Defense Satellite Communications System


Mission/Vision
Defense Satellite Communications System (DSCS) constellation provides nuclear-hardened, anti-jam, high data rate, long haul communications to users worldwide.

DSCS supports: the defense communications system, the Army’s ground mobile forces, the Air Force’s airborne terminals, Navy ships at sea, the White House Communications Agency, the State Department, and special users.

Background
The first DSCS III satellite was launched in October 1982. The final DSCS III satellite, B6, was launched in August 2003. In all, DSCS III successfully launched 14 satellites, seven of which are still operational and continue to be used in various capacities, from operational communications in Southwest Asia to research and development of ground-based support capabilities.

The MILSATCOM Systems Directorate, Space and Missile Systems Center (SMC), Los Angeles Air Force Base, Calif. sustains the DSCS Space Segment under contract with Lockheed Martin Space Systems Company in Sunnyvale, Calif., who is responsible for DSCS satellite sustainment.

Description
DSCS III satellites support globally distributed Department of Defense (DoD) and national security users. The final 4 of 14 satellites received Service Life Enhancement Program (SLEP) modifications. These changes provide 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. Three receive and five transmit antennas provide selectable options for Earth coverage, area coverage and/or spot beam coverage. A special purpose single-channel transponder is also on board.

Part of directorate’s Wideband SATCOM Group, the DSCS III system provides the capabilities needed for effective implementation of worldwide military communications. It can adapt rapidly to dynamic operating conditions and perform under stressed environments. DSCS III operates with large or small terminals, and with Code Divisional Multiple Access, Frequency Division Multiple Access or Time Division Multiple Access multiplexing. DSCS’s independent channels group users by operational needs or geographical location by allocating receiver sensitivity and transmitter power, thus providing maximum efficiency.

General Characteristics
Primary function: high-capacity military communications satellite
Primary contractor: Lockheed Martin Space Systems Company – Sunnyvale Operations
Payload: six-channel SHF transponded system Single Channel Transponder (UHF/X, crossband)
Antennas: wideband multi-beam and two earth coverage receive antennas; two transmit multi-beam, gimbaled dish, and two earth coverage antennas
Capability: up to 200 Mbps

Launches
A-1 Oct 30, 1982 Decommissioned
B-4 Oct 3, 1985 Decommissioned
B-5 Oct 3, 1985 Decommissioned
A-2 Sept 4, 1989 Decommissioned
B-14 Feb 11, 1992 Decommissioned
B-12 July 2, 1992 Decommissioned
B-9 Jul 19, 1993 Decommissioned
B-10 28 Nov 1993 Operational
B-7 July 31, 1995 Operational
B-13 Oct 25, 1997 Operational
B-8 Jan 21, 2000 Operational
B-11 20 Oct 2000 Operational
A-3 Mar 11, 2003 Operational
B-6 Aug 29, 2003 Operational

(Current as of November 2015)

Point of Contact: Air Force Space Command Public Affairs; 150 Vandenberg St., Suite 1105; Peterson AFB, Colo., 80914-4500;
DSN 692-3731 or (719) 554-3731. 

Source