The AO-7 Amateur Radio satellite turned 39 years old on November 15. Launched in 1974 from Vandenberg Air Force Base in California as the second AMSAT Phase 2 ham satellite, AO-7 continues to amaze.

After its batteries succumbed to old age, AO-7 went silent in 1981, only to spring back to life in 2002, although some believe it may have resurrected itself as much as a year earlier. AMSAT describes the Mode A/B bird as “semi-operational” and “almost certainly” running solely from its solar panels.

The ham satellite organization theorizes that AO-7’s batteries shorted when they failed, but the short circuit subsequently opened, allowing the satellite to return to life. This means AO-7 only works when it receives direct sunlight, and it shuts down when in eclipse. Since the satellite became undead, terrestrial users have enjoyed numerous contacts via AO-7.

AMSAT-NA this week offered its congratulations to all involved in the designing, building, launching, and operating the satellite, adding, “It's an amazing achievement that, other than the batteries, most of the circuitry continues to function normally 39 years after launch.”

AMSAT newsletters from the 1970s and early 1980s are available, courtesy of KA9Q. N4HY offers a photo gallery depicting AO-7’s construction and launch of AO-7. — Thanks to Paul Stoetzer, N8HM, via AMSAT News Service