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Defense Satellite Communications System
By Editor | August 19, 2008
The first important landmark in defence satellite communications system and especially U.S. defense satellite communications system was when the U.S. army established radar contact with the moon. The navy started to experiment with the moon as a sort of reflector in 1954 and in 1959 it successfully established a communication link between Washington D.C. and Hawaii.
Project SCORE (acronym for Signal Communication by Orbiting Relay Equipment) was the first artificial military satellite that was launched in 1958 to demonstrate that Atlas missiles could be put into orbit. Demonstrating how communications repeaters built into the missiles functioned was a secondary objective. A repeater received signals, amplified them and then retransmitted them. The transmissions also included Eisenhower’s Christmas message. Courier was the next satellite. This satellite of a higher capacity had longer life than SCORE but still it existed for only 17 days after the second launch which took place in 1960. Advent satellite in 1960 was the next more advanced satellite but in 1962 it was cancelled.
Project West Ford, the next big thing, used copper wire communications reflectors. This technology was not repeated in the history of U.S. defense satellite communications system. With the cancellation of the Advent in 1962, there was a recommendation for an operational instead of an experimental programme. Thus was started the Initial Defense Communication Satellite Program (IDCSP). 1966 saw the launch of the first IDCSP. The year saw the launch of seven more IDCSP satellites and groups of three to eight satellites were launched between 1967 and 1968. 28 satellites in total were launched, operating for 1 to 10 years. The IDCSP satellites’ orbits were slightly below geostationary orbits.
1966 also saw the agreement between USA and UK on defense satellite communications system. This was the forerunner of the Skynet programme of the United Kingdom. NATO made use of the IDCSP as part of their NATO I satellite system in 1967. The Lincoln Experiment Satellites (LES) by the Lincoln Laboratory were launched between 1967 and 1969 – the Lincoln 5 and 6. The Tactical Communication Satellite (Tacsat) was started for working with small land, airborne, mobile or shipborne tactical terminals. This was the progenitor of the narrowband segment of military satellite communications.
The major satellites after these were the Department of Defense’s (DOD) communication satellites, the Defense Satellite Communication System (DSCS), Air Force satellite communication (AFSATCOM), Fleet satellite communications (FLTSATCOM), the Milstar system and SICRAL, an Italian defence satellite communications system.
The future of milsatcom (as military satellite communication is known as for short) is in wideband communications like the Global Broadcast Service (GBS), the wideband gapfiller satellites, advanced polar systems, advanced EHF, the advanced wideband system, and the advanced narrowband system in narrowband communications.
In the defence services, spying and intelligence play an important role. Quick communication is also extremely necessary. Defense services technology have played a major role in the history of satellite communications and this needs to be recognised as technology is primarily fuelled by governments for military benefits. Communication satellites are important in such circumstances as they help to transmit globally and also in an unrestricted manner.
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