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More on Orbital Space Debris 275

Posted by michael from the clean-sweep dept.
wvanhuffel writes "This is a call for /.'s to put their thinking caps on. The US Airforce, NASA and other agencies are looking for ideas to find and eliminate threats from space debris to craft (space, in the use of). Personally I like the idea of "robots to serve as roving garbage scowls" - my question is "How do they identify 'garbage'?" - Would the ISS qualify?" I don't know what happened to the laser broom.
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More on Orbital Space Debris More

More on Orbital Space Debris

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  • Sticky Umbrella (Score:3, Insightful)

    by nagora ( 177841 ) on Friday July 12, 2002 @06:58AM (#3869729)
    How about a large dish coated with a think layer of soft material which you put into an orbit you want to clean and after its been there for a while fire the retros and burn the lot up in the atmosphere.

    Obviously this only works for grit and other small things.

    TWW

    • Re:Sticky Umbrella (Score:3, Insightful)

      by Wonko42 ( 29194 )
      The biggest problem with this is that there aren't specific "debris-only" orbits. In addition, space is *vast*, even just the immediate area around our planet. Putting this dish in a new orbit for every clump of debris we want to collect would be extremely expensive in terms of energy, which translates directly to expense in terms of money.

      • Re:Sticky Umbrella (Score:2, Interesting)

        by nagora ( 177841 )
        The biggest problem with this is that there aren't specific "debris-only" orbits.

        But there are "useful-only" orbits that we want clear. You would have to do some sort of analysis of how long a given size disc would have to be in orbit to clear it to a specific level of safety.

        Well, it was just an idea.

        TWW

      • Energy consumption can be dealt with in terms of nuclear propulsion. We've done it before in space - not sure the ramifications of using it in near-earth orbit, though.

        I know that a large quantity of what's up there has solar power - I'm not versed well enough to know if we can easily convert solar power into movement (I imagine we can, though). If solar could be used it would cut huge amounts of money off the project. Of course, it the Debris Collection Satellite might have to sit and charge for a while to be prepared to chase debris.

        Right now we track much of our orbital debris with radar, but we lose decent resolution around 10 cm. Tracking from a satellite could be much better, as we don't have to account for weather and variables, like birds (hopefully ;). This would allow us to determine what's up there.

        The hard part is getting everyone to tell whoever is doing the cleanup what needs to stay up there. Multiple countries, companies, all would have to either provide the location of their equipment to not have it damaged/destroyed, or make a massive effort to have it all change orbit so we could clear an orbit at a time.

        I like the theorum of throwing things back into the atmosphere, but I think it would be better to collect it, say, at the ISS, and attempt some sort of salvage. There is millions of dollars in technology floating around up there unused, so why not save on launch costs if some of it can be reclaimed?

        Of course, collecting technology with the untent to re-use it would be even more expensive...

        --
        Curiouser and Curiouser...

    • Yeah but get a better name for it. I can see the stories now.

      In a bold move yesterday, president Bush declared that a sticky umbrella would save us from meteorites

    • Deja Vu, No? (Score:2, Insightful)

      by 2g3-598hX ( 586789 )
      This discussion has come up before. [slashdot.org]

      And before you get modded up further, small pieces of grit are capable of creating holes in the the space shuttle's windshield. [aero.org]

    • Re:Sticky Umbrella (Score:5, Insightful)

      by God! Awful ( 181117 ) on Friday July 12, 2002 @08:31AM (#3870055) Journal

      How about a large dish coated with a think layer of soft material which you put into an orbit you want to clean and after its been there for a while fire the retros and burn the lot up in the atmosphere.
      For some reason, one thing I haven't seen people mention so far in this thread is the fact that to be in orbit at a given height above Earth, you have to be travelling at a very specific orbital velocity. So the umbrella either has to be going with the flow, in which case it's not going to catch up to any of the space debris (unless the debris has an eccentric orbit), or against the flow, in which case it is going to impact the space debris with a very high velocity.

      I suppose a third option is to have it going with the flow, but faster than orbital velocity, in which case it's going to need a lot of fuel... (remember, a spacecraft has to eject balast every time it changes direction, otherwise conservation of momentum would be violated.)

      -a
      • So the umbrella either has to be going with the flow, in which case it's not going to catch up to any of the space debris (unless the debris has an eccentric orbit),

        I was assuming that the debris would be in an eccentric orbit and that some number of "umbrella orbits" would be needed to reach a desired level of confidence.

        TWW

  • How do they know if it's trash? (Score:3, Funny)

    by Qender ( 318699 ) on Friday July 12, 2002 @06:59AM (#3869730) Homepage Journal
    "No, bad robot, the earth is not debris."
  • A big freakin' magnet?
    Make a satellite that's nothing more than a huge electro-magnet, launch it, turn it on, attract junk, do either a controlled descent or shoot off towards the sun (or other nearby, large orbital body.)
    • Hmmm, feels like there would be an energy problem with that soloution. OTOH, I don't know much about top of the line electromagnets. Maybe its is possible to make something that ha near supra conductor capabilities in that enviroment.

      But to be able to shoot off debris sounds far over the top. But then again, what do I know?

      Anyone who have worked with high capacity electromagnets care to comment?
    • I agree a magnet is not a bad idea, but heres an idea. Attach smaller electro magnets to stuff, sattelites, space stations, orbiters etc. and have them pick up the junk thats coming at them and passively sweep. Thats gotta be cheaper than building a dedicated satelite. Couldnt someone come up with a way of processing those collected scraps for fuel onboard said satelites/heavenly vehicles??...

      Just an Idea...


    • Just curious as I am under the impression that not all of the debris is composed of ferrous material that could be affected by a large magnet. Some of the debris is little more then chips of paint that fell off of satellites, shuttles and other space craft.

