ISS Could Be Fitted With Lasers To Shoot Down Space Junk 167
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."
Still There? (Score:5, Insightful)
Does poking holes space junk make it disappear or make more of it?
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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?
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space has always been militarized, get over it
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Haven't you been alive long enough to realize that ANY "thing" will be used to destroy, maim and enslave?
Corrected that for you.
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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?
Conservation of momentum (Score:2)
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.
Re:Conservation of momentum (Score:5, Insightful)
How does heat affect the orbit?
You vaporize one side of the object, and the expanding gases provide some thrust.
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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 [stockarch.com]?
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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 [stockarch.com]?
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 [wikipedia.org] 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 [wikipedia.org] could indeed push objects out of orbit, but I'm too busy/
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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 hav
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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.
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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.
Re:Still There? (Score:5, Insightful)
Does poking holes space junk make it disappear or make more of it?
Ablative Laser Propulsion [wikipedia.org].
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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.
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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.
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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 int
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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
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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. [wikipedia.org]
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Vaporizing the surface of the junk generates thrust.
Why on the ISS? (Score:2)
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Revising a previous concept (Score:5, Interesting)
The idea of using lasers to de-orbit space debris has been around for a while.
http://adsabs.harvard.edu/abs/... [harvard.edu]
Back when I was working on lasers for power beaming, the idea was discussed as an alternate use for the ground-based lasers.
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> Back when I was working on lasers for power beaming
Short or long haul? Down or up?
Power beaming [Re:Revising a previous concept] (Score:2)
> 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... [ieee.org]
http://proceedings.spiedigital... [spiedigitallibrary.org]
http://www.sciencedirect.com/s... [sciencedirect.com]
http://arc.aiaa.org/doi/pdf/10... [aiaa.org]
http://ntrs.nasa.gov/search.js... [nasa.gov]
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> 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.
This topic... (Score:2)
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... [wikipedia.org]
Re:This topic... (Score:5, 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.
Doesn't work (Score:1)
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?
Re:Doesn't work (Score:5, 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.
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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.
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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%?
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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.
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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 bot
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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.
Re:Doesn't work (Score:5, Funny)
Yes, then you have to shoot them again to score more points. At least this doesn't have B&W vector graphics.
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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...)
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Dunno why but I was just thinking about this movie. Death Blossom FTW.
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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.
Or (Score:1)
Why not use a giant magnifying glass instead?
Re:Or (Score:4, Funny)
think of the ants, you insensitive clod!
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Nice for R&R (Score:5, Funny)
Space junk... yeah, right (Score:1)
Yeah, right, this technology will totaly be used against space junk and not against sattelites of foreign countries.
ISS as a space garbage bulldozer? (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
Aerogel (Score:2, Interesting)
Launch "Aerogel" producing satellite robot.
Grow immense Aerogel sponge(s).
Push the sponge(s) through the most contaminated orbits.
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I thought of the same idea - except my version uses a giant can of expanding foam. Just easier to package.
Cool Shit! (Score:2)
Finally.... Lasers doing cool shit! Que the song about it: https://www.youtube.com/watch?... [youtube.com]
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Finally.... Lasers doing cool shit! Que the song about it: https://www.youtube.com/watch?... [youtube.com]
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 [wiktionary.org].
In space, no one can hear you laser go 'pew pew' (Score:5, Funny)
It always struck me (Score:1)
Physics (Score:2)
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.
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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.
better links (Score:5, Informative)
there is a better article here: http://www.csmonitor.com/Scien... [csmonitor.com]
you can read the full paper (for free) here: http://www.researchgate.net/pr... [researchgate.net]
Power (Score:4, 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.
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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
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Targeting proof of concept?
One flaw (Score:5, Interesting)
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Russians still have access? (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. Th
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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...
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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 m
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The words you're using don't mean what you think they mean. ;D
energy needed (Score:3)
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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 isn't the pro
sigh (Score:2)
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. Di
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One of the definitions of "blast", is "to shoot".
Stop getting worked up over nothing.
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Lasers are most certainly used to "blast" things. Start reading for example here [wikipedia.org].
Totally Not a Death Ray (Score:2)
some problems with this (Score:2)
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
3,000 TONS (Score:2)
New TV series. You cross Monster Garage with Survivor. First one to build a shelter lives.
I couldn't understand why that fuel tank (Score:2)
that will only make small space junk, and lots (Score:2)
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.
what could possibly go wrong? (Score:2)
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?
Re:after I destroy Washington D.C... I will destro (Score:5, Interesting)
After all, if you destroy DC, you destroy the people that are authorized to pay you in the first place.
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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.
Re: after I destroy Washington D.C... I will destr (Score:2)
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will it be using excited bromide in an argon matrix?
https://www.youtube.com/watch?... [youtube.com]
The real question is how to get the sharks into orbit
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Re:The real question is.. (Score:5, Insightful)
And the answer is...
None! We're not even talking enough laser to blind someone at that range, much less vaporize something/someone....
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What about to eyes? Either directly, or reflected off the copious shiny things we have around
Plus the Atmosphere (Score:2)
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...
Re:The real question is.. (Score:4, 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.
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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.
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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.
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