Comment Re:expensive clean up (Score 1) 142
surely it would be possible to use existing vehicles and relatively inexpensive thrusters to boost the ISS into some kind of parking orbit which, even if not permanently stable, would keep it aloft for another 15-20 years until we figure out a long-term solution for it?
I agree with others that it's worth an attempt to keep it for historical purposes, but it's also hard to see how spending a billion dollars is the cheapest option.
The ISS is quite heavy. Boosting it would require really a lot of v! You'd either need to run the station thrusters for a *long* time, with probably thousands of refuelings from vehicles that currently don't have the ability to reach it at those higher orbits, or you'd need an external booster with something like 900 *tons* of propellant. You'd also have to worry about it just gradually falling apart mechanically as things wear out from thermal cycling and collisions. But you're right, this proposal is not the cheapest option. The cheapest option would be to do nothing, let it enter uncontrolled, and roll the dice as to where the parts come down.