Editing Apollo program (section)

===Production lunar landings===
In November 1969, [[Pete Conrad|Charles "Pete" Conrad]] became the third person to step onto the Moon, which he did while speaking more informally than had Armstrong:
{{blockquote|Whoopee! Man, that may have been a small one for [[Neil Armstrong|Neil]], but that's a long one for me. |source=Pete Conrad<ref name=journal>{{cite web |url=https://www.hq.nasa.gov/alsj/a12/a12.eva1prelim.html |publisher=NASA |work=Apollo 12 Lunar Surface Journal |title=That may have been a small one for Neil... |last1=Jones |first1=Eric |access-date=February 5, 2018}}</ref>}}

<imagemap>
File:Apollo lunar landing missions insignia.png|thumb|right|upright=1.15|Apollo production crewed lunar landing mission patches. Click on a patch to read the main article about that mission.|alt=Composite image of six production crewed Apollo lunar landing mission patches, from Apollo 12 to Apollo 17.
rect    0   0  602 600 [[Apollo 12|Apollo 12 second crewed Moon landing]]
rect  603   0 1205 600 [[Apollo 13|Apollo 13 unsuccessful Moon landing attempt]]
rect 1206   0 1885 600 [[Apollo 14|Apollo 14 third crewed Moon landing]]
rect    0 601  602 1200 [[Apollo 15|Apollo 15 fourth crewed Moon landing]]
rect  603 601 1205 1200 [[Apollo 16|Apollo 16 fifth crewed Moon landing]]
rect 1206 601 1885 1200 [[Apollo 17|Apollo 17 sixth crewed Moon landing]]
</imagemap>

Conrad and rookie [[Alan Bean|Alan L. Bean]] made a precision landing of Apollo 12 within walking distance of the [[Surveyor 3]] uncrewed lunar probe, which had landed in April 1967 on the [[Ocean of Storms]]. The command module pilot was Gemini veteran [[Richard F. Gordon Jr.]] Conrad and Bean carried the first lunar surface color television camera, but it was damaged when accidentally pointed into the Sun. They made two EVAs totaling 7{{nbsp}}hours and 45 minutes.<ref name=statrefeva>{{cite web |url=https://history.nasa.gov/SP-4029/Apollo_18-30_Extravehicular_Activity.htm |title=Extravehicular Activity |access-date=June 11, 2016}}</ref> On one, they walked to the Surveyor, photographed it, and removed some parts which they returned to Earth.<ref>{{cite book |last1=Conrad |first1=Charles Jr. |author-link1=Pete Conrad |last2=Shepard |first2=Alan B Jr. |author-link2=Alan Shepard |editor-last=Cortright |editor-first=Edgar M |editor-link=Edgar Cortright |title=Apollo Expeditions to the Moon |url=http://www.hq.nasa.gov/pao/History/SP-350/cover.html |access-date=August 1, 2013 |date=1975 |publisher=Scientific and Technical Information Office, NASA |location=Washington, D.C. |oclc=1623434 |lccn=75600071 |id=NASA SP-350 |chapter=Tan Dust On Surveyor |chapter-url=https://history.nasa.gov/SP-350/ch-12-3.html |archive-date=February 19, 2008 |archive-url=https://web.archive.org/web/20080219204538/https://history.nasa.gov/SP-350/ch-9-5.html |url-status=dead }}</ref>

The contracted batch of 15 Saturn Vs was enough for lunar landing missions through Apollo 20. Shortly after Apollo 11, NASA publicized a preliminary list of eight more planned landing sites after Apollo 12, with plans to increase the mass of the CSM and LM for the last five missions, along with the payload capacity of the Saturn V. These final missions would combine the I and J types in the 1967 list, allowing the CMP to operate a package of lunar orbital sensors and cameras while his companions were on the surface, and allowing them to stay on the Moon for over three days. These missions would also carry the [[Lunar Roving Vehicle]] (LRV) increasing the exploration area and allowing televised liftoff of the LM. Also, the Block II spacesuit was [[Apollo/Skylab A7L#A7LB Spacesuit (Apollo, Skylab and ASTP)|revised for the extended missions]] to allow greater flexibility and visibility for driving the LRV.<ref>{{Cite web|title=Where No Man Has Gone Before, Ch12-4|url=https://www.hq.nasa.gov/office/pao/History/SP-4214/ch12-4.html|access-date=2023-02-12|website=www.hq.nasa.gov|archive-date=February 12, 2023|archive-url=https://web.archive.org/web/20230212183759/https://www.hq.nasa.gov/office/pao/History/SP-4214/ch12-4.html|url-status=dead}}</ref>

