# Could lasers be used to destroy or deorbit space junk? **URL:** \ **Category:** Factual Questions\ **Created:** [October 25, 2012, 2:57pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825 "2012-10-25T14:57:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [October 25, 2012, 2:57pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/1 "2012-10-25T14:57:58Z")
Could an orbiting laser platform be used to destroy space junk? I would expect not since it seems like a really obvious solution. What are the technical problems? Thanks, Rob ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 25, 2012, 3:10pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/2 "2012-10-25T15:10:06Z")
First, lasers aren’t necessarily that powerful. If you blast something so it falls apart, you simply create 10 pieces of junk where there was 1. A hot piece of junk is just a piece of junk. The “light pressure” is not going to have much effect - even if it did, hitting from below could be counterproductive. the ideal would be vaporizing it - but the amount of laser light needed to create iron vapour is pretty high. Also note a laser tends to be incredibly inefficient - about 2% or 3% of the energy used to power a laser comes out as the beam. Maybe a more effcient method might be to hit thing with a particle beam. collisions with high speed particles could help - but that would have to happen from above the atmosphere, meaning the need to lift a powerful beam weapon into space. Weapons in space are kind of discouraged right now. ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [October 25, 2012, 3:24pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/3 "2012-10-25T15:24:12Z")
And spitting out particles from a satellite would screw up the orbit of the satellite as well as what ever it was shooting at. Perhaps if it shot at several different pieces in several different directions, the momentum would average out. Would such a cannon necessarily qualify as a weapon? Rob P.S. I was also thinking of a satellite-based laser. ---
**Author:** ![zoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zoid/32/336_2.png) [@zoid](https://boards.straightdope.com/u/zoid)\ **Post date:** [October 25, 2012, 3:26pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/4 "2012-10-25T15:26:10Z")
> [@md2000](#): > > Weapons in space are kind of discouraged right now. I blame the pope. ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [October 25, 2012, 3:38pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/5 "2012-10-25T15:38:12Z")
> [@sweeteviljesus](#): > > What are the technical problems? The biggest technical problem is generating a powerful enough beam. As a point of comparison, the [Boeing YAL-1](http://en.wikipedia.org/wiki/Boeing_YAL-1) project involved mounting a megawatt laser in a 747, and was designed to shoot down ballistic missiles. There were a couple successful tests, but it destroyed the missiles by heating them enough to cause structural failure under aerodynamic stress, not by melting through it’s skin. Such a laser would be completely ineffective against space junk. The cost of the program was about $5 billion. ---
**Author:** ![CutterJohn](https://avatars.discourse-cdn.com/v4/letter/c/91b2a8/32.png) [@CutterJohn](https://boards.straightdope.com/u/CutterJohn)\ **Post date:** [October 25, 2012, 4:15pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/6 "2012-10-25T16:15:01Z")
> [@md2000](#): > > First, lasers aren’t necessarily that powerful. If you blast something so it falls apart, you simply create 10 pieces of junk where there was 1. A hot piece of junk is just a piece of junk. The “light pressure” is not going to have much effect - even if it did, hitting from below could be counterproductive. the ideal would be vaporizing it - but the amount of laser light needed to create iron vapour is pretty high. > > Also note a laser tends to be incredibly inefficient - about 2% or 3% of the energy used to power a laser comes out as the beam. > > Maybe a more effcient method might be to hit thing with a particle beam. collisions with high speed particles could help - but that would have to happen from above the atmosphere, meaning the need to lift a powerful beam weapon into space. Weapons in space are kind of discouraged right now. Lasers are power intensive, but electricity doesn’t cost much. Say they had something crazy, like a 100 megawatt laser that pulsed for 1 second, 2% efficiency. Thats 1400 kwh, or around $200 in power costs. Remember, they don’t have to or want to destroy the fragment, or melt it, or anything. They want to superheat a surface to vaporize some material, which will push the fragment in another direction and cause it to change orbits. This is known as ablative propulsion. This will either steer it away from something in orbit, or lower its perigee to a point in the upper atmosphere so its orbit can decay. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 25, 2012, 6:53pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/7 "2012-10-25T18:53:01Z")
> [@CutterJohn](#): > > Lasers are power intensive, but electricity doesn’t cost much. But the most powerful lasers are not powered by electricity. The YAL-1 mentioned above uses a [chemical oxygen iodine laser](http://en.m.wikipedia.org/wiki/Chemical_oxygen_iodine_laser) which needs to be fed with “gaseous chlorine, molecular iodine, and an aqueous mixture of hydrogen peroxide and potassium hydroxide.” ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [October 25, 2012, 6:54pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/8 "2012-10-25T18:54:09Z")
Obligatory [what if](http://what-if.xkcd.com/13/). ---
**Author:** ![CutterJohn](https://avatars.discourse-cdn.com/v4/letter/c/91b2a8/32.png) [@CutterJohn](https://boards.straightdope.com/u/CutterJohn)\ **Post date:** [October 26, 2012, 12:55am UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/9 "2012-10-26T00:55:12Z")
> [@scr4](#): > > But the most powerful lasers are not powered by electricity. The YAL-1 mentioned above uses a [chemical oxygen iodine laser](http://en.m.wikipedia.org/wiki/Chemical_oxygen_iodine_laser) which needs to be fed with “gaseous chlorine, molecular iodine, and an aqueous mixture of hydrogen peroxide and potassium hydroxide.” Very good point. 🙂 ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [October 26, 2012, 1:13am UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/10 "2012-10-26T01:13:30Z")
Let’s say you had some kind of magic snot cannon that could deploy huge balls of fibrous mucus, like dozens of meters across. More and more junk would get embedded until the whole thing came crashing back to earth like a fiery space booger of justice. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [October 26, 2012, 2:25am UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/11 "2012-10-26T02:25:21Z")
