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 21. Armstrong and See watched the launch at Cape Kennedy, then flew to the Manned Spacecraft Center in Houston. The mission was generally successful, despite a problem with the fuel cells that prevented a rendezvous. Cooper and Conrad practiced a "phantom rendezvous", carrying out the maneuver without a target. The crew assignments for Gemini 8 were announced on September 20, 1965. Under the normal rotation system, the backup crew for one mission became the prime crew for the third mission after, but Slayton designated David Scott as the pilot of Gemini 8. Scott was the first member of the third