Project Mercury also excluded civilian NASA X-15 pilot Neil Armstrong, though he had been selected by the US Air Force in 1958 for its Man In Space Soonest program, which was replaced by Mercury. Although Armstrong had been a combat-experienced NAP during the Korean War, he left active duty in 1952. Armstrong became NASA's first civilian astronaut in 1962 when he was selected for NASA's second group, and became the first man on the Moon in 1969. It was further stipulated that candidates should be between 25 and 40 years old, no taller than , and hold a college degree in a
Neil Armstrong group of astronauts, whose selection was announced on October 18, 1963, to receive a prime crew assignment. See was designated to command Gemini 9. Henceforth, each Gemini mission was commanded by a member of Armstrong's group, with a member of Scott's group as the pilot. Conrad would be Armstrong's backup this time, and Richard F. Gordon Jr. his pilot. Armstrong became the first American civilian in space. (Valentina Tereshkova of the Soviet Union had become the first civilian (and first woman) nearly three years earlier aboard Vostok 6 when it launched on June 16, 1963.) Armstrong would also be the