Defense Satellite Communications System Phase III

Overview
Before September 11, 2001, the majority of DOD's SATCOM capacity was provided by the Defense Satellite Communications System Phase III (DSCS III) program, a five-satellite military constellation. DSCS III capability was augmented by commercial SATCOM in support of U.S. military operations abroad, such as Operation Desert Storm, and humanitarian relief efforts. The Wideband Global SATCOM (WGS) satellite system began replacing DSCS III in 2007, and each satellite provides about 10 times the capacity of its predecessor.

Source

 * Defense Satellite Communications: DOD Needs Additional Information to Improve Procurements, at 5.