1. Who is paying for thousands of these Hoovers?
2. Why did we not launch our own "Dyson"? (c) (r)
The US and Russia may be working on Mars missions, but the galactic ambitions of the Swiss are far more modest: they want to tidy up the Earth's atmosphere. The clock-and-choc-making country today announced plans for a rubbish-grabbing space bot. Swiss Janitor Satellite, credit EPFL The tiny 30cm-long (11.8-inch) CleanSpace …
I'm sure all those actual swiss rocket scientists hadn't thought of that. You should send them a letter at once, warning them of their colossal folly before it is too late!
Or y'know, think about it for maybe 5-10 seconds.
Responsibly launched and correctly functiong sattelites will have their own disposal mechanisms already. A rocket designed for launching space-junk cleaners certainly will.
But lets not even worry about technical details. Instead think about why a single launcher couldn't carry more than one cleaning device. You muppet.
Something iffy in that - as the article notes, NASA are tracking 16,000+ bits of junk that are >10cm? Perhaps a better solution could be investigated (after all, it *is* rocket science). Perhaps useful for the really large bits that are difficult to catch, but the teeny-tiny stuff needs hoovering up (metaphorically, I suspect a vacuum cleaner approach may have a few flaws in space)
An electro-magnet might be a good idea, but would require that the space junk to be cleared contained ferrous metals (in layman's language, iron). Ordinarily because such metals would tend to be heavy to lift into space I would think that space junk would tend to be made of non-ferrous materials such as aluminium and carbon fibre.
Personally I'd fire up an object which when it got near to a piece of space junk it spat out a spiders web of something gooey, or maybe splat the junk with a goo-ball with a weight which gravity could act upon, so as to degrade the orbit of the junk, so that the junk did a graceful swan-dive into the earths atmosphere.
Alternatively, see if the dolly-the-sheep people could do a job with Ronald Raygun, ressurect the star wars armenents from the 80's, and have some fun with a live asteroids game. Practice on some bunkers in Iran until you got your sights properly aimed.
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The big parts are not the problem, but rather the little ones which are difficult to detect and which number the tens of thousands.
Also, I doubt it really is a problem, as the number of satellites hit are pretty small. Also, the alleged collision of those two sats two years ago did never happen. Space is indeed - spacy. There is very little chance a sat will hit these objects because of the huuuge volume that boxes a satellite orbit.
Little ones can easily be created by smashing big bits together or ramming big bits with small bits. So the big ones are a big issue. I recon the big fear is a cascade effect and big pieces would be vital for that to happen. Kind of like nuclear material reaching critical mass, or rather super-critical.
How about some kind of net - maybe a four-piece satellite that is deployed spinning so it opens out and stretches a net between the pieces.
Let it drift through orbit for a while, catching little bits of junk, and gradually the momentum of all the bits slows it until it makes the death plunge (perhaps a set of small retro-thrusters could hasten it's demise...).
The net would have to be pretty strong - carbon fibre or perhaps just kevlar - to catch things rather than being punctured by them
Orbital speeds are very high, so while a net might seem to be a good idea I doubt in practice one could be made strong enough to absorb the impact of something(s) travelling at high speed - even relative to something that has just got to orbit itself.
Shooting a laser at the target might work if the surface ablates enough to provide some reaction.
Also orbiting a large mass to disrupt the orbits of other objects (hopefully the stuff we still want up there can have their orbits corrected) might be worth investigating.
Orbital speeds are high, but the flying net would be orbiting at the same kind of velocity. So it should be a relatively gentle catch. Unless you launched it in the opposite direction to everything else...
This is going to sound stupid, but the extent of my orbital mechanics training is playing Kerbal Space Program. Could a net like this be flown into a slightly elliptical orbit, so that at apogee it's velocity is slightly less than the debris in circular orbits at that altitude. Then at perigee it's velocity would be slightly higher than objects orbiting at that level. If the net/gauze was adhesive enough it could accumulate debris over time. Eventually it could be brought back to earth for re-entry, or with it's large area it would probably come down on it's own.
