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 astronauts, they were younger, and had more impressive academic credentials. On February 8, 1965, Armstrong and Elliot See were announced as the backup crew for Gemini 5, with Armstrong as commander, supporting the prime crew of Gordon Cooper and Pete Conrad. The mission's purpose was to practice space rendezvous and to develop procedures and equipment for a seven-day flight, all of which would be required for a mission to the Moon. With two other flights (Gemini 3 and Gemini 4) in preparation, six crews were competing for simulator time, so Gemini 5 was postponed. It finally lifted off on August