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. First conceived during Dwight D. Eisenhower's administration as a three-man spacecraft to follow the one-man Project Mercury which put the first Americans in space, Apollo was later dedicated to President John F. Kennedy's national goal of "landing a man on the Moon and returning him safely to the Earth" by the end of the 1960s, which he proposed in an address to Congress on May 25, 1961. It was the third US human spaceflight program to fly, preceded by the two-man Project Gemini conceived in 1961 to extend spaceflight capability in support of Apollo.
Kennedy's goal was accomplished on the Apollo 11 mission when astronauts Neil Armstrong and Buzz Aldrin landed their Lunar Module (LM) on July 20, 1969, 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 destroyed the Service Module's capability to provide electrical power, crippling the CSM's propulsion and life support systems. 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 US-Soviet Union Earth-orbit mission 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.
||Feb 26, 1966
||First flight of Saturn IB and Block I CSM; suborbital to Atlantic Ocean; qualified heat shield to orbital reentry speed.
||Jul 5, 1966
||No spacecraft; observations of liquid hydrogen fuel behavior in orbit, to support design of S-IVB restart capability.
||Aug 25, 1966
||Suborbital flight of CSM to Pacific Ocean.
||Feb 21, 1967
Roger B. Chaffee
|Not flown; all crew members perished in fire on launch pad on January 27, 1967.
||Nov 9, 1967
||First test flight of Saturn V, placed a CSM in a high Earth orbit; demonstrated S-IVB restart; qualified CM heat shield to lunar reentry speed.
||Jan 22–23, 1968
||Earth orbital flight test of LM, launched on Saturn IB; demonstrated ascent and descent propulsion; man-rated the LM.
||Apr 4, 1968
||Unmanned, attempted demonstration of trans-lunar injection, and direct-return abort using SM engine; three engine failures, including failure of S-IVB restart. Flight controllers used SM engine to repeat Apollo 4's flight profile. Man-rated the Saturn V.
||Oct 11–22, 1968
|First manned Earth orbital demonstration of Block II CSM, launched on Saturn IB. First live television publicly broadcast from a manned mission.
||Dec 21–27, 1968
|First manned flight to Moon; CSM made 10 lunar orbits in 20 hours.
||Mar 3–13, 1969
|First manned flight of CSM and LM in Earth orbit; demonstrated Portable Life Support System to be used on the lunar surface.
||May 18–26, 1969
||CSM-106 Charlie Brown
|Dress rehearsal for first lunar landing; flew LM down to 50,000 feet (15 km) from lunar surface.
||Jul 16–24, 1969
|First manned landing, in Tranquility Base, Sea of Tranquility. Surface EVA time: 2:31 hr. Samples returned: 47.51 pounds (21.55 kg).
||Nov 14–24, 1969
||CSM-108 Yankee Clipper
|C. "Pete" Conrad
|Second landing, in Ocean of Storms near Surveyor 3 . Surface EVA time: 7:45 hr. Samples returned: 75.62 pounds (34.30 kg).
||Apr 11–17, 1970
|Third landing attempt aborted near the Moon, due to SM failure. Crew used LM as "life boat" to return to Earth.
||Jan 31 – Feb 9, 1971
||CSM-110 Kitty Hawk
|Third landing, in Fra Mauro formation, located northeast of the Sea of Storms. Surface EVA time: 9:21 hr. Samples returned: 94.35 pounds (42.80 kg).
||Jul 26 – Aug 7, 1971
|First Extended LM and rover, landed in Hadley-Apennine, located near the Sea of Showers/Rains. Surface EVA time:18:33 hr. Samples returned: 169.10 pounds (76.70 kg).
||Apr 16–27, 1972
T. Kenneth Mattingly
|Landed in Plain of Descartes. Surface EVA time: 20:14 hr. Samples returned: 207.89 pounds (94.30 kg).
||Dec 7–19, 1972
|Only Saturn V night launch. Landed in Taurus-Littrow. First geologist on the Moon. Final manned Moon landing. Surface EVA time: 22:02 hr. Samples returned: 243.40 pounds (110.40 kg).