S63-03978 (1963) --- Astronaut L. Gordon Cooper Jr., prime pilot for the Mercury-Atlas 9 (MA-9) mission, is strapped into the gondola while undergoing tests in the centrifuge at the Naval Air Development Center, Johnsville, Pennsylvania. The centrifuge is used to investigate by simulation the pilot's capability to control the vehicle during the actual flight in its booster and reentry profile. Photo credit: NASA