The Apollo program, also known as Project Apollo, was the third United States human spaceflight program carried out by the National Aeronautics and Space Administration (NASA), which accomplished landing the first humans on the Moon from 1969 to 1972. During the Apollo 11 mission, astronauts Neil Armstrong and Buzz Aldrin landed their Lunar Module (LM) and walked on the lunar surface, while Michael Collins remained in lunar orbit in the Command/Service Module (CSM), and all three landed safely on Earth on July 24. Five subsequent Apollo missions also landed astronauts on the Moon, the last in December 1972. In these six spaceflights, twelve men walked on the Moon.
Apollo ran from 1961 to 1972, with the first manned flight in 1968. It achieved its goal of manned lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a prelaunch test. After the first landing, sufficient flight hardware remained for nine follow-on landings with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but the Apollo 13 landing was prevented by an oxygen tank explosion in transit to the Moon, which damaged the CSM's propulsion and life support. The crew returned to Earth safely by using the Lunar Module as a "lifeboat" for these functions. Apollo used Saturn family rockets as launch vehicles, which were also used for an Apollo Applications Program, which consisted of Skylab, a space station that supported three manned missions in 1973-74, and the Apollo-Soyuz Test Project, a joint Earth orbit mission with the Soviet Union in 1975.
Apollo set several major human spaceflight milestones. It stands alone in sending manned missions beyond low Earth orbit. Apollo 8 was the first manned spacecraft to orbit another celestial body, while the final Apollo 17 mission marked the sixth Moon landing and the ninth manned mission beyond low Earth orbit. The program returned 842 pounds (382 kg) of lunar rocks and soil to Earth, greatly contributing to the understanding of the Moon's composition and geological history. The program laid the foundation for NASA's subsequent human spaceflight capability, and funded construction of its Johnson Space Center and Kennedy Space Center. Apollo also spurred advances in many areas of technology incidental to rocketry and manned spaceflight, including avionics, telecommunications, and computers.
The Apollo program used four types of launch vehicles. The Little Joe II, which was used for unmanned suborbital launch escape system development. The Saturn I, which was used for unmanned suborbital and orbital hardware development. The Saturn IB which was used for preparatory unmanned missions, and Apollo 7, the first manned (Earth orbit) mission. Last, the Saturn V which was used for unmanned and manned earth orbit and lunar missions. The Marshall Space Flight Center, which designed the Saturn rockets, referred to the flights as Saturn-Apollo (SA), while Kennedy Space Center referred to the flights as Apollo-Saturn (AS). This is why the unmanned Saturn 1 flights are referred to as SA and the unmanned Saturn 1B are referred to as AS.
Some incongruity in the numbering and naming of the first three unmanned Apollo-Saturn (AS), or Apollo flights, is due to the posthumous honorary renaming of the flight which would have been AS-204, to Apollo 1. This manned flight was to have followed the first three unmanned flights. After the fire which killed the AS-204 crew on the pad during a test and training exercise, unmanned Apollo flights resumed to test the Saturn V launch vehicle and the Lunar Module; these were designated Apollo 4, 5 and 6. The first manned Apollo mission was thus Apollo 7. Simple "Apollo" numbers were never assigned to the first three unmanned flights, although renaming AS-201, AS-202 and AS-203 as Apollo 1-A, Apollo 2 and Apollo 3, had been briefly considered.
