British Columbia radio amateur Scott Tilley, VE7TIL, has found another “zombie satellite,” as he calls them. This time, he tracked and identified radio signals from the experimental UHF military communication satellite LES-5. Tilley says he found the satellite in what he called a geostationary “graveyard” orbit after noting a modulated carrier on 236.7487 MHz.

“Most zombie satellites are satellites that are no longer under human control, or have failed to some degree,” Tilley told National Public Radio (NPR) earlier this month. It’s not clear whether LES-5 is still capable of receiving commands.

LES-5 was built by MIT’s Lincoln Laboratory and launched in 1967 as part of the military’s Tactical Satellite Communication Program. It was supposed to shut down in 1972, but it continues to operate as long as its solar panels are facing the sun. Tilley told NPR that he was inspired by a ham in Cornwall who, in 2016, found an earlier satellite — LES-1 — built by the same lab and launched in 1965. What intrigued Tilley about LES-5 was that it might be the oldest functioning geostationary satellite in space.

After British Columbia went on lockdown due to the COVID-19 pandemic, Tilley found himself with a lot of free time for such a search. He located LES-5 on March 24.

From his home in Roberts Creek, British Columbia, Tilley, an amateur astronomer, routinely scans the skies for radio signals from classified objects orbiting Earth. Since he started, he’s located dozens of secret or unlisted satellites.

In 2018, while hunting for an undisclosed US government spacecraft lost in a launch mishap, he spotted the signature of IMAGE (Imager for Magnetopause-to-Aurora Global Exploration), a NASA spacecraft believed to have died in December 2005. The discovery delighted space scientists. NASA and another ham in the UK confirmed his finding. Launched in 2000 on a mission to monitor space weather, IMAGE mapped plasma patterns around Earth.