Advanced Extremely High Frequency
The Advanced Extremely High Frequency system ( AEHF ) is a common satellite communication system of the U.S. armed forces for secure, bandwidth- resistant, worldwide communications and serves to secure this. During crises and wartime It is intended to complement the existing Milstar system initially and eventually replace.
History
AEHF is the global secure communication to air, land and naval forces, and is protected against interference. AEHF provides ten times the network capacity and six times the data rate of the Milstar system.
The original contract for the AEHF system was awarded to Lockheed Martin Space Systems and Northrop Grumman Space Technology (formerly TRW) in November 2001. In this first phase, two satellites and associated ground control segment to be developed. The project management is performed by the Milsatcom Program Office of the Space and Missile Systems Center of the United States Air Force. 2006, the third satellite was ordered. The first launch will take place in 2008.
The final AEHF constellation will consist of three or four standing in radio contact with each other satellites and cover the earth globally between 65 ° North and 65 ° South.
Originally only three AEHF satellites have been ordered since the AEHF system by the more advanced system TSAT ( Transformational Satellite Communications System) should be replaced, which also offers laser communication links. Since the TSAT program was stopped for reasons of cost, two more AEHF satellites were ordered. Meanwhile nor was added a sixth.
Satellite
The startup about 6500 kg satellite will be built by Lockheed Martin Space Systems, based on the commercial satellite platform A2100. The cost per satellite will be approximately 580 million U.S. dollars. Originally known as Milstar -3 satellite are backward compatible with the existing Milstar satellites.
The satellites have a signal processing means for enabling the connection of the EHF / SHF communications. To communicate the AEHF satellites contribute to a series of antennas that allow both hemispherical coverage and very limited spot beams. In addition, two other antennas for communication are with the neighboring Milstar / AEHF satellites, so that this constellation a communication from anywhere in the world (except for the polar regions) with every other point is possible. The data rates are from 75 bit / s in the safest mode up to 8 Mbit / s with less protection. This relatively low data rates result from the requirement that the communication must be maintained under the influence of jamming even in a crisis. Up to 6000 user terminals are supported. The configuration of spot beams can be changed within minutes.
Swell
- System Fact Sheet (English)