5-unexplained-shutdown-of-the-saturn-v-center-engine/|last=Atkinson|first=Nancy|title=13 things that saved Apollo 13, Part 5: Unexplained shutdown of the Saturn V center engine|date=April 14, 2010|journal=[[Universe Today]]|access-date=September 16, 2019}}</ref> A post-flight investigation revealed the engine was one cycle away from catastrophic failure.{{sfn|Larsen|2008|p=5-13}} The four outboard engines and the [[S-IVB]] third stage burned longer to compensate, and the vehicle achieved very close to the planned circular {{convert|190|km|mi nmi|sp=us}} [[parking orbit]], followed by a translunar injection (TLI) about two hours later, setting the mission on course for the Moon.<ref name="lver" />{{sfn|Benson & Faherty|1979|pp=494–499}}

After TLI, Swigert performed the separation and transposition maneuvers before docking the CSM ''Odyssey'' to the LM ''Aquarius'', and the spacecraft pulled away from the third stage.<ref name = "journal extraction">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/03tde.html|title=Day 1: Transposition, Docking and Extraction|date=February 17, 2017|access-date=August 12, 2019|last1=Woods|first1=W. David |last2=Kemppanen |first2=Johannes|last3=Turhanov|first3=Alexander|last4=Waugh |first4=Lennox J.}}</ref> Ground controllers then sent the third stage on a course to impact the Moon in range of the Apollo 12 seismometer, which it did just over three days into the mission.{{sfn|Orloff & Harland|2006|p=367}}

The crew settled in for the three-day trip to Fra Mauro. At 30:40:50 into the mission, with the TV camera running, the crew performed a burn to place Apollo&nbsp;13 on a hybrid trajectory. The departure from a [[free-return trajectory]] meant that if no further burns were performed, Apollo&nbsp;13 would miss Earth on its return trajectory, rather than intercept it, as with a free return.<ref name = "journal midcourse">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/05day2-mcc2-tv.html|title=Day 2: Midcourse correction 2 on TV|date=February 17, 2017|access-date=August 7, 2019}}</ref> A free return trajectory could only reach sites near the lunar equator; a hybrid trajectory, which could be started at any point after TLI, allowed sites with higher latitudes, such as Fra Mauro, to be reached.<ref name = "journal hybrid">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/launchwindow/lw1.html|title=Apollo lunar landing launch window: The controlling factors and constraints|year=2009|access-date=December 2, 2019|author=Robin Wheeler}}</ref> Communications were enlivened when Swigert realized that in the last-minute rush, he had omitted to file his [[Form 1040|federal income tax return]] (due April 15), and amid laughter from mission controllers, asked how he could get an extension. He was found to be entitled to a 60-day extension for being out of the country at the deadline.{{sfn|NASA 1970|p=8}}

Entry into the LM to test its systems had been scheduled for 58:00:00; when the crew awoke on the third day of the mission, they were informed it had been moved up three hours and was later moved up again by another hour. A television broadcast was scheduled for 55:00:00; Lovell, acting as emcee, showed the audience the interiors of ''Odyssey'' and ''Aquarius''.<ref name=storm>{{cite web |url=https://history.nasa.gov/afj/ap13fj/07day3-before-the-storm.html |title=Day 3: Before the storm |year=2016 |editor-last=Woods |editor-first=W. David |editor-last2=Turhanov|editor-first2=Alexandr|editor-last3=Waugh|editor-first3=Lennox J. |work=Apollo 13 Flight Journal |publisher=NASA |access-date=August 27, 2019}}</ref> The audience was limited since none of the television networks were carrying the broadcast,{{sfn|Houston, Heflin & Aaron|2015|p=206}} forcing Marilyn Lovell (Jim Lovell's wife) to go to the VIP room at Mission Control if she wanted to watch her husband and his crewmates.{{sfn|Chaikin|1995|pp=285–287}}
{{clear}}

=== Accident ===
{{For|the cause of the accident|Apollo 13#Investigation and response}}

About six and a half minutes after the TV broadcast{{snd}}approaching 56:00:00{{snd}}Apollo&nbsp;13 was about {{convert|180000|nmi|mi km}} from Earth.<ref name = "journal Houston">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/08day3-problem.html|title=Day 3: 'Houston, we've had a problem'|date=May 30, 2017|access-date=August 18, 2019|last1=Woods|first1=W. David|last2=Kemppanen|first2=Johannes|last3=Turhanov|first3=Alexander|last4=Waugh|first4=Lennox J.}}</ref> Haise was completing the shutdown of the LM after testing its systems while Lovell stowed the TV camera. [[Jack Lousma]], the [[Flight controller#CAPCOM|CAPCOM]], sent minor instructions to Swigert, including changing the [[orientation (geometry)|attitude]] of the craft to facilitate photography of [[Comet Bennett]].<ref name = "journal Houston" />{{sfn|Chaikin|1995|p=292}}

The pressure sensor in one of the SM's oxygen tanks had earlier appeared to be malfunctioning, so [[Seymour Liebergot|Sy Liebergot]] (the [[Flight controller#Electrical, environmental, and consumables manager (EECOM)|EECOM]], in charge of monitoring the CSM's electrical system) requested that the stirring fans in the tanks be activated. Normally this was done once daily; a stir would [[Thermal destratification|destratify]] the contents of the tanks, making the pressure readings more accurate.<ref name = "journal Houston" /> The Flight Director, Kranz, had Liebergot wait a few minutes for the crew to settle down after the telecast,{{sfn|Houston, Heflin & Aaron|2015|p=207}} then Lousma relayed the request to Swigert, who activated the switches controlling the fans,<ref name = "journal Houston" /> and after a few seconds turned them off again.{{sfn|Chaikin|1995|p=292}}

{{Listen|filename=Apollo13-wehaveaproblem.ogg|title=Houston, we've had a problem.|description=Swigert and Lovell reporting the incident on April 14, 1970 [2:59] "[[Houston, we have a problem|Houston, we've had a problem]]"|format=[[Ogg]]}}

Ninety-five seconds after Swigert activated those switches,{{sfn|Houston, Heflin & Aaron|2015|p=207}} the astronauts heard a "pretty large bang", accompanied by fluctuations in electrical power and the firing of the attitude control thrusters.{{sfn|Orloff & Harland|2006|p=368}}{{sfn|Orloff|2000|pp=152–157}} Communications and telemetry to Earth were lost for 1.8&nbsp;seconds, until the system automatically corrected by switching the [[directional antenna|high-gain]] [[Unified S-band|S-band]] antenna, used for translunar communications, from narrow-beam to wide-beam mode.{{sfn|Accident report|p=4-44}} The accident happened at 55:54:53 (03:08 UTC on April 14; 10:08 PM EST, April 13). Swigert reported 26&nbsp;seconds later, [[Houston, we have a problem|"Okay, Houston, we've had a problem here,"]] echoed at 55:55:42 by Lovell, "Houston, we've had a problem. We've had a Main&nbsp;B Bus undervolt."<ref name = "journal Houston" /> William Fenner was the [[Flight controller|guidance officer]] (GUIDO) who was the first to report a problem in the control room to Kranz.<ref name = "journal Houston" />

Lovell's initial thought on hearing the noise was that Haise had activated the LM's cabin-repressurization valve, which also produced a bang (Haise enjoyed doing so to startle his crewmates), but Lovell could see that Haise had no idea what had happened. Swigert initially thought that a [[meteoroid]] might have struck the LM, but he and Lovell quickly realized there was no leak.{{sfn|Chaikin|1995|p=293}} The "Main Bus&nbsp;B undervolt" meant that there was insufficient [[voltage]] produced by the SM's three [[fuel cell]]s (fueled by hydrogen and oxygen piped from their respective tanks) to the second of the SM's two electric power distribution systems. Almost everything in the CSM required power. Although the [[Bus (computing)|bus]] momentarily returned to normal status, soon both buses A and B were short on voltage. Haise checked the status of the fuel cells and found that two of them were dead. Mission rules forbade entering lunar orbit unless all fuel cells were operational.{{sfn|Chaikin|1995|pp=293–294}}

In the minutes after the accident, there were several unusual readings, showing that tank{{nbsp}}2 was empty and tank{{nbsp}}1's pressure slowly falling, that the [[Apollo Guidance Computer|computer on the spacecraft]] had reset and that the high-gain antenna was not working. Liebergot initially missed the worrying signs from tank{{nbsp}}2 following the stir, as he was focusing on tank{{nbsp}}1, believing that its reading would be a good guide to what was present in tank{{nbsp}}2, as did controllers supporting him in the "back room".  When Kranz questioned Liebergot on this, he initially responded that there might be false readings due to an instrumentation problem; he was often teased about that in the years to come.<ref name = "Cass 1">{{cite web|last=Cass|first=Stephen|title=Apollo 13, we have a solution|url=https://spectrum.ieee.org/apollo-13-we-have-a-solution|date=April 1, 2005|access-date=October 13, 2022|website=IEEE}}</ref> Lovell, looking out the window, reported "a gas of some sort" venting into space, making it clear that there was a serious problem.{{sfn|Houston, Heflin & Aaron|2015|p=215}}

Since the fuel cells needed oxygen to operate, when Oxygen Tank{{nbsp}}1 ran dry, the remaining fuel cell would shut down, meaning the CSM's only significant sources of power and oxygen would be the CM's batteries and its oxygen "surge tank". These would be needed for the final hours of the mission, but the remaining fuel cell, already starved for oxygen, was drawing from the surge tank. Kranz ordered the surge tank isolated, saving its oxygen, but this meant that the remaining fuel cell would die within two hours, as the oxygen in tank{{nbsp}}1 was consumed or leaked away.{{sfn|Chaikin|1995|pp=293–294}} The volume surrounding the spacecraft was filled with myriad small bits of debris from the accident, complicating any efforts to use the stars for navigation.{{sfn|Chaikin|1995|p=299}} The mission's goal became simply getting the astronauts back to Earth alive.<ref name = "Cass 2" />

