If there was a chance to save it they would raise its orbit, for later rescue. This is the first response to any disaster.
If not, if it is really dying and can't be saved, they de-orbit using two progress spacecraft.
Details here Bringing down the ISS - Plans for Station’s demise updated
And - this is from 2010, Page on nasa.gov
There are more detailed plans also available not sure where to find them right now.
It is something that could happen. Has to dodge space debris from time to time. Rarely, they get notification too late and the crew go into the Soyuz and just sit it out and hope it misses (as it normally will).
Low probability but not impossible that some debris hits them too late, and in some vital place, and the crew in the Soyuz can't repair it and have to abandon the ISS and return to Earth - after all that's why they get into the Soyuz TMA in the event of this happening, in case they have to return to Earth (as well as it being a safe place to be if the ISS depressurizes).
But it's low probability anyway, and if it did happen, probably decent chance of fixing it too eventually. It's just that they have to have contingency plans for everything, even if it is quite unlikely.
If not, if it is really dying and can't be saved, they de-orbit using two progress spacecraft.
“They will have 180 days to get down to deorbit altitude. This would give them time to get two Russian Progress vehicles launched to autonomously dock, autonomously transfer propellant to the Service Module, and to provide propulsion to deorbit. This would provide a good, safe, controlled deorbit.”
Details here Bringing down the ISS - Plans for Station’s demise updated
And - this is from 2010, Page on nasa.gov
There are more detailed plans also available not sure where to find them right now.
It is something that could happen. Has to dodge space debris from time to time. Rarely, they get notification too late and the crew go into the Soyuz and just sit it out and hope it misses (as it normally will).
Low probability but not impossible that some debris hits them too late, and in some vital place, and the crew in the Soyuz can't repair it and have to abandon the ISS and return to Earth - after all that's why they get into the Soyuz TMA in the event of this happening, in case they have to return to Earth (as well as it being a safe place to be if the ISS depressurizes).
But it's low probability anyway, and if it did happen, probably decent chance of fixing it too eventually. It's just that they have to have contingency plans for everything, even if it is quite unlikely.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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