[emtel]

There actually is one idea for cleaning up debris in high orbit: You launch tons of very fine powder into the orbits you wish to clear. These orbiting particles create drag on anything up there, so that their orbits degrade much faster. But the because the particles themselves are so tiny, they have a very low ballistic coefficient, and will deorbit quickly.

More: https://caseyhandmer.wordpress.com/2019/10/25/space-debris-p...

[modeless]

Hmm, seems like it would work for 800 km, but maybe not for 1000+ km? Just based on what he says there, which is that each 100 km increase is a factor of 10 in deorbit time, and it's 1 year at 800 km.

[oofbey]

That’s a solid idea. Never heard that before. And it really seems like it would solve an otherwise extremely difficult problem.

It would not discriminate though. Everything in that orbit would be taken down - debris and any functional satellites.

[emtel]

You should read the linked post. You can tune the particle size to affect only objects below a certain size.

[modeless]

I'm not sure I believe that operational satellites would be unaffected by sustained bombardment with tungsten particles at orbital velocity (x2 for head on collisions), even if they are 10 microns.

[emtel]

a reasonable concern

[toast0]

If we assume there's some altitude that's so polluted by debris that we need to intervene, it might not have that many functional satellites left. Cleanup the orbit in 1 year might be something the world could agree to if the alternative is waiting 5 years for it to clear up by itself.