=== Looping around the Moon ===
[[File:Direct Abort Trajectory - Lunar Landing Symposium, MSC Jun66.jpg|upright=1.2|thumb|This depiction of a direct abort (from a 1966 planning report) contemplates returning from a point much earlier in the mission, and closer to Earth, than where the Apollo&nbsp;13 accident occurred.]]
[[File:NASA-Apollo13-ViewsOfMoon-20200224.webm|thumb|upright=1.18|NASA – Apollo 13 Lunar Mission – Views Of The Moon (2:24)]]
The lunar module had charged batteries and full oxygen tanks for use on the lunar surface, so Kranz directed that the astronauts power up the LM and use it as a "lifeboat"<ref name = "Cass 1" />{{snd}}a scenario anticipated but considered unlikely.{{sfn|Lovell & Kluger|2000|pp=83–87}} Procedures for using the LM in this way had been developed by LM flight controllers after a training simulation for Apollo 10 in which the LM was needed for survival, but could not be powered up in time.<ref name = "Cass 2" /> Had Apollo&nbsp;13's accident occurred on the return voyage, with the LM already jettisoned, the astronauts would have died,<ref name="LM-ALSEP">{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-029C|title=Apollo 13 Lunar Module/ALSEP|website=NASA Space Science Data Coordinated Archive|access-date=October 31, 2009}}</ref> as they would have following an explosion in lunar orbit, including one while Lovell and Haise walked on the Moon.<ref name = "Yahoo 50th" />

A key decision was the choice of return path. A "direct abort" would use the SM's main engine (the [[Apollo command and service module#Service propulsion system|Service Propulsion System]] or SPS) to return before reaching the Moon. However, the accident could have damaged the SPS, and the fuel cells would have to last at least another hour to meet its power requirements, so Kranz instead decided on a longer route: the spacecraft would swing around the Moon before heading back to Earth. Apollo&nbsp;13 was on the hybrid trajectory which was to take it to Fra Mauro; it now needed to be brought back to a free return. The LM's [[Descent propulsion system|Descent Propulsion System]] (DPS), although not as powerful as the SPS, could do this, but new software for Mission Control's computers needed to be written by technicians as it had never been contemplated that the CSM/LM spacecraft would have to be maneuvered from the LM. As the CM was being shut down, Lovell copied down its guidance system's orientation information and performed hand calculations to transfer it to the LM's guidance system, which had been turned off; at his request Mission Control checked his figures.<ref name = "Cass 2">{{cite web|last=Cass|first=Stephen|title=Houston, we have a solution, part 2|url=https://spectrum.ieee.org/apollo-13-we-have-a-solution-part-2|date=April 1, 2005|website=IEEE|access-date=August 31, 2019}}</ref>{{sfn|Chaikin|1995|pp=297–298}} At 61:29:43.49 the DPS burn of 34.23&nbsp;seconds took Apollo&nbsp;13 back to a free return trajectory.{{sfn|Orloff & Harland|2006|p=369}}

[[File:Mare Moscoviense AS13-60-8648.jpg|thumb|The Apollo&nbsp;13 crew photographed the Moon out of the [[Apollo Lunar Module|Lunar Module]].]]
The change would get Apollo&nbsp;13 back to Earth in about four days' time{{snd}}though with splashdown in the [[Indian Ocean]], where NASA had few recovery forces. Jerry Bostick and other [[Flight controller#FDO|Flight Dynamics Officers]] (FIDOs) were anxious both to shorten the travel time and to move splashdown to the [[Pacific Ocean]], where the main recovery forces were located. One option would shave 36 hours off the return time, but required jettisoning the SM; this would expose the CM's heat shield to space during the return journey, something for which it had not been designed. The FIDOs also proposed other solutions. After a meeting involving NASA officials and engineers, the senior individual present, [[Johnson Space Center|Manned Spaceflight Center]] director [[Robert R. Gilruth]], decided on a burn using the DPS, that would save 12&nbsp;hours and land Apollo&nbsp;13 in the Pacific. This "PC+2" burn would take place two hours after [[pericynthion]], the closest approach to the Moon.<ref name = "Cass 2" />  At pericynthion, Apollo&nbsp;13 set the record (per the ''Guinness Book of World Records''), which still stands, for the furthest distance from Earth by a crewed spacecraft: {{convert|400171|km|mi nmi|sp=us}} from Earth at 7:21&nbsp;pm EST, April 14 (00:21:00&nbsp;UTC April 15).{{sfn|Glenday|2010|p=13}}{{NoteTag|The record was set because the Moon was nearly at [[Apsis|its furthest from Earth]] during the mission. Apollo&nbsp;13's unique free return trajectory caused it to go approximately {{convert|100|km|-1|sp=us}} further from the [[Far side (Moon)|lunar far side]] than other Apollo lunar missions, but this was a minor contribution to the record.{{sfn|Adamo|2009|p=37}} A reconstruction of the trajectory by astrodynamicist Daniel Adamo in 2009 records the furthest distance as {{convert|400046|km|sp=us}} at 7:34&nbsp;pm&nbsp;EST (00:34:13&nbsp;UTC). Apollo 10 holds the record for second-furthest at a distance of {{convert|399806|km|sp=us}}.{{sfn|Adamo|2009|p=41}}}}

While preparing for the burn, the crew was told that the S-IVB had impacted the Moon as planned, leading Lovell to quip, "Well, at least something worked on this flight."<ref name = "journal leaving" />{{sfn|Cooper|2013|pp=84–86}} Kranz's White team of mission controllers, who had spent most of their time supporting other teams and developing the procedures urgently needed to get the astronauts home, took their consoles for the PC+2 procedure.{{sfn|Houston, Heflin & Aaron|2015|pp=221–222}} Normally, the accuracy of such a burn could be assured by checking the alignment Lovell had transferred to the LM's computer against the position of one of the stars astronauts used for navigation, but the light glinting off the many pieces of debris accompanying the spacecraft made that impractical. The astronauts accordingly used the one star available whose position could not be obscured{{snd}}the Sun. Houston also informed them that the Moon would be centered in the commander's window of the LM as they made the burn, which was almost perfect{{snd}}less than 0.3 meters (1 foot) per second off.<ref name = "journal leaving" /> The burn, at 79:27:38.95, lasted four minutes and 23&nbsp;seconds.{{sfn|Orloff & Harland|2006|p=391}} The crew then shut down most LM systems to conserve consumables.<ref name = "journal leaving">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/13day4-leaving-moon.html|title=Day 4: Leaving the Moon|date=February 17, 2017|access-date=September 7, 2019}}</ref>

=== Return to Earth ===
[[File:Apollo13 apparatus.jpg|thumb|Swigert with the rig improvised to adapt the CM's [[lithium hydroxide]] canisters for use in the LM]]

The LM carried enough oxygen, but that still left the problem of [[carbon dioxide scrubber|removing carbon dioxide]], which was absorbed by canisters of [[lithium hydroxide]] pellets. 
The LM's stock of canisters, meant to accommodate two astronauts for 45 hours on the Moon, was not enough to support three astronauts for the return journey to Earth.{{sfn|Houston, Heflin & Aaron|2015|p=224}} The CM had enough canisters, but they were of a different shape and size to the LM's, hence unable to be used in the LM's equipment. Engineers on the ground devised a way to bridge the gap, using plastic covers ripped from procedure manuals, duct tape, and other items available on the spacecraft.<ref>{{cite news|url=https://www.newspapers.com/clip/36237422/detroit_free_press/|title=Astronauts Beat Air Crisis By Do-It-Yourself Gadget|newspaper=Detroit Free Press|location=Detroit, Michigan|date=April 16, 1970|page=12–C|last1=Pothier|first1=Richard|via=Newspapers.com}}</ref>{{sfn|Barell|2016|p=154}} NASA engineers referred to the improvised device as "the mailbox".<ref>{{Cite web|last=Smith|first=Yvette|date=2015-09-24|title=Putting a Square Peg in a Round Hole|url=http://www.nasa.gov/image-feature/putting-a-square-peg-in-a-round-hole|access-date=2021-05-20|website=NASA}}</ref> The procedure for building the device was read to the crew by CAPCOM [[Joseph P. Kerwin|Joseph Kerwin]] over the course of an hour, and was built by Swigert and Haise; carbon dioxide levels began dropping immediately. Lovell later described this improvisation as "a fine example of cooperation between ground and space".{{sfn|Cortright|1975|pp=257–262}}

[[File:Apollo 13 Hasselblad image from film magazine 62-JJ (cropped).jpg|thumb|left|Lovell tries to rest in the frigid spacecraft]]

The CSM's electricity came from fuel cells that produced water as a byproduct, but the LM was powered by [[Silver-oxide battery|silver-zinc batteries]] which did not, so both electrical power and water (needed for equipment cooling as well as drinking) would be critical. LM power consumption was reduced to the lowest level possible;{{sfn|Mission Operations Report 1970|pp=III‑17, III-33, III-40}} Swigert was able to fill some drinking bags with water from the CM's water tap,<ref name = "journal leaving" /> but even assuming rationing of personal consumption, Haise initially calculated they would run out of water for cooling about five hours before reentry. This seemed acceptable because the systems of Apollo 11's LM, once jettisoned in lunar orbit, had continued to operate for seven to eight hours even with the water cut off. In the end, Apollo&nbsp;13 returned to Earth with {{convert|28.2|lb|order=flip}} of water remaining.{{sfn|Cortright|1975|pp=254–257}} The crew's ration was 0.2&nbsp;liters (6.8&nbsp;fl&nbsp;oz) of water per person per day; the three astronauts lost a total of {{convert|31|lb|order=flip}} among them, and Haise developed a [[urinary tract infection]].<ref name = "mission summary">{{cite web|last=Jones|first=Eric M.|date=January 4, 2006|url=https://history.nasa.gov/alsj/a13/a13.summary.html|title=The frustrations of Fra Mauro: Part I|work=Apollo Lunar Surface Journal|access-date=September 7, 2019}}</ref>{{sfn|Cortright|1975|pp=262–263}} This infection was probably caused by the reduced water intake, but microgravity and effects of cosmic radiation might have impaired his immune system's reaction to the pathogen.<ref>{{cite journal |last1=Kennedy |first1=A.R. |date=2014 |title=Biological effects of space radiation and development of effective countermeasures |journal=Life Sciences in Space Research |volume= 1|issue=1 |pages=10–43 |doi=10.1016/j.lssr.2014.02.004|pmid=25258703 |pmc=4170231 |bibcode=2014LSSR....1...10K }}</ref>

