Man made Junk is building up. Solutions seem weak.

Ok, heres the thing. In the sixty or so years since man first chucked an object beyond the confines of our atmosphere, we have produced, literally MILLIONS of individual bits of debris, and thats just the stuff that is large enough to actually see with our plethora of detectors.

Within the number of those millions of objects, are allegedly thirty two or so nuclear power plants, which used to run satellites and other defunct space machinery, but are now just free floating junk, hurtling around the space close to Earth, at more than twenty thousand miles an hour, along with all the other, less terrifying, but still dangerous lumps of debris up there. At such speeds, a chip of paint can put a crack in a space ship window, which come in inches thick, and are designed to be very hard indeed.

Now, I have been watching a few programmes, looking around the internet, and have found a few solutions being thought about in the space industry at the moment. One involves attatching solar sail like contraptions to the larger bits of orbiting refuse, to slow them down to the point where Earths gravity can grasp them more firmly, pull them in, and therefore see the object burn up in the atmosphere. Another idea, which is similar in its aim, is to attatch a ruddy great big balloon to these objects, having the same braking effect, and having the same end result, of an atmospheric burn up of the offending article. Perhaps the most interesting is a harpoon, being developed in the UK, which, using compressed air apparantly, will lob a barbed arrow into chunks of satellites. Those arrows will be attatched to wires, linked back to the launch platform. At this point, having been secured in such a fashion to the launch platform the whole thing, launcher and captured object, will again plummet to Earth.

Is it just me that considers all these solutions to be somewhat...pathetic? Is the best we can do with this junk, to slow it down, and drop it on our planet? Some of these objects contain significant levels of radiation after all, and so I really am not even remotely comfortable with something like that being burnt up in the atmosphere, since we have done enough radioactive polution of our atmosphere in the decades recently passed.

I wish therefore to pose a question. What do the membership think, would be a better solution? I am personally in favour of a solution that involves recycling these objects, using collector vessels to entrap the objects, and either re-purpose them while the vehicle is moving through space, or bring them down to be used again, either in experimentation to refine our understanding of how long exposure to space alters the material strength of various metals and plastics. Merely transporting these objects (which must come together to weigh some considerable hundreds of tonnes or more) to the atmosphere, where they can be destroyed, seems a little lazy to me. Is there no way we could do something more positive with these things? I mean, they are already up there after all right? So maybe we could re-use these things in future orbiting structures, if we could capture them in the first place?

I sort of like a harpoon-type of solution, but with some modifications.

I think that a harpoon could be spring-powered like the old toy dart guns. Instead of having to have compressed gas, it could just have an electric motor reel in a harpoon on an attached cable. Everything could be electric -- powered by solar panels. An option to what to have on the end of the harpoon might be a large clamp instead of a spear-point to "grab" the target instead of piercing it.

Once the target is brought in closer, the satellite could then salvage useable parts for re-use later. Now, when the object is "cleaned" and ready for "disposal", I'm thinking that instead of having the entire satellite and its collected junk sent back to burn up, it could have electric gyros onboard that would cause everything to spin. Then at a precisely calculated time, the space junk would be released so that it is "thrown" into the atmosphere to burn up, while the satellite would be sent in the opposite direction that is calculated to also bring it close to its next targeted space junk.

This idea uses electricity from solar panels to power the harpoon and gyroscopes for maneuvering so it would not need any refueling and unless it gets damaged, it should not require any servicing. The calculated throwing of trash would serve to continue to keep it in orbit, so technically, it would not itself be at risk of coming back down until it runs out of trash to clean up.

I guess every so often, it could throw the salvaged parts towards the space station when someone there would be ready to "catch" the reuseable items and either incorporate them into the space station, or send it back to Earth on the next supply vessel.

What do you think?

I think you have a fascinating idea there. The orbital cast offs must have good things to salvage and maybe the next orbital platform shouldn't be a science station like the ISS as much as a big collection and processing one, like you say. Whatever couldn't be salvaged could then be fired into the atmosphere below I'd guess and burn into nothingness in small pieces rather than the overall objects which all too often seem too large to burn entirely as it is now.

