Slashdot Mirror
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.
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!
"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.
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.