[[File:Apollo 13 Houston, We've Got a Problem.ogv|thumb|''Apollo 13: Houston, We've Got a Problem'' (1970) — Documentary about the mission by NASA (28:21)]]

Inside the darkened spacecraft, the temperature dropped as low as {{convert|38|F|order=flip}}.<ref>{{Cite web|last=Mars|first=Kelli|date=2020-04-16|title=50 Years Ago: Apollo 13 Crew Returns Safely to Earth|url=http://www.nasa.gov/feature/50-years-ago-apollo-13-crew-returns-safely-to-earth|access-date=2021-05-20|website=NASA}}</ref> Lovell considered having the crew don their spacesuits, but decided this would be too hot. Instead, Lovell and Haise wore their lunar EVA boots and Swigert put on an extra coverall. All three astronauts were cold, especially Swigert, who had got his feet wet while filling the water bags and had no lunar overshoes (since he had not been scheduled to walk on the Moon). As they had been told not to discharge their urine to space to avoid disturbing the trajectory, they had to store it in bags. Water condensed on the walls, though any condensation that may have been behind equipment panels{{sfn|Cortright|1975|pp=257–263}} caused no problems, partly because of the extensive electrical insulation improvements instituted after the [[Apollo 1]] fire.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/constellation/main/A13_panel.html|title=Generation Constellation Learns about Apollo 13|last=Siceloff|first=Steven|date=September 20, 2007|work=[[Constellation program|Constellation Program]]|publisher=NASA|access-date=September 7, 2019}}</ref> Despite all this, the crew voiced few complaints.<ref name = "Cass 3">{{cite web|last=Cass|first=Stephen|title=Houston, we have a solution, part 3|url=https://spectrum.ieee.org/apollo-13-we-have-a-solution-part-3|date=April 1, 2005|website=IEEE|access-date=September 8, 2019}}</ref>

Flight controller [[John Aaron]], along with Mattingly and several engineers and designers, devised a procedure for powering up the command module from full shutdown{{snd}}something never intended to be done in flight, much less under Apollo&nbsp;13's severe power and time constraints.<ref>{{cite journal|last=Leopold|first=George|date=March 17, 2009|title=Power engineer: Video interview with Apollo astronaut Ken Mattingly|journal=[[EE Times]]|publisher=UMB Tech|url=https://www.eetimes.com/power-engineer-video-interview-with-apollo-astronaut-ken-mattingly/|access-date=August 14, 2010}}</ref> The astronauts implemented the procedure without apparent difficulty: Kranz later credited all three astronauts having been test pilots, accustomed to having to work in critical situations with their lives on the line, for their survival.<ref name = "Cass 3" />

Recognizing that the cold conditions combined with insufficient rest would hinder the time-critical startup of the command module prior to reentry, at 133 hours into flight Mission Control gave Lovell the okay to fully power up the LM to raise the cabin temperature, which included restarting the LM's guidance computer.  Having the LM's computer running enabled Lovell to perform a navigational sighting and calibrate the LM's Inertial Measurement Unit (IMU).  With the lunar module's computer aware of its location and orientation, the command module's computer was later calibrated in a reverse of the normal procedures used to set up the LM, shaving steps from the restart process and increasing the accuracy of the [[Apollo PGNCS|PGNCS]]-controlled reentry.<ref>{{cite web|url=https://www.history.nasa.gov/afj/ap13fj/25day6-thelastcoursecorrection.html|title=Apollo Flight Journal: Day 6 Part 4|publisher=NASA|access-date=May 17, 2021|archive-date=January 18, 2022|archive-url=https://web.archive.org/web/20220118020508/https://www.history.nasa.gov/afj/ap13fj/25day6-thelastcoursecorrection.html|url-status=dead}}</ref>

=== Reentry and splashdown ===

Despite the accuracy of the transearth injection, the spacecraft slowly drifted off course, necessitating a correction. As the LM's guidance system had been shut down following the PC+2 burn, the crew was told to use [[solar terminator|the line between night and day]] on the Earth to guide them, a technique used on NASA's Earth-orbit missions but never on the way back from the Moon.<ref name = "Cass 3" /> This DPS burn, at 105:18:42 for 14&nbsp;seconds, brought the projected entry flight path angle back within safe limits. Nevertheless, yet another burn was needed at 137:40:13, using the LM's [[reaction control system]] (RCS) thrusters, for 21.5&nbsp;seconds. The SM was jettisoned less than half an hour later, allowing the crew to see the damage for the first time, and photograph it. They reported that an entire panel was missing from the SM's exterior, the fuel cells above the oxygen tank shelf were tilted, that the high-gain antenna was damaged, and there was a considerable amount of debris elsewhere.{{sfn|Orloff & Harland|2006|pp=370–371}} Haise could see possible damage to the SM's engine bell, validating Kranz's decision not to use the SPS.<ref name = "Cass 3" /> The crew then moved out of the LM back into the CM and reactivated its life support systems.<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-029C |title=Apollo 13 Lunar Module / EASEP |publisher=[[NASA Space Science Data Coordinated Archive]] |access-date=July 9, 2024}}</ref> 

[[File:Apollo13 splashdown.jpg|thumb|left|alt=Spaceship contacts ocean under parachute|Apollo&nbsp;13 splashes down in the South Pacific on April 17, 1970]]

The last problem to be solved was how to separate the lunar module a safe distance away from the command module just before reentry. The normal procedure, in lunar orbit, was to release the LM and then use the service module's RCS to pull the CSM away, but by this point, the SM had already been released. [[Grumman]], manufacturer of the LM, assigned a team of [[University of Toronto]] engineers, led by senior scientist [[Bernard Etkin]], to solve the problem of how much air pressure to use to push the modules apart. The astronauts applied the solution, which was successful.<ref name="G&M">{{cite news|title=Bernard Etkin helped avert Apollo 13 tragedy|url=https://www.theglobeandmail.com/technology/science/bernard-etkin-helped-avert-apollo-13-tragedy/article19735265/#dashboard/follows/|access-date=September 7, 2019|newspaper=The Globe and Mail}}</ref> The LM reentered Earth's atmosphere and was destroyed, the remaining pieces falling in the deep ocean.<ref name="LM-ALSEP" /><ref name=impact>{{cite web|url=https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_impact.html|title=Impact Sites of Apollo LM Ascent and SIVB Stages|website=NASA Space Science Data Coordinated Archive|access-date=August 27, 2019}}</ref> Apollo&nbsp;13's final midcourse correction had addressed the concerns of the Atomic Energy Commission, which wanted the cask containing the plutonium oxide intended for the SNAP-27 RTG to land in a safe place. The impact point was over the [[Tonga Trench]] in the Pacific, one of its deepest points, and the cask sank {{convert|10|km|mi nmi|sp=us|0}} to the bottom. Later helicopter surveys found no radioactive leakage.<ref name = "Cass 3" />

Ionization of the air around the command module during reentry would typically cause a four-minute communications blackout. Apollo&nbsp;13's shallow reentry path lengthened this to six minutes, longer than had been expected; controllers feared that the CM's heat shield had failed.<ref>{{cite magazine|title=Did Ron Howard exaggerate the reentry scene in the movie Apollo 13?|first=Joe|last=Pappalardo|url=http://www.airspacemag.com/need-to-know/did-ron-howard-exaggerate-the-reentry-scene-in-the-movie-apollo-13-17639496/|magazine=[[Air & Space/Smithsonian]]|publisher=[[Smithsonian Institution]]|location=Washington, D.C.|date=May 1, 2007|access-date=September 8, 2019}}</ref> ''Odyssey'' regained radio contact and splashed down safely in the South Pacific Ocean, {{Coord|21|38|24|S|165|21|42|W|type:event|name=Apollo 13 splashdown}},{{sfn|Apollo 13 Mission Report 1970|p=1-2}} southeast of [[American Samoa]] and {{convert|6.5|km|mi nmi|abbr=on}} from the recovery ship, [[USS Iwo Jima (LPH-2)|USS ''Iwo Jima'']].{{sfn|Orloff & Harland|2006|p=371}} Although fatigued, the crew was in good condition except for Haise, who had developed a serious urinary tract infection because of insufficient water intake.{{sfn|Cortright|1975|pp=262–263}} The crew stayed overnight on the ship and flew to [[Pago Pago]], [[American Samoa]], the next day. They flew to Hawaii, where President [[Richard Nixon]] awarded them the [[Presidential Medal of Freedom]], the highest civilian honor.<ref>{{cite news|url=https://www.newspapers.com/clip/39764154/the_philadelphia_inquirer/|title=Heroes of Apollo 13 Welcomed by President and Loved Ones|agency=Associated Press|newspaper=The Philadelphia Inquirer|location=Philadelphia, Pennsylvania|date=April 19, 1970|via=Newspapers.com|page=1}}</ref> They stayed overnight, and then were flown back to Houston.{{sfn|Apollo 13 Mission Report 1970|p=10-5}}

