[choeger]

I think it's important to note that not all collisions are equally dangerous. Consider a sat on a polar orbit colliding with one on a equatorial orbit. Or two satellites on different directions. That is going to be spectacular. Otoh, these kind of collisions are unlikely and should be manageable by just assigning certain shells (say 5km) for every possible direction and orientation.

If two Starlink satellites collide that go roughly in the same direction, it's not exactly a huge problem.

I think the biggest issue is to coordinate this and potentially disallow some excentric orbits.

[bell-cot]

Not quite how it works, unfortunately.

Once you've got even hundreds of satellites in non-equatorial orbits, trying to provide global coverage - their ground tracks very frequently cross each other. Even if they're all at the same orbital inclination. While those mostly won't be 90 degree crossings - the great majority will involve several km/s relative velocity. And you'd run out of (say) 5km LEO shells very quickly.

[kbelder]

But the orbit is a minimum of about 50,000 kilometers, and the satellite is maybe a meter across. That's a very low probability of a collision per crossing.

I get that 'probably safe' or '0.001% chance of destruction per day' is not very satisfying for an investment that cost millions, but everything always comes down to odds. None of these satellites are eternal, even if they're the only thing in their orbit.