An artist's concept of a DSCS satellite in space. Photo: Lockheed Martin

The Defense Satellite Communications Systems Phase 3 (DSCS 3) is an important part of the comprehensive plan to support globally distributed military users.

Currently, ten Phase 3 DSCS satellites operate in geosynchronous orbit at an altitude of more than 23,000 miles above the Earth. Each satellite utilizes six super high frequency transponder channels capable of providing worldwide secure voice and high rate data communications. DSCS 3 also carries a single channel transponder used for disseminating emergency action and force direction messages to nuclear capable forces.

The 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 3 to transmit space operations and early warning data to various systems and users.

DSCS 3-B11 facts
Altitude	23,230 miles
Power	Solar arrays; avg of 1500 watts
Dimensions	Rectangle body 6 x 6 x 7 feet 38-foot span
Weight	2,716 pounds
Primary Contractor	Lockheed Martin Missiles & Space
Launch Vehicle	Atlas EELV (last 2)
Source: U.S. Air Force

The Air Force began launching the current DSCS 3 satellites in 1982. The system uses multiple-beam antennas that provide more flexible coverage than its predecessor, as well as a gimballed-dish antenna for spot coverage and earth-coverage antennas. 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 3 satellites can resist jamming and have an expected design life that is twice as long as its predecessor.

The next DSCS 3 launch is scheduled for October 2000. This will be the deployment of the second DSCS 3 System Life Enhancement Program (SLEP) satellite, utilizing 50 watt traveling wave tube amplifiers in all six channels, providing users with a 200 percent increase in tactical communications capability.

DSCS users operate on the ground, at sea or in the air. Members of Air Force Space Command units and the 50th Space Wing's 3rd Space Operations Squadron at Schriever Air Force Base, CO, provide satellite bus command and control for all DSCS satellites.

Air Force Materiel Commands Space and Missile Systems Center at Los Angeles Air Force Base, CA, is responsible for development and acquisition of DSCS satellites.