Set to celebrate its silver anniversary next year, LUSAT-1 — which is also known as OSCAR 19 or LO-19 — appears once again to be functioning, sort of, when not in sunlight. At this point, OSCAR 19 is only transmitting telemetry; its digital transponder has not been reported to be operational.

“We knew that our LUSAT started transmitting again a couple of years ago, but only when illuminated by sunlight and was not heard during the night,” Pedro Converso, LU7ABF, reported to the AMSAT-BB. During a recent nighttime pass, though, he was surprised to hear “the usual strong 900 mW continuous carrier on 437.125 MHz,” 22 minutes after LO-19 had emerged from Earth’s shadow.

“It’s almost a miracle that after almost 25 years, LUSAT’s vintage Ni-Cd batteries can receive and hold [a] charge,” he said.

Launched in 1990 from Kourou, French Guyana, on an Ariane 4 vehicle, the satellite — Argentina’s first — has completed more than 128,000 orbits, and is one of the oldest active Amateur Radio satellites. The satellite carries a digital store-and-forward packet transponder with uplink frequencies at 145.84, 145.86, 145.88, and 145.90 MHz 1200 bps FM, with AX.25 protocol downlink at 437.125 MHz SSB.

An audio clip, tracking information, and listener reports are available via the AMSAT-LU website. Reports are welcome via e-mail.