Decluttering low-Earth orbit: It's time to tidy up space

Post by 4ggr0 » Mon, Jan 18, 2021, 12:52 PM UTC

ehnto wrote: post #12

onethought wrote: post #3

Is this really a thing... orbit is a vastly bigger place than the earths surface... you’d have to try pretty hard to hit that junk wouldn’t you?

Check this site out, it's a catalogue of known stuff in space http://stuffin.space/ The ISS has regular enough operations required to dodge debris detected approaching for a near miss in space that I think it's definitely a concern for future operations. Consider as well that stuff in orbit is going ~25,000km/h or more and at that speed even a small bolt would decimate a spacecraft on impact.

Post by narag » Mon, Jan 18, 2021, 12:54 PM UTC

Post by hiharryhere » Mon, Jan 18, 2021, 1:04 PM UTC

copperwater69 wrote: post #13

gchamonlive wrote: post #11

> In the long term, this accumulation of junk may lead to a chain reaction, known as Kessler syndrome, that would make some low-Earth orbits unusable. I read about it, and it seems a little counter-intuitive for me. I would expect that in a collision in space, some of the kinetic energy would be used in internal structural changes, and not all converted to the resulting motion. Am I wrong here? If not, does it still…

Imagine two objects hitting each other perpendicularly, as opposed to head on. Plenty of momentum could be conserved and thrown out in a median vector. Edit: Not only that, but even if 90% of momentum was lost - it only takes another satellite going in the opposite direction to supply all the energy. Here's what 2 ounces of plastic does at 15,000mph to a block of aluminium. https://imgur.com/gallery/8NwAhgK

Post by f-word » Mon, Jan 18, 2021, 1:04 PM UTC

jl6 wrote: post #21

f-word wrote: post #19

Suppose you put a largeish amount of polyurethane foam in orbit, possibly around some scaffold to take up even more space, had it inflate when up there and had it absorb any wandering garbage for a while. How long would it take for the giant garbage mound to deorbit and burn?

There’s a lot of junk but it’s spread out over a lot of space. You probably won’t catch much by accident. Also, it may be going dramatically faster than your catcher, in which case it would be less like a mitten catching a ball and more like a mitten catching a bullet.

Post by f-word » Mon, Jan 18, 2021, 1:06 PM UTC

mdotshell wrote: post #23

f-word wrote: post #19

Suppose you put a largeish amount of polyurethane foam in orbit, possibly around some scaffold to take up even more space, had it inflate when up there and had it absorb any wandering garbage for a while. How long would it take for the giant garbage mound to deorbit and burn?

Because of orbital mechanics, anything that would be traveling faster than the scaffold would be at a higher orbit and wouldn't be able to be caught. The exception to this would be if the object were in an elliptical orbit, which would allow for contact to be made with the scaffold at its perigee, which be impossibly rare.