  • Simple. (Score:1, Interesting)

    by drdata.nl ( 584604 )
    Let devices with a steel 'fishnet' orbit the earth in predetermined lanes. Connect them to a central 'space traffic control' which keeps track of registered objects. Remove all objects that are not registered, either by laser, or by using the fishnet (and bringing it back for examination)
  • Why not just a Bloody Great Chunk Of Metal that just whips along absorbing everything that hits it? Or is getting something that heavy into orbit too much hassle?
  • Wonder if this is entirely a cost without possibility of earning a buck or two.

    If this is a cost only thing, shouldn't the countries/companies that have 'polluted' the 'area' pay for the cleaning themselves? If not I'll bet you that some distant russian company already offers this service if you are a youg popstar or you just are loaded with cash.
  • Is There research or prototypes of Force Fields? As such in Science Fiction? Are Force Fields possible..and if so, how/what they work? If they were feasible, would this not be able to protect against debris?

    what are some of the common protections/ideas used in sci fi against interstellar/orbital debris.

    I think trying to locate every nut and bolt leftover in space is not feasible...and those small items are probably the most dangerous as they are difficult, if not impossible to detect...right?
  • Anyone ever seen 'Junkyard wars'/'Scrap heap challenge'? Just send the contestants up there and use the orbiting resources for their creations :-)

  • Here it comes... (Score:5, Funny)

    by JohnPM ( 163131 ) on Friday July 12, 2002 @07:04AM (#3869746) Homepage
    Yes it's time for slashdotters to put their thinking caps on. I'm sure our geek aura will penetrate a problem that has had the best minds of the world's space agencies stumped for decades.

    I await with glee the hoards of posts suggesting enormous ballistic inflatable penguins and fleets of linux powered robotic red swingline staplers. But what about prevention in the future? Easy, just make all space objects run Windows, that way they will crash themselves into the blue ocean of death eventually.

    There, I've got it out of the way early so hopefully others won't need to.

    • what abou the space pen? (Score:3, Insightful)

      by Juju ( 1688 )
      When you think that NASA spent countless $$$ to come up with a pen that would work in space (in a zero grav environment) to come up with a very expensive system (involving ink being put under pression) where each pen would cost over $10,000.

      When the obvious solution (used by the Russians) was to use a pencil...

      I think that having this kind of question opened to anybody can only help...

      • NASA spent countless $$$ to come up with a pen that would work in space

        Not true. Check out http://www.snopes.com/business/genius/spacepen.htm The Fisher Space Pen (and I happen to own one) was developed without NASA requesting it, or paying for the research.
      • When you think that NASA spent countless $$$ to come up with a pen that would work in space (in a zero grav environment) to come up with a very expensive system (involving ink being put under pression) where each pen would cost over $10,000.

        When the obvious solution (used by the Russians) was to use a pencil...
        This urban legend has been thoroughly debunked [snopes.com]. NASA didn't spend a dime developing the space pen. They were completely developed by a private company. You can even buy them [thewritersedge.com] for $40.
    • I'm actually disgusted that my post was modded to 5:Funny. This is exactly the sort of post that makes me want to set a -2 penalty on funny posts in my preferences!

  • Don't make it worse (Score:3, Insightful)

    by seosamh ( 158550 ) on Friday July 12, 2002 @07:06AM (#3869752)
    Nowhere in the article do they discuss plans/methods to avoid making the problem worse. Shouldn't there be an international standard, at least among the ISS participants, for getting new space junk out of the way? A French satellite collided with remains of a French Arianne booster. Wouldn't it make sense now to define a standard procedure for ensuring that junk is sent on a destructive re-entry? If they use a verifiable method of ensuring destruction, it could help in assigning responsibility. And insurance companies could use that in assigning premiums (or littering fines ;>) on satellites, etc.
    • Wouldn't it make sense now to define a standard procedure for ensuring that junk is sent on a destructive re-entry?

      How about writing legislation that says people can't litter. That'll keep the Earth clean. And maybe fine people for littering - that'll be a good incentive.

      What do you mean that we already have that??

  • Adhesive tape and a large hand (Score:3, Funny)

    by Little Dave ( 196090 ) on Friday July 12, 2002 @07:06AM (#3869753) Homepage
    When I was a young 'un, my mother used to cure the embarrassing problem of wool-bobbles on clothes by wrapping a hand in inverted adhesive tape (sticky side out) and running it bruskly over the surface of the affected garment. These days, the rise of the mighty Remmington Fuzzaway (tm) has largely rendered this practise useless.

    I believe however, in consultation with my mother, that this might still be applied to the above problem. I propose a giant space hand, sheathed in cellotape and waved liberally about in orbit would be the best method.

  • There is bound to be some sort of RF admission or electrical noise that these LEO emit. Therefore, it would be possible to detect debris from which that is not. A garbage robot can sweep the area with sonar to detect leftover boosters; bolts, foot clamps or whatever else is up there. When the garbage holding area is full, the robot will destroy itself by falling into the ocean where the rightful owners can pick it up
  • This would be a prime application for nanotechnology. Unfortunately, we haven't quite advanced that far yet. Even so, once the technology is available, it wouldn't be hard (or particularly costly) to release clouds of self-propelled (maybe even solar-powered) nanobots into orbit that would target orbital debris and disassemble it on a molecular level, using the resulting extra molecules to build more trash-seeking nanobots or, alternatively, simply dispersing the trash molecules over a large area, thus removing any threat presented to other spacecraft.

    There's only one potential problem I can imagine with this scenario. We'd need to figure out how to teach the nanobots the difference between functional satellites and nonfunctional trash. It wouldn't be good at all if we suddenly found that our nanobots had accidentally disassembled all our low-orbit satellites.

