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 earlier advice of Mission Control, they undocked, but the roll increased dramatically until they were turning about once per second, indicating a problem with Gemini's attitude control. Armstrong engaged the Reentry Control System (RCS) and turned off the OAMS. Mission rules dictated that once this system was turned on, the spacecraft had to reenter at the next possible opportunity. It was later thought that damaged wiring caused one of the thrusters to stick in the on position. A few people in the Astronaut Office, including Walter Cunningham, felt Armstrong and Scott "had botched their first mission". There was speculation that