Of course it would have to stay up for years, and be a couple of kilometres across, and would have to be rigid enough that it wouldn't fold in on itself every time something hits it. Probably not practical yet, if at all.
Also: At 30cm long, are these things based on the cubesat? Cubesat kits are supposed to be relatively cheap.
What about having a small rail gun on board.
Grapple target, turn it towards earth, or back along it's orbital path, then fire the rail gun.
The impact would slow the target down enough to de-orbit (at some point), and the cleaner-sat can use the momentum gain to send itself to the next target.
Would be a great game.... (tm)
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It would be firing BACKWARDS. Meaning it would fire the junk backwards, slowing it down potentially to the point of de-orbit. Meanwhile, the reaction from the firing would work propel it FORWARD.
That being said, I don't think you could collect enough juice to fire the junk properly on pure energy. You'd need something close to the MJ range, which solar collection wouldn't provide in a timely manner.
Going back to the idea of a net, understood that most materials have trouble with high-speed impacts, but what about several somewhat loose layers of kevlar with a little bit of give in them so as to help absorb some of the kinetic energy? Besides vests, some shooting ranges use kevlar for shooting range backstop curtains, so there is some history to using it like a net for small objects at speed.
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Junk is a problem in geostationary orbit. So far no collisions have occurred, but that has been through foresight.
Gravitational perturbations from the Sun and Moon mean that satellites don't remain on station. All geosynchronous satellites require regular 'station keeping' burns to keep them more or less in place. After they have been abandoned they can wander significantly away from where we thought they are and since comms sats are clustered over the most advantageous positions, that is a serious risk. Operators are now required to demonstrate that their satellites can be fired into a graveyard orbit a few hundred km further away from Earth at the end of their lives.
Navigate to junk. Grab. Apply delta-V to deorbit. Ungrab and reverse delta-V (quickly!). Rinse & repeat. It would need lots of fuel though, or a Tesco filling station in orbit. It's probably only practical for LEO objects though. As for getting it up there cleanly, booster stages should be designed to deorbit themselves.
What it needs is some sort of gun mechanism to put the delta-v into just the junk, not itself.
I think develop something like a big duvet, spinning, and with inbuilt stiffeners and dampers to keep it in the right shape while it fills up with space-crap and can be deorbited / tracked / boosted / maintained / forgotten about / hidden behind.
Would make it very difficult to do that, the best you could hope for is that the process increases the orbit of the device, whilst degrading the orbit of the target. Even for a missile, you still need to push the projectile away from the launch vehicle, before it fires.
Oh, and aren't missiles and guns banned in space. I should think the satellite owning countries might be a bit twitchy about the Swiss putting, what are in effect, hunter killer satellites into orbit.
But if someone was going to do it, to tidy up, you would want it to be the Swiss, so lets hope they get the security right, you wouldn't want the these satellites hijacked by anybody.
I thought about trying to translate that for my fellow Yanks, but I think the cultural barrier is a trifle high when it comes to The Wombles :-)
I never recommend Wiki for anything, but I suspect that it has a fairly decent overview of the subject. I can't be arsed to look.
The objects being considered are traveling AT SPEED, more like a Marlin dashing through the ocean at 30kph or something like that. The point is, when something that fast hits your supposed trawling net, it has a distinct chance of having enough kinetic energy and inertia to punch through.
For the net to work, you'd need something designed to catch those kinds of objects. Which is why I thought a while back on several loose layers of kevlar: an idea which is already being used on the ground for shooting range backstop curtains (where they experience the kinds of projectiles they would encounter in space--small objects at speed). Kevlar mesh is designed to absorb kinetic energy, so that helps. Keeping them loose (or perhaps using a more-flexible armature) allows them to give and absorb more energy, and using layers means that even if it manages to penetrate one or two layers, each penetration knocks out more energy that may allow it to be caught by the next layer.
OK, I know you're just making a little joke, but this perception of the Swiss has annoyed me ever since I visited one of their machine-tool companies in the eighties. For years I had to listen to Thatcherites saying that we could base an economy on financial services, "like the Swiss", knowing it to be utter bullshit.
this is a very true cliche - they even wash the streets here every morning. I am not at all surprised that they have come up with a satellite to do the same thing in orbit!
