Slashdot Mirror


ISS Could Be Fitted With Lasers To Shoot Down Space Junk

An anonymous reader writes Japan's Riken research institute has suggested a new idea for dealing with space junk. They say a fiber optic laser mounted onto the International Space Station could blast debris out of the sky. From the article: "To combat the increasingly dense layer of dead satellites and miscellaneous space debris that are enshrouding our planet, no idea — nets, lassos, even ballistic gas clouds — seems too far-fetched to avoid. Now, an international team of researchers led by Japan's Riken research institute has put forward what may be the most ambitious plan to date. They propose blasting an estimated 3,000 tons of space junk out of orbit with a fiber optic laser mounted on the International Space Station."

167 comments

  1. after I destroy Washington D.C... I will destroy a by Anonymous Coward · · Score: 0, Redundant

    after I destroy Washington D.C... I will destroy another major city every hour on the hour. That is, unless, of course, you pay me...one hundred billion dollars.

  2. Still There? by Wild_dog! · · Score: 5, Insightful

    Does poking holes space junk make it disappear or make more of it?

    1. Re:Still There? by sidrosao · · Score: 2

      Not sure I understand it well, but the use of laser would create heat which would affect the orbit and therefore causing the junk to burn on reentry? That s my guess. Exciting stuff if you ask me!

    2. Re:Still There? by ShanghaiBill · · Score: 4, Insightful

      Does poking holes space junk make it disappear or make more of it?

      Ablative Laser Propulsion.

    3. Re:Still There? by Anonymous Coward · · Score: 0

      They probably plan to de-orbit the material with the vaporized gasses that will be coming off it.

    4. Re:Still There? by Anonymous Coward · · Score: 1

      You find the militarization of space to be "exciting stuff"?
      This is the first step: a useful purpose.
      The next step is a killing machine.
      Haven't you been alive long enough to realize that ANY scientific "thing" will be used to destroy, maim and enslave?

    5. Re:Still There? by rubycodez · · Score: 2, Insightful

      space has always been militarized, get over it

    6. Re:Still There? by Drethon · · Score: 1

      Haven't you been alive long enough to realize that ANY "thing" will be used to destroy, maim and enslave?

      Corrected that for you.

    7. Re:Still There? by sidrosao · · Score: 2

      Well, have not gotten into the details, but surely a laser for changing the orbit of space junk would not be the kind of laser that you could use to say, fry a plane or a boat or a city. I think that the atmosphere would interfere and make that a very difficult endeavor. Also, being hosted at the ISS would mean there would be international supervision on it. So yes, I think it is exciting that we might be coming closer to the implementation of actual solutions to reduce space junk. And it's done with lasers, so yes, exciting stuff. So we should not pursue any scientific "thing" as you call it? Seriously, what are you doing here?

    8. Re:Still There? by Anonymous Coward · · Score: 1

      Ablation was also covered by XKCD What-If 13 in brief, worth a read if you need some levity in your day.

    9. Re:Still There? by Anonymous Coward · · Score: 0

      I'm concerned with a more practical aspect of the idea.

      Where is the ISS going to get enough energy to generate a beam strong enough to destroy something that was designed to withstand being strapped to a rocket and shot out of the of the atmosphere?

      We're talking about cooking-metal-grade lasers here, not blinding-pilots-grade lasers. It'll take more than some AAA batteries.

    10. Re:Still There? by Anonymous Coward · · Score: 0

      I think it does both. It makes more of it, then it makes it disappear. I'm 99 to 100% sure that the inspiration for this plan came from the classic video game "Asteroids"

    11. Re:Still There? by MobSwatter · · Score: 1

      ALF: "How kind of you to bring a gun up here my pretty's, and install it on something that is representing the presence of your entire species. We have a sort of gun too you know, want to see?"

      If they are thinking of cleaning up the space junk, perhaps they might want to develop that thought process on the Pacific garbage patch, then expand on it in a zero G environment. Plenty of what is in the garbage patch is actually of value in reclaimed materials, so is the space junk.

    12. Re:Still There? by cyberchondriac · · Score: 1

      "..my prettys" ? .. sounds more like the Wicked Witch of the West than an alien.

      --

      Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
    13. Re:Still There? by Anonymous Coward · · Score: 0

      Followed by

      ALF: "Ha! I kill me!"

    14. Re:Still There? by MobSwatter · · Score: 1

      Why yes, remove the hat and gown and you have a pale, short, skinny and almost unrecognizable humanoid with Jedi mind tricks.

    15. Re:Still There? by avgjoe62 · · Score: 1

      Yeah, these sharpened sticks sure make hunting easier, but how long until people start pointing them at each other and suddenly we've got killing machines destroying, maiming and enslaving each other?

      --

      How come Slashdot never gets Slashdotted?

    16. Re:Still There? by smithmc · · Score: 1

      Haven't you been alive long enough to realize that ANY scientific "thing" will be used to destroy, maim and enslave?

      Haven't you? So what are you suggesting, a halt to all science?

      --
      Downmodding is the refuge of the weak. Don't downmod, make a better argument!
    17. Re: Still There? by Anonymous Coward · · Score: 0

      And exactly how does the US get to the ISS when the Russkis boot the sole American out the airlock?
      Hitch a rode on Soyuz?

    18. Re:Still There? by Holi · · Score: 1

      More likely using the laser to push the objects into a decaying orbit. I am sure the article goes into detail, I'm just to lazy to read it.

      --
      Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
    19. Re:Still There? by Runaway1956 · · Score: 1

      Two points for having more of a clue than the author. Yes, the laser will poke holes through most of the space junk. A laser isn't going to blast anything out of the sky. That crap is floating in vacuum. Laser hits, it burns through, a little bit of the skin is vaporized into the vacuum, and you're left with just as much debris up there as you started with. Some of it has been heated, liquified, and "evaporated" into space is all.

      --
      "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
    20. Re:Still There? by Runaway1956 · · Score: 1

      We see this on earth all the time. Heat a pan of water, and it jumps off of the kitchen range.

      Changing the temperature of an item doesn't change it's trajectory, or orbit. Thermal energy doesn't magically change itself into kinetic energy. All that is going to happen is, the cold bits of scrap will turn into warm bits of scrap.

      --
      "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
    21. Re:Still There? by Wild_dog! · · Score: 1

      I guess some folks are suggesting you can heat up on side and guide it into the atmosphere so it will burn up on re-entry. I didn't know that this is what they are talking about. Wink Wink Nudge Nudge... say no more.

