STS-51C Mission Patch

15th Space Shuttle Mission 3rd Flight of Discovery Crew: Thomas K. Mattingly II, Commander Loren J. Shriver, Pilot James F. Buchli, Mission Specialist Ellison S. Onizuka, Mission Specialist Gary E. Payton, Payload SpecialistThis was the first dedicated Department of Defense mission. Elements of the mission were kept secret. However, it was reported that a U.S. Air Force Inertial Upper Stage (IUS) booster successfully deployed a secret payload.