On a pedantic note, is it from the University of Lausanne, or EPFL? The two are separate entities...
Surely the best way to tidy up debris without destroying the craft is to use good old newtonian physics. Turn the craft (and attached debris) round to face the opposite way to the trajectory and eject the debris 'backwards'. This will both slow the debris (sending it into a decaying orbit) and slightly speed up the hoover-ship, helping it on its way to the next piece of scrap. A simple spring mechanism should suffice, with a little motor to wind the spring back in again ready for the next mission.
I am not very sure of this, but I believe that slowing down an orbiting object actually raises its orbit. For example, low Earth orbit satellites whiz around the Earth several times a day, while those way up higher can be geostationary. What you need to do is the opposite of what you propose: speed up the junk, to lower its orbit.
Erm, the further out the orbit is, the lower the speed, but the sum of potential and kinetic energy is higher. Any burst in any direction will throw any satellite into an elliptic orbit, and then the math gets complicated.
So, yes, you need energy to reach a higher orbit and yes the velocity will be lower there, and of course the angular velocity will be even lower since the length of the orbit is increased in addition to the lower velocity.
To the original poster. A decaying orbit will only be achieved when there is a drag at some point, just lowering the speed won't accomplish anything since once in has fallen down a bit it will gain it back and then some. A drag can be accomplished if the elliptic orbit goes through the atmosphere. Shooting the debris "backwards" with a spring won't even make a dent on the velocity.
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What we need is some satellites fitted with lots of lasers and these lasers are controlled and aimed by anyone who coughs up the dosh. Points could be awarded for the most rubbish hit and a small refund given. Points would have to be deducted for shooting down something important like a comms satellite etc.
Great fun and it would have people queuing up to have a go. Make a fortune :-)
How much space junk, of all types, will it take before damaging the atmosphere? Does anyone know?
Can these proposed "de-orbiting" devices determine the composition of a piece of junk, to selectively avoid those objects that it might be better to leave up there?
Given the proposed level of expenditure, would it be possible to recover these materials back to terra firma rather than looking to burn/melt/atomise them in the atmosphere?
Is there a contamination risk? -No.
How much junk can it take? -One piece, as stated in the article
Can they determine the composition of a piece of junk? -No, but since it probably will go for the larger pieces I would think that asking the manufacturer is easier. As for the objects better left up there I have no idea what that would be. Are you thinking of the sun or something like that?
Would it be possible to recover these materials? -Yes, but I think, I am not sure, that it is more expensive to recover things in space than to get it back, and it is at least way more expensive than the junk is worth. It is after all junk. The bots themselves are worth more, not to mention the putting them up there.
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Almost all of them. Most satellites are in Low Earth Orbit in the (lower) Exosphere (some are in the Thermosphere). LEO is where almost all of the junk is as well. Then there are the satellites in Medium Earth orbit which is still in the Exosphere, as far as I know . Don't think High Earth Orbit is, though, but there are very few up there.
Maybe not blu-tak but we've been using foam-based coatings to protect space-stuff from high-speed micrometeorite impacts for decades so why not have a satellite with a large umbrella coated with the same stuff just fly in circles until it has swept out a clean area? Bigger stuff can be dealt with using different techniques.
Use a gigantic magnet made of a flexibile material similar in deployment to a large solar sail.
Powered by a small nuclear reactor.
The "sail" material would need to be able to reverse polarity in order to prevent a high speed collision. This would also be used to eject the material back towards the earth once captured.
Heck it might. It not even have to actually capture the junk. Just slow it down enough that gravity would take it over, or a simple course correction.
One time seems like a huge waste of everything from the collector itself to the fuel to get it into orbit.
Maybe more of a trash bin than a suicide satellite would be better. Also make it so it can throw the waste downwards when it gets to a place in orbit where the waste will hit an ocean area that is not usually busy with fishing ships, freighters, or such.
Basically pick up the stuff and toss it into the ocean. Sure would lower the mission cost substantially.
This is a really disturbing plan, and it's not even April 1. On the surface it seems to be in the running for "stupidest thing I've ever heard in my whole life".