[[File:Apollo landing sites.jpg|thumb|left|Apollo landings on the Moon, 1969–1972]]
The success of the first two landings allowed the remaining missions to be crewed with a single veteran as commander, with two rookies. Apollo 13 launched Lovell, [[Jack Swigert]], and [[Fred Haise]] in April 1970, headed for the [[Fra Mauro formation]]. But two days out, a liquid oxygen tank exploded, disabling the service module and forcing the crew to use the LM as a "lifeboat" to return to Earth. Another NASA review board was convened to determine the cause, which turned out to be a combination of damage of the tank in the factory, and a subcontractor not making a tank component according to updated design specifications.<ref name="KSC-Apollo_13" /> Apollo was grounded again, for the remainder of 1970 while the oxygen tank was redesigned and an extra one was added.<ref>{{Cite web|title=Where No Man Has Gone Before, Ch11-7|url=https://www.hq.nasa.gov/office/pao/History/SP-4214/ch11-7.html|access-date=2023-02-12|website=www.hq.nasa.gov|archive-date=February 12, 2023|archive-url=https://web.archive.org/web/20230212183759/https://www.hq.nasa.gov/office/pao/History/SP-4214/ch11-7.html|url-status=dead}}</ref>

====Mission cutbacks====
About the time of the first landing in 1969, it was decided to use an existing Saturn V to launch the Skylab orbital laboratory pre-built on the ground, replacing the original plan to construct it in orbit from several Saturn IB launches; this eliminated Apollo 20. NASA's yearly budget also began to shrink in light of the successful landing, and NASA also had to make funds available for the [[Space Shuttle design process|development]] of the upcoming [[Space Shuttle]]. By 1971, the decision was made to also cancel missions 18 and 19.<ref>{{Cite web|title=Where No Man Has Gone Before, Ch12-2|url=https://www.hq.nasa.gov/office/pao/History/SP-4214/ch12-2.html|access-date=2023-02-12|website=www.hq.nasa.gov|archive-date=February 12, 2023|archive-url=https://web.archive.org/web/20230212183758/https://www.hq.nasa.gov/office/pao/History/SP-4214/ch12-2.html|url-status=dead}}</ref> The two unused Saturn Vs became museum exhibits at the [[John F. Kennedy Space Center]] on Merritt Island, Florida, [[Marshall Space Flight Center|George C. Marshall Space Center]] in [[Huntsville, Alabama|Huntsville]], Alabama, [[Michoud Assembly Facility]] in [[New Orleans]], Louisiana, and [[Lyndon B. Johnson Space Center]] in Houston, Texas.<ref>{{cite web |url=http://history.msfc.nasa.gov/saturn_apollo/display.html |archive-url=https://web.archive.org/web/20051115064337/http://history.msfc.nasa.gov/saturn_apollo/display.html |url-status=dead |archive-date=November 15, 2005 |title=Three Saturn Vs on Display Teach Lessons in Space History |publisher=Marshall Space Flight Center History Office |first=Mike |last=Wright |access-date=July 19, 2016}}</ref>

The cutbacks forced mission planners to reassess the original planned landing sites in order to achieve the most effective geological sample and data collection from the remaining four missions. [[Apollo 15]] had been planned to be the last of the H series missions, but since there would be only two subsequent missions left, it was changed to the first of three J missions.<ref>{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_18_20.html |last1=Williams |first1=David |website=NASA Space Science Data Coordinated Archive |title=Apollo 18 through 20 – The Cancelled Missions |access-date=June 11, 2016 |date=December 11, 2003}}</ref>