|Mission||LV Serial No||Launch Date||Launch Time||Remarks||Sources|
|27 October 1961||15:06 GMT||Test of Saturn I first stage S-I; dummy upper stages carried water|||
|25 April 1962||14:00 GMT||Dummy upper stages released 22,900 U.S. gallons (86,685 l) of water into upper atmosphere, to investigate effects on radio transmission and changes in local weather conditions|||
|16 November 1962||17:45 GMT||Repeat of SA-2 mission|||
|28 March 1963||20:11 GMT||Test premature shutdown of a single S-I engine|||
|29 January 1964||16:25 GMT||First flight of live second stage; first orbital flight|||
|28 May 1964||17:07 GMT||Tested first boilerplate Apollo Command/Service Module (CSM) for structural integrity|||
|18 September 1964||17:22 GMT||Carried first programmable-in-flight computer on the Saturn I vehicle; last launch vehicle development flight.|||
|16 February 1965||14:37 GMT||Carried first Pegasus micrometeorite satellite (Pegasus A) in addition to boilerplate CSM|||
|25 May 1965||07:35 GMT||Carried Pegasus B and boilerplate CSM|||
|30 July 1965||13:00 GMT||Carried Pegasus C and boilerplate CSM|||
|AS-201||Saturn IB AS-201||26 February 1966||16:12 GMT||First test of Saturn IB. First flight of Block I Apollo Command/Service Module (CSM). After a suborbital flight the command module (CM) landed in the Atlantic Ocean demonstrating the heat shield; however a propellant pressure loss caused premature service module (SM) engine shutdown.|||
|AS-203||Saturn IB AS-203||5 July 1966||14:53 GMT||No Apollo spacecraft carried; successfully verified restartable S-IVB stage design for Saturn V. Additional testing designed to rupture the tank inadvertently destroyed the stage.|||
|AS-202||Saturn IB AS-202||25 August 1966||17:15 GMT||Longer duration suborbital to Pacific Ocean splashdown; CM heat shield tested to higher speed; successful SM firings.|||
|Apollo 4||Saturn V AS-501||9 November 1967||12:00 GMT||First flight of Saturn V rocket; successfully demonstrated S-IVB third stage restart and tested CM heat shield at lunar re-entry speeds.|||
|Apollo 5||Saturn IB AS-204||22 January 1968||22:48 GMT||First flight of Lunar Module; successfully fired descent engine and ascent engine; demonstrated "fire-in-the-hole" landing abort test.|||
|Apollo 6||Saturn V AS-502||4 April 1968||16:12 GMT||Second flight of Saturn V; severe "pogo" vibrations caused two second-stage engines to shut down prematurely, and third stage restart to fail. SM engine used to achieve high-speed re-entry, though less than Apollo 4. NASA identified vibration fixes and declared Saturn V man-rated.|||
From August 1963 to January 1966 a number of tests were conducted for development of the launch escape system (LES). These included simulated pad aborts, which might occur while the Apollo-Saturn space vehicle was still on the launch pad, and flights on the Little Joe II rocket to simulate Mode I aborts which might occur while the vehicle was in the air.
|Mission||Launch Date||Launch Time||Remarks||Sources|
|Pad Abort Test 1||7 November 1963||16:00 GMT||LES abort test from launch pad.|||
|Pad Abort Test 2||29 June 1965||13:00 GMT||LES pad abort test of near Block-I CM.|||
|Mission||Launch Date||Launch Time||Remarks||Sources|
|QTV||28 August 1963||13:05 GMT||Little Joe II qualification test.|||
|A-001||13 May 1964||13:00 GMT||Launch escape system (LES) transonic test, success except for parachute failure.|||
|A-002||8 December 1964||15:00 GMT||LES maximum altitude, Max-Q abort test.|||
|A-003||19 May 1965||13:01 GMT||LES canard maximum altitude abort test.|||
|A-004||20 January 1966||15:17 GMT||LES test of maximum weight, tumbling Block-I CM.|||
The Block I Command/Service Module spacecraft did not have capability to fly with the Lunar Module, and the three crew positions were designated Command Pilot, Senior Pilot, and Pilot, based on U.S. Air Force pilot ratings. The Block II spacecraft was designed to fly with the Lunar Module, so the corresponding crew positions were designated Commander, Command Module Pilot, and Lunar Module Pilot regardless of whether a Lunar Module was present or not on any mission.
A total of fifteen Saturn V vehicles were ordered (through AS-515), which would have been enough for three more Moon landing missions through Apollo 20. This flight was cancelled around the time of the Apollo 11 first landing mission, to make the launch vehicle available for the Skylab space station. Shortly thereafter, Apollo 18 and 19 were cancelled in response to Congressional cuts in NASA's budget.
