S81-34432 (July 1981) --- Astronaut C. Gordon Fullerton, STS-3 pilot, takes part in a suit donning and doffing exercise aboard a KC-135 "zero-gravity" aircraft. Mission specialist/astronaut William F. Fisher holds a mirror to assist Fullerton with hose and cable linkups to his suit. A special parabolic pattern flown by the KC-135 provides short durations of weightlessness. Fullerton's suit is an Extravehicular Mobility Unit (EMU), used by astronauts when leaving the shirt-sleeve environment of their shuttle orbiter to go outside and perform tasks in the vacuum of space. There are no such EVA plans on STS-3, but the crewmen are trained in this area in the event of a contingency. Photo credit: NASA