DSCS-3 (Defense Satellite Communications System 3) are geostationary communications satellites, which provide a robust anti-jam, nuclear hardened capability that supports Department of Defense (DoD) worldwide requirements, White House and Diplomatic communications. They are the follow-on generation of the DSCS-2 satellites.
The system is used for high priority communications such as the exchange of wartime information between defense officials and battlefield commanders. The system provides uninterrupted secure voice and high-data rate communications to globally fixed and mobile DoD users, NATO, the United Kingdom, the Diplomatic Telecommunications Service, and the White House Communications Agency.
DSCS-3 carries:
- six independent Super High Frequency (SHF) transponders and one special purpose single channel transponder operating on both SHF and Ultra High Frequency
- Three receive antennas (two Earth coverage horns, one steerable 61-beam nulling lens)
- Five transmit antennas (two Earth coverage horns, two steerable 19-beam wave guide lens, one high gain parabolic gimbaled dish)
DSCS-3 B7 also carried the CHARGECON-GEO (Charge Control at Geosynchronous Altitude, S90-3) experiment for the Space Test Program.
Two solar wings produce 1700 Watts of onboard power at the beginning of life and 1230 watts at the end of life.
DSCS-3 satellites were designed to be injected directly into GEO by the launch vehicle (Titan-34D IUS, Titan-34D Transtage or Shuttle IUS) without the need to incorporate an apogee kick engine. Switching to Atlas-2, Atlas-2A and Delta-4M launch vehicles made it necessary to include a dedicated apogee kick stage (IABS) with the satelite for injecting the DSCS-3 into GEO orbit.
Another DSCS-3 satellite was constructed under the name STARSAT to be used as a test object in the "Huron King" nuclear weapons test for the effects of system generated electromagnetic pulse (SGEMP) on a full-scale operating DSCS-3 military communications satellite. The spacecraft was contained in a large above-ground tank.
The DSCS-3 is succeeded by the WGS series of satellites.
DSCS-3 B12 was retired in 2015 and was moved into a graveyard orbit above the geostationary belt.
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