Transit 5A via Wikipedia
Many thanks to SWLing Post contributor, Dan Robinson, who shares the following article, which explores the story of Transit 5B-5 — a U.S. Navy satellite launched in 1964 that remains in orbit, continues transmitting telemetry signals, and is still monitored by amateur radio operators around the world more than six decades later. Fueled by a long-lived radioisotope power source and tracked by the SDR and ham radio community, this “zombie satellite” stands as a fascinating reminder of Cold War-era engineering built to endure.