Born March 17, 1930, in Pittsburgh, Pennsylvania. He received a Bachelor of Science degree in Naval Science from the United States Naval Academy in 1951 and Master of Science degrees in Aeronautical Engineering and Instrumentation Engineering from the University of Michigan in 1957. During his military career, he accumulated more than 7,015 hours flying time, 5,300 hours in jet aircraft. Irwin served as lunar module pilot for Apollo 15, which was the fourth manned lunar landing. In completing his first flight, Irwin logged 295 hours and 11 minutes in space - 19 hours and 46 minutes of which were in EVA (extra-vehicular activity).