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
Orland K. Armstrong with a bachelor's degree in education. Armstrong's first teaching position came at Southwest Baptist College in Bolivar, Missouri, where he taught English and served as basketball coach. Southwest Baptist was a natural fit for Armstrong for it was his maternal grandfather, Reverend Daniel Preston, who was one of the college founders. With America's entry into World War I in April 1917 Armstrong took a leave of absence to serve in the U.S. Army. Assigned to the Army Signal Corps, he received pilot training and would serve as an instructor pilot for the duration of the war. While serving as an