You are mixing up two different Star Trek movies. The ship from 'The Voyage Home' wasn't a man made satellite, it was an alien "whale" ship. However in the first Star Trek movie, a massive ship threatens Earth but turns out to be Voyager 1 returning home.

Dang, that right! Always thought those two were stangely similar...

You're getting old enough to mix the plots of the 1st and 4th movies together. V'ger was the early earth satellite that the enterprise chased down. The probe seeking humpback whales was of alien origin. According to what I remember of the novelization, the aliens had visited earth before recorded history.

I'm not happy I read the novelization of a Star Trek movie, but there we are.

V'ger stands for Voyager, with some letters faded-out. Thus, not an earth satellite...

I guess we are all getting old here.