There is a single satellite launched by the US Navy in 1964 that is still in orbit, still transmitting, and still being used by amateur radio operators around the world — and nobody at the Navy has been in charge of it for decades

From Space Daily

On December 28, 1964, a Thor-Able-Star rocket lifted off from Vandenberg Air Force Base in California and put a small US Navy satellite into a low polar orbit.

The satellite was called Transit 5B-5. It weighed about 70 kilograms. It was part of the first satellite-based navigation system in human history — the predecessor to GPS, designed to help American submarines fix their position anywhere in the world. It was given a working lifetime of a few years. Maybe five, if everything went well.

That was sixty-one years ago.