It’ll act like nuclear fission in a reactor. Once a critical point is reached where a few satellites collide, their debris will spread and cause cascading collisions with other satellites. Some of that debris will quickly fall out of orbit but it may take hundreds of years for the rest to deorbit.
So the most basic way orbits work, the faster you go, the higher your orbit. Any collision has to conserve momentum, so any collision will be a net deceleration.
There WILL be things that get ejected at higher velocity, but most would cause the orbit to decay instead.
Also, while there are thousands of satellites up there, they really aren’t very close to one another.
You’d need to put a LOT of really small pieces of debris, like a shuttle exploding, to cause them to spread over LEO to a point where the random collisions really out things under threat.
It’s possible of course. But Starlink satellites orbit at around 500 km and LEO ends at 2000km. It requires a significant amount of energy to push things from 500km high out of LEO. And even if debris flies out of LEO it will still come down to lower orbits and get affected by drag since it doesn’t orbit in a perfect circle. If the debris hits satellites in higher orbit it will most likely be satellites that are in LEO as well and thus still be affected by orbital decay. The higher things are in LEO the longer it takes to come down, but it’s still not forever.
Decay times grow very quickly though. At 500km altitude a debris falls back in a few months up to a couple of years, but at 800km you are looking at centuries.
Those LEO satellites don’t even stay 10 years in orbit without additional orbital maneuvers. It’s not forever.
It’ll act like nuclear fission in a reactor. Once a critical point is reached where a few satellites collide, their debris will spread and cause cascading collisions with other satellites. Some of that debris will quickly fall out of orbit but it may take hundreds of years for the rest to deorbit.
Is it not possible that an impact at LEO could send debris into higher orbit potentially hitting more satellites?
Yes, but…
So the most basic way orbits work, the faster you go, the higher your orbit. Any collision has to conserve momentum, so any collision will be a net deceleration.
There WILL be things that get ejected at higher velocity, but most would cause the orbit to decay instead.
Also, while there are thousands of satellites up there, they really aren’t very close to one another.
You’d need to put a LOT of really small pieces of debris, like a shuttle exploding, to cause them to spread over LEO to a point where the random collisions really out things under threat.
Not likely. Gravity is pulling it all in all the time.
LEOs are at 500km.
GPS are at 26,000km.
GEOs are 35-40,000 km.
Came here to say this in a way clunkier fashion. The orbit levels aren’t even in the same neighborhood.
It’s possible of course. But Starlink satellites orbit at around 500 km and LEO ends at 2000km. It requires a significant amount of energy to push things from 500km high out of LEO. And even if debris flies out of LEO it will still come down to lower orbits and get affected by drag since it doesn’t orbit in a perfect circle. If the debris hits satellites in higher orbit it will most likely be satellites that are in LEO as well and thus still be affected by orbital decay. The higher things are in LEO the longer it takes to come down, but it’s still not forever.
Decay times grow very quickly though. At 500km altitude a debris falls back in a few months up to a couple of years, but at 800km you are looking at centuries.