James Alton McDivitt (b. June 10, 1929, Chicago, IL) is an American former test pilot, United States Air Force pilot, aeronautical engineer, and NASA astronaut who flew in the Gemini and Apollo programs. He commanded the Gemini 4 flight during which Ed White performed the first U.S. spacewalk, and later the Apollo 9 flight which was the first manned flight test of the Lunar Module and the complete set of Apollo flight hardware. He later became Manager of Lunar Landing Operations and was the Apollo Spacecraft Program Manager from 1969 to 1972.