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The Amateur Satellite That Went Silent for 21 Years — and Is Still Active in 2026
AMSAT-OSCAR 7 launched in 1974, fell silent after a battery failure in 1981, and was heard again in 2002. Its continued activity makes it an excellent historical investigation into aging spacecraft, power-system failures, transponders, and the remarkable longevity of radio hardware.
On November 15, 1974, AMSAT-OSCAR 7 entered orbit as a small amateur-radio satellite with a planned life measured in years, not decades. It weighed about 29.5 kilograms, carried two linear transponders, telemetry transmitters, redundant command systems, and a store-and-forward experiment. Its orbit was roughly 1,460 kilometres above Earth in a sun-synchronous path.
By mid-1981, AO-7 was silent.
For 21 years, that seemed like the end of the story. Then, on June 21, 2002, British radio amateur Pat Gowen, G3IOR, heard a familiar Morse telemetry signal near the satellite’s old beacon frequency. The Doppler shift matched an orbiting transmitter. Other observers confirmed it: AO-7 had returned.
In late October 2026, the satellite is still operating when sunlight reaches its…
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