Lockheed Martin Space Systems is the prime contractor for theUS$750 million 4537 kg (10,000 lbm) military satellite communications system. The satellite system provides the U.S. Department of Defense with reliable, secure, jam-proof communications between fixed-site, mobile, and portable terminals.

Each Milstar satellite serves as a switchboard in space directing traffic from terminal to terminal anywhere on Earth. Since the satellite processes the communications signal and can link with other 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. Milstar provides interoperable communications among 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.

The MILSTAR uplink/downlink frequency is 44/20 GHz.