    Now that I think about it, though, it occurs to me that nanobots would most likely be very susceptible to solar radiation, which they wouldn't be protected from outside Earth's atmosphere. I wonder how hard it would be to construct radiation-shielded nanobots?

    • Even so, once the technology is available, it wouldn't be hard

      Quite right. Also, once the technology is available, teleporting the debris to the centre of the sun wouldn't be that hard or costly either.

      • The difference here (and this explains what I meant by that statement) is that in terms of nanotechnology, we already know exactly what we need to be able to do in order to build nanobots. The only thing limiting us right now is the difficulty involved in manipulating matter on the small scale required. However, advances in this field are being made at a very quick pace, and I'm confident we'll start seeing nanotechnology used widely within at least the next 25 years.

    • Nanotbot .. Garbage (Score:2, Interesting)

      by OzPeter ( 195038 )
      Hmmm .. so we send up a zillion nanobots who recycle all the debris into more nanobots .. end result is that we end up with a (zillion * mass of one nanobot) more stuff in orbit threatening the innocent space based weapons that are just minding their own business. This is worse than just leaving the garbage all alone.

      You need to *remove* the garbage from orbit, not just transform it from one sort of item to another.

      Now if they could all assemble together into one big nanobot ball as the process progresses, then that would be another thing. But if they are delicate little beasties, then I can't see that happening.
      • Er, nanobots are called nanobots for a reason. These things are tiny, microscopic. They can be small enough to manipulate individual atoms. If you printed out this comment, millions upon millions of nanobots could live in the period at the end of this sentence.

        Now imagine these nanobots disassembling space debris into its component atoms and dispersing it. Instead of having, say, an old rocket booster casing that could do massive amounts of damage to an orbiting spacecraft, you now have trillions of individual, unconnected atoms that are being dispersed over a wide area. These dispersed atoms aren't even visible, and they certainly wouldn't do any damage to spacecraft. And that's the goal here.

        Who cares if the actual atoms themselves remain in orbit, as long as they're dispersed enough that they can't hurt anything?

    • Been watching too much SG-1 lately? You know what happened to them, don't you? If NASA takes your idea, the Asgard are gonna be pissed.
  • "How do they identify 'garbage'?" - Would the ISS qualify?"

    Oh dear God, that'd be the BEST! Imagine being able to hack a garbage collection satellite, and knock random satellites out of orbit.

    Some people consider defacing Yahoo as having enough people see. Imagine having a flickering bright light fall over the city of your choice.

    Damn I... uhhm, I can't wait to get my friend... ummm, yeah, my friend more information on how to hack... Ummm, yeah.

  • Everything for which there is no record of the object's orbit is garbage. I wonder how many military satellites that strategy would take out?

  • A lot of work (Score:3, Interesting)

    by theolein ( 316044 ) on Friday July 12, 2002 @07:13AM (#3869774) Journal
    IIRC there are about 200 000 objects ranging from milimeter size pieces to fat chunks of metal in orbit around our planet. Someday one is going to take out a spacecraft or satellite or damage one seriously. Obviously, it is going to be a lot of work to get rid of these pieces of scrap. So my carefully thought out proposition ;)...
    1.Catalogue them -- A database with all known objects and their orbits is the obvious first step
    2.Build a sateliite with a relatively low power laser, charged by solar panels. An alternative would be a simple kind of large, thick metal "shield" that would simply get in the way of the space debris.
    3.Place a ion engine on the craft.
    4.Write software that would automatically select the nearest target from the db and move the satelite into position to evaporate or impact with the debris.
    5.Very importantly, have an operator or command center that would be required by the software to OK each impact so that the satelite doesn't get misused or highjacked.
    6.If using the satelite with a big metal "target shield", eventually the shield will become useless. It can be pushed into reentry by the ion engine and can then burn up on reentry, the ion engine then climbs back into normal orbit and is fitted out with a new shield by a drone rocket.
    7.It will take many years but will start to show progress over time. Good that it will give the operators in the command center work and enable them to read books, playgames etc inbetween hits.
    • Lets just say that the laser would have to charge for a VERY long time if only solar panels powered it. (assuming you want to convert the garbage into gas)
    • An important extension to #4 is to not only calculate the route to the next piece of junk, but to calculate the lowest fuel consumption route through as many pieces as possible. Hitting the next one in the database may put you way far out for hitting the next one after that; maybe orbits will make that one more fuel efficient to hit somewhere down the line.

      It's kind of like thinking ahead in billiards about where your ball will be after the shot.
    • 4.Write software that would automatically select the nearest target from the db and move the satelite into position to evaporate or impact with the debris.

      Sounds a lot to me like the algorithms required would have a lot in common with some well-known CS research problems, like the moving of the head of a hard disk. I'm sure some existing knowledge could be applied, but the space junk problem could also be a source of new research money...

      Christopher
    • IRC there are about 200 000 objects ranging from milimeter size pieces to fat chunks of metal in orbit around our planet.

      1.Catalogue them -- A database with all known objects and their orbits is the obvious first step
      Done, mostly. The US Air Force tracks about 9,000 pieces of space junk using radar. Then they steer satellites around the junk to avoid collisions.

      Here's a story [af.mil] about it from Air Force News.
  • Take a sheet of metal, thick enough to withstand an impact from most pieces it will run into. On either side of the metal sheet, attach a few layers of mattresses or something similar. The metal would shoot through the mattress, hit the metal plate, lose most of its energy, and the pieces would generally get caught in the ricochet (if not the initial entry).

