Discussion Cleaning up the space junk?

[Evil_Onyx]

It looks like this issue has started to get people thinking.
http://www.bbc.co.uk/news/science-environment-14405118

 

[orb]

SPACE.com: Space Junk Cleanup Poses Grand Challenge for 21st Century

 

[jimblah]

Space Junk

I still think a good add on is lurking amidst the topic of space junk.

 

[N_Molson]

In terms of physics, the idea is to convert all that mass into energy. The ideal would be some kind of orbital "recycler". No idea of the technology required, though, seems difficult to do anything like that without the power of a nuclear reactor.

 

[Capt_hensley]

Build a newer, cheaper shuttle fleet(more than 5), lauch them up empty, bring them back full of defunct equipment, then recycle, study, whatever.

IT WILL COST no matter what, so in the words of Nike, "Just do it!"

 

[T.Neo]

IT WILL COST no matter what, so in the words of Nike, "Just do it!"

:lol:

Seriously though, I think the first step is an international treaty demanding debris mitigation strategies and ensuring mandatory deorbit of spacecraft at the end of their useful lives.

I'm sure changing several systems on a spacecraft to be more "environmentally friendly" (i.e. latches and springs instead of explosive bolts, etc) would already help in preventing the creation of new small debris. Ensuring the deorbit of rocket stages and satellites would help to prevent the creation of new larger debris- and new smaller debris via spallation.

Making the installation of residual propellant venting systems mandatory, at least, could prevent spent stages from exploding after mission completion.

In addition there should be a complete ban on kinetic kill ASAT weapons. Not a ban on KK ASAT testing, or ASAT testing below a certain altitude... a total ban. This is because these weapons are intrinsically dirty and could lead to an unsuitable pollution of Earth Orbit for all users of space.

And there should be a certain amount of funding put into debris removal strategies. You could theoretically fly a tug to a lot of the larger debris and deorbit them (though cost and technological requirements are an issue), but smaller debris are more difficult to remove. All the concepts for small debris removal I've seen so far are kinda... 'out there'.

 

[Keatah]

Short of building very large structures miles across and the maneuvering those structures to different orbits; I wouldn't know where to even begin!

---------- Post added at 07:26 PM ---------- Previous post was at 07:00 PM ----------

Also, I'm not too worried, the problem will sort itself out sooner or later. Low orbits may become unusable if debris isn't cleaned up. That's a no-brainer. If it happens it happens!

And from the get-go in the 60's, unneeded items should be deorbited or ejected. Sure it would have have cost more. But it will cost more now. Sooner or later the price will be paid somehow - either in lost capabilities, lost equipment, or additional removal equipment. Somehow it will balance out.

 

[n0mad23]

If satellites and stages carried some cable and means of generating some electricity, you could use the Lorentz force generated by the interaction between the current in the wire and the geomagnetic field of the Earth to produce an electrodynamic drag that will lead to a really fast orbital decay. There's a lot of literature out there supporting this idea.

 

[Keatah]

What about some sort of tether or gravity gradient de-stabilization?
Anyways, the problem is economically getting the system up there and attached to existing hardware. I could see this working for future satellites. And also for existing satellites if you apply it to 10 or 20 per year. Eventually the number will go down.

What about the smaller particles though? We're going to need some form of radiation pressure or something that can change the orbit of paint chips and small screws and brackets and Tool Bags!

Perhaps a huge-ass satellite or aerostat that can project a drag-inducing ion radiation beam that hits a piece of junk every orbit (for several orbits) eventually effecting a loss of velocity.

We may simply need a way to smash those items into Goran Dust.. Goran Dust can be blown around by the sun's radiation and the remnants will deorbit rather quickly! Big mirrors, lasers, ion cannons.. Things like that!

 

[River Crab]

That is a serious proposal, you know...
[ame="http://en.wikipedia.org/wiki/Laser_broom"]Laser broom - Wikipedia, the free encyclopedia[/ame]
Albeit still very impractical.

 

[SandroSalgueiro]

And it's been only 50 years of human spaceflight.

 

[Sky Captain]

Big pieces like dead sattelites and used upper stages could be deorbited by small tugs. It is the thousands of smaller debris that cause the biggest problem. Obviously sending tugs to catch each of those small pieces is impractical. Only solution would be to use methods that don't need physical contact with debris to deorbit them. A laser would work although it still would be limited to objects big enough to be tracked.

 

[Artlav]

Hm, how much Dv an ion engine powered spacecraft with large mass ratio would have?
We are not in a hurry, and such satellite could slowly move from plane to plane, debris piece to debris piece, and slow them down.
High ISP beats high thrust in this case.

Why could it not work or not be cheap?

 

[orb]

SPACE.com:

• Space Junk Problem Is More Threatening Than Ever, Report Warns
• Worst Space Debris Events of All Time

Florida Today - The Flame Trench: Report: NASA must address space debris crisis

 

[Keatah]

It is amusing to read; that the author of this article -- http://space.flatoday.net/2011/09/washington-correspondent-bart-jansen.html -- seems to imply that the shuttle could be used to clean up the debris. Because it has retrieved satellites before.. IIRC the shuttle only bought 2 satellites back to earth for repair.

 

[Capt_hensley]

^ Yes but it was designed to do much more. Cleaning up the junk was a perfectly legitamate use for the shuttle. But no more. Were to cheap and petty to put such a fine craft to such a noble use. For every trip up to release something we should have brought back as much junk. One would argue that there was simply no time to do such things, but I argue there was no inclination. We could have found the time, and the made the effort. We just got lazy and cheap!

 

[Tacolev]

[ame="http://en.wikipedia.org/wiki/Planetes"]Make a TV show about it![/ame]:lol:

Space junk is a very clear example of a market externality. Regulation could help prevent new space debris but don't expect anyone to go looking for money cleaning up what's already there. That is, until to do otherwise would be utterly catastrophic...

With commercial operations in LEO becoming more and more of "a thing" and taking over what have traditionally been government programs, government space agencies should be encouraged to make clean-up of space debris among their active tasks and duties.

 

[orb]

SPACE.com: Want to Get Rid of Space Junk? Catch It in a Giant Net:

A small fleet of net-flinging spacecraft could clear every big piece of space junk out of low-Earth orbit within a dozen years, according to a researcher working on the concept.

Each spacecraft, known as an ElectroDynamic Debris Eliminator (EDDE), would capture orbital debris in a net, then drag the junk down out of harm's way. The EDDEs would draw their power from the sun and from Earth's magnetic field rather than rely on costly chemical propellants, helping keep costs down, said Jerome Pearson, president of Star Technology and Research, Inc.

And the cleanup of low-Earth orbit (LEO) could start happening soon, Pearson added.

{...}

 

[RisingFury]

Hm, how much Dv an ion engine powered spacecraft with large mass ratio would have?

Probes like Deep space 1 and Dawn have delta-V in range of 10 000 m/s and more. If you optimized the engine to be a tug and included enough fuel with it, you could conceivably get some 20 000 m/s delta-v, even once you include tugging large sats.

The cool thing about such a tug is that it uses chemically inert fuel that does not escape from the tanks. The life span of such a sat would be long. The ISS could even serve as a refueling hub. Shipments to ISS could include fuel for such a tug.

The problem is that an ion drive does not have much acceleration. The only thing such a tug could do is place a satellite into an elliptical orbit with periapsis at around 150 km or so, so that drag would deorbit the satellite in a controlled reentry.

 

[Urwumpe]

I suggest launching tons of aerogel into space for forming a huge brick and let it sweep the orbit clean of everything...