    22. Re:Still There? by Anonymous Coward · · Score: 0

      a little bit of the skin is vaporized into the vacuum

      That vaporized material leaves with a rather high velocity, carrying with it a fair bit of momentum given its mass. The object will then get a change of momentum in the opposite direction. There is no need to burn through the whole mass or make a deep hole, and considering the focal point of this laser will probably be centimeters or larger, it wouldn't be good at making a deep hole anyway.

    23. Re:Still There? by sootman · · Score: 1

      If you shoot a piece of space junk, it splits into two. You shoot each of those, you get two more. You shoot those, they disappear. Documentary on the process here.

      --
      Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
    24. Re:Still There? by sjames · · Score: 1

      Vaporizing the surface of the junk generates thrust.

    25. Re:Still There? by Runaway1956 · · Score: 1

      That's the best explanation yet - but I don''t think it's accurate. They'll have to demonstrate before I buy into it. Remember, the skin of a spacecraft is thin. Getting the surface hot enough to melt and sublime will necessarily mean that the skin is just about the same temperature on the other side. Your molten metallic material is going to be subliming into space in equal and opposite directions. Net sum? No change in inertia.

      A thicker skin would actually be better, because the laser could burn into it, effectively scooping out a poorly shaped jet or rocket nozzle that would focus all of the hot metal and gasses in the direction that the laser came from.

      If a satellite has a few hard points on it that the laser can be focused on, then I can see how your view would work. But, we gotta remember, everything sent into space is as light as technology can make it. There's no metal body panels as thick and heavy as is found on our cars. It's all paper thin!

      --
      "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
    26. Re:Still There? by Anonymous Coward · · Score: 0

      There is already research into ablative laser propulsion, and you can find papers even going as far to estimate specific impulse in different scenarios, including when not purposely building an craft to use it as a propulsion means. The U. of Alabama was doing some experimental work on this at one point, but I don't know if they are still doing it.

      But for the most point, that the process works can be seen from just about any experience with pulsed lasers. Pulsed lasers can heat up surfaces much faster than thermal diffusion timescales, so no matter how thick it is, you end up just blowing off the outer layer (and judging from damaged mirrors, sometimes just the thickness of a couple wavelengths sometimes). Even in air, with just a tabletop laser (much less efficient than modern fiber lasers), you can hold a piece of target burn paper in the beam and feel the kick back with your own hand. Or for stronger lasers, noticed how it doesn't burn a hole in the paper, but will blow a hole in it ripping it up around where the laser hits.

    27. Re:Still There? by Firethorn · · Score: 1

      Getting the surface hot enough to melt and sublime will necessarily mean that the skin is just about the same temperature on the other side.

      Most lasers for these sorts of purposes would be 'pulse' lasers anyways. Think of it like the difference between trying to melt part of an aluminum can with a MAPP torch or a match.

      The higher heat of the torch, properly focused, can burn a hole in the can before the rest of the can heats up.

      I'd imagine that there's a few options, but one is to hit the junk with a microsecond level pulse that indeed just vaporizes a flake of material, providing a relatively very small kick. But timed right, that kick will cause the junk to orbit a touch on a more elliptical orbit. A little deeper into the atmosphere lowers it's orbit much faster, and you can reduce something that will be up there for the next couple centuries without intervention to burning up in the atmosphere within a decade.

      I'd just create a list - stuff that threatens the ISS first, then other satellites, then in descending order of hassle. Then program up the laser such that the highest priority object with a proper firing line available is shot first.

      --
      I don't read AC A human right
    28. Re:Still There? by Anonymous Coward · · Score: 0

      Thermal energy doesn't magically change itself into kinetic energy.

      Except for something like a rocket engine... you just need to constrain the motion of the hot gas, and even a flat plate would work at the cost of fuel efficiency.

    29. Re:Still There? by lucien86 · · Score: 1

      It was when they militarized thee hippies that was the real thing. Hippies turned out to be the ultimate weapon, blew up the whole world. Yup.

      The real ultimate weapon in the human arsenal is the human hand - not many weapons made .. or fired .. without using hands. Hands have been killing before we even evolved away from the other monkeys. The other human weapon - the brain - that's killed a fair few as well. - The human body is a well oiled killing machine, and killing and hunting is in every drop of human blood. .

      --
      Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
    30. Re:Still There? by catprog · · Score: 1

      Because the Pacific garbage path and zero G do not share any characteristics that would allow you to share tech between them.

      --
      My Transformation Website
      Kindle Books http://www.catprog.org/rev
      Interactive CYOA http://www.catprog.org/st
  3. Why on the ISS? by Nimloth · · Score: 1

    I'd sooner put a giant laser on the moon.

    1. Re:Why on the ISS? by hcs_$reboot · · Score: 2

      Maybe they thought the closer the better?

      --
      Slashdot, fix the reply notifications... You won't get away with it...
    2. Re:Why on the ISS? by kaizendojo · · Score: 0

      That's no moon.....

    3. Re:Why on the ISS? by Anonymous Coward · · Score: 0
    4. Re:Why on the ISS? by necro81 · · Score: 1

      That was my reaction, too: what advantage does putting it on the ISS get you, balanced against any added costs / difficulties / constraints, compared to a standalone satellite? On the plus side, you have an abundance of solar power available, along with cooling loops, attitude control, etc. What is more, you may be able to make use of astronauts to provide debug and repair capabilities. On the other hand, you are limited to the ISS' orbital inclination and altitude, and probably a variety of added design constraints and safety standards.

    5. Re:Why on the ISS? by camperdave · · Score: 1

      For the love of sanity why? The moon is 770 times as far away, which means you'd need a laser almost 600,000 times more powerful than one in Low Earth Orbit to deliver the same "punch". (Lasers spread out like any other beam of light, so inverse square law applies). Your aiming mechanism also needs to be magnitudes more accurate. If you're running this off solar power, then the moon based laser is going to be out of commission half the time, and is not going to be at peak energy most of the time. Furthermore, the launch costs are going to be astronomical.

      A satellite based system can be in perpetual sunlight, with the solar panels constantly at the optimum angle for energy collection. You're right on top of the target, so aiming is easier and power delivered on target is greater.

      --
      When our name is on the back of your car, we're behind you all the way!
    6. Re:Why on the ISS? by Anonymous Coward · · Score: 0

      I'd sooner put a giant laser on the moon.

      Well sure, if you like standing behind your target at the shooting range.

      If we're gonna take this route, why not just build the damn thing here on earth.

    7. Re:Why on the ISS? by Anonymous Coward · · Score: 0

      (Lasers spread out like any other beam of light, so inverse square law applies).

