Defense Satellite Communications System

[3] In April 1960, the Advanced Research Projects Agency (ARPA) initiated the Advent program, aiming to deliver a military communication satellite.

The IDCSP delivered a simple, spin-stabilized satellite placed into a sub-synchronous orbit that did not require station-keeping or active altitude control.

[5] DSCS II, developed under Program 777[6] provided secure voice and data transmission for the United States Armed Forces.

[7] On 12 December 1975, research and development contracts were awarded to General Electric and Hughes Aircraft Company[8] to begin DSCS III design studies, with the first Block 1 launch on 30 October 1982.

[4] DSCS III satellites support globally distributed Department of Defense (DoD) and national security users.

These changes provided substantial capacity improvements through higher power amplifiers, more sensitive receivers, and additional antenna connectivity options.

The DSCS communications payload includes six independent Super High Frequency (SHF) transponder channels that cover a 500 MHz bandwidth.