Program: Vortex

Also called Chalet

Operated by the USAF. Chalet was the second generation of US GEO COMINT satellites (Canyon was the first series, with first launch in 1968, targetting Russia). Chalet was operated from Menwith Hill, UK. Under NSA project P-285, US companies were contracted to install and assist in operating the satellite control system and downlinks (RUNWAY) and ground processing system (SILKWORTH).

After the name of the first satellite appeared in the US press, the program was renamed Vortex. In 1982, NSA obtained approval for expanded "new mission requirements" and were given funds and facilities to operate four Vortex satellites simultaneously. A new 5000 m² operations center (STEEPLEBUSH) was constructed to house processing equipment.

The followup satellites after the Vortex are Mercury (in the 90ies). They are in the USA program.

Equipped with a 38 m antenna.

Vortex satellites and Magnum satellites (US GEO sigint satellites in general) might be operating from the following slots: 0°E, 44°E, 75°E, 82°E, 92°E, 110°E, 10°W, 13°W, 24°W, 30°W, 141°W and 144°W. The frequencies for uplink/downlink of collected signals would be in 17.8-21.2 GHz and 30-31 GHz. Non GEO SIGINT satellites such as the Jumpseat and Trumpet satellites (63-64° with highly elliptical orbits) might also used the same frequencies.

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External resources

http://www.fas.org/spp/military/program/sigint/chalet.htm

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