S84-40538 (24 Aug 1984) --- Two 41-G payload specialists and a backup for one of them appear to be at home in zero gravity in this scene photographed aboard a KC-135 "Zero gravity" aircraft flying one of its weightlessness opportunity parabolas. Paul D. Scully-Power, a civilian oceanographer with the U.S. Navey, is flanked by Marc Garneau (left) and Robert Thirsk, both representing the National Research Council of Canada. Thirsk is back up payload specialist for Garneau.