Advanced Extremely High Frequency (EHF)
In Nov. 2001, the U.S. Air Force awarded Lockheed Martin Space Systems and Northrop Grumman Space Technology (Formerly TRW Space & Electronics) a $2.698 billion contract to begin the System Development and Demonstration (SDD) phase of the Advanced Extremely High Frequency (Advanced EHF) Program. The Advanced EHF Program is the next generation of global, highly secure, survivable communications system for Warfighters within all services of the Department of Defense.
The SDD phase will deploy two Advance EHF satellites and the Advance EHF mission control segment. The new mission control segment will support both Milstar and AEHF. Lockheed Martin will serve as the developer of the ground segment, satellite bus provider, space vehicle integrator and overall systems integrator and prime contractor. This role builds on Lockheed Martin's successful experience on Milstar and DSCS. Northrop Grumman will provide the payload and associated components (digital processor and RF equipment).
The MILSATCOM Program Office, located at the Space and Missile Systems Center, Los Angeles Air Force Base, Calif., is the Advanced EHF contract manager and lead agency for ensuring the secure communications capabilities of this system are made available to the warfighter.
The Advanced EHF Program is the follow-on to the DoD's Milstar highly secure communication satellite program, which currently has a four-satellite operational constellation. The last Milstar satellite was successfully launched in April 2003.
As envisioned by the Pentagon, the fully operational Advanced EHF constellation will consist of four crosslinked satellites providing coverage of the Earth from 65 degrees north latitude to 65 degrees south. These satellites will provide more data throughput capability and coverage flexibility to regional and global military operations than ever before. A fifth satellite built could be used as a spare or launched to provide additional capability to the envisioned constellation.
Advanced EHF satellites will provide 10 times greater total capacity and offer channel data rates six times higher than that of Milstar II communications satellites. The higher data rates permit transmission of tactical military communications such as real-time video, battlefield maps and targeting data.
To accomplish this, Advanced EHF adds new higher data rate modes to the low data rate and medium data rate modes of Milstar II satellites. The higher data rate modes will provide data rates up to 8.2 million bits of data per second (Mbps) to future Advanced EHF Army terminals. That rate is more than 150 times faster than the 56 kilobit-per-second modems of today's personal computers. Each Advanced EHF satellite employs more than 50 communications channels via multiple, simultaneous downlinks. For global communications, the Advanced EHF system uses inter-satellite crosslinks, eliminating the need to route messages via terrestrial systems.
Shown here is the first Advanced Extremely High Frequency (AEHF) satellite following the successful mate of the propulsion core structure and the payload module at Lockheed Martin's facilities in Sunnyvale, Calif.
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Lockheed Martin Technicians conduct a modal test of the second satellite structure for the Advanced Extremely High Frequency (Advanced EHF) program.
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Advanced EHF artwork
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