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MILSTAR SATELLITE COMMUNICATIONS SYSTEM
Mission
Milstar is a joint service satellite communications system that provides secure, jam resistant, worldwide communications to meet essential wartime requirements for high priority military users. The multi-satellite constellation links command authorities with a wide variety of resources, including ships, submarines, aircraft and ground stations.
Features
Milstar is the most advanced military communications satellite system to date. The operational Milstar satellite constellation consists of five satellites positioned around the Earth in geosynchronous orbits. Each mid-latitude satellite weighs approximately 10,000 pounds (4,536 kilograms) and has a design life of 10 years.
Each Milstar satellite serves as a smart switchboard in space by directing traffic from terminal to terminal anywhere on the Earth. Since the satellite actually processes the communications signal and can link with other Milstar satellites through crosslinks, the requirement for ground controlled switching is significantly reduced. The satellite establishes, maintains, reconfigures and disassembles required communications circuits as directed by the users. Milstar terminals provide encrypted voice, data, teletype or facsimile communications. A key goal of Milstar is to provide interoperable communications among the users of Army, Navy, and Air Force Milstar terminals.
Geographically dispersed mobile and fixed control stations provide survivable and enduring operational command and control for the Milstar constellation.
Background
The first Milstar satellite was launched Feb. 7, 1994 aboard a Titan IV expendable launch vehicle. The second was launched Nov. 5, 1995. The third launch on April 30, 1999, placed the satellite in a non-usable orbit. The fourth through six satellites have a greatly increased capacity because of an additional medium data rate payload and were launched on Feb. 27, 2001, Jan. 15, 2002, and April 8, 2003
The Milstar system is composed of three segments: space (the satellites), terminal (the users) and mission control. Air Force Space Command's Space and Missile Systems Center at Los Angeles Air Force Base, Calif., developed the Milstar space and mission control segments. The Electronics Systems Center at Hanscom AFB, Mass., developed the Air Force portion of the terminal segment. The 4th Space Operations Squadron at Schriever AFB, Colo., is the front-line organization providing real-time satellite platform control and communications payload management.
General Characteristics
Primary function: Global military communications system
Primary contractor: Lockheed Martin Missiles and Space
Power plant: Solar panels generating 8,000 watts
Weight: About 10,000 pounds (4,536 kilograms)
Orbit altitude: 22,250 nautical miles (geosynchronous orbit)
Payload:
Low data rate communications (voice, data, teletype and facsimile) at 75 bps to 2,400 bps (All satellites)
Medium data rate communications (voice, data, teletype, facsimile) at 4.8 kbps to 1.544 mbps (Satellites 4 through 6 only)
Launch vehicle: Titan IVB/Centaur upper stage
Inventory: 5
Unit Cost: $800 million
Point of Contact
Air Force Space Command, Public Affairs Office; 150 Vandenberg St., Suite 1105; Peterson AFB, CO 80914-4500; DSN 692-3731 or 719-554-3731.
March 2009
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