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.
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, and was supported by the two-man Gemini program which ran concurrently with it from 1962 to 1966. Gemini missions developed some of the space travel techniques that were necessary for the success of the Apollo missions. Apollo used Saturn family rockets as launch vehicles. Apollo/Saturn vehicles 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.
The Apollo program succeeded in achieving its goal of manned lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a pre-launch 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 disabled the command spacecraft's propulsion and life support. The crew returned to Earth safely by using the Lunar Module as a "lifeboat" for these functions.
