"No satellite will last anywhere close to 100 years. "
Working satellite? No.
Lump of metal that can crash into something.
Definitely.
At not much higher altitude 1000 year stable orbits are possible.
This is why modern satellites have "graveyard burn" fuel to get them to either re-enter or push them out of the way (Like geo comm sats that are pretty far out already).
Biting the hand that feeds IT