    Send a bunch of these up and send them to the predicted "hot spots." Over a period of a few years, they could absorb quite a bit of material. Being low-tech, they're cheap to make. Costly to get into orbit because of the weight, but seems like it could be affordable enough.
  • The only way this would work would be if they could identify every satellite in orbit around the planet, which would be hard even if every satellite was American. Once you start thinking about the Russian, Chinese, European ones etc. it becomes more complicated, especially if you consider that probably some goverments won't want to tell the US what satelittes they have, and what they do. I bet that not all of the old Russian 'junk' up there is as useless as its supposed to be.

  • Just fly up and use a tractor beam to tow it into the Sun. Duh.

  • An collector in space is impractical (Score:3, Insightful)

    by ShooterNeo ( 555040 ) on Friday July 12, 2002 @07:17AM (#3869783)
    First off, any kind of collector device deployed in space is totally impractical. For one thing, the mass of the device could easily end up being equivalent or even greater than any debris collected. That is, you'd need as much or more propellant and material to grab the micrometeorites and garbage in the collection robot as the mass of the stuff being collected. This means you'd have to spend as much money on boosters as we spent putting junk in orbit over the past 40 years. That's a lot of money...

    Why launch anything into orbit at all? A far better solution would be to build a powerful enough ground based laser system to convert the garbage into vapor. It would be cheaper, as you would not have to spend vast sums of money trying to minimize failures (if the laser on the ground breaks, you get out tools and fix it. If the orbital robot breaks you just blew a lot of money). To detect the rapidly moving orbital debris you would need an extremely high resolution radar...at least one of the X band things being build in Alaska.

    The laser would be an array of linear accelerators in parallel (or cyclotrons) that would accelerate electrons that would release the energy in the beam. (A free electron laser) Such lasers are inherently very efficient, and the system would only use electric power that could be obtained off an ordinary power grid (a LOT of electric power...you'd need some sort of temporary storage perhaps giant rotating drums or something)

    And the best part? A multi-megawatt laser array, capable of hitting extremely small fast moving targets with enough power to vaporize them...

    Certainly the Pentagon could think of a use for one of those.

    Say, missile defense?

    Such a system would be FAR more reliable than a rocket booster interceptor that has THOUSANDS of possible points of failure. If the wrong part fails, the booster fails. With a parallel array of lasers if one fails its no big deal. In addition, given enough power it would be able to vaporize all the incoming targets, decoys and bits of insulation and all.
    • A far better solution would be to build a powerful enough ground based laser system to convert the garbage into vapor.

      How can you possibly believe that?

      First, a laser on the ground would have to have a crapload of power since the vast majority of it would be dissipated by the atmosphere.

      Next you have to refine the optics to an extremely high degree so that the beam is still focused at the target. Even the slightest bit of divergence really adds up over hundreds of kilometers. To vaporize high tensile strength steel requires a lot of energy, and most of these objects are very small -- both are reasons for needing a focused beam.

      Also consider that they are traveling at tens of thousands of MPH. It would be almost impossible to servo track the object, so your laser would have to work with a single high-energy pulse. You'll need a very high peak pulse power to deliver enough energy to do any serious damage. And this ignores the fact that we can't actually track the majority of the debris. The ground based laser thing would need extremely precise tracking information which is just not available for anything but the large stuff -- which we can already do a fine job of working around. Also consider the aiming accuracy necessary to precisely hit a small target a few centimeters or smaller from hundreds or thousands of kilometers away. Then there's the issue of all the crap in the way between your laser and the target which could cause diffraction, scattering, dissipation, etc.

      In the 80s the Star Wars thing was going to cost how many billions (75?) to disable (not totally vaporize as you propose) much larger objects traveling at more certain orbits, and was called a technical impossibility by many engineers who read the proposal. And even this plan would have used space-based lasers so the distances and dissipation factors was not as bad.

      What you are proposing would never work. Get real.

      • How about a laser based on the ISS? Would solve most of your objections. In space, it wouldn't have to go thru the atmosphere or as far, and since the space station is orbiting like the trash, it would be much easier to track. Put some radar on the space station, hook it up to the laser, and fire away. The only consern is making sure the earth isn't behind the shot (in case you miss), but other than that, it should work.
        • Only gets the debris that gets near the ISS. Though it would make a useful ISS-only defense, and you could also make a virtue of making the beam low enough power that, if it misses and goes more than several kilometers from the ISS, it disperses out enough to have no effect.

          Though, thinking about it, might this be the excuse for spacecraft to get armed? "Of course I've got a giant freakin' laser on this bird. Gotta shoot down any debris that get too close, don'tcha know. True, I could also fux0r any other ships or sats that I don't like that I happen to get close to - or who get close to me, say if they try to board to enforce whatever law is up here - but in the name of clearin' debris, the laser itself is perfectly legit."
      • Your objections might have been reasonable in the 1970's, but not today.

        The US Air Force has an airborne laser designed to destroy missile boosters at a range of 200 miles - THROUGH THE atmosphere. So much for dissipation.

        Optics that can resolve small details of satellites have been around for a long time. If you can see the detail, you can focus a beam on it. And this is without adaptive optics, and these days adaptive optics are what would be used.

        As far as tracking.... no problem. Remember a couple of things... they are quite a ways off. They are travelling in a ballistic path - very smooth trajectory. And furthermore, the imaging cameras I described above had to be able to do that tracking in order to do the imaging. They ahve been running a long time. The Multiple Mirror Telescope, for example, has that tracking capability (yes, it is an astronomical instrument, but it was paid for by the Air Force, used spare spy satellite mirrors, and has an AZ/EL mount, and the Air Force used to borrow it for their own quiet purposes). It had that capability in the early 80's when I visited the site.

        Oh, and star wars?

        I won't even bother to refute the various errors you managed to stick into a couple of sentences.

        I don't know if a ground based laser system is appropriate, but I do know that the previous posters objections are based on ignorance, not science or engineering.
  • Move a few big asteroids into low earth orbit. That way everytime it goes around its gravity would give any debris a small kick. This will change the orbital eccentricity, and after a while the debris will intersect the atmosphere and reenter.