      Only once you get far enough away from the laser, where "far" depends on the beam size and optics quality. TFA gives a range of 100 km for a 3 m set of optics, which works out to a focal point of about about ~10 cm in diameter, if assuming a 1064 nm laser. If you built a 532 nm laser on the Moon with a 30 m output optics, you could get a focal point ~ 5 m in diameter, needing "only" 2500 times as much power. Certainly wouldn't be easy to target though...

    8. Re:Why on the ISS? by jbengt · · Score: 1

      Putting it on the ISS also gets you the advantage of being able to more easily target junk on orbits that may intersect with the orbit of the ISS.

    9. Re:Why on the ISS? by Anonymous Coward · · Score: 0

      If you read the article, they want to repurpose a telescope already on the ISS to use for tracking and targeting. They might later upgrade to a larger laser, but the ultimate plan would be a standalone satellite in a higher, polar orbit that could then reach the majority of the junk.

    10. Re:Why on the ISS? by Anonymous Coward · · Score: 0

      Plus, if you're on the moon and you miss your target, you hit the Earth. Actually, with a 5m diameter beam width, even if you hit your target dead on, you'd still hit the Earth with the bulk of the beam.

    11. Re:Why on the ISS? by topologicalanomaly47 · · Score: 1

      After the humans onboard the ISS test, refine and repeatedly upgrade various aspects of the system, while also shooting stuff that is closest to the ISS in the process nothing stops us from mounting the final all better and improved (tm) version on a satellite in another area of interest.

  4. Revising a previous concept by Geoffrey.landis · · Score: 4, Interesting

    The idea of using lasers to de-orbit space debris has been around for a while.
    http://adsabs.harvard.edu/abs/...
    Back when I was working on lasers for power beaming, the idea was discussed as an alternate use for the ground-based lasers.

    --
    http://www.geoffreylandis.com
    1. Re:Revising a previous concept by Maury+Markowitz · · Score: 1

      > Back when I was working on lasers for power beaming

      Short or long haul? Down or up?

  5. This topic... by iamwhoiamtoday · · Score: 1

    Have been covered pretty well in Sci-fi by Planetes, a manga / anime. I would very highly recommend checking it out. It does help to emphasize the problems that space debris can easily cause, especially when space travel becomes more common.

    http://en.wikipedia.org/wiki/P...

    1. Re:This topic... by Dutch+Gun · · Score: 4, Insightful

      Planetes was a cool anime until near the end when the characters all when off the damn rails.

      Anyhow, the headline and description are terrible. The plan is not "blasting" debris out of space. They're using the lasers to degrade the orbit. The atmosphere would then destroy the debris. Of course, using lasers to "burn", "propel", or "push" the debris out of orbit doesn't sound nearly as sexy as "blasting" it. So, for everyone talking about how "blasting" will simply create more debris, it's not an issue.

      --
      Irony: Agile development has too much intertia to be abandoned now.
  6. Until someone hacks it by Anonymous Coward · · Score: 0

    Sounds like part of the plot of an evil genius,

  7. Doesn't work by Stormcrow309 · · Score: 0

    Here is the problem. Blowing up or melting items does not work. Just leaves smaller material in orbit. Solution would likely be either breaking up space junk and then bringing it down or ejecting it out. Both are fraught with problems, mainly with timing and making sure we don't make the problem worse. Of course, if you want to clear out the orbit really quick, just grind up an asteroid and toss the resulting pebbles and sand into a retrograde, slowly diminishing orbit. What satellites?

    --

    In God we trust, all others require data.

    1. Re:Doesn't work by MightyYar · · Score: 4, Informative

      Here is the problem. Blowing up or melting items does not work.

      But if you heat up one side of an object, that side out-gasses or vaporizes and alters the orbit. Pick the side intelligently and you can slowly nudge stuff into a decaying orbit.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    2. Re:Doesn't work by rodrigoandrade · · Score: 5, Funny

      > Just leaves smaller material in orbit.

      Yes, then you have to shoot them again to score more points. At least this doesn't have B&W vector graphics.

    3. Re:Doesn't work by Anonymous Coward · · Score: 0

      Smaller objects have more friction. They fall down quicker.

    4. Re:Doesn't work by Anonymous Coward · · Score: 1

      Here is the problem. Blowing up or melting items does not work.

      But if you heat up one side of an object, that side out-gasses or vaporizes and alters the orbit. Pick the side intelligently and you can slowly nudge stuff into a decaying orbit.

      Because nothing spins in space.

    5. Re:Doesn't work by Drethon · · Score: 1

      If the object is overtaking the ISS it can just heat the facing side up on approach, if the ISS is overtaking the object the ISS can heat up the facing side after passing it. Either should work to reduce orbital velocity, hopefully enough to drop it into the atmosphere. If my weak grasp on orbital mechanics is correct enough...

    6. Re:Doesn't work by Anonymous Coward · · Score: 0

      And lasers are always on, and the aim is stationary? I'm pretty sure that I could write an algorithm which switches the laser on when the desired part is in range, and off when it isn't.

    7. Re:Doesn't work by Anonymous Coward · · Score: 0

      What about using the laser to heat one side of the debris, causing outgassing and a change in orbit to something less stable it currently has?

    8. Re:Doesn't work by MightyYar · · Score: 1

      The side currently facing the laser is still going to out-gas slightly more than the side that just turned away from the laser. Net effect might be less for a spinning object, but it will still be an effect. Besides, no one says this has to work for every single piece of space debris. So what if it "only" reduced the problem by 10%?

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    9. Re:Doesn't work by MightyYar · · Score: 1

      Since we are orbiting a sphere and not a circle, the calculations will be a tad more complex - but yes, that is the right idea.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    10. Re:Doesn't work by Anonymous Coward · · Score: 0

      Even if it is spinning, you still get a net effect: Yarkovsky effect

    11. Re:Doesn't work by wonkey_monkey · · Score: 2

      Doesn't work

      Yes it does.

      Here is the problem. Blowing up or melting items does not work.

      Here is the solution: don't do either of those things.

      --
      systemd is Roko's Basilisk.
    12. Re:Doesn't work by Anonymous Coward · · Score: 0

      Of course, if you want to clear out the orbit really quick, just grind up an asteroid and toss the resulting pebbles and sand into a retrograde, slowly diminishing orbit. What satellites?

      There are actual proposals very similar to this, but not necessarily retro-grade and definitely not from an asteroid. Different sized dust will have orbits that decay at different rates from pressure from light and atmospheric drag. The size and amount of dust also affects how much pressure it applies to other objects in orbit. There have been some talks and papers on how this could be optimized, not only so it will tend to clean out smaller stuff more so than satellite stuff, but also how it could also target a specific satellite (due to a tendency of things returning to a point of origin even if they initially spread out), and can also be optimized such that the orbital decay they cause on the target satellite matches the decay of the dust. The last point allows you to use a very small amount of dust that will continue to apply pressure on the target satellite for many orbits.

