1927-

American astronaut whose flights generated crucial data on the challenges of long-duration space missions. Cooper, one of the seven original NASA astronauts, orbited Earth for 34 hours on the last of the Project Mercury missions and for eight days as commander of the Gemini 5 mission. Scheduled to command a lunar landing flight, Cooper was eased out of the NASA flight rotation because of his reputation as a maverick and a daredevil.