I remember asking once, we don't we just shoot our surplus trash off into the sun and was told that by the cost of launching it outweighs the benefits. Fair!
But what about all of the old satellites and space stations? Why don't we just send a giant magnet around the earth once or twice and then slingshot all that space junk into the sun and thus giving all science fiction writers (when they return from their strike) a plot point they can no longer use in their film scripts?
Seriously though, without the cost of breaching the atmosphere, this seems really cheap to pull, why don't we do this? Why isn't this a standard thing?
But sling shots? I saw something that mentioned NASA used sling shots and centrifugal force to get something somewhere and in fact, haven't they sent a bunch of stuff to Venus lately? We just need so keep sling shotting around planets until boom, we're in orbit of the sun circling until we get low enough to get melted!
It’s called a gravity assist and can save a lot of fuel at the cost of travel time. (no centrifugal force involved) It also takes a lot of planning effort. It still takes a fair amount of fuel to reach the moon, and to set up more gravity assists. It’s much easier to slow things down just enough that they will fall and burn in the atmosphere.