DSCS

The Defense Satellite Communications System (DSCS) provides the United States with military communications to support globally distributed military users. DSCS will be replaced by the Wideband Global SATCOM system. A total of 14 DSCS III satellites were launched between the early 1980s and 2003. Two satellites were launched aboard the Space Shuttle Atlantis in 1985 during STS-51J. As of 23 November 2015, seven DSCS III satellites were still operational. DSCS operations are currently run by the 3d Space Operations Squadron out of Schriever AFB.

DSCS went though three major phases - IDCSP (Interim Defense Communication Satellite Program), DSCS- II, and DSCS-III. Since the first launch, DSCS has been the "workhorse" of military satellite communications. All DSCS III satellites have exceeded their 10-year design life. The National Science Foundation are proceeding with plans to use the DSCS satellites to provide additional bandwidth to Amundsen-Scott South Pole Station and McMurdo Station on Ross Island on the continent of Antarctica.

In April 1960, the Advanced Research Projects Agency (ARPA) began work on the Advent program, which was intended to deliver a military communication satellite. The design concept proved too advanced for the technology of the time, and the program was cancelled in May 1962. IDCSP was one of two recommended follow up approaches to deliver a working satellite.

Philco (now Ford Aerospace) was contracted for the work. The IDCSP delivered a simple, spin-stabilized satellite placed into a sub-synchronous orbit that did not require station-keeping or active altitude control. The capacity was approximately 1 Mbps digital data.

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