      The dust would be small enough to not damage other satellites, but the main disadvantage is it would apply a small pressure to other satellites depending on their orbit. The impact on other satellite's station keeping is calculable, and while not any where close to an engineering challenge to deal with, there is the legal/financial issue of other satellite owners not being happy about having to use a couple percent more fuel.

    13. Re:Doesn't work by Herkum01 · · Score: 2

      Little did I know that this was the long-term plan planted by the Government implemented by Atari. My years of playing Asteroids will now lead me to picked up by a government van, dropped at Fort Lauderdale, where I will be immediately transported into space to fill my destiny.

      Just like The Last Starfighter! (Did I date myself too much...)

    14. Re:Doesn't work by Last_Available_Usern · · Score: 1

      I get that you saw an article about adjusting an asteroid's path and you're excited to share that, but you need to consider a few things:

      1) That method requires a wealth of energy/time and makes very miniscule adjustments that are applicable to asteroids because their orbit is so huge that small changes a long ways out can make a significant difference. This debris is literally right next to our planet.
      2) For the amount of time, energy, and (most of all) money you'd spend doing this you could send both Bruce Willis and Ben Affleck in a Kerbal-inspired space ship zipping around LEO picking up all this debris and still have money left over.

    15. Re:Doesn't work by MightyYar · · Score: 1

      I don't know enough information to do an economic feasibility study - I was just addressing the concerns of Stormcrow309 that it would not work. It obviously would work, but as you point out it might not be worth the cost.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    16. Re: Doesn't work by Anonymous Coward · · Score: 0

      Just remember to leave a clone of yourself on earth so no one will be suspicious. And my kingdom for mod points.

    17. Re:Doesn't work by cant_get_a_good_nick · · Score: 1

      Just like The Last Starfighter! (Did I date myself too much...)

      Dunno why but I was just thinking about this movie. Death Blossom FTW.

  8. Or by Anonymous Coward · · Score: 1

    Why not use a giant magnifying glass instead?

    1. Re:Or by rubycodez · · Score: 3, Funny

      think of the ants, you insensitive clod!

    2. Re:Or by Virtex · · Score: 1

      I did think of the ants. And I for one welcome our new insect overlords.

      --
      For every post, there is an equal and opposite re-post.
  9. Re:after I destroy Washington D.C... I will destro by TWX · · Score: 4, Interesting

    See, that's the mistake supervillains make... You need to start small. Start with a wealthy but small place, like Martha's Vineyard, so that the powerful know that this is coming for them, so that they can put pressure on their private government officials to make it happen. Then move on to bigger and bigger wealthy suburbs and cities until you get to Washington.

    After all, if you destroy DC, you destroy the people that are authorized to pay you in the first place.

    --
    Do not look into laser with remaining eye.
  10. Nice for R&R by zipherx · · Score: 5, Funny

    Just imagine, you are done with they days duties on-board the ISS, then you slip into your jumpsuit and grab a stick and shoot down space junk. This is simply put, SPACE INVADERS for real :D

  11. Re:The real question is.. by CrimsonAvenger · · Score: 4, Insightful

    .. how much damage is this going to do to us when someone definitely turns this around and aims it at the ground?

    And the answer is...

    None! We're not even talking enough laser to blind someone at that range, much less vaporize something/someone....

    --

    "I do not agree with what you say, but I will defend to the death your right to say it"
  12. Space junk... yeah, right by Anonymous Coward · · Score: 1

    Yeah, right, this technology will totaly be used against space junk and not against sattelites of foreign countries.

    1. Re:Space junk... yeah, right by Anonymous Coward · · Score: 0

      There's nothing more adorable than the special brand of naivete that tries to pass itself off as cynicism.

  13. Frickin' sharks... by Anonymous Coward · · Score: 0

    ... with lasers on their head on the ISS already. Space debris would be nullified in an instant.

  14. ISS as a space garbage bulldozer? by userw014 · · Score: 1

    This is not exactly how I envisioned the ISS years and years ago - as a kind of space going pooper-scooper.

    Unless the laser can cause the space junk to emit reaction mass - from the space junk, I don't see how heating it with a laser is going to be effective. It's space-junk, after all - and while we sort of know what we put up there (for certain values of "we") I doubt we know the characteristics well enough to blast the stuff from orbit well enough to avoid causing more problems.

    Lastly, 3000 tons (metric or english) is a lot of mass to do this with over the anticipated remaining life of the ISS and the power available - but I'm just going by a gut feeling about the power budget of the ISS.

    1. Re:ISS as a space garbage bulldozer? by Anonymous Coward · · Score: 0

      Well, that's the fault of your feverish imagination. Space is mostly useless, people certainly have no business there either.

    2. Re:ISS as a space garbage bulldozer? by Anonymous Coward · · Score: 0

      I don't see how heating it with a laser is going to be effective.

      The lasers don't really care if you understand how ablation propulsion works. Its effectiveness is independent of your comprehension.

    3. Re:ISS as a space garbage bulldozer? by userw014 · · Score: 1

      I understand the idea of ablation propulsion works - I just have no (intuitive) feel for it. I can't help but think that it amounts to burning off paint on one side of an object in order to provide reaction mass for pushing it the other way. Perhaps if the system could survey the space junk and was able to target within a millimeter or so at a range of 1000Km, it might be able to push the junk into a different orbit - but deorbiting seems very ambitious.

    4. Re:ISS as a space garbage bulldozer? by Anonymous Coward · · Score: 0

      I can't help but think that it amounts to burning off paint on one side of an object in order to provide reaction mass for pushing it the other way.

      This is what it amounts to. A low end estimate of the specific impulse of laser ablation is around 200 s, which gives that burning off 1 gram of material is enough to give a delta-v of 50 m/s to ~40 g of material. That would be enough of a delta-v to take something from the ISS's orbit of ~400 km to the minimum orbit of ISS of 300 km, where drag gets larger. Higher specific impulses are possible, and the power required to burn off a gram of material is well within reach of a small fiber laser setup, even if assuming most of the power misses the target or is reflected. This isn't designed to take down large satellites, but other junk that would be uneconomical to collect or deorbit in any mechanical way.