En route to Honolulu, President Nixon stopped at Houston to award the Presidential Medal of Freedom to the Apollo&nbsp;13 Mission Operations Team.<ref name="nixon">{{cite web|title=Behind the Scenes of Apollo 13|url=https://www.nixonfoundation.org/2016/04/behind-scenes-apollo-13/|website=Richard Nixon Foundation|access-date=June 27, 2019|date=April 11, 2016}}</ref> He originally planned to give the award to NASA administrator [[Thomas O. Paine]], but Paine recommended the mission operations team.<ref>{{cite web|url=https://www.presidency.ucsb.edu/node/241054|title=Remarks on Presenting the Presidential Medal of Freedom to Apollo 13 Mission Operations Team in Houston.|publisher=The American Presidency Project|access-date=December 27, 2017}}</ref>

== Public and media reaction ==
[[File:Jim Lovell newspaper.jpg|thumb|upright=1.5|{{blockquote|text=Nobody believes me, but during this six-day odyssey, we had no idea what an impression Apollo{{nbsp}}13 made on the people of Earth. We never dreamed a billion people were following us on television and radio, and reading about us in banner headlines of every newspaper published. We still missed the point on board the carrier ''Iwo Jima'', which picked us up, because the sailors had been as remote from the media as we were. Only when we reached Honolulu did we comprehend our impact: there we found [[Richard Nixon|President Nixon]] and [NASA Administrator] [[Thomas O. Paine|Dr. Paine]] to meet us, along with my wife Marilyn, Fred's wife Mary (who, being pregnant, also had a doctor along just in case), and bachelor Jack's parents, in lieu of his usual airline stewardesses.|source = Jim Lovell{{sfn|Cortright|1975|pp=262–263}}|style=padding: 15px; margin: 0;text-align: justify;}}]]

Worldwide interest in the Apollo program was reawakened by the incident; television coverage was seen by millions. Four Soviet ships headed toward the landing area to assist if needed,{{sfn|NASA 1970|p=15}} and other nations offered assistance should the craft have to splash down elsewhere.{{sfn|Benson & Faherty|1979|pp=489–494}} President Nixon canceled appointments, phoned the astronauts' families, and drove to NASA's [[Goddard Space Flight Center]] in [[Greenbelt, Maryland]], where Apollo's tracking and communications were coordinated.{{sfn|NASA 1970|p=15}}

The rescue received more public attention than any spaceflight to that point, other than the first Moon landing on Apollo 11. There were worldwide headlines, and people surrounded television sets to get the latest developments, offered by networks who interrupted their regular programming for bulletins. [[Pope Paul VI]] led a congregation of 10,000 people in praying for the astronauts' safe return; ten times that number offered prayers at a religious festival in India.{{sfn|Chaikin|1995|p=316}} The [[United States Senate]] on April 14 passed a resolution urging businesses to pause at 9:00{{nbsp}}pm local time that evening to allow for employee prayer.{{sfn|NASA 1970|p=15}}

An estimated 40{{nbsp}}million Americans watched Apollo{{nbsp}}13's splashdown, carried live on all three networks, with another 30{{nbsp}}million watching some portion of the 6½ hour telecast. Even more outside the U.S. watched. [[Jack Gould]] of ''[[The New York Times]]'' stated that Apollo{{nbsp}}13, "which came so close to tragic disaster, in all probability united the world in mutual concern more fully than another successful landing on the Moon would have".<ref>{{cite news|last=Gould|first=Jack|author-link=Jack Gould|newspaper=[[The New York Times]]|url=https://www.nytimes.com/1970/04/18/archives/tv-millions-of-viewers-end-vigil-for-apollo-13-unusual-color.html|date=April 18, 1970|page=59|title=TV: Millions of viewers end vigil for Apollo 13|url-access=subscription}}</ref>

== {{anchor|Review board report}}Investigation and response ==

=== Review board ===
[[File:Apollo13 tank2.jpg|thumb|Oxygen tank number 2, showing heater and thermostat unit]]
Immediately upon the crew's return, NASA Administrator Paine and Deputy Administrator [[George Low]] appointed a review board to investigate the accident. Chaired by NASA [[Langley Research Center]] Director [[Edgar Cortright|Edgar M. Cortright]] and including Neil Armstrong and six others,{{NoteTag|The others were Robert F. Allnutt (Assistant to the Administrator, NASA Hqs.); John F. Clark (Director, Goddard Space Flight Center); Brig. General Walter R. Hedrick Jr. (Director of Space, DCS/RED, Hqs., USAF); Vincent L. Johnson (Deputy Associate Administrator-Engineering, Office of Space Science and Applications); [[Milton Klein (engineer)|Milton Klein]] (Manager, AEC-NASA Space Nuclear Propulsion Office); [[Hans M. Mark]] (Director, Ames Research Center).{{sfn|Accident report|pp=1-1–1-4}}
}} the board sent its final report to Paine on June 15.{{sfn|Accident report|p=15}}
It found that the failure began in the service module's number{{nbsp}}2 oxygen tank.{{sfn|Accident report|p=4-36}} Damaged [[Polytetrafluoroethylene|Teflon]] insulation on the wires to the stirring fan inside Oxygen Tank{{nbsp}}2 allowed the wires to [[short circuit]] and ignite this insulation. The resulting fire increased the pressure inside the tank until the tank dome failed, filling the fuel cell bay (SM Sector{{nbsp}}4) with rapidly expanding gaseous oxygen and combustion products. The pressure rise was sufficient to pop the rivets holding the aluminum exterior panel covering Sector{{nbsp}}4 and blow it out, exposing the sector to space and snuffing out the fire. The detached panel hit the nearby high-gain antenna, disabling the narrow-beam communication mode and interrupting communication with Earth for 1.8&nbsp;seconds while the system automatically switched to the backup wide-beam mode.{{sfn|Orloff & Harland|2006|pp=372–373}} The sectors of the SM were not airtight from each other, and had there been time for the entire SM to become as pressurized as Sector{{nbsp}}4, the force on the CM's heat shield would have separated the two modules. The report questioned the use of Teflon and other materials shown to be flammable in supercritical oxygen, such as aluminum, within the tank.{{sfn|Accident report|pp=5-6–5-7, 5-12–5-13}} The board found no evidence pointing to any other theory of the accident.{{sfn|Accident report|p=4-37}}
{{multiple image
 | align = left
 | direction = vertical
 | width = 200
 | header =
 | image1 = Honeycomb panel test (S70-41982).jpg
 | alt1 = Panel in the process of being blown out
 | caption1 = 
 | image2 = Honeycomb panel test (S70-41983).jpg
 | alt2 = Further along in the process
 | caption2 = Panel similar to the SM Sector{{nbsp}}4 cover being ejected during a test performed as part of the investigation
}}
[[Shock (mechanics)|Mechanical shock]] forced the oxygen valves closed on the number{{nbsp}}1 and number{{nbsp}}3 fuel cells, putting them out of commission.{{sfn|Accident report|p=4-40}} The sudden failure of Oxygen Tank{{nbsp}}2 compromised Oxygen Tank{{nbsp}}1, causing its contents to leak out, possibly through a damaged line or valve, over the next 130&nbsp;minutes, entirely depleting the SM's oxygen supply.{{sfn|Orloff & Harland|2006|p=372}}{{sfn|Accident report|p=4-43}} With both SM oxygen tanks emptying, and with other damage to the SM, the mission had to be aborted.{{sfn|Orloff & Harland|2006|p=375}} The board praised the response to the emergency: "The imperfection in Apollo&nbsp;13 constituted a near disaster, averted only by outstanding performance on the part of the crew and the ground control team which supported them."{{sfn|Accident report|p=ii}}

Oxygen Tank&nbsp;2 was manufactured by the [[Beechcraft|Beech Aircraft Company]] of Boulder, Colorado, as subcontractor to [[Rockwell International|North American Rockwell]] (NAR) of Downey, California, prime contractor for the CSM.{{sfn|Accident report|p=4-2}} It contained two thermostatic switches, originally designed for the command module's 28-volt DC power, but which could fail if subjected to the 65 volts used during ground testing at KSC.{{sfn|Accident report|p=4-23}} Under the original 1962 specifications, the switches would be rated for 28 volts, but revised specifications issued in 1965 called for 65 volts to allow for quicker tank pressurization at KSC. Nonetheless, the switches Beech used were not rated for 65 volts.{{sfn|Orloff & Harland|2006|p=374}}

At NAR's facility, Oxygen Tank&nbsp;2 had been originally installed in an oxygen shelf placed in the [[Apollo 10]] service module, SM-106, but which was removed to fix a potential [[electromagnetic interference]] problem and another shelf substituted. During removal, the shelf was accidentally dropped at least {{convert|2|in|cm|0|order=flip|sp=us}}, because a retaining bolt had not been removed. The probability of damage from this was low, but it is possible that the fill line assembly was loose and made worse by the fall. After some retesting (which did not include filling the tank with liquid oxygen), in November 1968 the shelf was re-installed in SM-109, intended for Apollo&nbsp;13, which was shipped to KSC in June 1969.{{sfn|Accident report|pp=4-19, 4-21}}

