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Several design features distinguish Milstar from previous military and commercial satellite communications systems. First, the Milstar satellite serves as a smart switchboard in space, allowing users to establish critical communications networks on the fly, making Milstar extremely flexible and responsive to the needs of the tactical warfighters. Secondly, the Milstar system uses a satellite-to-satellite crosslink to provide worldwide connectivity without the use of vulnerable and expensive ground relay stations. Finally, the unique characteristics of the Milstar Extremely High Frequency   waveform prevent adversaries from using our communications signals to determine the location of our forces (Low Probability of Intercept), and allow Milstar to overcome all known jamming threats (Anti-Jam).

The Milstar system is composed of three distinct segments: the Space Segment (satellites), the Terminal Segment (users), and the Mission Control Segment (ground control stations). The Space Segment will be composed of six satellites positioned around the earth in low inclined geosynchronous orbits. The first Milstar satellite was launched on Feb.  7, 1994, and the second launched Nov.  6, 1995.  The remaining satellites, all upgraded with the  Medium Data Rate payload, are scheduled to be launched by 2001.  Milstar satellites are launched from Cape Canaveral, using the Titan IV/Centaur combination.

The Terminal Segment is comprised of Army, Navy, and Air Force terminals. Each service has several different types of terminals, each designed to meet specific platform requirements (ship, submarine, aircraft, etc.). Regardless of which service or which type of terminal is  used, the terminals are completely interoperable, guaranteeing joint communications into the 21st century. 

The Mission Control Segment, operated by the 4th Space Operations Squadron,  has two distinct operational components; the traditional Space-Ground-Link-System, and the Milstar unique fixed and mobile Constellation Control Stations. The SGLS system (using the Air Force Satellite Control Network) provides launch and anomaly resolution services.  The CCSs use dedicated EHF ground resources to communicate through the Milstar payload to the spacecraft, providing day-to-day support and operational command and control for the Milstar constellation. The 4th SOPS provides operators for three  mobile CCSs located at the 721st Mobile Command and Control Squadron, Peterson AFB, Colo., Schriever AFB, Colo., and the 55th Operations Squadron, Offutt AFB, Neb. At higher readiness levels and during exercises, these personnel deploy with CINC U.S. Space Command and U.S. Strategic Command respectively, providing survivable, enduring, and secure communications and constellation command and control throughout the entire conflict spectrum including trans and post attack phases of nuclear war.

General Characteristics

Weight: Approximately 10,000 pounds

Power: Solar panels generating 8000 watts

Payload: Communications (voice, data, teletype, and facsimile).

Orbit altitude: 22,300 miles (low inclined geosynchronous orbit)

Design Life: 10 years

Launch vehicle: Titan IV/Centaur

Primary Contractor: Lockheed Missiles and Space Company

Airborne and Ground Command Post Terminals

The Milstar Airborne and Ground Command Post Terminals are designed to be rugged, reliable and to survive extreme environments, including modern conventional and nuclear warfare. They provide secure, jam resistant, voice, data and teletype communications to both tactical and strategic commanders. They are also backwards compatible with existing upgraded AFSATCOM Terminals, in order to make full use of existing assets.

In May 1989, the Defense Acquisition Board approved low rate initial production (LRIP) of 43 Command Post terminals. In May 1993, a production contract was awarded for another 44 terminals, bringing the total production quantity to 87. Two prime contractors are producing these terminals, Rockwell International Corporations and Raytheon Company. To date, all LRIP terminals have been delivered and 15 have been installed and are ready for EHF operations. The remaining delivered terminals are currently undergoing installation. Additionally, there are approximately 15 Engineering Development Model (EDM) terminals currently in use by the Milstar community.

The terminals are to be used in several different configurations:

  • E-4B National Airborne Operations Center
  • Fixed Ground sites
  • Transportable Ground sites
These terminals are fully compatible with the EHF and UHF frequency bands currently used by Milstar, with a SHF band capability in development.

Installation and checkout testing has been performed on multiple airborne and ground terminals. All tests have been fully successful, proving the viability of the technology and interoperability between the Milstar system and other military communication systems. These successes have allowed the program to continue into the current production contracts, which are proceeding on schedule and under cost.