    Moving asteroids isn't that hard, although care is needed to ensure you don't reenter it. An asteroid big enough to make this work would be big enough to wipe out all life on earth- so be careful out there guys. ;-)

  • Obligatory Spaceballs reference (Score:5, Funny)

    by BabyDave ( 575083 ) on Friday July 12, 2002 @07:19AM (#3869792)
    "Spaceball 1 has now become ... Mega Maid!"
    • Y'know...that does suggest a possibility. Have some orbital craft go around to the debris, and shoot concentrated bursts of super-cooled air (liquid or solid so the projectile stays reasonably condensed en route to target) at each flake to decelerate it (dropping it into the atmosphere). When it runs low on ammunition, dip into a lower orbit to suck up more air, then rise up into a different orbital position (where, presumably, more debris lurk), chilling the air by shielding it from the sun and letting it radiate away heat. Also use stored air - heated up with energy from solar panels - as the reaction mass to move around. Wouldn't need to move very fast; just needs to be very reliable.

      "She's gone from suck to blow" indeed. ^_-
  • Why not just put up a sign that says "No littering"?

    All those I've seen on Earth are surrounded by empty drink cans, cigarette packs, discarded condoms, etc. Maybe the effect also works in space.
  • After I thought about this carefully I've come the conclusion that Lasers are cool and we should use them in space for any purpose we can find for them even if the application is less than ideal. Now I have a good reason for this. When ever NASA uses a big freak'n laser its bound to be front page news. If NASA can get the public ooh'ing over the neat stuff maybe they can get the funding to do some really cool stuff. Yes, I'm kidding.
  • No need for research. All we need is a pair of clones, a plant man, and transmute named Gene/Jean.

    See the IMDB for the details [imdb.com]

  • Where's Wilco when you need him!?! (Score:5, Funny)

    by rasjani ( 97395 ) on Friday July 12, 2002 @07:33AM (#3869835) Homepage
    I think NASA should hire Roger Wilco to clean up the mess. He has excellent CV for this kind of stuff..
  • Lets float all the RIAA execs in the path of the orbital debris, that should help stop it.

  • Nitpick (Score:2, Informative)

    by JohnPM ( 163131 )
    Carbon nanotubes have become a hot item of discussion across all fields of engineering because, in part, the cylinders constructed from hexagonal links of carbon atoms are believed to be perhaps the strongest manmade material.

    That should be "strongest material fullstop". The inference to natural materials can only be referring to spider silk. Spider dragline silk has a tensile strength comparable to steel, but will stretch 35% without breaking. It seems steel can achieve up to about 5 Gpa in tensile strength depending on quality, etc. Carbon nanotube fibres [nasa.gov] are expected to be in the hundreds of Gpa.

    There is a cautious belief amongst materials scientists that carbon nanotubes may in fact be the strongest substance possible in terms of tensile strength.

    A great overview of nanotubes as a construction material can be found in Bradley Edward's Space Elevator manuscript [usra.edu]. See also the slashdot discussion [slashdot.org] about it.
  • Why has no-one proposed this obvious solution? Recycle the materials that we have launched into space. The other proposed solutions aren't environmentally friendly. We've already sullied our planet. There's no need to likewise sully interplanetary space with our detritus.

  • collect the debris with bots and use it as mass (Score:2, Interesting)

    by Anonymous Coward
    On the garbage "scowl" front,

    Let's turn that space debris to raw materials. Clean up LEO, cut down the amount of stuff that needs to be hauled up the gravity well, and make money doing it.

    Build a system of robots that finds debris, cuts it up, hauls it to a refuse station, and reduces it to a reusable form.

    You use three types of robots.

    Many small mobile bots (solar powered and ion-engine driven) find space debris and boost it to collecting spots.

    The second type chops up debris and boosts it to stable higher orbits. More of the second type intersect at the higher orbit and bring debris to the third type, which

    vaporizes the debris (no big deal in space with unlimited solar power and no atmosphere), charges the vapor, and shoots the charged vapor down a long tube with a magnetic system designed to act like a big mass spectrometer, separating the vapor by composition and leaving hunks of iron, silicon, etc.

    Or use a low tech but more high maintenance design and spin the stuff to separate it. Either way you've got raw materials enough to say, triple the speed they're building the ISS with even the junk materials usable for shielding.

    Seems to me that this system could be built by graduate students from a school like Carnegie-Mellon for five or six million dollars, tops.

    Notes:If you think that solar power is too wimpy consider that with two or three hundred collectors in orbit it's no big deal if it takes a given collector six months to bring in a load. Also, the collectors can be programmed to keep a bit of debris and coat themselves in it, protecting them from radiation and prolonging their own useful life. Give the collectors swappable boards and perhaps a two year board replacement cycle and they should last for at least a decade each.

    As for how to get them up there armadillo aerospace and the like are more than capable of boosting plenty of small payloads to low earth orbit in the near future. Chances are the toughest issue would be the legal fooforah of who owns the abandoned gear. Guaranteed that as soon as people figure out that their dead telsat has market value LLoyds will be fighting the salvage declaration.

    So, if anybody wants to do this, look me up.
    Rustin H. Wright
    Information Geek, former inventor, founder and publisher, Reed&Wright

    pubgeek@netscape.net

  • We only need to use the United Galaxy Sanitation Patrol [primenet.com] ship to pick up the debris [tvparty.com].
  • It would be easier to come up with potential solutions if some of the statistical information that the US Space Command has on debris orbits were available. On the other hand, I would imagine that the researchers who are being paid to work on this problem have full access to that information.

    Christopher

  • Recycling, anyone? (Score:2, Interesting)

    by mahmud ( 254877 )
    It costs shitloads to get stuff into orbit, right?