  15. Re:The real question is.. by Jason+Levine · · Score: 3, Insightful

    My guess is that the power of the ISS laser, if aimed at the ground, would cause less damage than aiming a laser pointer at the ground. For all of the sci-fi programs showing space-based lasers decimating cities, our atmosphere is very good at diffusing light and the ISS's laser isn't going to have the power needed to overcome this.

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  16. Aerogel by Anonymous Coward · · Score: 2, Interesting

    Launch "Aerogel" producing satellite robot.

    Grow immense Aerogel sponge(s).

    Push the sponge(s) through the most contaminated orbits.

    1. Re:Aerogel by Anonymous Coward · · Score: 0

      How do these half-baked infantile ideas get rated up? Are we collectively living in a space cartoon?

    2. Re:Aerogel by SuricouRaven · · Score: 1

      I thought of the same idea - except my version uses a giant can of expanding foam. Just easier to package.

  17. Cool Shit! by TheCarp · · Score: 1

    Finally.... Lasers doing cool shit! Que the song about it: https://www.youtube.com/watch?...

    --
    "I opened my eyes, and everything went dark again"
    1. Re:Cool Shit! by QQBoss · · Score: 1

      Finally.... Lasers doing cool shit! Que the song about it: https://www.youtube.com/watch?...

      You can "cue" a song up, or you can put a song into the "queue", but the word you used doesn't mean what you think it does.

  18. In space, no one can hear you laser go 'pew pew' by jpellino · · Score: 4, Funny

    so why bother.

    --
    "Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
  19. It always struck me by Anonymous Coward · · Score: 1

    3,000 tons of space junk. What was the scientific community thinking, that putting a ring of trash in orbit traveling faster than the speed of a bullet wouldn't pose a hazard someday?

    1. Re:It always struck me by hab136 · · Score: 2

      All of it will eventually deorbit, it just might take a while.

      Much of the trash is from military and commercial launches - singling out "the scientific community" is silly.

  20. better links by Gravis+Zero · · Score: 4, Informative

    there is a better article here: http://www.csmonitor.com/Scien...
    you can read the full paper (for free) here: http://www.researchgate.net/pr...

    --
    Anons need not reply. Questions end with a question mark.
  21. Conservation of momentum by goombah99 · · Score: 1

    How does heat affect the orbit?
    if you break space junk up it continues on the same orbit.

    And radiative momentum transfer can't exceed the momentum of the photons hitting it which won't be a lot or you'd also be pushing on the space station too.

    --
    Some drink at the fountain of knowledge. Others just gargle.
    1. Re:Conservation of momentum by itzly · · Score: 4, Insightful

      How does heat affect the orbit?

      You vaporize one side of the object, and the expanding gases provide some thrust.

    2. Re:Conservation of momentum by Anonymous Coward · · Score: 2, Informative

      if you break space junk up it continues on the same orbit.

      The force of gravity is proportional to mass, so the acceleration doesn't change if you break an object into parts. However, other effects are not proportional to mass, in particular atmospheric drag and radiative pressure. In low Earth orbit, there is still enough gas around to drag small bodies and dust down over the timescale of months or years.

      And radiative momentum transfer can't exceed the momentum of the photons hitting it which won't be a lot or you'd also be pushing on the space station too.

      Radiative pressure is all about the ratio of surface area to total mass. Large objects like the space station are pushed on by radiative pressure, but they have relatively small surface area for their mass compared to say dust. Near earth, the pressure from sun light is about 9*10^-6 Pa. If this were applied to a 1 m^2 surface area object that had a mass of only 1 kg (e.g. a solar panel with nothing else attached), its speed would only change by ~1 cm/s after half an hour. For dust a couple microns across and made of metal, that would ~1 m/s delta-v instead. This adds up after many orbits.

    3. Re:Conservation of momentum by eth1 · · Score: 1

      How does heat affect the orbit?

      You vaporize one side of the object, and the expanding gases provide some thrust.

      I'm not sure you'd even need to vaporize anything. Ever seen one of these?

    4. Re:Conservation of momentum by ClickOnThis · · Score: 1

      How does heat affect the orbit?

      You vaporize one side of the object, and the expanding gases provide some thrust.

      I'm not sure you'd even need to vaporize anything. Ever seen one of these?

      I assume you're implying radiation pressure could push things out of orbit. Perhaps, but that device doesn't demonstrate radiation pressure.

      The Crookes Radiometer depends on air molecules being present to work. It spins with the dark side of the veins trailing, in the opposite direction you would expect from light pressure (for which the light side has a greater impulse due to recoil of the photons instead of absorption.)

      In theory, radiation pressure could indeed push objects out of orbit, but I'm too busy/lazy right now to run the numbers to find out how much energy it would require. Also, consider Newton's third law: any decent impulse given to space junk by the ISS using radiation pressure would affect the ISS as well.

      --
      If it weren't for deadlines, nothing would be late.
    5. Re:Conservation of momentum by SuricouRaven · · Score: 1

      If you blow it into tiny pieces, you up the cross-section-to-mass ratio. The ISS orbits low - there's still a slight atmospheric drag. Things will come down, and small things faster.

    6. Re:Conservation of momentum by catprog · · Score: 1

      Space junk: 10g
      ISS: 450,000 kg

      Also to deorbit the space junk you would have to boost the ISS which they do anyway.

      --
      My Transformation Website
      Kindle Books http://www.catprog.org/rev
      Interactive CYOA http://www.catprog.org/st
  22. Power by MrLint · · Score: 3, Insightful

    My understanding (as very limited as it is), is that you'd need to ablate enough material off the object to knock it out of orbit and to fall to earth.

    However do you even need to hit it that hard? Can you just put enough laser energy on to it to perturb it out of orbit without ablating/vaporizing material? More massive objects would of course require more power applied.

    1. Re:Power by Big+Hairy+Ian · · Score: 1

      I think the problem is available surface area to aim the laser at. In order to generate enough force to slow a satelite down over a year you'd probably need to focus enough power at it that it would melt in short order anyway. HTH

      --

      Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

    2. Re:Power by DerekLyons · · Score: 1

      Can you just put enough laser energy on to it to perturb it out of orbit without ablating/vaporizing material?

      In theory, yes. Light does exert pressure on objects.... In practice, the pressure is so infinitesimally small that's is much easier* to go the ablation/vaporization route.

      That being said, this device isn't actually useful other than as a proof-of-concept ISS's altitude (400km) is low enough that debris is eventually slowed and de-orbited by atmospheric drag, and the 100km range isn't enough to reach the altitude (600km+) where 90% of the long lived junk resides.

      * For certain values of "easier", in reality it's not very easy at all.

    3. Re:Power by PhuCknuT · · Score: 1

      This is about deorbiting small debris, not whole satellites.