Mir alone was travesty to imagine being allowed to just fall and burn if a way to salvage in orbit existed. Skylab too...to think of the waste that's happened. There is plenty up there that won't be useful forever or already dead though huh? So much effort and cost getting stuff there, after all. S/F!

reply to post by davidchin


I am in favour of any project or idea that does not involve throwing the capture vehicle back to Earth in a final manner. But I would still like to see development of plans that involve some level of recycling of all this valueable raw material.

reply to post by Wrabbit2000


I agree about MIR. Such a shame. I read that there was an upper limit placed on the wieght of debris that could theoretically be out there. That number is 5,400 long tons or 6,100 short ones. The ISS on the other hand, currently has a mass of 419.6 metric tons.

Imagine what you could construct, with that much material, if only you could reclaim all the miles of wire, the metre after metre of sheet metal. Its a proposition that I think is beserk enough to warrant further thought. I hope this thread can showcase some of our ingenuity here on ATS, as this is one of the areas in space research, that is going to be at the front of the queue over the next couple of decades.

Regarding the 'Nuclear power plants' the correct term for them used on satellites is an RTG, they usually only contain 1 or so Kg of Radioisotope.

For that to burn up in the atmosphere and be spread far and wide is not at all dangerous to life and health in comparison to things we do every single day.

We are not talking about multiple tones of material or indeed huge objects... RTGs are typically small.

The methods mentioned are not that weak, they are just not that fast. The issue with many of these plans is that a launch vehicle is not free, and you risk putting more material up there with each launch. So coming up with a solution that is easy to perform is likely the best one.

Meeting an object in orbit is not trivial also, let alone building a system that can be autonomous... launch, approach the target... plant something on the target... engage that plan and return... its more work and engineering than i think you realize. Plus getting your launch vehicle back in one piece or recovering objects is difficult too. It really is not the case that you can just essentially fly up, grab something and come back. It is not like pulling up on the side of the road to pick up a TV.

One mistake and you can end up having more 'debris' up there than you intended.

reply to post by ErosA433


Im not interested in a vehicle that comes back. Im talking about a vehicle which collects, strips and recycles all the junk it can lay its appendages on, and combines those components into a new, useful configuration, without them having to go back to Earth. Im talking a craft with the capability to return an old component to a pile of raw materials, and then recombine those raw materials in such a way as to be useful.

And regarding that nuclear material. In the last five or so years, there was a development in the feild of creating batteries, which use isotopes as a powersorce. The batteries consist of the powersource, surrounded by a sandwhich of dimpled silicon layers. By some arcane means, the silicone interacts with the particle which is released by that isotope and the energy is converted into electrical power. Meanwhile, these batteries are capable of containing any potential leaks. They dont let by!

If the craft were to be furnished with the ability to encase the radioactive material onboard old RTG's (thank you for that, I knew there had to be a proper name) inside such a sandwhich, then there is even potential to recycle those elements, and use whatever energy they are still capable of outputing, in the constant retrieval and recycling of all the junk in space.

The end result could be a five thousand plus ton spacestation, that built itself out of trash. Incidentally, Im thinking that this ought to be an un-manned process, due to the potential dangers involved. What I am looking for in this thread is positive suggestions, workarounds for all the things that make such a venture a thing of fiction. We have to remember that the things that were science fiction when the space race had not even begun, were the basis for todays space exploration technology. Its audacious, but I think the more outrageous the premise, the more fascinating the possibilities.

I mean, who thought they would ever have tried to land a rover on Mars, by suspending it from a rocket platform on wires to ease the impact of landing?
Rumour has it, that such a thing could run a car for a century.

This is indeed a very interesting concept, apologies that I missed it. It too is actually one that creates an even larger technical challenge since alot of the objects that float around are the odd nut and bolt, the odd bit of rocket that fell off, the occasional piece of satellite. You would also need to collect it all, the orbital dynamics of doing so its pretty crazy and the craft would require the ability to make quite large adjustments in its orbit... gaining velocity for increasing altitude while doing so in a stable manner. It should also not run short of fuel while it does this.

LOTS of challenges for that


The batteries as you mention I know almost nothing about, though I could imagine a device would be possible using a weak (low energy) beta emitter... tritium maybe? the silicon could then probably act as a PV cell and absorb the energy and turn it into current.

HAHA did a quick google and found a site talking about tritium for it.
Tritium is however quite rare, and expensive... very interesting though!