1935-

American astronaut who was the tenth person to walk on the moon. Duke graduated from the U.S. Naval Academy and completed a master's degree in aeronautics and astronautics at the Massachusetts Institute of Technology. He served as an Air Force test pilot. As the lunar module pilot of Apollo 16, Duke spent several days on the moon in 1972. He was the backup pilot for Apollo 13 and 17. After retiring from NASA, he became an entrepreneur and minister. He published his autobiography, Moonwalk, in 1990.