The Cape, Chapter I, Section 8

USAF Space Organizations and Programs

Space Shuttle Support of Military Payloads

While the Space Shuttle did not become the all-encompassing spacelifter its planners hoped for, it would be extremely unfair to ignore the Shuttle's contribution to the military space effort in the 1980s and early 1990s. Following the first DOD/Shuttle mission launched in June 1982, the first two Defense Department payloads processed through the SPIF were launched on two mixed military/civilian missions on 30 August and 8 November 1984. Both of those military payloads were SYNCOM IV communications satellites destined to replace aging FLTSATCOM satellites. Two more SYNCOM IVs were launched on mixed missions in April and August 1985, and two Shuttle missions in January and October 1985 were completely devoted to classified Defense Department payloads. Military payloads continued to be launched on the Shuttle after the "return to flight" on 29 September 1988. Shuttle/DOD missions were launched in December 1988, August 1989, November 1989, February 1990, November 1990, April 1991 and November 1991. In addition to those mostly classified missions, the fifth SYNCOM IV satellite was launched on Columbia's Long Duration Exposure Facility retrieval mission in January 1990. Taken together, military space missions accounted for part or all of 14 out of 37 Shuttle flights launched from the Cape between August 1984 and July 1992. Unquestionably, this represented a major contribution to the U.S. military space effort in the 1980s and early 1990s.47

The Cape: Miltary Space Operations 1971-1992
by Mark C. Cleary, Chief Historian
45 Space Wing Office of History
1201 Minuteman Ave, Patrick AFB, FL 32925