This sort of thing has been studied for decades by groups with resources that completely eclipse the entire Swiss GDP. Of course they never really said THEY were paying for it.
The kinetic energies involved far exceed fly paper, and a large percentage of the stuff is probably non-ferrous. So their grabber thing might solve those problems. Of course the far more likely scenario is that the debris will puncture their toy and turn it into more space junk.
I read once that if there were 24ct gold bars sitting on the surface of the moon we couldn't afford to go get them. I think that would be downright profitable compared to this farce. At least they didn't say they were going to drive around and collect more than one piece. Changing orbit is the single most extravagant thing you can do. So at least it qualifies as bad science fiction instead of stupid science fantasy.
Maybe their next version will have Fairies on Unicorns packin' Disruptors. They can call it their FUD program.
That was my icky feeling also when I read about it, but when you look past the sales pitch and press release packages it might not be that bad of an idea. Isn't it essential an attempt to make an off the shelf defunct satellite deorbiter? Nothing else than a small booster and a simple grabber. The grabber won't need to be strong as long as you manage to match the speed first and the booster doesn't have to stronger than to gently push it out of orbit with a few Newtons of thrust.
Btw, there is no claim that this has to be profitable, or at least not in that sense. If those gold bars on the moon your were talking about somehow prevented us from having any satellites in orbit I bet we would contemplate moving them.
Apologies if anyone's already posted this, but in the time it took me to read the article I came up with a better idea - which begs the question how do these idiots get funding! Why not just float beside the piece of space debris and then ram it like a snooker ball, knocking it off course down to Earth, while leaving your DustStar (TM) free to target further junk until it's supply of compressed gas (or whatever for thrusters) runs out? You could attach something to the ramming side to make it so it didn't even have to be that accurate (like a bowl). If you need to control it around obstacles, just set up a few relay points. Or use the Hubble Telescope to focus sunshine and turn up bits that way.
There's so many other things you could do too, harness the kinetic energy of the debris, while sending the debris itself down on a slow path to Earth. Use the debris as a fuel source depending on what it is...anything, do anything but this crap idea!
Whatever it is doesn't have to stop the junk, just slow it down enough to deorbit. A big net held in the corners by some ion thruster satellites, let tidal forces stretch it out ... vertically anyway. Spider silk is weight for weight pretty damn strong and stretchy and if we can breed up some space spiders it'll be self healing. Just need some space flies to keep em alive...
This looks pretty cheap, as satellites go, and is going to be doing something rather difficult. The Swiss are developing something that will do an orbital rendezvous and docking with an un-instrumented target, and I bet everyone planning ISS robot cargo missions will be interested in the results. And for a first mission, a successful grab and de-orbit will be pretty good going. Then you can start to think about more complicated solutions, which would allow the sweeper satellite to stay in orbit and hunt down something else.
In the longer term, we're getting into space-tug territory. The control systems have a lot of applications.
Can't we just send up a white Transit up there? Blink of an eye and the local scrapyard will be £50 lighter, and space will be a ton cleaner!
Seriously though, given the amount of money it takes to send stuff into space, surely it would be a better plan to re-use everything we can up there. Remember the old days of insurance companies having their own fire brigades? (not literally, but you know what I mean). Maybe someone should put a plan together for a small orbiting scrapyard, paid for by the satellites' insurance companies, that has sufficient manoeuvrability to change orbit and some sort of capture device to reel the debris in. If you could stick a small steerable rocket on the end of a long wire, with a grapple / net / magnet / sticky gum on the end, you could send it out and pull it all back in again. Weight isn't really much of an issue once you are up there, so it could be miles long. All you need is enough strength to get over the inertia, and if the item is only 10Kg, you could do that with a bit of wet string.
Once you have retrieved a bit of scrap, a grapple arm puts it in the appropriate bin, and you repeat the process with a new or refuelled rocket. The smaller the thing that needs to move, the less fuel you need, and winches can be electric, powered by solar panels and batteries.
Right. All we need know before we hand it over to Special Projects is a name... How about DEL BOY: Debris Engaging Lasso Based On (scrap)Yard.
After all that thinking I need a pint.
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