    4. Re:Power by Anonymous Coward · · Score: 0

      However do you even need to hit it that hard? Can you just put enough laser energy on to it to perturb it out of orbit without ablating/vaporizing material?

      With pure photonic pressure, you need to account for the ISS experiencing an equal and opposite force. With ablation, the Newton's 3rd Law reaction occurs between the target and it's ablated molecules.

    5. Re:Power by MrLint · · Score: 1

      Targeting proof of concept?

  23. One flaw by Nidi62 · · Score: 5, Interesting

    Ok, this is a nice plan and all, but there is one little problem: how do you keep the sharks alive in a vacuum?

    --
    The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
    1. Re:One flaw by Big+Hairy+Ian · · Score: 1

      Moderation gone mad? It is a frickin LAYZZZER after all

      --

      Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

    2. Re:One flaw by Anonymous Coward · · Score: 0

      how do you keep the sharks alive in a vacuum?

      You use space sharks (obviously, duh).

    3. Re:One flaw by Anonymous Coward · · Score: 0

      Bah, vacuum sharks are easy! They've already got sharks in tornadoes, and there are a whole bunch of vacuums that use vortex technology. Combine the two and you have an easy-peasy vacuum shark.

      What could go wrong?

    4. Re:One flaw by ChrisMaple · · Score: 1
      --
      Contribute to civilization: ari.aynrand.org/donate
  24. ISS... or IS*I*S? by Anonymous Coward · · Score: 0

    Since we all know (or should know by now) that the Quran and the Hadiths order Muslims to kill Christians and Jews if they don't become submissive to them and kill people of other religions and Atheists if they don't become Muslims, make sure those lasers are for "ISS"... and not for "IS*I*S"!

    1. Re:ISS... or IS*I*S? by Anonymous Coward · · Score: 0

      you are a fucktard... the Quran does not state to kill Christians and Jews... in fact it mentions that they are not to be forcibly converted as they are "children of the book"

    2. Re:ISS... or IS*I*S? by Anonymous Coward · · Score: 0

      you are a fucktard... the Quran does not state to kill Christians and Jews... in fact it mentions that they are not to be forcibly converted as they are "children of the book"

      Learn about the Quran, and train your reading comprehension - i wrote (inside brackets adding some explanation):

      The Quran (and the Hadiths) orders Muslims to kill Christians and Jews if they don't become submissive to them [i.e., they can -because they are "children of the book" as you write- remain Christians and Jews and alive ONLY IF THEY ARE SUBMISSIVE TO MUSLIMS, e.g., by paying the submission tax, don't build churches, don't practice their religion in public, e.t.c.] and kill people of other religions and Atheists if they don't become Muslims [i.e., if someone is of any other religion or is an Atheist must die if does not convert to Islam]

  25. Russians still have access? by Karmashock · · Score: 1, Interesting

    I'm not putting space lasers on something the Russians can fuck with... At this point, I've gone full cold war on the Russians in my foreign policy thinking. I've had a few conversations with the Church of Putin and they're so fucking delusional that I have zero hope of a peaceful end to this crap. And that being the case, I don't want to give the russians any leverage on us what so ever.

    I'm not really worried about the Russians doing anything to the laser. I'm more worried about us CARING about the ISS. The Russians have already attempted to use access to the ISS as leverage against us and that frankly just burns me on the whole project. Decommission it or ideally pawn it off on someone else. Maybe the Chinese want it? I don't care.

    The ISS was a post cold war team building exercise between the US and the Russian Federation. And quite recently the US did a "trust fall" with the Russians and they said something to the effect of "we suggest the americans try trampolines to get into space"... Which means the team building exercise was a complete failure. And that means the ISS was a complete failure at its ACTUAL purpose.

    The Russians are going back to their old ways. So the ISS is dead to me.

    And that means I'm not putting anything of any value on it what so ever. I'm ready to deorbit it. The Russians can forge ahead with their own entirely independent space program with zero help from the US.

    --
    I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
    1. Re:Russians still have access? by Noryungi · · Score: 2

      Oh boy, that was such a flame-bait post.

      Just cool down, man, the ISS is still up there and still useful -- this (shooting space junk) is just a good example of it.

      Besides, if the US Governement had invested in space research and (cheap, reliable) space access, you guys would not be at the tender mercies of the naughty naughty Russian bear. So you only have yourselves to blame here...

      --
      The right to offend is far more important than the right not to be offended. (Rowan Atkinson)
    2. Re:Russians still have access? by Karmashock · · Score: 1, Flamebait

      As to flame baits... I am internet fearless... so I don't care.

      As to the ISS being useful... its purpose was to bridge relations with the Russians. It failed. Absent that we would not have built it at all.

      As to shooting space junk, remind me why we need to put a space laser on the ISS and not just on anything at all? We could have a space junk shooting satellite. The Russians will accuse us of putting weapons in space but what is new.

      As to the Russians not being able to put pressure on the US if we didn't make ourselves vulnerable to them... thank you for proving my fucking point. That is why I don't want to give them more leverage. They exploit EVERYTHING no matter how petty and rediculious.

      Newsflash, the US doesn't actually care about the ISS. As you point out, we didn't really fund space exploration for awhile. Why was that? Because we had more pressing concerns.

      If the Russians are going to exploit every moment of weakness to get something then they are terrible partners for ANYTHING.

      This is right up there with that dumb idea to put a tunnel between Alaska and Siberia so we could have a transcontinental train.

      No one is investing in SHIT to do with Russia because no one trusts them. Think about it. Russia sits between east asia and Europe. One of the busiest trade routes in the world. And what does everyone do? They bypass Russia by any means.

      If Russia were at all truthworthy there would be a big freight train service from China to Europe. But instead, everything is loaded on to boats and taken by sea. Think of the trade Russia would get if the cargo ran through their country? Warehouses, factories, all sorts of infrastructure investment, lots of transport jobs. I mean... we're talking about total economic benefits into the hundreds of billions per year at the very least.

      And Russia ruins any chance they'll have at getting any of that on a regular basis by being raging morons.

      And before anyone says "oh the US isn't trustworthy either"... well then why is the US getting massive investment from all over the world as well as a huge capital flight from China AND Russia into the US? It must be because these powerful interests want to lose their money. Because if the US isn't a trustworthy investment then putting your money in the US is stupid. So no... the US is exceptionally trustworthy. That isn't saying the US is perfect... and all things are relative.

      --
      I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
    3. Re:Russians still have access? by Anonymous Coward · · Score: 0

      I am internet fearless

      You're not, and everyone can tell.

