Recycling Orbital Debris

[shynung]

Over time, as you may have noticed, space programs leave literally tons of debris in space, particularly near Earth. These range from nuts, bolts, flakes of paint, and fairings to spent upper stages, inoperable satellites, and hapless souls stuck in out-of-fuel pods. Over time, these debris may hinder space operations, or render them impossibly dangerous.

Most proposals that I have read to deal with these debris either simply deorbits them outright, or lower their perigee to hasten orbital decay.

Why can't we simply collect them, I say, and recycle or refurbish it to become new spacecrafts?

We could launch a spacecraft designed to capture these debris. It could either use some sort of mechanism to gather nearby debris, or it could simply wait for incoming debris. It could either gather only useful debris like satellites, upper stages, or things like nuts, bolts, and scrap metal to be used as spare parts for other spacecrafts, or it could use some sort of solar furnace to melt these things and feed it into a 3D printer, making parts for other spacecraft.

I'd like to hear your opinions on the concept.

[Technical Ben]

It could be a possibility one day. Currently it requires a lot of energy and time just to recycle on earth. Making "new" can be easier. Same applies for space. Though look at the shuttle, ISS and others, they recycles stuff "inside" the craft.

[Runboy]

This DOES seem like a good idea,except that unlike some people think,the space around earth that space debris is found in is actually quite large.Why I said this is that you cannot just fly a certain direction and make minor adjustments to your "Flight path" so that you intercept space debris and collect it for recycling.Another reason of why this is not a practical idea is because of the fact that most of this space debris is just space trash,and is made so it is disposable.

[sgt_flyer]

One of the problems you will face, is that most current sytems use a lot of various composite materials - which will be very hard to process enough to be usable for 3d printers. I think You'd be better off directly reusing the full parts - although most electronics might have to be replaced - without thermal control on disabled stuff, the components would end up frying in the sun

[Motokid600]

I just cant imagine a spacecraft that has enough Dv to rendezvous with every piece of debris up there. I mean think about it in KSP. I play with unlimited debris so after a month I have a good 30 - 50 pieces of debris in LKO. The craft would have to be... very intricate. Not just being able to rendezvous with each piece, but they deploying the means to deorbit it... and then again for everyone one. Idk.. it could be done, but id be hard. Not to mention having to avoid creating more debris in the process.

[KASASpace]

So, you want a cure for Kessler Syndrome?

Besides that, how about this:

A large vehicle is LEO, capable of collecting HUGE amounts of debris.

Once it collects its maximum payload, yes, payload, it deorbits slowly, very slowly over many orbits. It then uses its "wings" to provide lift once it gets deep enough in the "pea soup"

It's massive and has low density, ideal for efficient reentry. (Literally huge, perhaps over 100 hundred meters wingspan!)

[KASASpace]

I just cant imagine a spacecraft that has enough Dv to rendezvous with every piece of debris up there. I mean think about it in KSP. I play with unlimited debris so after a month I have a good 30 - 50 pieces of debris in LKO. The craft would have to be... very intricate. Not just being able to rendezvous with each piece, but they deploying the means to deorbit it... and then again for everyone one. Idk.. it could be done, but id be hard. Not to mention having to avoid creating more debris in the process.

Well, Ion engine's have Isp's in the thousands, so why not use them? Sure, it has tiny thrust (even still, in KSP I mean), but it can be done.

[Nuke]

most satellites in geo are required to be sent to a graveyard orbit at the end of their life, if all the things go to the same graveyard orbit, then its not hard to stick a space station in a concentric orbit and grab pieces of debris with a small robotic retrieval probe. disassemble and sort parts. this makes sense in the transition period between zero infrastructure and lunar manufacturing. a stripped old screw might be able to sell for hundreds or even thousands of dollars. a retired topaz satellite's nuclear reactor would be priceless. harvesting junkyard stuff is a redneck tradition, even in space.