The [[Terminal countdown demonstration test|Countdown Demonstration Test]] took place with SM-109 in its place near the top of the Saturn&nbsp;V and began on March 16, 1970. During the test, the cryogenic tanks were filled, but Oxygen Tank&nbsp;2 could not be emptied through the normal drain line, and a report was written documenting the problem. After discussion among NASA and the contractors, attempts to empty the tank resumed on March 27. When it would not empty normally, the heaters in the tank were turned on to boil off the oxygen. The thermostatic switches were designed to prevent the heaters from raising the temperature higher than {{convert|80|F|C|order=flip}}, but they failed under the 65-volt power supply applied. Temperatures on the heater tube within the tank may have reached {{convert|1,000|F|C|order=flip|-1}}, most likely damaging the Teflon insulation.{{sfn|Accident report|p=4-23}} The temperature gauge was not designed to read higher than {{convert|85|F|C|order=flip}}, so the technician monitoring the procedure detected nothing unusual. This heating had been approved by Lovell and Mattingly of the prime crew, as well as by NASA managers and engineers.{{sfn|Chaikin|1995|pp=330–331}}<ref>{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/lunar/ap13acc.html|last=Williams|first=David R.|title=The Apollo 13 Accident|website=NASA Space Science Data Coordinated Archive|access-date=December 31, 2012}}</ref> Replacement of the tank would have delayed the mission by at least a month.<ref name = "mission summary" /> The tank was filled with liquid oxygen again before launch; once electric power was connected, it was in a hazardous condition.{{sfn|Orloff & Harland|2006|p=375}} The board found that Swigert's activation of the Oxygen Tank{{nbsp}}2 fan at the request of Mission Control caused an [[electric arc]] that set the tank on fire.{{sfn|Chaikin|1995|p=333}}

The board conducted a test of an oxygen tank rigged with hot-wire ignitors that caused a rapid rise in temperature within the tank, after which it failed, producing telemetry similar to that seen with the Apollo&nbsp;13 Oxygen Tank&nbsp;2.{{sfn|Accident report, appendix F–H|pp=F-48–F-49}} Tests with panels similar to the one that was seen to be missing on SM Sector{{nbsp}}4 caused separation of the panel in the test apparatus.{{sfn|Accident report, appendix F–H|pp=F-70–F-82}}

=== Changes in response ===
[[File:Apollo 14 redesigned oxygen tank (S71-16745).jpg|thumb|Redesigned oxygen tank for Apollo{{nbsp}}14]]

For [[Apollo 14]] and subsequent missions, the oxygen tank was redesigned, the thermostats being upgraded to handle the proper voltage. The heaters were retained since they were necessary to maintain oxygen pressure. The stirring fans, with their unsealed motors, were removed, which meant the oxygen quantity gauge was no longer accurate. This required adding a third tank so that no tank would go below half full.{{sfn|Gatland|1976|p=281}} The third tank was placed in Bay{{nbsp}}1 of the SM, on the side opposite the other two, and was given an isolation valve that could isolate it from the fuel cells and from the other two oxygen tanks in an emergency and allow it to feed the CM's environmental system only. The quantity probe was upgraded from aluminum to stainless steel.{{sfn|Apollo 14 Press Kit|1971|pp=96–97}}

All electrical wiring in Bay{{nbsp}}4 was sheathed in stainless steel. The fuel cell oxygen supply valves were redesigned to isolate the Teflon-coated wiring from the oxygen. The spacecraft and Mission Control monitoring systems were modified to give more immediate and visible warnings of anomalies.{{sfn|Gatland|1976|p=281}} An emergency supply of {{convert|5|USgal|L|order=flip}} of water was stored in the CM, and an emergency battery, identical to those that powered the LM's descent stage, was placed in the SM. The LM was modified to make transfer of power from the LM to the CM easier.{{sfn|Apollo 14 Press Kit|1971|pp=96–98}}

== Aftermath ==
[[File:President Richard Nixon speaks before awarding the Apollo 13 astronauts the Presidential Medal of Freedom.jpg|thumb|President [[Richard Nixon]] awarding the Apollo&nbsp;13 astronauts the [[Presidential Medal of Freedom]]]]

On February 5, 1971, [[Apollo&nbsp;14]]'s LM, ''Antares'', landed on the Moon with astronauts [[Alan Shepard]] and [[Edgar Mitchell]] aboard, near Fra Mauro, the site Apollo&nbsp;13 had been intended to explore.<ref>{{cite web|website=[[Universities Space Research Association|USRA]]|publisher=Lunar and Planetary Institute|title=Apollo 14 mission|url=https://www.lpi.usra.edu/lunar/missions/apollo/apollo_14/|access-date=September 15, 2019}}</ref> Haise served as CAPCOM during the descent to the Moon,<ref>{{cite web |url=https://history.nasa.gov/alsj/a14/a14.landing.html|title=Landing at Far Mauro |editor-last=Jones |editor-first=Eric M. |work=Apollo 14 Lunar Surface Journal |publisher=NASA |access-date=November 24, 2019|date=January 12, 2016}}</ref> and during the second EVA, during which Shepard and Mitchell explored near Cone crater.<ref>{{cite web |url=https://history.nasa.gov/alsj/a14/a14.tocone.html|title=Climbing Cone Ridge – where are we? |editor-last=Jones |editor-first=Eric M. |work=Apollo 14 Lunar Surface Journal |publisher=NASA |access-date=November 24, 2019|date=September 29, 2017}}</ref>

None of the Apollo&nbsp;13 astronauts flew in space again. Lovell retired from NASA and the Navy in 1973, entering the private sector.<ref name="nasabio">{{cite web |url=http://www.jsc.nasa.gov/Bios/htmlbios/lovell-ja.html |title=Astronaut Bio: James A. Lovell |access-date=December 16, 2016|publisher=NASA|url-status=dead|archive-url=https://web.archive.org/web/20170112213829/https://www.jsc.nasa.gov/Bios/htmlbios/lovell-ja.html|archive-date=January 12, 2017}}</ref>  Swigert was to have flown on the 1975 [[Apollo–Soyuz|Apollo–Soyuz Test Project]] (the first joint mission with the Soviet Union) but was removed as part of the fallout from the [[Apollo 15 postal covers incident]]. He took a leave of absence from NASA in 1973 and left the agency to enter politics, being elected to the House of Representatives in 1982, but died of cancer before he could be sworn in.<ref>{{cite web|title=For Jack Swigert, on his 83rd birthday|last=Carney|first=Emily|url=https://www.americaspace.com/2014/08/29/for-jack-swigert-on-his-83rd-birthday/|publisher=AmericaSpace|date=August 29, 2014|access-date=November 24, 2019}}</ref> Haise was slated to have been the commander of the canceled [[Apollo 19]] mission, and flew the [[Space Shuttle]] [[Approach and Landing Tests]] before retiring from NASA in 1979.<ref>{{Cite web |first1=Elizabeth|last1=Howell|last2=Hickok|first2=Kimberly|title=Astronaut Fred Haise: Apollo 13 Crewmember |url=http://www.space.com/20318-fred-haise-apollo-13-biography.html |website=Space.com|publisher=Future US |date=April 10, 2020 |access-date = April 11, 2020}}</ref>

Several experiments were completed during Apollo 13, even though the mission did not land on the Moon.<ref name = "13 science" /> One involved the launch vehicle's [[S-IVB]] (the Saturn&nbsp;V's third stage), which on prior missions had been sent into solar orbit once detached. The seismometer left by Apollo 12 had detected frequent impacts of small objects onto the Moon, but larger impacts would yield more information about the Moon's crust, so it was decided that, beginning with Apollo&nbsp;13, the S-IVB would be crashed into the Moon.{{sfn|Harland|1999|p=50}} The impact occurred at 77:56:40 into the mission and produced enough energy that the gain on the seismometer, {{convert|73|mi|order=flip|sp=us}} from the impact, had to be reduced.{{sfn|Orloff & Harland|2006|p=367}} An experiment to measure the amount of atmospheric electrical phenomena during the ascent to orbit{{snd}}added after Apollo 12 was struck by lightning{{snd}}returned data indicating a heightened risk during marginal weather. A series of photographs of Earth, taken to test whether cloud height could be determined from [[geosynchronous satellite|synchronous satellites]], achieved the desired results.<ref name = "13 science">{{cite web|title=Apollo 13 mission: Science experiments|website=[[Universities Space Research Association|USRA]]|publisher=Lunar and Planetary Institute|url=https://www.lpi.usra.edu/lunar/missions/apollo/apollo_13/experiments/|access-date=August 8, 2019|archive-url=https://web.archive.org/web/20180915105402/https://www.lpi.usra.edu/lunar/missions/apollo/apollo_13/experiments/|archive-date=September 15, 2018|url-status=dead}}</ref>

As a joke, Grumman issued an invoice to North American Rockwell, prime contractor for the CSM, for "towing" the CSM most of the way to the Moon and back. Line items included 400001<!--conversion makes no sense here--> miles at $1 each (plus $4 for the first mile); $536.05 for battery charging; oxygen; and four nights at $8 per night for an "additional guest in room" (Swigert). After a 20% "commercial discount", and a 2% discount for timely payment, the final total was $312,421.24. North American declined payment, noting that it had ferried three previous Grumman LMs to the Moon without compensation.<ref>{{cite web|url=https://www.spaceflightinsider.com/space-centers/kennedy-space-center/the-apollo-13-invoice/|title=The Apollo 13 Invoice...|website=Spaceflight Insider|access-date=September 17, 2019|date=December 8, 2013|archive-date=November 12, 2020|archive-url=https://web.archive.org/web/20201112041957/https://www.spaceflightinsider.com/space-centers/kennedy-space-center/the-apollo-13-invoice/|url-status=dead}}</ref><ref>{{cite news|title=Tongue-in-Cheek-Bill Asks Space Tow Fee|url=https://news.google.com/newspapers?nid=1338&dat=19700418&id=Owg0AAAAIBAJ&sjid=O_gDAAAAIBAJ&pg=5822,839543|newspaper=[[The Spokesman-Review|Spokane Daily Chronicle]]|date=April 18, 1970|page=7|access-date=September 17, 2019}}</ref><ref>{{cite news|newspaper=[[The New York Times]]|date=April 18, 1970|access-date=September 17, 2019|title='Towing' Fee Is Asked by Grumman|page=13|url=https://www.nytimes.com/1970/04/18/archives/towing-fee-is-asked-by-grumman.html}}</ref>

