January 24, 1985

The 15th space shuttle mission (51-C) is the first all-military flight. The Discovery crew of Navy Capt. Thomas K. Mattingly (mission commander), Air Force Lt. Col. Loren J. Shriver (pilot), and Air Force mission specialists Lt. Col. Ellison S. Onizuka and Maj. Gary E. Payton, along with Marine Lt. Col. James F. Buchli, deploy a classified payload, believed to be a signals intelligence satellite.