Since lasers are not miracle “make shit not exist anymore” like on movies and tv, no they can’t “destroy” space debris. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [October 26, 2012, 12:15pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/12 "2012-10-26T12:15:07Z")
> [@HMS\_Irruncible](#): > > Let’s say you had some kind of magic snot cannon that could deploy huge balls of fibrous mucus, like dozens of meters across. More and more junk would get embedded until the whole thing came crashing back to earth like a fiery space booger of justice. Or maybe it would turn into a star of its very own consisting of paper clips, cruise ships, and unfortunate poodles. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 26, 2012, 12:41pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/13 "2012-10-26T12:41:43Z")
The idea of using space lasers to de-orbit orbital junk has been around for a while now. I dobn’t know if anyone’s done a numerical analysis (probably they have), but the idea is to use laser light pressure (and possibly laser ablation, which is a lot bigger and more impressive – we speaks from experience) to slow down small objects in orbit to the point where they start encountering more atmospheric friction, where they will slow down even more, and so on, until they get so low that they fall into the atmosphere. Laser pressure is good for this application because, even though it’s a small push, it can be applied for long periods of time and from long distances, and there’s no satmospheric attenuation or thermal blooming to mess up the beam. It’s the perfect environment for using laser light pressure. Obvuiously this would require lasers that _coukld_ provide continuous push, so this doesn’t seem like a good application for chemical lasersw, which would exhaust their constituent gases. And if you question the ability of lasers to provide the _oomph_ to do this, observe that Leik Myrabo, Arthur Kantrowitz, Jordin Kare, and others have been advocating using laser propulsion _from the ground_ to put objects into orbit. Using lasers to change orbits is trivial by comparison. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 26, 2012, 3:10pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/14 "2012-10-26T15:10:19Z")
> [@Ludovic](#): > > Or maybe it would turn into a star of its very own consisting of paper clips, cruise ships, and unfortunate poodles. Then I vote ☑YES! on Proposal Space Booger. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [October 26, 2012, 5:01pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/15 "2012-10-26T17:01:25Z")
> [@HMS\_Irruncible](#): > > Let’s say you had some kind of magic snot cannon that could deploy huge balls of fibrous mucus, like dozens of meters across. More and more junk would get embedded until the whole thing came crashing back to earth like a fiery space booger of justice. I’ve heard of proposals to deploy a kind of very wispy foam or gel to do exactly this. Well, actually I think the idea isn’t to trap the junk, but to slow it down as it punches through the “cloud” of space booger, so it falls out of orbit faster. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [October 26, 2012, 5:04pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/16 "2012-10-26T17:04:56Z")
Another idea I’ve toyed around with: Does anyone remember the old arcade game Xevious with the flying indestructable plates? Maybe we could set up some large iron plates in space, and angle them so any space junk that hits them would be deflected towards the atmosphere. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 26, 2012, 6:40pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/17 "2012-10-26T18:40:12Z")
> [@CalMeacham](#): > > Laser pressure is good for this application because, even though it’s a small push, it can be applied for long periods of time and from long distances, and there’s no satmospheric attenuation or thermal blooming to mess up the beam. It’s the perfect environment for using laser light pressure. … And if you question the ability of lasers to provide the _oomph_ to do this, observe that Leik Myrabo, Arthur Kantrowitz, Jordin Kare, and others have been advocating using laser propulsion _from the ground_ to put objects into orbit. Using lasers to change orbits is trivial by comparison. Laser propulsion usually involves using a laser to heat up the propellant (reaction mass) carried on the projectile/spacecraft. It’s not photon pressure that provides thrust. Using this method to deorbit space junk would require enough power density to heat up and vaporize the surface of the space junk. That means a _very_ powerful laser and a large aperture optical system. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 26, 2012, 11:29pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/18 "2012-10-26T23:29:23Z")
> [@scr4](#): > > Laser propulsion usually involves using a laser to heat up the propellant (reaction mass) carried on the projectile/spacecraft. It’s not photon pressure that provides thrust. Using this method to deorbit space junk would require enough power density to heat up and vaporize the surface of the space junk. That means a _very_ powerful laser and a large aperture optical system. I’ve worked on laser propulsion, and , as my post indicates, it doesn’t use photon pressure, but gives more oomph. People have suggested using both photon pressure and photon ablation. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 26, 2012, 11:31pm UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/19 "2012-10-26T23:31:01Z")
> [@CalMeacham](#): > > I’ve worked on laser propulsion)using the ablation method)\*, and , as my post indicates, it doesn’t use photon pressure, but gives more oomph. People have suggested using both photon pressure and photon ablation. > > \*which doesn’t necessarily require huge laser powers, by the way. We were blasting dime-sized pieces of plastic with considerable velocity. Most debris would likely be much smaller. cc ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [October 27, 2012, 12:31am UTC](https://boards.straightdope.com/t/could-lasers-be-used-to-destroy-or-deorbit-space-junk/638825/20 "2012-10-27T00:31:48Z")
> [@scr4](#): > > But the most powerful lasers are not powered by electricity. The YAL-1 mentioned above uses a [chemical oxygen iodine laser](http://en.m.wikipedia.org/wiki/Chemical_oxygen_iodine_laser) which needs to be fed with “gaseous chlorine, molecular iodine, and an aqueous mixture of hydrogen peroxide and potassium hydroxide.” As an aside…man that sounds scary…now I know why someone referred to that laser as a rocket engine with mirrors on each end.