Dave is an MIT-educated engineer, retired U.S. Air Force officer, former test pilot, and former NASA astronaut. Dave flew on the Gemini 8 and Apollo 9 missions, and as commander of Apollo 15, he became the seventh person to walk on the Moon. Before becoming an astronaut, Dave graduated from the United States Military Academy at West Point and joined the United States Air Force. He graduated from the Air Force Experimental Test Pilot School and Aerospace Research Pilot School. Dave retired from the Air Force in 1975 with the rank of colonel and more than 5,600 hours of flying time. Through his role in the development and operation of the Apollo guidance system, Dave was an early proponent of automated systems that fully embrace human skill and judgment.