As part of the Apollo program by NASA, 24 astronauts flew nine lunar missions between December 1968 and December 1972. During six successful two-man landing missions, twelve men walked on the lunar surface, six of whom drove Lunar Roving Vehicles as part of the last three missions. Three men have reached the Moon twice, one on both an orbital mission and a circumlunar flight, while the other two landed once apiece after previous orbital missions. As of August 2025, five of the 24 remain alive. Apart from these 24 men and the three men and one woman on the Artemis II lunar flyby in 2026, no human has gone beyond low Earth orbit. Several non-human animals have circled or orbited the Moon, including two tortoises, several turtles, and five mice. Apollo 8 and 10–17 were the nine crewed Apollo lunar missions. Apollo 4–6 and AS-201 and AS-202 were uncrewed, while AS-203 is considered a test flight. The Apollo program included three other crewed missions: Apollo 1 (AS-204) did not launch and its crew died in a ground-based capsule fire, while Apollo 7 and Apollo 9 were low Earth orbit missions that tested spacecraft components and docking maneuvers. Apollo missions 18, 19, and 20 were canceled. Twelve astronauts later flew unused Apollo command modules in the Apollo Applications Program's Skylab and Apollo–Soyuz Test Project. Of the 24 astronauts who reached the Moon, two went on to command a Skylab mission, one commanded Apollo–Soyuz, one flew as commander for Approach and Landing Tests of the Space Shuttle, and two commanded orbital Space Shuttle missions.
Prime crew members NASA's Director of Flight Crew Operations during the Gemini and Apollo programs was Donald K. "Deke" Slayton, one of the original Mercury Seven astronauts, who was medically grounded in September 1962 due to a minor cardiac arrhythmia – paroxysmal atrial fibrillation. Slayton was responsible for making all Gemini and Apollo crew assignments. In March 1972, Slayton was restored to flight status, and flew on the 1975 Apollo–Soyuz Test Project mission. The prime crew members selected for actual missions are here grouped by their NASA astronaut selection groups, and within each group in the order selected for flight. Two versions of the Apollo Command/Service Module (CSM) spacecraft were developed: Block I, intended for preliminary low Earth orbit testing; and Block II, redesigned for the lunar landing. The Block I crew position titles were Command Pilot, Senior Pilot (second seat), and Pilot (third seat). The corresponding Block II titles were: Commander, Command Module Pilot, and Lunar Module Pilot. The second seat pilot was given secondary responsibility for celestial navigation to keep the CSM's guidance computer accurately calibrated with the spacecraft's true position, and the third seat pilot served as a flight engineer, monitoring the health of the spacecraft systems.
Apollo astronauts by their dates of selection by NASA
1959
Virgil I. "Gus" Grissom began his career at NASA in 1959. In 1966, he was selected as Command Pilot for the first crewed Apollo mission, a low Earth orbit test. This mission ended a month before its scheduled launch, when a cabin fire on the launch pad killed Grissom, Ed White and Roger Chaffee on January 27, 1967. Walter M. Schirra Jr. also began his NASA career in 1959. He was selected in October 1968 as Command Pilot for Apollo 7, an 11-day, low Earth orbit shakedown test of the three-man Apollo Command/Service Module and the first crewed launch for the Apollo project. Alan B. Shepard Jr. – America's first man in space on Freedom 7 was originally selected to command Gemini 3, but was medically grounded for the duration of Gemini due to Ménière's disease and assisted Slayton in Flight Operations. After corrective surgery, Shepard was restored to flight status and commanded Apollo 14, the third successful Moon landing mission.
1962
All of these astronauts flew on Gemini, and except for White, each commanded one Gemini and one Apollo mission:
Edward H. White II – Second-seat veteran of Gemini 4 who made the United States' first walk in space, selected as Senior Pilot (second seat) on Apollo 1. White was killed in the Apollo 1 fire along with Grissom and Chaffee. James A. McDivitt – Commander of Gemini 4, selected in late 1966 to command the first Earth orbital flight test of the Apollo Lunar Module with the CSM. This mission flew in March 1969 as Apollo 9. After his flight, McDivitt was promoted to Manager of Lunar Landing Operations, and in August 1969 was promoted to Manager of the Apollo Spacecraft Program. Frank F. Borman II – Commander of Gemini 7, selected to command a higher Earth orbit test of the complete Apollo spacecraft. But when delays prevented the LM from being ready in time for its first flight in December 1968, Borman's mission was changed to the first lunar orbital flight of the CSM on Apollo 8. James A. Lovell Jr. – Second-seat veteran of Gemini 7, and commander of Gemini 12, flew as Command Module Pilot (second seat) on Apollo 8. Lovell became the first to fly a second Apollo mission as commander of Apollo 13, the third lunar landing attempt. This mission was unsuccessful, due to a Service Module electrical system failure caused by an oxygen tank explosion. Lovell and his crew managed to return to Earth safely. Lovell is the only person to fly to the Moon's vicinity twice without landing there. Thomas P. Stafford – Second-seat veteran of Gemini 6A and commander of Gemini 9A, commanded a lunar orbital test of the Lunar Module on Apollo 10. He also commanded the Apollo–Soyuz Test Project mission. John W. Young – Second-seat veteran of Gemini 3 and commander of Gemini 10, flew as Command Module Pilot on Apollo 10. Young later commanded the successful Apollo 16 lunar landing. He also commanded the first Space Shuttle flight, STS-1 Columbia, April 12–14, 1981, and STS-9, also on Columbia, November 28 – December 8, 1983. Neil A. Armstrong – Commander of Gemini 8, commanded Apollo 11, becoming the first human to set foot on the Moon. Charles "Pete" Conrad Jr. – Second-seat veteran of Gemini 5 and commander of Gemini 11, commanded Apollo 12, the second lunar landing. He went on to command Skylab 2, successfully completing repairs to the spacecraft that saved it for this and two subsequent missions.
1963
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