[[File:Apollo13 CommandModule Kansas.JPG|thumb|The Apollo&nbsp;13 command module ''Odyssey'' on display at the [[Cosmosphere]] in Hutchinson, Kansas]]
The CM was disassembled for testing and parts remained in storage for years; some were used for a trainer for the [[Skylab Rescue|Skylab Rescue Mission]]. That trainer was subsequently displayed at the [[Kentucky Science Center]]. Max Ary of the [[Cosmosphere]] made it a project to restore ''Odyssey''; it is on display there, in [[Hutchinson, Kansas]].<ref>{{cite news|url=https://www.newspapers.com/clip/35462879/the_manhattan_mercury/|title=Apollo 13 Capsule Headed for Kansas|agency=Associated Press|date=December 29, 1996|page=A2|via=Newspapers.com|location=Manhattan, Kansas|newspaper=The Manhattan Mercury}}</ref>

Apollo&nbsp;13 was called a "successful failure" by Lovell.{{sfn|Cortright|1975|pp=247–249}} [[Mike Massimino]], a [[Space Shuttle]] astronaut, stated that Apollo 13 "showed teamwork, camaraderie and what NASA was really made of".<ref name = "Yahoo 50th">{{cite news|publisher = [[Yahoo! News]]|url=https://news.yahoo.com/houston-ve-had-problem-remembering-050652323.html|access-date=April 11, 2020|date=April 9, 2020|title='Houston, we've had a problem': Remembering Apollo 13 at 50|last=Dunn|first=Marcia|agency=Associated Press}}</ref> The response to the accident has been repeatedly called "NASA's finest hour";<ref name="Walt Disney's Honorary Oscars">{{cite web|first=Kim|last=Shiflett|url=https://www.nasa.gov/content/members-of-apollo-13-team-reflect-on-nasas-finest-hour|title=Members of Apollo 13 Team Reflect on 'NASA's Finest Hour'|date=April 17, 2015|access-date=June 16, 2018|publisher=[[NASA]]|archive-date=September 24, 2018|archive-url=https://web.archive.org/web/20180924162717/https://www.nasa.gov/content/members-of-apollo-13-team-reflect-on-nasas-finest-hour/|url-status=dead}}</ref><ref>{{cite journal|editor-last1=Foerman |editor-first1=Paul |editor-last2=Thompson |editor-first2=Lacy|date=April 2010|title=Apollo 13 – NASA's 'successful failure'|journal=Lagniappe|volume=5|issue=4|pages=5–7|location=Hancock County, Mississippi|publisher=[[John C. Stennis Space Center]]|access-date=July 4, 2013|url=http://www.nasa.gov/centers/stennis/pdf/445767main_April_10_Lagniappe.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.nasa.gov/centers/stennis/pdf/445767main_April_10_Lagniappe.pdf |archive-date=2022-10-09 |url-status=live}}</ref><ref>{{cite web|url=http://www.cgpublishing.com/Rpdf/Apollo%20EECOM%20Boeing%20News%201(FL)1.pdf|title=NASA's Finest Hour: Sy Liebergot recalls the race to save Apollo 13|last=Seil|first=Bill|date=July 5, 2005|work=Boeing News Now|publisher=[[Boeing|Boeing Company]] |url-status=dead|archive-url=https://web.archive.org/web/20120409192033/http://www.cgpublishing.com/Rpdf/Apollo%20EECOM%20Boeing%20News%201(FL)1.pdf|archive-date=April 9, 2012}}</ref>{{sfn|Chaikin|1995|p=335}} it is still viewed that way.<ref name = "Yahoo 50th" /> Author [[Colin Burgess (author)|Colin Burgess]] wrote, "the life-or-death flight of Apollo&nbsp;13 dramatically evinced the colossal risks inherent in manned spaceflight. Then, with the crew safely back on Earth, public apathy set in once again."{{sfn|Burgess|2019|p=23}}

William R. Compton, in his book about the Apollo Program, said of Apollo&nbsp;13, "Only a heroic effort of real-time improvisation by mission operations teams saved the crew."{{sfn|Compton|1989|pp=196–199}} Rick Houston and [[Milt Heflin]], in their history of Mission Control, stated, "Apollo&nbsp;13 proved mission control could bring those space voyagers back home again when their lives were on the line."{{sfn|Houston, Heflin & Aaron|2015|p=199}} Former NASA chief historian [[Roger D. Launius]] wrote, "More than any other incident in the history of spaceflight, recovery from this accident solidified the world's belief in NASA's capabilities".{{sfn|Launius|2019|p=187}} Nevertheless, the accident convinced some officials, such as Manned Spaceflight Center director Gilruth, that if NASA kept sending astronauts on Apollo missions, some would inevitably be killed, and they called for as quick an end as possible to the program.{{sfn|Launius|2019|p=187}}  Nixon's advisers recommended canceling the remaining lunar missions, saying that a disaster in space would cost him political capital.{{sfn|Chaikin|1995|p=336}} Budget cuts made such a decision easier, and during the pause after Apollo&nbsp;13, two missions were canceled, meaning that the program ended with [[Apollo 17]] in December 1972.{{sfn|Launius|2019|p=187}}{{sfn|Burgess|2019|pp=22–27}}

== Popular culture, media and 50th anniversary ==
[[File:Universal Studios Hollywood 2012 58.jpg|thumb|alt=see caption|Command module replica used during ''[[Apollo&nbsp;13 (film)|Apollo&nbsp;13]]'' filming]]
The 1974 movie ''[[Houston, We've Got a Problem]]'', while set around the Apollo&nbsp;13 incident, is a fictional drama about the crises faced by ground personnel when the emergency disrupts their work schedules and places further stress on their lives. Lovell publicly complained about the movie, saying it was "fictitious and in poor taste".<ref name=irks>{{cite news|url=https://www.newspapers.com/clip/35088956/the_south_bend_tribune/|title=Apollo 13 Movie Irks Lovell|agency=Associated Press|newspaper=The South Bend Tribune|location=South Bend, Indiana|date=February 28, 1974|page=5|via=Newspapers.com}}</ref><ref>{{cite news|url=https://www.washingtonpost.com/news/retropolis/wp/2017/04/13/houston-we-have-a-problem-the-amazing-history-of-the-iconic-apollo-13-misquote/|title='Houston, we have a problem': The amazing history of the iconic Apollo 13 misquote|archive-url=https://web.archive.org/web/20190521183910/https://www.washingtonpost.com/news/retropolis/wp/2017/04/13/houston-we-have-a-problem-the-amazing-history-of-the-iconic-apollo-13-misquote/|archive-date=May 21, 2019|url-status=live|newspaper=The Washington Post|date=April 13, 2017|last1=Rosenwald|first1=Michael S.}}</ref>

"Houston{{nbsp}}... We've Got a Problem" was the title of an episode of the [[BBC]] documentary series ''A Life At Stake'', broadcast in March 1978. This was an accurate, if simplified, reconstruction of the events.<ref>{{cite news|url=https://www.newspapers.com/clip/35940813/the_observer/|title=The Week in View|last1=Meades|first1=Jonathan|newspaper=The Observer|location=London, England|date=March 26, 1978|page=29|via=Newspapers.com}}</ref> In 1994, during the [[Apollo 11 anniversaries|25th anniversary of Apollo 11]], PBS released a 90-minute documentary titled ''Apollo&nbsp;13: To the Edge and Back''.<ref>{{cite news|url=https://www.newspapers.com/clip/35947551/chicago_tribune/|title=Wednesday Highlights|department=TV Week|newspaper=Chicago Tribune|location=Chicago, Illinois|date=July 17, 1994|page=25|via=Newspapers.com}}</ref><ref>{{cite news|url=https://www.newspapers.com/clip/35947573/florida_today/|title=Space Specials at a Glance|newspaper=Florida Today|department=TV Week|location=Cocoa, Florida|date=July 17, 1994|page=3|via=Newspapers.com}}</ref>

Following the flight, the crew planned to write a book, but they all left NASA without starting it. After Lovell retired in 1991, he was approached by journalist [[Jeffrey Kluger]] about writing a non-fiction account of the mission. Swigert died in 1982 and Haise was no longer interested in such a project. The resultant book, ''[[Lost Moon|Lost Moon: The Perilous Voyage of Apollo&nbsp;13]]'', was published in 1994.<ref>{{cite news|url=https://www.newspapers.com/clip/39589313/the_postcrescent_11_december_1994/|title=Lovell Describes the Dark Side of Moon Shots|newspaper=The Post-Crescent|location=Appleton, Wisconsin|agency=Associated Press|last1=Dunn|first1=Marcia|date=December 11, 1994|page=F-8|via=Newspapers.com}}</ref>

The next year, in 1995, a film adaptation of the book, ''[[Apollo&nbsp;13 (film)|Apollo&nbsp;13]]'', was released, directed by [[Ron Howard]] and starring [[Tom Hanks]] as Lovell, [[Bill Paxton]] as Haise, [[Kevin Bacon]] as Swigert, [[Gary Sinise]] as Mattingly, [[Ed Harris]] as Kranz, and [[Kathleen Quinlan]] as Marilyn Lovell. James Lovell, Kranz, and other principals have stated that this film depicted the events of the mission with reasonable accuracy, given that some [[artistic license|dramatic license]] was taken. For example, the film changes the tense of Lovell's famous follow-up to Swigert's original words from, "Houston, we've had a problem" to "[[Houston, we have a problem]]".<ref name = "journal Houston" /><ref name = "nasaMembers" /> The film also invented the phrase "[[Failure is not an option]]", uttered by Harris as Kranz in the film; the phrase became so closely associated with Kranz that he used it for the title of his 2000 autobiography.<ref name="nasaMembers">{{Cite web|url=http://www.nasa.gov/content/members-of-apollo-13-team-reflect-on-nasas-finest-hour|title=Members of Apollo 13 Team Reflect on 'NASA's Finest Hour'|last=Granath|first=Bob|date=April 17, 2015|website=NASA|access-date=July 1, 2019|archive-date=July 13, 2019|archive-url=https://web.archive.org/web/20190713193613/https://www.nasa.gov/content/members-of-apollo-13-team-reflect-on-nasas-finest-hour/|url-status=dead}}</ref> The film won two of the nine Academy Awards it was nominated for, Best Film Editing and Best Sound.<ref>{{cite news|url=https://www.newspapers.com/clip/35088898/the_heraldpalladium/|title=The Winners|agency=Associated Press|newspaper=The Herald-Palladium|location=Saint Joseph, Michigan|date=March 26, 1996|page=4B|via=Newspapers.com}}</ref><ref>{{cite news|url=https://www.newspapers.com/clip/35088927/st_louis_postdispatch/|title='Braveheart', 'Apollo 13' Lead Oscar Nominees|newspaper=St. Louis Post Dispatch|location=St. Louis, Missouri|date=February 14, 1996|page=4A|via=Newspapers.com|last1=Barnes|first1=Harper}}</ref>