Apollo 13's Fra Mauro mission was reassigned to [[Apollo 14]], commanded in February 1971 by Mercury veteran [[Alan Shepard]], with [[Stuart Roosa]] and [[Edgar Mitchell]].<ref name=apollo14>{{cite web |url=https://www.nasa.gov/mission_pages/apollo/missions/apollo14.html#.V1xEp5ErJeU |title=Apollo 14 |website=NASA |access-date=June 11, 2016 |date=July 8, 2009}}</ref> This time the mission was successful. Shepard and Mitchell spent 33 hours and 31 minutes on the surface,<ref>{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-008A |title=Apollo 14 Command and Service Module (CSM) |website=NASA Space Science Data Coordinated Archive |access-date=June 11, 2016}}</ref> and completed two EVAs totalling 9{{nbsp}}hours 24 minutes, which was a record for the longest EVA by a lunar crew at the time.<ref name=apollo14/>

In August 1971, just after conclusion of the Apollo 15 mission, President [[Richard Nixon]] proposed canceling the two remaining lunar landing missions, Apollo 16 and 17. [[Office of Management and Budget]] Deputy Director [[Caspar Weinberger]] was opposed to this, and persuaded Nixon to keep the remaining missions.<ref>"MEMORANDUM FOR THE PRESIDENT" by Caspar Weinberger (via George Shultz), Aug 12, 1971, Page32(of 39) [http://ocw.mit.edu/courses/aeronautics-and-astronautics/16-885j-aircraft-systems-engineering-fall-2005/video-lectures/logsdn_lec_notes.pdf]</ref>

====Extended missions====
[[File:Apollo 15 Lunar Rover and Irwin.jpg|thumb|[[Lunar Roving Vehicle]] used on Apollos 15–17]]

Apollo 15 was launched on July 26, 1971, with [[David Scott]], [[Alfred Worden]] and [[James Irwin]]. Scott and Irwin landed on July 30 near [[Mons Hadley|Hadley Rille]], and spent just under two days, 19 hours on the surface. In over 18 hours of EVA, they collected about {{convert|77|kg|lb}} of lunar material.<ref>{{cite web |url=https://www.nasa.gov/mission_pages/apollo/missions/apollo15.html |title=Apollo 15 |date=July 8, 2009 |website=NASA |access-date=June 9, 2016}}</ref>

Apollo 16 landed in the [[Descartes Highlands]] on April 20, 1972. The crew was commanded by John Young, with [[Ken Mattingly]] and [[Charles Duke]]. Young and Duke spent just under three days on the surface, with a total of over 20 hours EVA.<ref>{{cite web |url=https://www.nasa.gov/mission_pages/apollo/missions/apollo16.html |title=Apollo 16 |website=NASA |date=July 8, 2009 |access-date=June 9, 2016}}</ref>

Apollo 17 was the last of the Apollo program, landing in the [[Taurus–Littrow]] region in December 1972. Eugene Cernan commanded [[Ronald Evans (astronaut)|Ronald E. Evans]] and NASA's first scientist-astronaut, geologist [[Harrison Schmitt|Harrison H. Schmitt]].<ref name=apollo17>{{cite web |url=http://www.nasa.gov/mission_pages/apollo/missions/apollo17.html |title=Apollo 17 |website=NASA |date=July 30, 2015 |access-date=June 9, 2016}}</ref> Schmitt was originally scheduled for Apollo 18,<ref>{{cite web |url=http://www.nasa.gov/centers/kennedy/about/history/Apollo_18.html |title=Apollo 18' Myths Debunked, NASA-style |website=NASA |date=September 28, 2011 |access-date=June 10, 2016 |last1=Grinter |first1=Kay}}</ref> but the lunar geological community lobbied for his inclusion on the final lunar landing.<ref>{{cite web |url=http://www.space.com/20789-harrison-schmitt-astronaut-biography.html |title=Harrison Schmitt: Geologist on the Moon |date=April 23, 2013 |access-date=June 10, 2016 |last1=Howell |first1=Elizabeth |website=Space.com}}</ref> Cernan and Schmitt stayed on the surface for just over three days and spent just over 23 hours of total EVA.<ref name="apollo17" />

==== Canceled missions ====
{{Main|Canceled Apollo missions}}

Several missions were planned for but were canceled before details were finalized.