From what I understand, the new International Space Station is much bigger than Mir. So, what happens when it gets too old to manage and they adandon it?
Is the plan to drop it in the ocean like Mir? Is anyone worried that it may be less manageable to bring down because of its larger size? Is there any way to launch it out of orbit and to the Sun or something?
Yes, the new station will have to be deorbited at some point.
One important point to consider is that the Russians managed to nail their target pretty much dead-on. As long as we’re still in contact with the ISS, we should have no trouble doing the same. The only way the station could land at a random location would be if we lost radio contact and therefore couldn’t carry out a planned burn.
While it’s theoretically possible to raise the orbit much higher, or move it completely out of orbit, the amount of fuel is prohibitive. It would take a rocket many times larger than currently exists to do the job. And if you did it with a bunch of small rockets, the chance of some sort of failure is much greater than simply deorbiting the thing in the first place.
Drake’s right, of course. But to add another point, remember that the ISS is modular. If they anticipated problems with a big deorbit maneuver, they could always take it apart into smaller pieces and drop them one at a time. I think most of the modules are smaller than Mir, and few will be too much larger. That would require a few more rockets, but they’d be smaller.
Well, Mir was also built up from several modules. There’s a lot more to unhooking them than closing the hatch and releasing the latches. Specifically, there’s only one module that controls the orientation of the entire station. Unhooking any modules would mean that the individual deorbit rocket(s) would have to take over that duty. That’s also non-trivial. I suspect that sort of scenario will be considered at the appropriate time, but it’ll probably turn out to be safer to bring it down in one piece.