    Wouldn't it than be smarter to accumulate all the space junk in a big orbital junkyard?
    This could also include all the obsolete satelites currently burned down in the atmosphere.

    Next to this junkyard there could be an orbital factory using the scrap metal and other debris for raw materials.
    Furthermore, this facility wouldn't be *THAT* expensive to build, and i.e. the accumulation of all the used satelites in the same place would be trivial, by programming their final thrust to get them to the place. The compound in question could use solar energy, and be fully automatic.

    Building the trivial things, like the replacement solar panels for the ISS as well as other relatively easy to produce things in space would seem like a wiser way to deal with stuff that cost millions to launch up there!

  • Put a big snowplow on the front of a bunch of those suckas and just clear the path. You don't have to destroy the debris - you just have to move it the hell out the way.
  • ...consoles.

    Let's launch a bunch of satellites into orbit with lasers or some kinetic energy weapon and wire them into video game consoles back on the ground here. Kids can drop $.50 for a chance to blast away at space debris. That way we can use those well-honed reflexes of the future space cadets (take that how you want to) and maybe even raise some money for NASA with the fees.

    (You can implement a targeting/size filter to keep from shooting at real satelites.)
  • It seems the best way to start is by collecting the debris into repositories. I would suggest using some sort of netting that can be spanned between collector satellites (four - one on each corner) and moved in sync to sweep paths along hotspots clean. Then bring the corners together and draw a perimeter string closed for packaging.

    What NASA needs to do from that point depends on what they want with the junk. Just launching it out of orbit or toward the moon won't make the problem go away. Maybe there is a way to incinerate the collected garbage while in orbit. Just as long as flaming debris doesn't come back our way.

  • How about aerogel? (Score:3, Interesting)

    by MouseR ( 3264 ) on Friday July 12, 2002 @09:05AM (#3870190) Homepage
    NASA is already using AeroGel [nasa.gov] in the StarDust [nasa.gov] mission to collect high-velocity particles.

    Thick enough, it could be used to capture those tiny bolts and fragments they can't track by radar.

    Also, one of their concerns about using lasers to zap bigger debris was the fear of generation bazillion smaller particles that couldn't be collected or tracked thereafter.

    Why not create an autonomous robot that circles the globe, zap the objects it can while collecting the smaller debris in an AeroGel fish net?

    Think it won't hold up to the task? Check out the photos [nasa.gov] of AeroGel. The fluffy thing can hold up a brick!
  • We'll do the jobs no one else will do! Give us an old Space Shuttle, some suits and jetpacks, and some extra-large Hefty garbage bags. We'll take care of that for ya!

    Another idea: have organizations "Adopt-an-Orbit" and keep our skyways clean. Unfortunately all the brag signs they put up will cause the same problem....

    Why is NASA so scared about rocks hitting their spacecraft? All they need to do is sit in the middle and shoot the biggest pieces, then shoot the small fragments one at a time. Never shoot another big one until you've cleaned up all the tiny pieces, and you'll be fine.

    Ever see an old steam engine? Notice that big angular piece of metal just above the track in front? It's called a cowcatcher. The premise is, whatever is in your way (be it a cow or some girl tied to the tracks) will either be pushed to one side or split to either side. Depending on how tough your metal is, it'll deflect a lot of lesser junk too. That's the way to deal with it. Even the Enterprise had a deflector shield; you can't avoid or clean up every little piece of material in space.

    And finally: who says all that junk isn't worth something? It's just a treasure waiting to be discovered! Put Martha Stewart in a spacesuit and provdide her with gold rickrack and glitter glue, and we'll be able to provide even the poorest third-world peasant with a stunning centerpiece on their dining room table.

  • Terminator Tether (Score:3, Informative)

    by XNormal ( 8617 ) on Friday July 12, 2002 @09:30AM (#3870312) Homepage
    You can always trust Rober Forward [whidbey.com] to come up with a good idea.

    See his Terminator Tether [tethers.com] page. It's a great way to bring down an orbiting mass without actually having to carry the mass of fuel that would be required for a deorbiting burn.
  • Personally I like the idea of "robots to serve as roving garbage scowls".

    Boy, what world do you live in? I'm not sure that a nasty look from a robot will do much to solve the space debris problem. Perhaps a robot with a garbage pick, plastic bag, and orange vest would be a better place to start...

    ;^)

  • Collect it as ballast for tether/space elevator (Score:5, Interesting)

    by apsmith ( 17989 ) on Friday July 12, 2002 @09:39AM (#3870356) Homepage
    The Spring 2002 [lrcpubs.com] issue of Artemis Magazine [lrcpubs.com] had an excellent article on this by Henry P. Cate, Jr., titled the "Junk Man's Ladder". The idea is to put up a tether (many kilometers long "rope") in a convenient orbit with electrodynamic lift capabilities and some thrust, move it around to "catch" space debris, and move the junk up to the center of mass of the tether, to give it greater stability. Tethers like this are form of "space elevator", able to lift move things from low to high orbit with high efficiency. More on orbital tethers can be found at Tethers Unlimited Inc., run by Robert L. Forward and Robert P. Hoyt (who I was fortunate to have dinner with a couple of months ago).

  • Are giant Nets too low tech? (Score:3, Interesting)

    by Uttles ( 324447 ) <[moc.liamg] [ta] [selttu]> on Friday July 12, 2002 @09:48AM (#3870394) Homepage Journal
    Get some sort of mesh "net" made out of whatever metal is deemed strong enough and have these nets surround whatever it is you don't want to get damaged. I know it sounds really low tech and bulky, but hell it's cheap and would probably work.

