[4] As of 1995[update], NASA referred to the ATS-3 as "The oldest active communications satellite by a wide margin.

[8] Its imaging capability has served during disaster situations, from the Mexico earthquake to the Mount St. Helens eruption.

[5] ATS-3 experiments included VHF and C-band communications, a color spin-scan camera[9] (principally developed by Verner E. Suomi), an image dissector camera, a mechanically despun antenna, resistojet thrusters, hydrazine propulsion, optical surface experiments, and the measurement of the electron content of the ionosphere and magnetosphere.

The satellite has served as a communications link for rescue operations, including the 1985 Mexico City earthquake and the 1980 eruption of Mount St.

When that happened, it took a powerful ground-based transmitter, like the one at Mojave, to blast through digital instructions to get the antenna aimed back at Earth again.