How old is the oldest working satellite? US’s Vanguard 1 is still in orbit 50+ years later, but it’s long since stopped working. Still pretty impressive considering most orbits decay over time and they meet a fiery death.
The most definitive list of old satellites I could find is this:
Satellite Year of Launch Type Operator Status
(EGRS 7 1966 ITT Secor US Army Last report 1980) [not functioning]ATS 3 1967 Hughes HS-306 NASA Still working 1990s [decomissioned] (NATO IIA 1970 Ford Skynet NATO/USAF At 105W, status unknown) (DSCS II F-1 1971 TRW DSCS 2 USAF At 100-110W since 1979) IMP 8 1973 GSFC IMP NASA Still OK 1998 Skynet IIB 1974 Marconi Skynet UK MoD Still OK 1994 LES 8 1976 Lincon Labs USAF Still OK 1992 LES 9 1976 Lincon Labs USAF Still OK 1992 [decomissioned]Marisat 103 1976 Hughes HS-333 INMARSAT Active GOES 2 1977 Ford SMS NOAA Active [decomissioned]FLTSATCOM 1 1978 TRW FLTSAT USN Active [likely decommissioned] GOES 3 1978 Ford SMS NOAA Active
I was able to clean up this list a bit. My notes are in [brackets] to the right. For certain GOES 3 is still operational for communications purposes and is certainly one of the oldest if not the oldest working satellites in orbit.
It’s possible IMP 8 is still working as well, the most recent evidence I can find was from 2006 suggesting it was operational. FLTSATCOM 1 is likely decommissioned but I can’t find solid confirmation.
Several of the other ones are of a mystery. I suspect most of them had military elements to them and were quietly disposed of if they are no longer in use. If I had to bet, I’d say GOES 3 is most likely the oldest satellite in operation as of 2012.
GOES 3 is impressive. Who in 1978 would think it would be providing 1-megabit per second data transmission to the South Pole for communications purposes.