    4. Re:Russians still have access? by Karmashock · · Score: 1

      The words you're using don't mean what you think they mean. ;D

      --
      I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
    5. Re:Russians still have access? by Anonymous Coward · · Score: 0

      They do, and you know it. You're upset because you know I'm right.

    6. Re:Russians still have access? by Anonymous Coward · · Score: 0

      As to shooting space junk, remind me why we need to put a space laser on the ISS and not just on anything at all? We could have a space junk shooting satellite

      RTFA

  26. Physics by Overzeetop · · Score: 1

    When you run a marathon, nobody asks the runners why they don't bring all of their own water on the run.

    When you're payload mass fraction to get into orbit is less than 2%, there's little incentive to keep spare fuel for decommissioning, and that doesn't count all of the little bits that fall off along the way.

    --
    Is it just my observation, or are there way too many stupid people in the world?
  27. Did no one else by Anonymous Coward · · Score: 0

    Am I the only one who read this as "IS could be fitted with lasers to shoot down space junk"?

    Shit, I thought we had a real life COBRA for a second.

  28. energy needed by kqc7011 · · Score: 2

    All the laser has to do is slow the junk down, just shining the object with the laser will impart a force which will cause a slowing of momentum. Once momentum of the object has slowed below orbital speed, it should fall towards earth and burn up in the atmosphere. Tracking should not be that hard as radar aimed weapons have been around for many years. How much energy and for how long to illuminate is up to the designers.

    --
    Passionately Indifferent
    1. Re:energy needed by DerekLyons · · Score: 1

      Once momentum of the object has slowed below orbital speed, it should fall towards earth and burn up in the atmosphere.

      Slowing it below orbital speed just makes the whole problem 100x harder due to the vastly increased amount of time you need to hold the laser steady on target. All you actually need to do is get the periapsis down to around 200-300km, and atmospheric drag will do the rest.
       

      Tracking should not be that hard as radar aimed weapons have been around for many years.

      Tracking isn't the problem - aiming the laser at, and holding it steady on, the target is the problem.

  29. Re:after I destroy Washington D.C... I will destro by jeffmeden · · Score: 2

    After all, if you destroy DC, you destroy the people that are authorized to pay you in the first place.

    That, and you completely destabilize/devalue the very thing you are demanding. Your $100B USD won't go far if the US government collapses. Better ask for Gold or Bitcoins.

  30. sigh by argStyopa · · Score: 1

    This is supposed to be a technically-minded site, not FARK.

    "Blasting" with lasers? Really?

    - first, nothing gets "blasted" with a laser; a laser is - optimally - a point extreme heat source. The "shooting crap down" thing going on in the military today really is about DISABLING the guidance, control, or propulsive systems on whatever aerial platform they're shooting at, or at least disrupting (for missiles) their aerodynamics enough that their own velocity tears them apart. The laser "blasts" nothing. Disabling the guidance, control, or propulsive systems on what is already "space junk" is logically, pointless.

    - even assuming a laser did "blast" something, it's pretty much the last thing you want to do in orbit. Unless you're pulverizing it to flecks so tiny that a) they simply don't carry enough kinetic energy to harm something (ie dust) or b) a signficant fraction of them will be deorbited by air-friction in low orbit, you're simply trading one character of threat with another. The Chinese "blasted" a satellite, so now instead of one piece of dangerous junk we need to track and avoid, there's 12000+.

    --
    -Styopa
    1. Re: sigh by Anonymous Coward · · Score: 0

      Unfortunately the lack of understanding is your own. The idea is to use the laser to de-orbit the space junk, not to blow them up.

    2. Re:sigh by Wraithlyn · · Score: 1

      One of the definitions of "blast", is "to shoot".

      Stop getting worked up over nothing.

      --
      "Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson
    3. Re:sigh by Urkki · · Score: 1

      Lasers are most certainly used to "blast" things. Start reading for example here.

  31. Giant sticky balloons by Anonymous Coward · · Score: 0

    We need giant, sticky, balloons launched in an intentionally retrograde slowly diminishing orbit. Along the way, they pick up all the small dust and junk, dragging it back down to earth.

  32. Shortly after the system is online... by Anonymous Coward · · Score: 0

    US President: "Oh, I am so sorry, Mr Putin. You had not declared that was your super-secret spy satellite, so naturally we assumed it was a big hunk of space junk. Maybe you should give us a list of all your secret satellites so we won't make the mistake again?"

  33. Totally Not a Death Ray by wisnoskij · · Score: 1

    Sure, its for frying space junk. Ya, that is far more comforting than outfitting the space-station with a space-to-ground death ray.

    --
    Troll is not a replacement for I disagree.
  34. ObPlanetes by Anonymous Coward · · Score: 0
  35. Anybody else read ISIS? by linkdude64 · · Score: 1

    If we gave them improved laser weaponry, maybe they would let us ship them all to space to destroy the space debris.

    (Please forget to include a return capsule)

    1. Re:Anybody else read ISIS? by OakDragon · · Score: 1

      Yes, I did too. They have been too much in the news lately.

  36. Re: after I destroy Washington D.C... I will destr by jd2112 · · Score: 1

    Just do like Dr. Evil and show them a clip from "Independence Day".

    --
    Any insufficiently advanced magic is indistinguishable from technology.
  37. Re:after I destroy Washington D.C... I will destro by bhcompy · · Score: 2

    Everyone would cheer if they went after Martha's Vineyard or Cape Cod. It would solve more problems than it causes

  38. junk already has decaying orbit by Anonymous Coward · · Score: 0

    The ISS is on a decaying orbit, and anything that passes near it will also have a decaying orbit. The junk at this altitude doesn't need help and will come down on its own within a few years. But the junk in geosynchronous orbit could use help...

  39. some problems with this by slashmydots · · Score: 1

    I see a couple problems.
    1. lasers don't magically make things go away like in the cartoons. They just break it into smaller pieces by making it hot
    2. photons don't impart much inertial energy onto an object compared to radiation beams
    3. the space station has very limited power and it is carefully allocated to good use

  40. Frikin Laser Beams? by 0xG · · Score: 1

    TFA Says Nothing About Sharks Though

    --
    A pox on web designers who feel that window.innerWidth == screen.availWidth
  41. You don't see any problems, you're just dumb by Anonymous Coward · · Score: 0

    1. They're not intended to. RTFA.
    2. They don't need to. RTFA.
    3. You have no idea what the laser's power requirements are or what the station's power-generation capabilities are, so you're just making things up.