  • Collecting debris (Score:2, Insightful)

    by rednaxel ( 532554 )
    My suggestion is create a large group of little robots with bags (this would make them light and easy to put in orbit - a shuttle's cargo bay full of them could make wonders). They may have arms to grab things, or just catch the debris with the bag (like a butterfly collector). With the bag full they would return to a manned depot (ISS?), empty it and go back to work. The debris could be recycled by humans in a junkyard manner.

    The bags could have a simple mechanical one-way opening, to avoid inertia to make things scape. The main criteria of (automatic?) selection would be the size, since most of the junk in orbit is small, and the main problem is this - big things are more likely to be avoided by spaceships.

    Alex.

  • An Alchemist's Solution (Score:4, Interesting)

    by RhettLivingston ( 544140 ) on Friday July 12, 2002 @10:07AM (#3870543) Journal

    First and foremost, any solution needs to consider the economic factor. A solution that pays for itself will be a hands down winner.

    Second, it seems like many of the solutions here would create more debris than already exists. A single large satellite is far simpler to track and avoid than a few thousand pieces of that large satellite. Unless your lasers or other weapons completely convert the debris into energy, you're wasting your time. Even if they force the debris toward Earth, the question would remain of "how did they do it"? The answer is by vaporizing matter which blasted away in the opposite direction. That matter is now not only debris in space, but untrackable debris. Even a paint fleck can do (and has done) serious damage to another orbiting object.

    Third, THIS SPACE JUNK HAS VALUE!!! If its matter, and its in orbit, it is worth thousands of dollars a pound. It blows my mind everytime they guide something down that took millions too get up there instead of coming up with a way to get stuff into a parking orbit. Eventually, probably even today, there should be enough materials in space to justify manufacturing in space instead of sending more stuff up.

    Steps we should take to turn this lead into gold include a) all future items launched should have provisions to reach an orbiting factory/storage facility at the end of their expected life. b) they need to all have provisions for capture via forces instead of mechanical means. This might mean adding magnetic materials or something. This way, an orbiting vehicle could capture them without contact that could cause further scattering of debris. c) software needs to be developed that can calculate capture plans for multiple objects that utilize the energy (stored in the momentum) of the objects captured effectively to help reach the next object and eventually get back to the orbiting factory/storage facility. Sort of like a game of 3D billiards. d) automated recycling and manufacturing technologies need to be developed to turn these raw materials into useful things like airtight habitat shells. At least initially, we'd probably have to keep bringing the high tech chips and stuff up the hard way, but the heavy shells and stuff could likely be very effectively manufactured in space. Things like girders for the space station should be relatively easy to do.

    • Eventually, probably even today, there should be enough materials in space to justify manufacturing in space instead of sending more stuff up.

      Chyeah, right! Let's start with the fact that no one's done any serious development of zero-G menufacturing. (Sure, there's been a few research studies, but right now it's just a lab curio.) Pair that with the fact that any such space manufacturer would necessarily be contracting out, sharing a lot of clients, and totally exposed to all who wish to see the satellite being manufactured (trade secret or national secret violations, anyone?), while (in theory, at least) ground manufacture can be a "private" collaboration hidden from prying eyes until the bird is sealed up and launched.

      Which is not to say it will never become a good idea. Just to say that the market will seriously have to change - say, by getting a lot of people living in space for other reasons - before orbital manufacturing of satellites intended to help Earth can become viable...so, right now, it's a non-starter.
    • " It blows my mind everytime they guide something down that took millions too get up there instead of coming up with a way to get stuff into a parking orbit. "

      I always figured the Hubble's main lens would make a great start for a 0-g foundry.

      You know, focusing the sun's light onto unrefined ore to melt it.
  • A large net orbiting a spacecraft (that is in turn orbiting the earth) can catch debris that comes across the space craft. The idea is that the net would have several radial fins, with magnets every few meters. The whole mess would be held out by centrifugal force. Anything that comes in contact with it, will (if it's moving fast) cause the fin it contacts to colapse around it, and will impart it's energy to the links in the net. Once the object is slowed down enough, if it's metal it will just drift over to a magnet. Everyonce in a while the net is replaced, and the old one, can be sent down to the atmosphere to burn up.

  • Nanosatellites (Score:3, Interesting)

    by Troodon ( 213660 ) on Friday July 12, 2002 @10:52AM (#3870821) Homepage

    BBCnews reported [bbc.co.uk] some time ago on such a posible role for Surrey Satellite Technology's nanosatellite [sstl.co.uk] SNAP program [sstl.co.uk]. A swarm of cheap (at about 100,000 UK sterling) manuverable tiny satellites that can latch onto and gradually deorbit junk.

    How though could such carry enough reaction mass to actually slow something down enough? Info on its propulsion system is here (pdf) [sstl.co.uk]. Could you just do it via its flywheel? Or use such to cluster together junk for collection by something bigger?I could certainly see a role as a beacon to actively tag stuff (on the net even! [bbc.co.uk])rather than relying upon constant ground based monitoring.

  • Two Words.... (Score:2, Funny)

    by lanej0 ( 118070 )
    Death Star.
  • I will freely admit that (probably) neither of these images/ideas are practical.

    The first thing that came to mind was this image of the shuttle towing the biggest horseshoe magnet imaginable through the orbital plane. Besides all the bits of space junk, it had also attracted (and grabbed) a conical spacecraft as seen in the old Gerry & Sylvia Anderson series "UFO" (does anyone besides me still remember that?)

    The next thing that came to mind was a whole bunch of spacewalking astronauts, all armed with enormous titanium-mesh butterfly nets and maneuvering jet backpacks.

