Tenth Atlantis flight. A dedicated mission for the Department of Defense to gather data for their programs. Deployed Defense Support Program satellite (DSP). The mission was shortened when an inertial measurement unit failed on the sixth day of the mission. Landed at Edwards Air Force Base, CA. December 1, 1991. Mission Duration 166 hours 52 minutes 27 seconds.

Launch Date: November 24, 1991 Launch Vehicle: Atlantis Crew: Commander: Frederick D. Gregory, Pilot: Terence T. Henricks, Mission Specialists: F. Story Musgrave, Mario Runco, Jr., James S. Voss, Payload Specialists:Thomas J. Hennen