Canyon (satellite)

Canyon was a series of seven United States spy satellites launched between 1968 and 1977. Also known by its SIGAD as AFP-827, the satellites were developed with the participation of the Air Force. The Canyon project is credited as being the first American satellite system tasked for COMINT.

The satellites each had a mass of 700 kg and were launched from Atlas/Agena D rockets into near-geosynchronous orbits. They carried large parabolic reflecting dishes, estimated at 10m in diameter. The Canyon satellites were eventually replaced with the next generation of COMINT satellites, the Vortex/Chalet series. The program is still classified.

Seven Canyon satellites were launched from 1968 to 1977, all with Atlas Agena D vehicles from LC-13 at Cape Canaveral and there was one failure in 1971. The first four Canyons apparently remained attached to the Agena after achieving orbit, using its engine for maneuvering (the missions would have been concluded after Agena propellant depletion). Later Canyons were reputedly larger in size and did separate from the booster.