  42. ISIS has Lasers? by Anonymous Coward · · Score: 0

    I thought they hated education and technology

  43. Could be .. suggested .. could .. by Anonymous Coward · · Score: 0

    A big net could be strung between the moon and earth, I suggest, which could catch space debris. I mean, if this is pure speculation, why not make it more fun? Wake me up when there's actual news content in an article.

  44. Re:after I destroy Washington D.C... I will destro by garlicbready · · Score: 1

    will it be using excited bromide in an argon matrix?

    https://www.youtube.com/watch?...

    The real question is how to get the sharks into orbit

  45. 18" fiber optic lasers, no less! by Anonymous Coward · · Score: 0

    > Japan's Riken research institute has suggested a new idea for dealing with space junk. They say a fiber optic laser mounted onto the International Space Station ...

    Corrected for you:

    Japan's Riken research institute has suggested a new idea for dealing with space junk. They say a fiber optic laser mounted onto the Space Battleship Yamato ...

  46. Shield that thermal exhaust port! by Anonymous Coward · · Score: 0

    As long as they remember to shield that vulnerable thermal exhaust port (this time)

  47. 3,000 TONS by Lodlaiden · · Score: 1

    I've always been told we're having difficulty getting enough stuff into space to build a decent sized base.3,000 tons is an awful lot of raw materials.

    New TV series. You cross Monster Garage with Survivor. First one to build a shelter lives.

    --
    Suborbital [spaceflight] is the special olympics of spaceflight. - Rei
    1. Re:3,000 TONS by Anonymous Coward · · Score: 0

      Considering a large part of the problem of getting things into space is the delta-v needed to get that stuff up to orbital speed, and a lot of this junk is in different orbits, you're going to still need a large delta-v to accumulate it. It doesn't seem likely that a rocket + catching mechanism undergoing these delta-v's going to need less fuel than just launch the material from the ground in the first place.

  48. Re:after I destroy Washington D.C... I will destro by Tighe_L · · Score: 2

    Therefore, we shall call it the Alan Parsons Project.

  49. Re:The real question is.. by Sir_Substance · · Score: 2

    None because the atmosphere does a fantastic job of absorbing energy from laser blasts.

    If you want to kill people from orbit, you should take bricks up with you and throw them out the airlock, it's way more likely to succeed.

  50. Re:The real question is.. by Kardos · · Score: 1

    What about to eyes? Either directly, or reflected off the copious shiny things we have around

  51. Palpatine Said... by Anonymous Coward · · Score: 0

    ... armed and fully operational battle station!

  52. Re:The real question is.. by itzly · · Score: 1

    If you want to kill people from orbit, you should take bricks up with you and throw them out the airlock, it's way more likely to succeed.

    No, the bricks will just enter a slightly tilted orbit, intersecting the original one at the point of throw.

  53. I couldn't understand why that fuel tank by jpellino · · Score: 1

    was getting larger. Then it struck me.

    --
    "Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
  54. Power beaming [Re:Revising a previous concept] by Geoffrey.landis · · Score: 1

    > Back when I was working on lasers for power beaming

    Short or long haul? Down or up?

    We looked at lasers for space-to-Earth power beaming, but it's less practical than you might think-- heat rejection gets to be a serious problem. Most of the practical applications were Earth-to-space or space-to-space power beaming.

    http://ieeexplore.ieee.org/xpl...
    http://proceedings.spiedigital...
    http://www.sciencedirect.com/s...
    http://arc.aiaa.org/doi/pdf/10...
    http://ntrs.nasa.gov/search.js...

    --
    http://www.geoffreylandis.com
    1. Re:Power beaming [Re:Revising a previous concept] by Maury+Markowitz · · Score: 1

      > We looked at lasers for space-to-Earth power beaming, but it's less practical than you might think

      Actually that's precisely why I asked. I recall this was offered up as a solution to the inefficiencies of microwave beaming, only to find that it was even worse.

      Space power is a bad idea, but it refuses to die.

  55. Plus the Atmosphere by Etherwalk · · Score: 1

    .. how much damage is this going to do to us when someone definitely turns this around and aims it at the ground?

    And the answer is...

    None! We're not even talking enough laser to blind someone at that range, much less vaporize something/someone....

    Plus the atmosphere, you know, exists...

  56. Re:The real question is.. by SuricouRaven · · Score: 1

    That depends how hard you can throw them. The ISS orbits at 7.8KM/s. A quick google shows the highest-velocity tank guns can fire at 1.7KM/s. Modify for vacuum and aim it retro and you should be able to de-orbit your brick. Aiming might be tricky though, as no active guidance system is withstanding that much acceleration - if you want precision you'd be better off just using a small rocket.

  57. Darned glasses. by Anonymous Coward · · Score: 0

    I read that as 'ISIS could be fitted with lasers to shoot down space junk'.

    Those guys just get everywhere, and CIA/NSA/GCHQ can do diddly squat about it.

  58. that will only make small space junk, and lots by swschrad · · Score: 1

    to get rid of the slop, you have to net it and destroy it. the Japanese have proposed a craft to net the slop and burn it up on re-entry. that's a PLAN.

    --
    if this is supposed to be a new economy, how come they still want my old fashioned money?
  59. ISIS Could Be Fitted With Lasers To Shoot by Anonymous Coward · · Score: 0

    I literally read this headline as "ISIS Could Be Fitted With Lasers To Shoot Down Space Junk", thought it might be some new idea by the Obama Administration.

  60. what could possibly go wrong? by lophophore · · Score: 1

    what could possibly go wrong with this plan? would a laser that powerful represent a destabilizing weapon? If you can de-orbit "space junk" what else can you de-orbit? How could you regain control over a ISS taken by person(s) intent on using it as a weapon?

    --
    there are 3 kinds of people:
    * those who can count
    * those who can't
    1. Re:what could possibly go wrong? by Anonymous Coward · · Score: 0

      How could you regain control over a ISS taken by person(s) intent on using it as a weapon?

      By doing nothing. They do need supplies up there, after all.

  61. Re: after I destroy Washington D.C... I will destr by Anonymous Coward · · Score: 0

    Fricking lasers on space stations...

  62. Next innovation by Anonymous Coward · · Score: 0

    ... space suits for sharks?

  63. Start with FOX satellites by Anonymous Coward · · Score: 0

    It's a "two birds with one stone" solution!

    We can clean up our orbits AND our airwaves!

  64. Re:The real question is.. by athenaprime · · Score: 1

    .. how much damage is this going to do to us when someone definitely turns this around and aims it at the ground?

    And the answer is...

    None! We're not even talking enough laser to blind someone at that range, much less vaporize something/someone....

    Just you wait until the cats see that red dot...