8 ms·

I can't help thinking that in the anti-mortar role, there are very simple countermeasures that would severely reduce the laser's effectiveness. Reflective pain

I can't help thinking that in the anti-mortar role, there are very simple countermeasures that would severely reduce the laser's effectiveness. Reflective paint, ablative coatings, internal vacuum layer, heat insulation, thermally insensitive explosive and detonators, etc.

cli 11y ago
I think that demonstration was to show that the laser system can be useful against very cheap home-made mortars and rockets. The military would rather use a laser that costs tens or hundreds of dollars per shot to defend against mortars that cost perhaps several hundred dollars, rather than the current conventional methods that cost tens of thousands of dollars per shot.
- jessaustin 11y ago
  The military would rather use a laser that costs tens or hundreds of dollars per shot... than the current conventional methods that cost tens of thousands of dollars per shot. Wait, I thought we were talking about the USA military? When have their weapons systems ever gotten cheaper? The only time they buy something cheap is when there is no more expensive option that does the same thing available (e.g. drones). If the only consideration is cost/shot, lasers will never be deployed. The point of TFA is that the new systems do things that haven't been done before, like stopping a mortar round in flight.
walshemj 11y ago
yes but most of the mortars this will be facing will be diy ones or at best ww2 era 80 or 120 mm fired by insurgent's who wont have these exotic rounds.
andrewflnr 11y ago
The reflective coating one in particular was explicitly covered in the article. The rest mostly add weight for dubious benefit; I'm guessing increasing laser power will win that arms race decisively. And it doesn't seem like you have to cook off the explosives to beat the mortar round, since they mention that some don't explode when they're destroyed.
gliese1337 11y ago
Reflective paint is surprisingly ineffective. In order to work at all, it needs to be tuned to the frequency of the attacking laser, and not get dirty, or scratched up, or otherwise gain significant imperfection in the finish, which is rather difficult to achieve when firing out a cannon and flying through the air. Even if those conditions are met, however, mirrors still make for surprisingly bad defense against weaponized lasers, simply because no mirror is 100% efficient. The 0.1-ish% of a well focused, high-powered weapons laser that doesn't get reflected by a ridiculously high quality mirror on initial contact will still damage and deform the mirror, thus allowing more and more of the laser's power to be deposited in the target with increasing dwell time. Laser weapons avoid destroying their own optics by, first, using optics tuned exactly to the specific frequencies the weapon is designed to fire, and second, by using relatively large focusing mirrors / lenses which keep the power/area on the weapon optics below dangerous levels. Even so, real laser weapons have ridiculous cooling requirements to keep from destroying themselves with waste heat, which keeps their efficiency rather low. There are other countermeasures that can be used against lasers, to be sure; mirrors just ain't one of them.
- andrewflnr 11y ago
  Would it work to lead your mortar round or whatever with something leaving a smoke trail?
- ghostberry 11y ago
  You took "reflective" too literally. I just meant more reflective to IR than dark green paint that most military stuff gets painted with. I never meant a mirror surface. Just the IR equivalent of white paint.
  - gliese1337 11y ago
    White paint (or IR-colored paint, in this case) is worse than a mirror surface; it starts out at a disadvantage already. By assuming a mirror surface, I'm giving you the benefit of the doubt- anything else would be even more useless.
deleted 11y ago
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cli 11y ago

I think that demonstration was to show that the laser system can be useful against very cheap home-made mortars and rockets. The military would rather use a laser that costs tens or hundreds of dollars per shot to defend against mortars that cost perhaps several hundred dollars, rather than the current conventional methods that cost tens of thousands of dollars per shot.

jessaustin 11y ago
The military would rather use a laser that costs tens or hundreds of dollars per shot... than the current conventional methods that cost tens of thousands of dollars per shot. Wait, I thought we were talking about the USA military? When have their weapons systems ever gotten cheaper? The only time they buy something cheap is when there is no more expensive option that does the same thing available (e.g. drones). If the only consideration is cost/shot, lasers will never be deployed. The point of TFA is that the new systems do things that haven't been done before, like stopping a mortar round in flight.

walshemj 11y ago

yes but most of the mortars this will be facing will be diy ones or at best ww2 era 80 or 120 mm fired by insurgent's who wont have these exotic rounds.

andrewflnr 11y ago

The reflective coating one in particular was explicitly covered in the article. The rest mostly add weight for dubious benefit; I'm guessing increasing laser power will win that arms race decisively. And it doesn't seem like you have to cook off the explosives to beat the mortar round, since they mention that some don't explode when they're destroyed.

gliese1337 11y ago

Reflective paint is surprisingly ineffective. In order to work at all, it needs to be tuned to the frequency of the attacking laser, and not get dirty, or scratched up, or otherwise gain significant imperfection in the finish, which is rather difficult to achieve when firing out a cannon and flying through the air. Even if those conditions are met, however, mirrors still make for surprisingly bad defense against weaponized lasers, simply because no mirror is 100% efficient. The 0.1-ish% of a well focused, high-powered weapons laser that doesn't get reflected by a ridiculously high quality mirror on initial contact will still damage and deform the mirror, thus allowing more and more of the laser's power to be deposited in the target with increasing dwell time. Laser weapons avoid destroying their own optics by, first, using optics tuned exactly to the specific frequencies the weapon is designed to fire, and second, by using relatively large focusing mirrors / lenses which keep the power/area on the weapon optics below dangerous levels. Even so, real laser weapons have ridiculous cooling requirements to keep from destroying themselves with waste heat, which keeps their efficiency rather low. There are other countermeasures that can be used against lasers, to be sure; mirrors just ain't one of them.

andrewflnr 11y ago
Would it work to lead your mortar round or whatever with something leaving a smoke trail?
ghostberry 11y ago
You took "reflective" too literally. I just meant more reflective to IR than dark green paint that most military stuff gets painted with. I never meant a mirror surface. Just the IR equivalent of white paint.
- gliese1337 11y ago
  White paint (or IR-colored paint, in this case) is worse than a mirror surface; it starts out at a disadvantage already. By assuming a mirror surface, I'm giving you the benefit of the doubt- anything else would be even more useless.

deleted 11y ago

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