Several of the missions involved extravehicular activity (EVA), "space walks" or "Moon walks" outside of the spacecraft. These were of three types: testing the lunar EVA suit in Earth orbit (Apollo 9), exploring the lunar surface, and retrieving film canisters from the Scientific Instrument Module stored in the Service Module.
|Mission||Launch date||Crew||Launch Vehicle[a]||CM Name||LM Name||Duration||Notes||Sources|
||21 February 1967 (planned)||Gus Grissom
Edward H. White II
Roger B. Chaffee
|N/A||N/A||N/A||Never launched; 27 January 1967 fire in command module during a launch pad test killed crew and destroyed the module|||
||11 October 1968
Donn F. Eisele
|Test flight of Block II CSM in Earth orbit; included first live TV broadcast from American spacecraft.|||
|Apollo 8||21 December 1968
|Circumlunar flight of CSM; first manned flight of Saturn V. Ten lunar orbits in 20 hours.|||
|Apollo 9||3 March 1969
|First manned flight test of Lunar Module: propulsion, rendezvous and docking. EVA tested the Portable Life Support System (PLSS).|||
|Apollo 10||18 May 1969
|Thomas P. Stafford
|Charlie Brown||Snoopy||08d 00h
|"Dress rehearsal" for lunar landing: LM descended to 8.4 nautical miles (15.6 km) from lunar surface.|||
||16 July 1969
Edwin "Buzz" Aldrin
|First manned landing in Sea of Tranquility; single surface EVA|||
||14 November 1969
|Charles (Pete) Conrad
Richard F. Gordon, Jr.
|Yankee Clipper||Intrepid||10d 04h
|First precise Moon landing in Ocean of Storms near Surveyor 3 probe. Two surface EVAs; returned parts of Surveyor to Earth|||
||11 April 1970
|Intended Fra Mauro landing cancelled after SM oxygen tank exploded. LM used as "lifeboat" for safe crew return. First S-IVB stage impact on Moon for active seismic test.|||
||31 January 1971
|Kitty Hawk||Antares||09d 00h
|Successful Fra Mauro landing. First color TV images from lunar surface; first materials science experiments in space; two surface EVAs.|||
||26 July 1971
|Landing at Hadley-Apennine; first Extended LM, 3-day lunar stay. First use of Lunar Roving Vehicle; 3 lunar surface EVAs; deep space EVA on return to retrieve orbital camera film from SM.|||
||16 April 1972
|Landing in Descartes Highlands; 3 lunar EVAs and deep space EVA.|||
||7 December 1972
|Landing at Taurus-Littrow. First professional geologist on the Moon; first night launch; 3 lunar EVAs and deep space EVA.|||
Several planned missions of the Apollo program of the 1960s and 1970s were canceled for a variety of reasons, including changes in technical direction, the Apollo 1 fire, hardware delays, and budget limitations.
|Mission name/designation||Commander||CM Pilot||LM Pilot||Mission date||Date of cancellation|
|AS-205||Schirra||Eisele||Cunningham||August 1967||December 22, 1966|
|Apollo 18||Gordon||Brand||Schmitt||February 1972||2 September 1970|
|Apollo 19||Haise||Pogue||Carr||July 1972||2 September 1970|
|Apollo 20||Conrad or Roosa||Weitz||Lousma||December 1972 to February 1973||4 January 1970|
|Launch vehicle needed to launch Skylab|
There were several missions that used Apollo hardware after the cancellation of Apollo 18, Apollo 19, and Apollo 20.
|Mission||Launch vehicle||Commander||Pilot||Science Pilot||Duration||Notes||Sources|
|1||14 May 1973
(AS-513 minus S-IVB)
|N/A||N/A||N/A||N/A||Unmanned launch of the Skylab space station. The space station was later crewed by missions Skylab 2, Skylab 3 and Skylab 4.|||
|2||25 May 1973
|Pete Conrad||Paul J. Weitz||Joseph P. Kerwin||28d 00h
|First crew of the Skylab space station.|||
|3||28 July 1973
|Alan Bean||Jack R. Lousma||Owen K. Garriott||59d 11h
|Second Skylab crew. Reaction Control System thruster malfunction nearly necessitated a Rescue Mission.|||
|4||16 November 1973
|Gerald P. Carr||William R. Pogue||Edward Gibson||84d 01h
|Third and final Skylab crew. Penultimate flight of Apollo.|||
|5||15 July 1975
|Apollo-Soyuz Test Project
|Thomas P. Stafford||Vance D. Brand||Deke Slayton||09d 01h
|Final flight of both Apollo and the Saturn IB. Rendezvous and docking with Soyuz 19 spacecraft. The inadvertent entry of toxic gases into the cabin atmosphere created a potentially life-threatening health risk to the astronauts during re-entry.|||