What was the 80s movie where the kid turns amusement park ride into space ship?

What was the 80s movie where the kid turns amusement park ride into space ship?
If we're thinking of the same movie, it's "Explorers"(1985). It had Ethan Hawke and River Phoenix in it.

The only other movie that I can think of that would "partially" fit the bill would be "Flight of the Navigator"(1986). which had Pee Wee Herman in it, lol, but the ship wasn't made from an amusement park ride, at least I don't think it was.