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 to the explosion. Cortright's report recommended the entire tank be redesigned at a cost of $40 million. Many NASA managers, including Armstrong, opposed the recommendation, since only the thermostat switch had caused the problem. They lost the argument and the tanks were redesigned. In 1986, President Ronald Reagan asked Armstrong to join the Rogers Commission investigating the destruction of the Space Shuttle "Challenger". Armstrong was made vice chairman of the commission, and held private interviews with contacts he had developed over the years to help determine the cause of the disaster. He helped limit the committee's recommendations to nine, believing