Editing Apollo program (section)

==Launch vehicles==
[[File:Saturnsandlittlejoe2.gif|thumb|right|upright=1.35|Four Apollo rocket assemblies, drawn to scale: [[Little Joe II]], [[Saturn I]], [[Saturn IB]], and [[Saturn V]]]]

Before the Apollo program began, Wernher von Braun and his team of rocket engineers had started work on plans for very large launch vehicles, the [[Saturn (rocket family)|Saturn series]], and the even larger [[Nova (rocket)|Nova]] series. In the midst of these plans, von Braun was transferred from the Army to NASA and was made Director of the Marshall Space Flight Center. The initial direct ascent plan to send the three-person Apollo command and service module directly to the lunar surface, on top of a large descent rocket stage, would require a Nova-class launcher, with a lunar payload capability of over {{convert|180000|lb|kg|abbr=out}}.<ref>{{Cite web|title=Aerospace Alphabet: ABMA, ARPA, MSFC|url=https://history.nasa.gov/SP-4206/ch2.htm|access-date=2023-02-12|website=history.nasa.gov}}</ref> The June 11, 1962, decision to use lunar orbit rendezvous enabled the Saturn V to replace the Nova, and the MSFC proceeded to develop the [[Saturn (rocket family)|Saturn rocket family]] for Apollo.<ref>{{Cite web|title=Missions, Modes, and Manufacturing|url=https://history.nasa.gov/SP-4206/ch3.htm|access-date=2023-02-12|website=history.nasa.gov}}</ref>

Since Apollo, like Mercury, used more than one launch vehicle for space missions, NASA used spacecraft-launch vehicle combination series numbers: AS-10x for Saturn I, AS-20x for Saturn IB, and AS-50x for Saturn V (compare [[Mercury-Redstone 3]], [[Mercury-Atlas 6]]) to designate and plan all missions, rather than numbering them sequentially as in Project Gemini. This was changed by the time human flights began.<ref name="missionNumbers" />

===Little Joe II===
{{main|Little Joe II}}

Since Apollo, like Mercury, would require a [[launch escape system]] (LES) in case of a launch failure, a relatively small rocket was required for qualification flight testing of this system. A rocket bigger than the [[Little Joe (rocket)|Little Joe]] used by Mercury would be required, so the [[Little Joe II]] was built by [[General Dynamics]]/[[Convair]]. After an August 1963 [[Little Joe II Qualification Test Vehicle|qualification test flight]],<ref>[[#Townsend|Townsend 1973]], p. 14</ref> four LES test flights ([[A-001]] through [[A-004|004]]) were made at the [[White Sands Missile Range]] between May 1964 and January 1966.<ref>[[#Townsend|Townsend 1973]], p. 22</ref>

===Saturn I===
{{main|Saturn I}}
[[File:Apollo 7 launch2.jpg|thumb|right|upright=0.7|A Saturn IB rocket launches [[Apollo 7]], 1968]]

Saturn I, the first US heavy lift launch vehicle, was initially planned to launch partially equipped CSMs in low Earth orbit tests. The [[S-I]] first stage burned [[RP-1]] with liquid oxygen (LOX) oxidizer in eight clustered [[Rocketdyne H-1]] engines, to produce {{convert|1500000|lbf|kN|sigfig=3}} of thrust. The [[S-IV]] second stage used six liquid hydrogen-fueled [[Pratt & Whitney Rocketdyne|Pratt & Whitney]] [[RL-10]] engines with {{convert|90000|lbf|kN|sigfig=3}} of thrust. The [[S-V]] third stage flew inactively on Saturn I four times.<ref>[[#Dawson & Bowles|Dawson & Bowles 2004]], p. 85. See footnote 61.</ref>

The first four Saturn I test flights were launched from LC-34, with only the first stage live, carrying dummy upper stages filled with water. The first flight with a live S-IV was launched from LC-37. This was followed by five launches of [[Boilerplate (spaceflight)|boilerplate]] CSMs (designated [[AS-101]] through [[AS-105]]) into orbit in 1964 and 1965. The last three of these further supported the Apollo program by also carrying [[Pegasus (satellite)|Pegasus]] satellites, which verified the safety of the translunar environment by measuring the frequency and severity of [[micrometeorite]] impacts.{{sfn|Brooks|Grimwood|Swenson|1979|loc=Ch. 7.6: [http://www.hq.nasa.gov/office/pao/History/SP-4205/ch7-6.html "Portents for Operations"]}}

