This is pretty much the limiting factor on how long satellites can operate.Įven with no atmosphere decay happens, a lot of the debris/spent stages from the apollo missions which were in orbit eventually crashed into the moon. All satellites have some sort of propulsion to allow orbital station-keeping, ion engines getting popular lately. The ISS needs to get regular boosts of a few dozen delta-v per year to keep its orbit (which is why missions need to be often enough), even Hubble which is on a higher orbit needs them although less frequently. You also have to take into consideration the pull of other bodies which does change orbits, tidal effects are why Phobos will eventually crash into Mars. Planets are not perfect spheres, there are variations in gravitational pull which do affect orbits, also atmospheric drag affects objects a lot further out than people think. Click to expand.Depends how long it has been stuck there and on what orbit.