[Dwayne_Knight]

I'd try laser ablation to push the junk into collection paths with intercepts with a collection vehicle that don't lose momentum. I'd deorbit some of the junk to propel my system. The key thing I'm trying to imagine is what to do with the material other than propulsion. We have limited fabrication capability at this point. Perhaps building that asteroid tug that's been proposed. Junk mass is as good as any mass for that I suppose.

[lajoswinkler]

Recycling on Earth sometimes is an useless and stupid endeavour. In space, it's always useless and stupid. Materials degrade. What's up there is just junk.

[KASASpace]

Recycling on Earth sometimes is an useless and stupid endeavour. In space, it's always useless and stupid. Materials degrade. What's up there is just junk.

But the raw materials, at least for the most part, can be used again if recovered.

[lajoswinkler]

But the raw materials, at least for the most part, can be used again if recovered.

Such effort would be completely futile from an economic standpoint. Something like recycling spent bubblegum stuck to the pavement to make new bubblegum. Dreadfully futile.

[K^2]

Recycling on Earth sometimes is an useless and stupid endeavour. In space, it's always useless and stupid. Materials degrade. What's up there is just junk.

On Earth, pretty much the only material worth recycling is aluminum, because of the amount of energy it takes to recover metallic aluminum from ores. Everything else is cheaper to just dig out and refine afresh. Consideration for recovering space debris are pretty much the same. It's all trash, but there is a lot of energy in it. I don't know if there is any practical way to do so, but if one could cheaply recover debris, it'd be worth just for the mass that's already orbiting. That's a big "if", I know.

[KASASpace]

Such effort would be completely futile from an economic standpoint. Something like recycling spent bubblegum stuck to the pavement to make new bubblegum. Dreadfully futile.

No, it's not like recycling bubblegum that way.

It's like going out to sea, grabbing a sunken boat like salvage, and then towing it back for scrap.

[lajoswinkler]

On Earth, pretty much the only material worth recycling is aluminum, because of the amount of energy it takes to recover metallic aluminum from ores. Everything else is cheaper to just dig out and refine afresh. Consideration for recovering space debris are pretty much the same. It's all trash, but there is a lot of energy in it. I don't know if there is any practical way to do so, but if one could cheaply recover debris, it'd be worth just for the mass that's already orbiting. That's a big "if", I know.

Spent nuclear fuel, steel, aluminium, precious metals like gold, silver, platinum group, mercury... That's worth recycling.

Things like paper are laughably futile and stupid to recycle and are used as a bone tossed by politicians to hungry dogs of the ignorant public. Plastic is almost always better to burn and use the energy of burning.

You mean kinetic energy of the orbiting mass? How could that be harvested? I really see no solution for that.

No, it's not like recycling bubblegum that way.

It's like going out to sea, grabbing a sunken boat like salvage, and then towing it back for scrap.

Back? Where?

"Going out" means spending huge amounts of energy, something you can spend on making orders of magnitude more of identical, but new stuff.

Some steel and aluminium, degraded polymers, that's junk. Nobody needs that.

[Unit327]

Sounds like the army trying to recycle the bullets the enemy is firing at them by catching them mid flight.

[KASASpace]

Back? Where?

"Going out" means spending huge amounts of energy, something you can spend on making orders of magnitude more of identical, but new stuff.

Some steel and aluminium, degraded polymers, that's junk. Nobody needs that.

It was an example.

Let's say you had a (this is supposed to be dramatic) SPACE BARGE in orbit, getting refueled with small rockets every six months.

This space barge could use a manipulator arm to "drag" things closer to it, and then clamp on a retro-fire pack, and deorbit the thing. But not after adding a small heat shield.

The debris wouldn't be de-orbited instantly, but it would be in such a lower orbit it would come back down within the next few months, so not much of a heat shield is needed.

It would also possess a small space-pod for crew to inspect the debris.

This would cost a great sum of money to keep in orbit, but it would be a valuable asset.

Once the debris is recovered (a parachute of some kind is part of the retro pack) you can melt it down or do whichever and build something out of the raw materials.