In the 1998 miniseries ''[[From the Earth to the Moon (miniseries)|From the Earth to the Moon]]'', co-produced by Hanks and Howard, the mission is dramatized in the episode "We Interrupt This Program". Rather than showing the incident from the crew's perspective as in the ''Apollo&nbsp;13'' feature film, it is instead presented from an Earth-bound perspective of television reporters competing for coverage of the event.<ref>{{cite news|url=https://www.newspapers.com/clip/35053645/santa_cruz_sentinel/|title=Tom Hanks Flies us to the Moon via HBO|newspaper=Santa Cruz Sentinel|location=Santa Cruz, California|date=April 5, 1998|page=C-6|agency=The New York Times|via=Newspapers.com|last1=Sterngold|first1=James}}</ref>

In 2020, the [[BBC World Service]] began airing ''13 Minutes to the Moon'', radio programs which draw on NASA audio from the mission, as well as archival and recent interviews with participants. Episodes began airing for Season 2 starting on March 8, 2020, with episode 1, "Time bomb: Apollo 13", explaining the launch and the explosion. Episode 2 details Mission Control's denial and disbelief of the accident, with other episodes covering other aspects of the mission. The seventh and final episode was delayed due to the [[COVID-19 pandemic]]. In "Delay to Episode 7", the BBC explained that the presenter of the series, medical doctor [[Kevin Fong]], had been called into service.<ref>[https://www.bbc.co.uk/programmes/w13xttx2/episodes/downloads 13 minutes to the moon, season 2, BBC podcast] accessed April 14, 2020</ref><ref>{{cite web|url=https://www.bbc.co.uk/programmes/p083wp70 |title=13 Minutes to the moon|date=March 11, 2020 |publisher=BBC|access-date=December 28, 2022}}</ref>

In advance of the 50th anniversary of the mission in 2020, an [[Apollo in Real Time]] site for the mission went online, allowing viewers to follow along as the mission unfolds, view photographs and video, and listen to audio of conversations between Houston and the astronauts as well as between mission controllers.<ref>{{cite journal|title=Relive the drama of Apollo 13 in real time, as it happened|date=April 8, 2020|access-date=April 16, 2020|last=Reichhardt|first=Tony|url=https://www.airspacemag.com/daily-planet/relive-drama-apollo-13-real-time-it-happened-180974625/|publisher=[[Smithsonian Institution]]|journal=Air and Space Magazine}}</ref> Due to the COVID-19 pandemic, NASA did not hold any in-person events during April 2020 for the flight's 50th anniversary, but premiered a new documentary, ''Apollo 13: Home Safe'' on April 10, 2020.<ref>{{cite web|title=Celebrate Apollo 13 at 50 with NASA's 'Home Safe' documentary (and much more!)|last=Howell|first=Elizabeth|url=https://www.space.com/apollo-13-50th-anniversary-webcast-digital-celebrations.html|date=April 10, 2020|access-date=April 16, 2020|publisher=space.com}}</ref> A number of events were rescheduled for later in 2020.<ref>{{cite web|title=Houston, we've had a delay: Apollo 13 50th celebrations rescheduled|last=Pearlman|first=Robert Z.|url=https://www.space.com/apollo13-50th-celebrations-rescheduled.html|date=April 9, 2020|access-date=April 16, 2020|publisher=space.com}}</ref>

==Gallery==

<gallery widths="200" heights="200">

ALSEP Ap13-70-HC-77.jpg|Lovell practices deploying the [[Apollo Lunar Surface Experiments Package|ALSEP]] during training
Apollo 13 Saturn V during rollout.jpg|The Apollo 13 launch vehicle being rolled out, December 1969
Apollo 13 Mailbox at Mission Control.jpg|The "mailbox" at [[Christopher C. Kraft Jr. Mission Control Center|Mission Control]] during the Apollo&nbsp;13 mission
Apollo 13 LM undocking (AS13-59-8566) (cropped).jpg|Lunar Module ''Aquarius'' after it was jettisoned above the Earth
Mission Control Celebrates - GPN-2000-001313.jpg|Mission Control celebrates the successful splashdown
Apollo 13 Astronauts on the U.S.S. Iwo Jima - GPN-2002-000054.jpg|The crew on board the [[USS Iwo Jima (LPH-2)|USS ''Iwo Jima'']] following splashdown
Crew on the phone.png|The crew speaking with President Nixon shortly after their return
APOLLO 13 LUNAR PLAQUE replica.jpg|Replica of the [[lunar plaque]] with Swigert's name that was to cover the one attached to ''Aquarius'' with Mattingly's name
Apollo13-booster-crater.jpg|The crater created by the S-IVB's impact, as photographed by the [[Lunar Reconnaissance Orbiter]], 2010</gallery>

