The second flights of the United States Microgravity Payload (USMP-2) and Office of Aeronautics and Space Technology (OAST-2) packages of experiments were carried in Columbia's payload bay. Launch occurred on March 4, 1994, at 8:53 a.m. The crew was commander John Casper, with pilot Andy Allen and mission specialists Pierre Thuot, Charles Gemar and Marsha Ivins.