Air Force Lieutenant Colonel Ellison Ornizuka first flew as a mission specialist on STS 51-C, the first Space Shuttle Department of Defense mission, which launched from Kennedy Space Center, Florida on January 24, 1985. During the mission Onizuka was responsible for the primary payload activities, which included the deployment of a modified Inertial Upper Stage (IUS). STS 51-C Discovery completed 48 orbits of the Earth before landing at Kennedy Space Center, Florida, on January 27, 1985. Lieutenant Colonel Onizuka was a mission specialist on the fated Challenger flight STS 51-L which was launched from the Kennedy Space Center, Florida on January 28, 1986.