BTW, Steel and Aluminum is extremely useful, especially down here on Earth.

Degraded polymers could be perhaps degraded further and the respective elements used in other polymers.

[Tommygun]

DARPA's Phoenix program is trying to develop the technology to do some of this.

Ether by repairing or upgrading satellites in orbit or to salvage parts to upgrade or make new satellites from old ones.

They also want to make future satellite designs completely modular to make upgrading or disassembly easier.

Disassembly is a big issue in space as you don't want a bunch of loose parts coming off the satellite as you work on it.

http://www.darpa.mil/NewsEvents/Releases/2014/04/02a.aspx

[shynung]

So, you want a cure for Kessler Syndrome?

Besides that, how about this:

A large vehicle is LEO, capable of collecting HUGE amounts of debris.

This was the vehicle I had in mind, except that it is more like a 'fishnet' that captures stray junk, but doesn't leave orbit at all. Unmanned capsules such as SpaceX Dragon would regularly come up and take whatever it caught, then deorbit with the payload. Alternatively, a space tug could do the same, collecting whatever useful debris it caught, or anything it produced (most likely aluminium plates and ingots), and deliver them to operational spacecrafts in need of parts/materials.

I don't know if there is any practical way to do so, but if one could cheaply recover debris, it'd be worth just for the mass that's already orbiting. That's a big "if", I know.

If a spacecraft possessing a mass driver is in need of propellant, this is one way to feed it.

Edited April 21, 2014 by shynung

[WestAir]

If the speeds are in the thousands of meters per second, and the impacts are putting off enough newtons to vaporize the colliding parts, how could anything catch Kessler Syndrome objects?

If the net were somehow able to catch high velocity debris, I imagine an old hinge and bolt from a 1970's launch would be hard to catch in a net. Additionally, if it were in LEO wouldn't the debris decay into re-entry over the next decade or so anyways?

[shynung]

If it was an actual net, it would have been shredded away long before the accumulated payload becomes useful.

No, I was thinking of something like a metal box or cylinder, with some sort of mechanism to either capture nearby debris (robotic arm with a scoop?) or trap incoming debris that impacts them (the box had better be really durable), and store them in a container.

[K^2]

You mean kinetic energy of the orbiting mass? How could that be harvested? I really see no solution for that.

It's not so much about harvesting it, as it is about not wasting it. It's mass that's already in orbit, so it's free. You don't need to waste fuel to launch it. For example, a pair of tethered satellites can raise/maintain orbit by de-orbiting material without using any other propellant. If you have a good supply of co-orbital junk that you can collect without problem, it's a way to do station keeping while also clearing orbit of debris. Again, I don't have a clue how you'd collect the debris, since you'd need hundreds of square kilometers of capture area to be effective. Unless you fly-fish for them... Anyways, if you do figure that part out, finding use for that mass is not hard.

[dharak1]

I see what you mean, as opposed to needing 9k deltav to get one ton into orbit you only need a few hundred to bring it to where you want it. Right?

[K^2]

That's the idea, yes.

[lajoswinkler]

It was an example.

Let's say you had a (this is supposed to be dramatic) SPACE BARGE in orbit, getting refueled with small rockets every six months.

This space barge could use a manipulator arm to "drag" things closer to it, and then clamp on a retro-fire pack, and deorbit the thing. But not after adding a small heat shield.

The debris wouldn't be de-orbited instantly, but it would be in such a lower orbit it would come back down within the next few months, so not much of a heat shield is needed.

It would also possess a small space-pod for crew to inspect the debris.

This would cost a great sum of money to keep in orbit, but it would be a valuable asset.

Once the debris is recovered (a parachute of some kind is part of the retro pack) you can melt it down or do whichever and build something out of the raw materials.

BTW, Steel and Aluminum is extremely useful, especially down here on Earth.

Degraded polymers could be perhaps degraded further and the respective elements used in other polymers.

Trust me, the price of metals obtained this way would be many times higher than the metals obtained on Earth using most expensive methods. This is a futile task you're describing.