structural:scholar_edition, linguistic:paraphrasing
Leroy Gordon Cooper Jr. was an American aerospace engineer, test pilot, United States Air Force pilot, and the youngest of the seven original astronauts in Project Mercury, the first human space program of the United States. Cooper learned to fly as a child, and after service in the United States Marine Corps during World War II, he was commissioned into the United States Air Force in 1949. After service as a fighter pilot, he qualified as a test pilot in 1956, and was selected as an astronaut in 1959. In 1963 Cooper piloted the longest and last Mercury spaceflight, Mercury-Atlas 9. During that 34-hour mission he became the first American to spend an entire day in space, the first to sleep in space, and the last American launched on an entirely solo orbital mission. Despite a series of severe equipment failures, he successfully completed the mission under manual control, guiding his spacecraft, which he named Faith 7, to a splashdown just 4 miles (6.4 km) ahead of the recovery ship. Cooper became the first astronaut to make a second orbital flight when he flew as command pilot of Gemini 5 in 1965. Along with pilot Pete Conrad, he set a new space endurance record by traveling 3,312,993 miles (5,331,745 km) in 190 hours and 56 minutes—just short of eight days—showing that astronauts could survive in space for the length of time necessary to go from the Earth to the Moon and back. Cooper liked to race cars and boats, and entered the $28,000 Salton City 500 miles (800 km) boat race, and the Southwest Championship Drag Boat races in 1965, and the 1967 Orange Bowl Regatta with fire fighter Red Adair. In 1968, he entered the 24 Hours of Daytona, but NASA management ordered him to withdraw due to the dangers involved. After serving as backup commander of the Apollo 10 mission, he was superseded by Alan Shepard. He retired from NASA and the Air Force with the rank of colonel in 1970.