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

economist.com

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

#11

Post by gchamonlive »

> 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 preserve enough kinetic energy after collision to promote this chain reaction? And how long until lower space ring is actually unusable?

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

#12

Post by ehnto »

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.

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

#13

Post by copperwater69 »

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

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

#14

Post by spockz »

villgax wrote: post #4

Can a large magnetic pulse for a short duration get shards to at least come together & somehow be yeeted down towards earth?

I suppose a large blob of magnetic gel might be more useful, attached at the front of a rocket. Magnetic and gel like substance to trap any parts, dust, an debris from collisions.

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

#15

Post by hoseja »

immmmmm wrote: post #10

curious of the price of de-orbiting an m6 screw (say m = 4g, v = 8000m/s) given it has the same kinetic energy as a small car (m = 1000kg v = 16m/s).

You don't need to get rid of all those 8km/s. Just enough to drop down into the atmosphere, the rest is a shooting star.

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

#17

Post by tomhoward »

Fun fact: A hobby satellite my father helped build as a way to justify procrastinating during university in the late 60s is now low Earth orbit space junk. He says he's rather embarrassed to have learned, post launch, that it would likely remain in orbit for 100,000 years.

https://en.wikipedia.org/wiki/Australis-OSCAR_5

http://centralblue.williamsfoundation.org.au/oscar-5-the-fir...

https://www.youtube.com/watch?v=hjhto6wUQYQ

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

#18

Post by detritus »

villgax wrote: post #4

Can a large magnetic pulse for a short duration get shards to at least come together & somehow be yeeted down towards earth?

Sounds like a great idea! Although I imagine the size of pulse required would probably be such that it would have some less than desired secondary effects on the upper atmosphere, technologies at ground level and the various early warning systems deployed by our nuclear-armed nations... .

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

#19

Post by f-word »

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?

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

#20

Post by Retric »

nielsole wrote: post #8
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?

on the other hand you move a lot faster than one usually does on earths surface

If everything on a given orbit it going in the same general direction then their relative velocity is what matters. Collisions are not an issue at geosynchronous orbit for example.
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