Milstar (Military Strategic & Tactical Relay) is the tactical and strategic multiservice satellite system designed to provide survivable communications for U.S. forces worldwide. The program is managed by the U.S. Air Force Space and Missile Center.
The Milstar-1 satellites carry a secure, robust low-data-rate (LDR) communications payload, and a crosslink payload that allows the satellites to communicate globally without using a ground station. The Milstar-2 satellites extend the communications capabilities to higher data rates by adding a medium-data-rate (MDR) payload. The Milstar-1 and -2 satellites are fully interoperable for LDR communications and crosslinks.
Boeing has the prime responsibility for supplying the MDR and crosslink payloads to prime contractor Lockheed Martin Missiles and Space Company. BSS subcontracts with TRW Space and Electronics Group for the MDR antennas and digital subsystem, and provides portions of the LDR payload under subcontract to TRW.
Milstar satellites use a unique bus, consisting of three boxes, which are folded during launch and deploy in orbit.
The Milstar system provides uplink communications at extremely high frequency (EHF), 44 GHz, and ultrahigh frequency (UHF), 300 MHz, and downlink communications at super-high frequency (SHF), 20 GHz, and UHF, 250 MHz. The crosslinks operate in the 60 GHz region. Survivability and endurability requirements are satisfied by anti-jam, hardening and system autonomy features.
|Type / Application:||Comsat|
|Contractors:||Lockheed Martin (Bus), TRW (LDR payload), Hughes / Boeing (MDR payload)|
|Equipment:||LDR, MDR and Crosslink payloads|
|Propulsion:||2 × R-4D-12|
|Power:||2 deployable solar arrays, batteries|
|Milstar-2 1 (Milstar 3, USA 143)||1999-023A||30.04.1999||CC LC-40||f||Titan-4(01)B Centaur-T|
|Milstar-2 2 (Milstar 4, USA 157)||2001-009A||27.02.2001||CC SLC-40||Titan-4(01)B Centaur-T|
|Milstar-2 3 (Milstar 5, USA 164)||2002-001A||16.01.2002||CC SLC-40||Titan-4(01)B Centaur-T|
|Milstar-2 4 (Milstar 6, USA 169)||2003-012A||08.04.2003||CC SLC-40||Titan-4(01)B Centaur-T|