    I think I'd better go take my meds... ;-)

  • We have the technology... (Score:4, Insightful)

    by mysticgoat ( 582871 ) on Friday July 12, 2002 @11:02AM (#3870902) Homepage Journal
    • Gauss guns in orbit
    • Shooting hollow beebees full of water-ice at some multiple of escape velocity
    • Effective range: on the order of 1 Earth diameter (limited by accuracy aiming mechanism)
    • Solar powered
    • Using banks of capicitors extracted by /.ers from discarded disposable cameras
    • on-board robotics with Forth and Legos (well, maybe Legos only for the early prototypes)
    • strategic AI via earthbased voluntary distributed computing system (or a beowulf cluster of US Government excessed 486 boxen)
    • knock the junk
      1. into decaying orbits or
      2. a designated "trash ring" or
      3. push it to escape velocity
      depending on specifics of each piece of junk
    • Funding partially by corporate sponsorship ("Legos in orbit")

    Funny as it sounds, this could work. A proactive strategy would be based on using single hits over multiple targeting windows to push each piece of junk into decaying orbits or to shepherd junk into a trash ring where our grandkids could mine it (what will be the multiplier for the value of a chunk of scrap metal that is already at orbital velocity?). Beebees that miss would add an insignificant amount of water vapor to the upper atmosphere or leave near Earth space. Each shot would cost no more than the cost of the beebee-- the power is free. Someone could figure out the ratio of the size of the solar array to the number of shots that can be fired in month's time. My wag is that with collectors comparable with today's, the thing could manage a few shots a week.

    A program like this would need a good name. I suggest "Space Balls"

  • I know where you can get a bunch of surplus capacitors.

  • reality check (Score:3, Interesting)

    by stinky wizzleteats ( 552063 ) on Friday July 12, 2002 @11:31AM (#3871074) Homepage Journal

    The article is a bit heavy on the space-junk media hype. The practical answer is to let nature take its course and work toward prevention.

    Any method of attempting to destroy debris isn't going to be practical. Giant debris collectors deliberately placed in dangerous orbits are likely to simply be smashed to pieces rather than gather any meaningful quantity of debris. Laser systems could vaporize metal fragments, but this vapor will simply congeal into globlets and cool into the space equivalent of bird shot. Until we develop gravity disruption fields, there is no effective way to affect the orbits of debris. The best bet is to wait the problem out. LEO is unstable. The Earth's atmosphere bulges significantly during solar maximums, and this drag has the effect of cleaning out the spacelanes within a reasonable period of time. In time, the problem (at least at LEO) will take care of itself if we can stop adding to it.

    I'm pretty sure the following is being done, but there should be restrictions on any mass accelerated to orbital speeds. Specifically:

    • Upper stages, shrouds, and other spacecraft assemblies accelerated to orbital speeds must include a system to deorbit once the payload has been delivered.
    • All payload devices must have an end-of-life deorbit procedure so that 100% of the mass accelerated at the start of the project is safely deorbited.
    • Spacewalks and other activities involving the manipulation of assemblies/parts at orbital speed must include some sort of recovery system for parts that "get away". A bolo-style net gun comes to mind, as does a retaining net set up around the perimeter before the procedure begins. Indeed, small robotic spacecraft interceptors could be designed to chase down the odd foot clamp, grab it, and return the item to the work area.

    Or, we could just use the Q solution. Simply change the gravitational constant of the universe.

    • The practical answer is to let nature take its course and work toward prevention.

      My fear, based on the human record of resource usage in the past, is that few preventative measures will be enforced enough to reduce space debris. I suspect that there will be enough countries and organizations flaunting such rules that debris will continue to increase until it becomes a real problem.

      And once it becomes a serious enough problem, it becomes self-maintaining: collisions with debris creates even more debris.

      At this point, no amount of preventative measures help. You have to start actively cleaning things up. I suspect this won't happen until the lost revenue in damaged satellites starts to match the cleanup costs.

      As for changing the gravitational constant of the universe, I've never quite understood how Q could have suggested that. I mean, talk about throwing the baby out with the bathwater. The mass destruction that would ensue is beyond all possible imagination.

  • "my question is 'How do they identify 'garbage'?'"

    When it comes across an object within certain size constraints, it calculates it's orbital data and sends it down to NORAD, which matches the data up with their database of known space debris. If there's a match, the robot picks it up.

  • silicon foam (Score:3, Interesting)

    by roman_mir ( 125474 ) on Friday July 12, 2002 @12:12PM (#3871361) Homepage Journal
    Some sort of silicon foam that is pressurized in a gigantic can and when sprayed forms a cloud that hardens into some bubbly sticky material. Debris can hit this from any side and either stick to it or penetrate it and decellerate while inside and maybe not even exit it on the other side.
  • Why not use a Huge Vacuum cleaner ?
  • Personally I like the idea of "robots to serve as roving garbage scowls"
    It's certainly a cute image, but I'm not sure what having a robot make a squinty-mad face at the orbital debris is going to accomplish.
  • Electronic warfare in Afghanistan?
    Posted by Kredal [slashdot.org] on Friday July 12, @01:45PM
    from the c64s-in-the-middle-east dept.
    g-w-bush [mailto] asks: "I've been asked to come up with a plan to take out the bad men living in caves, and making sure they can't get to the internet. Does anyone know how I can best take care of this? I'd love to be able to tell those Generals that I'm actually smart, but I need your help. Email your suggestions to me [mailto]"
  • OK, time for a little orbital machanics

    Sweeping out a single orbit would be like driving through a staight city street at high speed with a bulldozer and then thinking you did not have to stop at stop lights on that road because you cleared everything out of that path two hours ago.

    Objects start mostly going in the same direction, but the tidal forces of the moon distort the orbit and twist it until it is following some other path. (of course we also have the polar orbits the military use)

    Most of these objects quickly hit the atmosphere, Many stay up for years and a few probably get ejected out of earth orbit.

    It is the intersections you have to watch out for

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