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Homing In On Laser Weapons
Bloodmoon1 writes "I just came across this article at GlobalSecurity.org that gives a very good summary of the current status of solid-state lasers as weapons. It gives you a good idea of where the JSF Laser system is at and just how much time, effort, and money has went into this project. Also has some basic, but very sufficent, explanations of some of the science behind the technology."
Defense Secretary Donald Rumsfeld "is hot on ... the notion of zapping people,"
Is it just me, or does this make someone else worried.
That man is kind of scary...
"First lesson," Jon said. "Stick them with the pointy end."
"The technology turns atomic particles into light with enough radiation to damage an object it encounters."
Umm... anyone know how that is supposed to happen?
But seriously, I'm sick and tired of science related articles being written by journalists with no clue about the science they're writing about. These articles should be checked for accuracy by the people the story is about.
CAUTION: DO NOT STARE DIRECTLY INTO LENS
Heh, like Claymore mines are labelled "FRONT TOWARDS ENEMY".
Instead of spending public money on researching new ways to blow each other up, I wonder if this technology could be put to better use, perhaps mounted on satellites as an asteroid defence system?
It's not entirely impossible that a large asteroid will head straight for us at some point... and somehow I don't think a re-enactment of Armageddon would work!
Not really.
Most mirrors are only about 95% reflective. The other 5% is transmitted through the mirror and absorbed (either by the mirror itself or the backing). Really good mirrors are about 99% reflective.
Now, let's assume that somehow you manage to "chrome" a missile such that it's 99% reflective (not bloody likely in real life, but we're talking theory here). Someone targets a 100 kW laser at you. The mirror reflects/scatters 99 kW of the energy, while 1 kW is absorbed by the missile itself.
It takes 216 kWs to heat 11 kg of steel by 10 deg C. Certainly you're not going to be able to keep the laser on the mirror for 216 seconds. But, that's ok, that's not the point. All you have to do is melt the mirror at contact point, degrading its reflectance so you can effect the missile itself. So how long does it take to boil the mirror into vapor? Probably a couple seconds. After which you have no effective defense and the 100 kW beam will boil off enough of the missile to render it ineffective. After all, you don't have to destroy it -- just alter the aerodynamics enough so it's incapable of targeting correctly.
You could spin the missile to reduce spot heating, but that's going to complicate guidance considerably. And, frankly, I doubt that you'll get more than 80% reflectance on this sucker, which changes the equation drastically. And, of course, your maintainance crew didn't leave any oil, grease, or fingerprints on the missile casing right? Uh huh.
The main stumbling block to SDI was tracking, targeting, and blasting a laser through several miles of atmosphere - all in about 10 seconds after launch. That or you wait until the ICBM is in space, in which case you now have to destroy (not merely damage) a dozen warheads and a couple dozen dummys. Which means you now have 20-30 targets to destroy in 30 seconds instead of 1 target in 10 seconds. Fun!
But then there is that overly logical Marine in me that says sounds unreliably. Much rather have a tried and true missile.
I've no doubt that the first laser weapons will be pretty poor. But back in the 50s there were probably overly logical Marines just like you saying they'd rather have a tried-and-true machine gun fitted to their planes. Once a concept has been proved to work, the military have a history of being quickly able to turn it into something practical.
Well, gee...I guess if you can power a laser pointer strong enough to blind you with a couple of AAA batteries, a 747 or Navy destroyer can supply enough power to run a laser strong enough to affect an incoming missile.
The big disadvantage to large laser weapons is that they give away their precise position since laser beams travel in perfectly straight lines.
You might think so, but tracer ammo has been around since WW2 and it's still in use today. That suggests that being able to locate a weapon that is firing at you while it is firing isn't as big a tactical advantage as it might first appear.
"a 100KW IR laser will vaporize pretty much anything that's not *perfectly* reflective, i.e. anything we can build with current technology."
yeah, but if you need to prevent this sort of thing from happening to keep your planes/boats/trucks up and running, then its worth looking into solutions. Who knows what`ll be effective? Perhaps some sort of sand/concrete which will degrade pleasantly? Layers of shiny foil which peels off revealing more foil below. Also, non/slow moving lasers will be the perfect target for counter-weapons to lock onto if they`re active for a few seconds at a time - usually you`d just get a flash as the weapon was fired - now you`ll have `I am here!` flashing lights (& heat).
Stealth material generally works by absorbing the energy. The two defences won't be able to co-exist.
Wonder what the Geneva Convention will be modified to say about this.
Provided you aren't relying on them to down a real inbound threat!
A Navy ship could use the laser, with its beam traveling at the speed of light, to fend off even the fastest missiles.
Pity about those torpedoes though huh! Launched by enemy submarine/ship/plane/whatever.
A laser will be useless under water.
At the end of the article, the author casually mentions that a direct energy weapon could be mounted on the AC-130. I think this is a highly likely scenario.
The AC-130 mounts extremely heavy weapons (105mm Howitzers, Miniguns, etc). It seems like this is a more likely platform for early laser weapons.
The simplest way to invite war is to not be prepared for it -- either in terms of actual power, or psychological capability.
/had/ the power. Militarily weak nations have, historically, been treated as such...
One of the reasons why the Great Powers were able to roundly abuse other nations is that they
And when nations, in the name of international law and peace, turn the other cheek to an aggressor when those same laws are abused, the results are generally obvious -- the aggression continues. Condemnations have never practically stopped a massacre, nor have battalions been routed by a tongue-lashing, while negotiations fail when there is genuinely nothing to discuss because there is nothing of perceived satisfactory mutual benefit regarding an issue.
Only the dead have seen the end of war.
Efficiency of mirrors aside, keep in mind the purpose of war is to kill people. Sure, having a nice shiny surface for laser defense can work (in principal) but it also makes you really, really, really visable. This would make you a great target. So, if we can mount a laser and make all the bad-guys dress in shiny suits, GREAT. The the camo guys with guns can just clean up. Any solution can't be that one sided.
"He who laughs last, didn't get the joke."-Cap
do against human carried warheads?
Or the next terrorists with suitcase nukes or truck bombs?
I mean we already have dozens of ways to stop trucks and commercial air planes.
The ABL is a great defense against WMD _missels_, but we have better defenses against _states_ that might launch missels: massive retaliation. From US vs Irag epsiode 1 to India v. Pakistan, evidense is MAD works.
Meanwhile, the ABL will not work well at all against human carried warheads, the most common forms of attack we are likely to suffer, the only real defense against these is to make the lives of the cannon fodder more pleasent than the glory of dying for the cause...
I think the guy's point was that the mirror isn't good for one shot; it'll pretty much vanish, and the laser'll keep going.
Perhaps not, but ablation takes time, so either designing one-shot disposable mirrors should be practical (just make the reflective material really, really thick), or do without the mirror and aim the turret manually.
Either would work, and the laser would still be much faster than a bullet or missile, which is traditionally aimed in the same, low tech manner.
The Future of Human Evolution: Autonomy
100 KW focussed onto what sized area for how long? You'd need pretty large active optics to create a small spot at a couple of miles through turbulent, dirty atmosphere. These weapons are not photon torpedoes: their main use will be to disable the sensors on missiles and humans (eyes); both will be blinded by a quick scan with a 100 KW laser. Forget star wars, these are anti-personnel and anti-sensor devices. The other issue is the laser tracking mechanism itself. This will rely on sophisticated and sensitive sensors : even a basic reflective mechanism might return enough energy for the laser to blind itself.Think 3 orthogonal mirrors, reflective bubbles etc.