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
Frank A. Armstrong Cross. He was also awarded the British Distinguished Flying Cross for the initial mission, the first U.S. officer to be so honored. Because he had not yet been checked out as a combat pilot in the B-17, Armstrong flew the first mission as the co-pilot of a Fortress piloted by Major Paul W. Tibbets, one of his squadron commanders. Armstrong returned to the staff of Bomber Command until January, 1943, when Eaker again used him to rebuild another bomb group performing below standards. From January 4 to February 17, 1943, Armstrong commanded the 306th Bomb Group at RAF Thurleigh, England,