James McDivitt was commissioned through the Air Force Aviation Cadet Program in 1951. During the Korean War he flew 145 combat missions. In 1959 he became a test pilot, and was selected as an astronaut by NASA in 1962. He was command pilot for Gemini IV, a 66-orbit, 4-day mission in June 1965. Highlights of the mission included opening of the spacecraft cabin doors, an extravehicular activity period performed by pilot Ed White, and the completion of 12 scientific and medical experiments. During March 1969 he was also commander of Apollo 9, an earth orbital mission, which was the first demonstration of the entire set of Apollo flight hardware. He retired in 1972 as a U.S. Air Force Brigadier General.