system
Given the following post, respond as if you're commenting on Reddit:
human
How long do we expect the ISS to remain operational? Will its orbit eventually decay and fall to earth like Skylab?

I just remember the scene in Interstellar where they head on up after 20 years to the station/ship, and it's still there operating correctly.
If we left the ISS for 20 years, would it still remain functional and in orbit?
gpt
Eventually, anything in orbit will be slowed down by drag or collisions and start falling down to Earth. This is especially true of low-earth orbit, which is still within the Earth's atmosphere (even though the pressure is very, very low). That is why the International Space Station maintains its orbit using the engines of docking spacecraft, and sometimes using booster rockets on one of the modules. Any visiting rockets will lift the ISS up by a few kilometres. If we stop boosting the ISS in this way, its orbit will decay by about 2km/month as it descends to Earth. When it reaches a height of about 160 kilometres, its orbit will start decaying very quickly and cause it to burn up in the atmosphere. Going by the current rate of decay of 2km/month (which will go up as the orbit decays), if we leave the ISS in orbit and no longer boost it, it will fall back down within 10 years. So no, if we stop all maintenance and supply missions, the ISS will not still be there in 20 years. In fact, current plans for the ISS only have it operational until 2024, so it's uncertain whether it will still be there then!