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. Overall DSCS responsibility resides in the United
States Strategic Command.
Defense Satellite Communications Systems (DSCS) is an important part of the comprehensive
plan to support globally distributed military users.
Currently, two Phase
II and eight Phase III DSCS satellites orbit the earth at an altitude of more
than 23,000 miles. DSCS III also carries a single channel transponder used for
disseminating emergency action and force direction messages to nuclear capable
forces. Each satellite utilizes six super high frequency transponder channels
capable of providing worldwide secure voice and high rate data communications.
system is used for high priority communication such as the exchange of wartime
information between defense officials and battlefield commanders. The military
also uses DSCS to transmit space operations and early warning data to various
systems and users.
The first of the operational DSCS II satellites was launched
in 1971. Their two-dish antennas concentrate electronic beams on small areas of
the Earth's surface, but have limited adaptability in comparison to the newer
The Air Force began launching the more advanced DSCS IIIs in 1982.
The system is built with single, multiple-beam antennas that provide more flexible
coverage than its predecessors. The single steerable dish antenna provides an
increased power spot beam which can be tailored to suit the needs of different
size user terminals. DSCS III satellites can resist jamming and are expected to
operate twice as long as DSCS IIs.
DSCS users operate on the ground, at
sea or in the air. A special-purpose (AFSATCOM) single channel transponder is
also on board the DSCS III satellite. Members of Air Force Space Command units,
the 50th Space Wing's 3rd Space Operations Squadron at Falcon Air Force Base,
Colo., and 5th Space Operations Squadron at Onizuka Air Force Station, Calif.,
provide command and control for all DSCS systems.
Air Force Materiel Command's
Space and Missile Center at Los Angeles Air Force Base, Calif., is responsible
for development and acquisition of DSCS satellites and ground systems.
Weight: DSCS II -- 1,350 pounds DSCS III -- 2,580 pounds
Altitude: Both: 23,230 miles
Power Plant: DSCS II -- solar arrays generating
535 watts decreasing to 358 watts after five years. DSCS III -- solar arrays generating
1,100 watts, decreasing to 837 watts after five years
Dimensions: DSCS II
-- cylindrical body is 9 feet in diameter, 6 feet high;13 feet high with antennas
deployed DSCS III -- rectangular body is 6 feet x 6 feet x 7 feet; 38-foot span
with solar arrays deployed
Launch Vehicle: On-orbit DSCS II and III -- Titan
34D, space shuttle Future Systems: Atlas II
Primary Contractor: DSCS II
-- TRW DSCS III -- Martin Marietta Astro Space
(Current as of May 1995)