Applications Technology Satellite 1 (ATS 1): 1966-1967

Aviation’s use of actual space-based technology was first demonstrated by the FAA using NASA’s Applications Technology Satellite 1 (ATS 1) to relay voice communications between the ground and an airborne FAA aircraft using very high frequency (VHF) radio during 1966 and 1967, with the aim of enabling safer air traffic control over the oceans.[199]

Launched from Cape Canaveral atop an Atlas Agena D rocket on December 7, 1966, the spin-stabilized ATS 1 was injected into geo­synchronous orbit to take up a perch 22,300 miles high, directly over Ecuador. During this early period in space history, the ATS 1 spacecraft was packed with experiments to demonstrate how satellites could be used to provide the communication, navigation, and weather monitor­ing that we now take for granted. In fact, the ATS 1’s black and white television camera captured the first full-Earth image of the planet’s cloud-covered surface.[200]

Eight flight tests were conducted using NASA’s ATS 1 to relay voice signals between the ground and an FAA aircraft using VHF band radio, with the intent of allowing air traffic controllers to speak with pilots flying over an ocean. Measurements were recorded of signal level, signal plus noise-to-noise ratio, multipath propagation, voice intelli­gibility, and adjacent channel interference. In a 1970 FAA report, the author concluded that the "overall communications reliability using the ATS 1 link was considered marginal.”[201]

All together, the ATS project attempted six satellite launches between 1966 and 1974, with ATS 2 and ATS 4 unable to achieve a useful orbit. ATS 1 and ATS 3 continued the FAA radio relay testing, this time includ­ing a specially equipped Pan American Airways 747 as it flew a commer­cial flight over the ocean. Results were better than when the ATS 1 was tested alone, with a NASA summary of the experiments concluding that

The experiments have shown that geostationary satellites can provide high quality, reliable, un-delayed communications

between distant points on the earth and that they can also be used for surveillance. A combination of un-delayed communi­cations and independent surveillance from shore provides the elements necessary for the implementation of effective traffic control for ships and aircraft over oceanic regions. Eventually the same techniques may be applied to continental air traffic control.[202]