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Question about missile defense systems and lasers

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  1. Aug 20, 2017 #1
    I was reading a news article about powerful lasers being used in missile defense systems, and I was wondering if multiple weak laser can work together to do the same job as one strong laser. For example can a thousand 1 Kw lasers in different locations be made to point at a single point on a fast moving target and cause an effect similar to a 1 Mw laser?
     
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  3. Aug 20, 2017 #2

    phinds

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    Theoretically I suppose so, but in practical terms it sounds ridiculous.
     
  4. Aug 21, 2017 #3

    boneh3ad

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    As long as they all focused on the exact same point so that you get the same beam intensity as the larger laser, then sure. That would be an extraordinary challenge to aim that precisely, though. In fact, given the unpredictable nature of density variations throughout the atmosphere, I'd say it would be effectively impossible since it will refract each beam slightly differently.
     
  5. Aug 22, 2017 #4
    Are you contemplating boring through the skin of the missile to disrupt internal systems?
    Or, perhaps blinding the missile by destroying or overloading the sensors?
    What type of missile - ballistic, cruise for example?
    Range to missile would most likely be a factor for focusing and effectiveness, through the atmosphere, as mentioned. Outer space?
    As well as intensity of the laser beam which could ionize the air and again render it in-effective.

    Just posting some areas that you could further investigate if you are inquisitive.
     
  6. Aug 22, 2017 #5
    This laser combining has been researched by DARPA some time back and met with little success. However with advancements in laser/optics this research has surfaced once again with some success. Some reading in the article lends some knowledge and difficulty in combining lasers.

    http://www.laserfocusworld.com/arti...ng-combining-beams-can-boost-total-power.html
     
  7. Aug 22, 2017 #6

    CWatters

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    They might not have to point at exactly the same point, just deliver enough energy to the missile to damage it.

    All my missiles have been polished to a mirror like shine :-)
     
  8. Aug 22, 2017 #7

    boneh3ad

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    Total energy doesn't matter for damage, though. Total energy per area, or intensity, matters. You could defocus a 1 MW laser so that it covered the continental united states and it would be harmless, but focused nearly to a point, it would poke a hole through just about anything.
     
  9. Aug 22, 2017 #8
    The area of a missile is much less then the areas of the united states. I'm guessing the missile can only shed excess heat to the surrounding air at a finite rate. If heat energy is continually added faster then it is taken away I imagine eventually the missile will get so hot it will fail for one reason or another. I'm not sure how many watts of laser such a thing would actually take though, but if most of the laser energy is converted into heat on the missile I can't help thinging a few GW or a TW would do it eventually.
     
  10. Aug 22, 2017 #9

    boneh3ad

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    Well the question would be whether you wanted to kill it with one big "POP!" before it is out of range or do you want to have to train your team of lasers on it over an extended period of time. The bigger lasers aren't working by putting a lot of energy into a small area in order to heat up the whole missile until it experiences thermal failure. They are working by putting a lot of energy into a small area so that a very small portion will fail and they can damage important internal components. For that, you need a lot of energy in a small area, i.e. a high intensity.
     
  11. Aug 22, 2017 #10

    CWatters

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    Don't they have re-entry heat shields? How does the heat of re-entry compare with a 1MW laser?
     
  12. Aug 23, 2017 #11

    boneh3ad

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    I don't know, but the lasers are designed to kill the missile in the boost phase before it reaches space. Really the goal is to rupture the fuel tank and cause the launch to fail, if I'm not mistaken.
     
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