A certain Quora user was curious about the matter, inquiring,
“When it’s time to retire the ISS, will it be broken down into its main (smaller) parts for eventual re-entry and burn-up in the atmosphere?”
While Quora enthusiasts jumped on the question without any substantial evidence and logic, fortunately there was a NASA mechanical engineer, Robert Frost, to our rescue. Frost explains that the ISS will be brought back the same way as the Russian station Mir and Skylab were done, although Skylab mission wasn’t really 100% successful and resulted in some debris landing in Australia.
He adds that with the exception of a couple of Russian modules that will remain on-orbit, the Space Station will not be disassembled after its retirement, since it would lead to the problem of a bunch of uncontrollable objects plummeting into the atmosphere upon reentry, presenting more danger of striking a populated area.
Instead, the ISS is scheduled to be de-orbited while it is still functioning to make sure its trajectory can be controlled while making sure that the structure falls apart in the middle of an ocean, away from people and resulting in no more than a splash, writes Frost.
In fact, NASA actively tries to make sure the disintegration doesn’t occur with its space shuttles and any other machinery hurling back towards Earth. To bring the shuttles back to safe and sound, NASA repairs all damages on the space shuttles and designs intricate and complex plans to ensure mishaps such as Columbia’s break up on re-entry doesn’t occur.