In September 1962, NASA planned to launch four crewed CSM flights on the Saturn I from late 1965 through 1966, concurrent with Project Gemini. The {{convert|22500|lb|kg|adj=on}} payload capacity<ref>{{cite book|url=http://www.alternatewars.com/SpaceRace/Saturn/ASD_II_Saturn_Launch_Vehicles-2-1964.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.alternatewars.com/SpaceRace/Saturn/ASD_II_Saturn_Launch_Vehicles-2-1964.pdf |archive-date=2022-10-09 |url-status=live|title=Apollo Systems Description|date=February 1, 1964|publisher=NASA|volume=II: Saturn Launch Vehicles|page=3|type=Technical Memorandum|id=NASA TM-X-881|access-date=August 1, 2013}}<!----Original URL for document on NTRS server: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710065502_1971065502.pdf----></ref> would have severely limited the systems which could be included, so the decision was made in October 1963 to use the uprated [[Saturn IB]] for all crewed Earth orbital flights.<ref>{{cite encyclopedia |url=http://www.astronautix.com/flights/apoosa11.htm |last=Wade |first=Mark |title=Apollo SA-11 |encyclopedia=Encyclopedia Astronautica |access-date=June 21, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120617193358/http://www.astronautix.com/flights/apoosa11.htm |archive-date=June 17, 2012 |df=mdy-all}}</ref>

===Saturn IB===
{{main|Saturn IB}}

The Saturn IB was an upgraded version of the Saturn I. The [[S-IB]] first stage increased the thrust to {{convert|1600000|lbf|kN|sigfig=3}} by uprating the H-1 engine. The second stage replaced the S-IV with the [[S-IVB|S-IVB-200]], powered by a single [[Rocketdyne J-2|J-2]] engine burning liquid hydrogen fuel with LOX, to produce {{convert|200000|lbf|kN|sigfig=3|lk=on}} of thrust.<ref>{{cite web|url=https://history.nasa.gov/SP-4205.pdf|title=Influences on Booster Determination|pages=44–46|website=NASA HQ|access-date=November 11, 2022}}</ref> A restartable version of the S-IVB was used as the third stage of the Saturn V. The Saturn IB could send over {{convert|40000|lb|kg|sigfig=3}} into low Earth orbit, sufficient for a partially fueled CSM or the LM.<ref>{{cite book |title=Saturn IB News Reference |url=https://www.scribd.com/doc/58939029/Saturn-IB-News-Reference |format=PDF |access-date=August 1, 2013 |date=December 1965 |publisher=NASA; [[Chrysler|Chrysler Corporation]]; [[Douglas Aircraft Company|McDonnell Douglas Astronautics Company]]; [[IBM|International Business Machines Corporation]]; [[Rocketdyne]] |oclc=22102803 |chapter=Saturn IB Design Features}}</ref> Saturn IB launch vehicles and flights were designated with an AS-200 series number, "AS" indicating "Apollo Saturn" and the "2" indicating the second member of the Saturn rocket family.<ref name="Origin of NASA's Names" />

===Saturn V===
{{main|Saturn V}}
[[File:Apollo 11 Launch - GPN-2000-000630.jpg|thumb|upright=0.7|A [[Saturn V]] rocket launches Apollo 11, 1969]]

Saturn V launch vehicles and flights were designated with an AS-500 series number, "AS" indicating "Apollo Saturn" and the "5" indicating Saturn V.<ref name="Origin of NASA's Names">{{cite web|url=https://history.nasa.gov/SP-4402/ch4.htm|title=Origin of NASA's Names: Manned Spaceflight |access-date=July 19, 2016}}</ref> The three-stage Saturn V was designed to send a fully fueled CSM and LM to the Moon. It was {{convert|33|ft|m|sigfig=3}} in diameter and stood {{convert|363|ft|m|sigfig=4}} tall with its {{convert|96800|lb|kg|sigfig=3|adj=on}} lunar payload. Its capability grew to {{convert|103600|lb|kg|sigfig=3}} for the later advanced lunar landings. The [[S-IC]] first stage burned RP-1/LOX for a rated thrust of {{convert|7500000|lbf|kN|sigfig=3}}, which was upgraded to {{convert|7610000|lbf|kN|sigfig=3}}. The second and third stages burned liquid hydrogen; the third stage was a modified version of the S-IVB, with thrust increased to {{convert|230000|lbf|kN|sigfig=3}} and capability to restart the engine for translunar injection after reaching a [[parking orbit]].<ref name="ABTN_LV1">{{Cite web|title=Launch Vehicle|url=https://history.nasa.gov/SP-4029/Apollo_18-11_Launch_Vehicle-Spacecraft_Key_Facts.htm|access-date=2023-02-12|website=history.nasa.gov}}</ref>