== Notes ==
{{NoteFoot}}

== References ==
{{Reflist}}

== Sources ==
* {{cite magazine|title=The Elusive Human Maximum Altitude Record|last1=Adamo|first1=Daniel|magazine=Quest: The History of Spaceflight Quarterly|volume=16|issue=4|year=2009|issn=1065-7738|url=http://www.aiaahouston.org/Horizons/ApolloMaxH.pdf}}
* {{cite book|title=Apollo 13 Press Kit|publisher=NASA|location=Washington, D.C.|year=1970|url=https://history.nasa.gov/alsj/a13/A13_PressKit.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/alsj/a13/A13_PressKit.pdf |archive-date=2022-10-09 |url-status=live|id=70-50K|ref={{sfnRef|Apollo 13 Press Kit|1970}}}}
* {{cite book|title=Apollo 14 Press Kit|publisher=NASA|location=Washington, D.C.|year=1971|url=https://www.nasa.gov/specials/apollo50th/pdf/A14_PressKit.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.nasa.gov/specials/apollo50th/pdf/A14_PressKit.pdf |archive-date=2022-10-09 |url-status=live|id=71-3K|ref={{sfnRef|Apollo 14 Press Kit|1971}}}}
*{{cite report|url=https://www.hq.nasa.gov/alsj/APSR-JSC-09423-OCR.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.hq.nasa.gov/alsj/APSR-JSC-09423-OCR.pdf |archive-date=2022-10-09 |url-status=live|title=Apollo Program Summary Report|date=1975|publisher=[[National Aeronautics and Space Administration]]|id=JSC-09423|ref={{sfnRef|Apollo Program Summary Report|1975}}}}
* {{cite book|last1=Barell|first1=John|title=Antarctic Adventures: Life Lessons from Polar Explorers|year=2016|publisher=Balboa Press|isbn=978-1-5043-6651-9|url=https://books.google.com/books?id=yJiaDQAAQBAJ&pg=PT154}}
* {{cite report |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790003956.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790003956.pdf |archive-date=2022-10-09 |url-status=live |title=Moonport: A History of Apollo Launch Facilities and Operations|first1=Charles D.|last1=Benson|first2=William Barnaby|last2=Faherty|year=1978|location=Washington, D.C.|series=NASA History Series|id=SP-4204|ref={{sfnRef|Benson & Faherty|1979}}}}
* {{cite book |last1=Brooks |first1=Courtney G. |last2=Grimwood |first2=James M. |last3=Swenson |first3=Loyd S. Jr. |title=Chariots for Apollo: A History of Manned Lunar Spacecraft |url=https://history.nasa.gov/SP-4205.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/SP-4205.pdf |archive-date=2022-10-09 |url-status=live|series=NASA History Series |date=1979 |publisher=Scientific and Technical Information Branch, NASA |location=Washington, D.C. |isbn=978-0-486-46756-6 |oclc=4664449 |lccn=79001042 |id=NASA SP-4205 |ref={{sfnRef|Brooks, Grimwood, & Swenson|1979}}}}
* {{cite book|last=Burgess|first=Colin|author-link=Colin Burgess (author)|year=2019|title=Shattered Dreams: The Lost and Canceled Space Missions|publisher=University of Nebraska Press|location=Lincoln, Nebraska|isbn=978-1-4962-1422-5|edition=eBook}}
* {{cite book|last=Chaikin|first=Andrew|title=A Man on the Moon: The Voyages of the Apollo Astronauts|location=New York|publisher=Penguin Books|author-link=Andrew Chaikin|year=1995|orig-year=1994|isbn=978-0-14-024146-4}}
*{{cite book|last1=Compton|first1=William David|title=Where No Man has Gone Before: A History of Apollo Lunar Exploration Missions|series=NASA History Series|publisher=NASA|id=SP-4214|year=1989|location=Washington, D.C.|oclc=1045558568}}
* {{cite book|last=Cooper|first=Henry S. F. Jr.|author-link=Henry S. F. Cooper Jr.|title=Thirteen: The Apollo Mission that Failed|orig-year=1972|year=2013|publisher=Open Road Integrated Media, Inc.|location=New York|isbn=978-1-4804-6221-2}}
* {{cite book|last=Cortright|first=Edgar M.|author-link=Edgar M. Cortright|title=Report of Apollo 13 Review Board|publisher=[[NASA]]|date=June 15, 1970|url=https://history.nasa.gov/ap13cortright.pdf |archive-url=https://web.archive.org/web/20230415005711/https://history.nasa.gov/ap13cortright.pdf |archive-date=2023-04-15 |url-status=live|ref={{sfnRef|Accident report}}}}
** {{cite book|title=Report of Apollo 13 Review Board, appendix F–H|url=https://history.nasa.gov/afj/ap13fj/pdf/a13-review-report-app-f-g-h-19700078913.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/afj/ap13fj/pdf/a13-review-report-app-f-g-h-19700078913.pdf |archive-date=2022-10-09 |url-status=live|ref={{sfnRef|Accident report, appendix F–H}}}}
* {{cite journal|last=Driscoll|first=Everly|date=April 4, 1970|title=Apollo 13 to the highlands|jstor=3954891|journal=[[Science News]]|volume=97|issue=14|ref={{sfnRef|''Science News'' 1970-04-04}}
  | pages = 353–355
  |doi=10.2307/3954891
 }}{{subscription required}}
* {{cite book|url=https://history.nasa.gov/alsj/a13/A13_MissionOpReport.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/alsj/a13/A13_MissionOpReport.pdf |archive-date=2022-10-09 |url-status=live|author=Flight Control Division|location=Houston, Texas|title=Mission Operations Report|date=April 1970|publisher=NASA Manned Spacecraft Center|ref={{sfnRef|Mission Operations Report 1970}}}}
* {{cite book|last=Gatland|first=Kenneth|title=Manned Spacecraft|publisher=MacMillan|edition=Second|year=1976|location=New York|isbn=978-0-02-542820-1}}
* {{cite book |editor-last=Glenday |editor-first=Craig |editor-link=Craig Glenday|title=Guinness World Records 2010|year=2010|publisher=[[Bantam Books]]|location=New York|isbn=978-0-553-59337-2|url=https://archive.org/details/guinnessworldrec00vari/page/13}}
* {{cite book |last1=Hacker |first1=Barton C. |last2=Grimwood |first2=James M. |title=On the Shoulders of Titans: A History of Project Gemini |url=http://history.nasa.gov/SP-4203.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://history.nasa.gov/SP-4203.pdf |archive-date=2022-10-09 |url-status=live |access-date=April 8, 2018 |series=NASA History Series |year=2010 |orig-year=1977 |publisher=NASA History Division, Office of Policy and Plans |location=Washington, DC |isbn=978-0-16-067157-9 |id=NASA SP-4203 |oclc=945144787 |ref={{sfnRef|Hacker & Grimwood|2010}}}}
* {{cite book|last=Harland|first=David |author-link=David M. Harland|title=Exploring the Moon: The Apollo Expeditions|location=London; New York|publisher=Springer|year=1999|isbn=978-1-85233-099-6}}
* {{cite book|last1=Houston|first1=Rick|last2=Heflin|first2=J. Milt|last3=Aaron|first3=John|author-link2=Milt Heflin|author-link3=John Aaron|title=Go, Flight!: the Unsung Heroes of Mission Control, 1965–1992|year=2015|publisher=University of Nebraska Press|edition=eBook|location=Lincoln, Nebraska|isbn=978-0-8032-8494-4|ref={{sfnRef|Houston, Heflin & Aaron|2015}}}}
* {{cite book|title=Houston, We've Got a Problem|publisher=NASA Office of Public Affairs|id=EP-76|year=1970|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700021741.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700021741.pdf |archive-date=2022-10-09 |url-status=live|location=Washington, D.C.|ref={{sfnRef|NASA 1970}}}}
* {{cite book|year=2000|last=Kranz|first=Gene|title=Failure Is Not an Option: Mission Control from Mercury to Apollo 13 and Beyond|location=New York|url=https://books.google.com/books?id=slQZ3JOUSKQC&pg=PA307|url-access=registration|publisher=Simon & Schuster|isbn=978-0-7432-0079-0}}
* {{cite conference|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080018689.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080018689.pdf |archive-date=2022-10-09 |url-status=live|title=NASA Experience with Pogo in Human Spaceflight Vehicles|conference=NATO RTO Symposium ATV-152 on Limit-Cycle Oscillations and Other Amplitude-Limited, Self-Excited Vibrations|location=Norway|last1=Larsen|first1=Curtis E.|website=NASA Johnson Space Center|date=May 22, 2008|id=RTO-MP-AVT-152}}
* {{cite book|last=Lattimer|first=Dick|others=Foreword by [[James A. Michener]]|title=All We Did Was Fly to the Moon|edition=2nd|series=History-alive series|volume=1|year=1988|orig-year=1983|publisher=Whispering Eagle Press|location=Gainesville, Florida|isbn=978-0-9611228-0-5|lccn=85222271|url-access=registration|url=https://archive.org/details/isbn_9780961122805}}
* {{cite book|last=Launius|first=Roger D.|author-link=Roger D. Launius|title=Reaching for the Moon: A Short History of the Space Race|publisher=Yale University Press|location=New Haven, Connecticut|edition=eBook|year=2019|isbn=978-0-300-24516-5}}
* {{cite book|last=Lovell|first=James A. |editor-last=Cortright |editor-first=Edgar M.|title=Apollo Expeditions to the Moon|url=https://history.nasa.gov/SP-350/cover.html|year=1975|publisher=NASA|location=Washington, D.C.|id=SP-350|chapter=Chapter 13: "Houston, We've Had a Problem"|chapter-url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760005868.pdf#page=261 |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760005868.pdf#page=261 |archive-date=2022-10-09 |url-status=live|ref={{sfnRef|Cortright|1975}}}}
* {{cite book|year=2000|orig-year=1994|last1=Lovell|first1=Jim|last2=Kluger|first2=Jeffrey|title=Lost Moon: The Perilous Voyage of Apollo 13|location=Boston|publisher=Houghton Mifflin|isbn=978-0-618-05665-1|ref={{sfnRef|Lovell & Kluger|2000}}}}
* {{cite book|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710003598.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710003598.pdf |archive-date=2022-10-09 |url-status=live|author=Mission Evaluation Team|id=MSC-02680|location=Houston, Texas|date=September 1970|publisher=NASA Manned Spacecraft Center|title=Apollo 13 Mission Report|ref={{sfnRef|Apollo 13 Mission Report 1970}}}}
*{{cite book|last1=Morgan|first1=Clay|year=2001|publisher=[[NASA]]|location=Houston, Texas|title=Shuttle–Mir|url=https://history.nasa.gov/SP-4225.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/SP-4225.pdf |archive-date=2022-10-09 |url-status=live|id=SP-4225}}
* {{cite book|last1=Orloff|first1=Richard W.|last2=Harland|first2=David M.|author-link2=David M. Harland|title=Apollo: The Definitive Sourcebook|year=2006|publisher=Praxis Publishing Company|location=Chichester, UK|isbn=978-0-387-30043-6|ref={{sfnRef|Orloff & Harland|2006}}}}
* {{cite book|last=Orloff|first=Richard W.|title=Apollo by the Numbers: A Statistical Reference|series=NASA History Series|year=2000|publisher=NASA History Division, Office of Policy and Plans|location=Washington, D.C.|isbn=978-0-16-050631-4|oclc=829406439|lccn=00061677|id=NASA SP-2000-4029|url=https://history.nasa.gov/SP-4029.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/SP-4029.pdf |archive-date=2022-10-09 |url-status=live}}
* {{cite book|last=Phinney|first=William C.|title=Science Training History of the Apollo Astronauts|publisher=[[NASA]]|year=2015|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190026783.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190026783.pdf |archive-date=2022-10-09 |url-status=live|id=SP-2015-626}}
* {{cite book|title=Deke! U.S. Manned Space: From Mercury to the Shuttle|last1=Slayton|first1=Donald K. "Deke"|author-link1=Deke Slayton|last2=Cassutt|first2=Michael|author-link2=Michael Cassutt|url=https://books.google.com/books?id=z8vl46GV2JYC&pg=PA236|year=1994|edition=1st|publisher=[[Tor Books|Forge]]|location=New York|isbn=978-0-312-85503-1|ref={{sfnRef|Slayton & Cassutt|1994}}}}
* {{cite book|last=Turnill|first=Reginald|year=2003|title=The Moonlandings: An Eyewitness Account|url=https://books.google.com/books?id=ou5ofrRh4-kC&pg=PA316|publisher=[[Cambridge University Press]]|location=New York|isbn=978-0-521-03535-4|author-link=Reginald Turnill}}

==External links==
{{Commons category}}
{{Wikiquote}}
'''NASA reports'''
* [https://history.nasa.gov/alsj/a13/a13trans.html All NASA mission transcripts]
* [https://history.nasa.gov/alsj/a13/AS13_TEC.PDF "Apollo 13 Technical Air-to-Ground Voice Transcription"] (PDF) NASA, April 1970
* [https://radiotapes.com/special-postings/#Apollo Coverage of the flight of Apollo 13 as heard on CBS Radio and WCCO-AM (Minneapolis/St. Paul, MN]

'''Multimedia'''
*{{Internet Archive short film | apollo13_houston_weve_got_a_problem | Apollo 13: "Houston, We've Got A Problem"}}

{{Apollo program| before=[[Apollo 12]]| after=[[Apollo 14]]}}
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{{Moon spacecraft}}
{{Orbital launches in 1970}}
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[[Category:Apollo 13| ]]
[[Category:Fred Haise]]
[[Category:Jim Lovell]]
[[Category:Jack Swigert]]
[[Category:Apollo program missions]]
[[Category:Spacecraft launched by Saturn rockets]]
[[Category:Articles containing video clips]]
[[Category:Crewed missions to the Moon]]