1932-

American astronaut who was the first U.S. physician in space. Kerwin earned a medical degree from Northwestern University Medical School and then graduated from the Naval School of Aviation Medicine. For 28 days in 1973 on Skylab 2, Kerwin assessed the crew's physical condition and determined that it was medically possible for astronauts to participate in sustained missions. He served as director of life sciences for NASA, evaluated biological aspects of shuttle flights, and worked as an aerospace industry consultant.