How accurately can they really de-orbit such a colossal object with so many parts that are bound to break off?
Is this a “it’s fine, they can model it so well that they’ll target a couple hundred square kilometres in the middle of the ocean” thing or a “pieces will be spread across many thousands of kilometres, but it probably won’t hit anyone because the earth is really big..” thing.
Mir space station was de-orbited without issues. Tho I remember media reporting back then that Japanese govt was ready for worst case scenario - the reentry track lead over southern Japan and the fear was that biggest parts of the station could hit the inhabited areas. Luckily that didn't happen and what's left of the station sunk near Fiji.
The NASA's document released on Wednesday and linked in the article, "International Space Station Deorbit Analysis Summary" states that various solutions were considered including disassembly the station in parts but "this a less feasible, riskier, more costly disposal method." so a complete de-orbiting operation seems is the best way.
I guess it would break up at some point, and the timing of that event would affect the re-entry characteristics. It seems like a challenge for modelling, but maybe it's possible to put upper and lower bounds on the ballistic coefficient.
That's why they aim at Point Nemo. Nearest land is 2,500 km away so there is plenty of margin for all the small "bits" that might spread during break up.
Is this a “it’s fine, they can model it so well that they’ll target a couple hundred square kilometres in the middle of the ocean” thing or a “pieces will be spread across many thousands of kilometres, but it probably won’t hit anyone because the earth is really big..” thing.