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."

Comments

Missile

[e8johan]

I still prefer a good old missile! It feels more destructive to fire a rocket at your enemies instead of just flashing (a really *big*) light at 'em. :-)

We`ll have to

[MrFredBloggs]

keep quiet about the whole light and mirrors thing, I guess...

Re:We`ll have to

[caveat]

if you hit a mirror with a powerful enough beam of laser light, the small fraction of light that's absorbed (no such thing as an ideal reflector) will rapidly ablate the mirror coat, and then you're screwed. we have problems with this with our pulsed IR laser at work - we need solid polished aluminum mirrors with heatsinks on the back, ad that's for a 500mJ, 500ns pulse; they don't last that long, either. a 100KW IR laser will vaporize pretty much anything that's not *perfectly* reflective, i.e. anything we can build with current technology.

Re:We`ll have to

[MrFredBloggs]

"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).

Re:We`ll have to

[!splut]

Perhaps some sort of sand/concrete which will degrade pleasantly?

Perhaps by playing a Bach concerto and releasing a soothing lavendar fragrance as it melts to form a replica of Rodin's The Thinker.

Is it just me...

[danro]

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...

Re:Is it just me...

[BabyDave]

I was scared from the moment I read

Donald Rumsfeld "is hot"

Re:Is it just me...

[T5]

First off, understand that we're reading quotes from John Pike. A little Googling will clearly reveal his politics to be somewhat at odds with the current administration. However, for Pike to admit that these solid-state lasers are moving
into the "engineering" phase (second phase of weapons development - research, engineering, and production) is quite revealing. For him to acknowledge publically any high-tech weaponry as making significant advances is, to me, quite shocking.

Also understand that the arms race, which has existed throughout human history, is exactly that: a contest to see who can come up with the most effective weaponry the quickest. In this era of asymmetric warfare, nukes are useless. We've got a rapidly growing asymmetrical threat against which our current best practices and tools are less than ideal. New weapons and tactics are needed to counter such a threat.

As to the open market availability of weapons for terrorists, sure, there's scuds (pun intended) available. As long as there are countries such as Russia and China producing cheap, reliable low-tech weapons, and other countries willing to act as brokers for these groups, there will be a channel. This, however, is a poor argument against transformation of our armed forces to respond to such threats, including development of new weapons that give our military another advantage. And, given the technical sophistication of the level of some of these new weapons systems being developed, it'll be years before opposing forces can produce clones in sufficient quantity to be worrisome. Case in point: look how long it's taken many countries to become nuclear capable. That technology is nearly 60 years old! Lasers have been around since 1954 (microwave, 1960 for an optical laser) and we still haven't been able to weaponize them to any significant degree. And much of laser theory and practice is in the open press, unlike many aspects of the nuclear weapons programs.

E = mc?

[Cutie Pi]

"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.

I can imagine.....

[Chardish]

The warning labels on the outsides of laser weapons:

CAUTION: DO NOT STARE DIRECTLY INTO LENS

-Evan

targeting system?

[sczimme]

A Navy ship could use the laser, with its beam traveling at the speed of light, to fend off even the fastest missiles. And ground troops could use a Humvee-mounted version of the weapon to instantly knock out incoming enemy artillery and mortar shells.

I would like to know how such a weapon will acquire/track/target an incoming projectile. (That was not sarcasm; I really would like to know.) Mortar rounds generally travel in a high parabolic path - think of the St. Louis arch. Larger artillery shells - such as those fired from a battleship - follow a flatter trajectory. The targeting system would have to acquire a small incoming object, predict the path it will follow, and fire within a few seconds. That looks like a daunting task.

Re:targeting system?

[FeloniousPunk]

The answer to your question is called AN/TPQ-36 and AN/TPQ-37 "Firefinder" target acquisition radars. We've had them for 20 years - the -36 is designed to track mortar shells and the -37 other types of artillery (though IIRC, the -37 has all the functionality of the -36).
They are very effective. They calculate the location of the firing tubes, and that information is passed to artillery units tasked to provide counterbattery fire (usually MLRS rocket artillery). This all happens very quickly - 30 seconds to a few minutes' time.

Re:targeting system?

[sql*kitten]

I would like to know how such a weapon will acquire/track/target an incoming projectile. (That was not sarcasm; I really would like to know.) Mortar rounds generally travel in a high parabolic path - think of the St. Louis arch. Larger artillery shells - such as those fired from a battleship - follow a flatter trajectory. The targeting system would have to acquire a small incoming object, predict the path it will follow, and fire within a few seconds. That looks like a daunting task.

It's a solved problem. The Sea Wolf point defence system can shoot down 4.5-inch shells as well as supersonic missiles. Sea Wolf was first deployed in combat in 1982. Of course, you are likely to run out of missiles before they run out of cannon ammo, but maybe you can buy enough time to hit them with an Exocet.

Warships are expensive, so a lot of money has been spent on ways to protect them!

Re:targeting system?

[Jester99]

The US Navy already has something like this in the form of giant guns mounted on some of its ships called "Phalanx" units. The thing fires thousands of bullets per minute, and it's all computer controlled. The purpose of this weapon is to track essentially anything that gets too close to the ship, and blow it to kingdom come. Missiles, planes, etc, are all valid targets. And it works, too.

More info is available. If you poke around online, you can also see some sweet movies of the thing. It just turns, tracks for a second, unleashes a wall of lead, then returns to the 'ready' position like it wasn't a big deal.

War is a daunting task. Fortunately, we've got some relatively clever folks thinking things like this up! :)

Soon (wrings hands)

[velcrokitty]

I'll be able to walk into a store and ask for: "Phased plasma rifle in 40-watt range. "

Excellent... Oh wait. 40-watts isn't very much. Is that what the Terminator really asked for? 40 watts? Sheesh. I could just hook up a light bulb and start shining bright lights in people's eyes. Perhaps the idea is to convince them to stare into the bulb for hours on end (like several of my classes that I attended) and eventually go blind-ish...

I will be back...

Re:Mirrors

[briggsb]

"We have a visual on the missile...er...wait...we're being attacked by a flaming disco ball!"

Re:Mirrors

[Idarubicin]

Wouldn't a couple of mirrors ruin the whole thing?

In principle, yes. In practice, no. If you were to put a very high quality coating of silver (for visible wavelength lasers) or gold (for IR lasers) on your missile, in principle you could reflect 95 to 98% of incident light. Special optical coatings can result in >99% reflectance, but only over narrow wavelength ranges.

In other words, if the enemy knows the wavelength at which your laser operates, he can reduce the effectiveness of your laser weapons. For ground based installations, this still isn't a big problem--you just need a laser that's an order of magnitude more powerful, and you can cook even the reflective coatings on the other guy's missiles. I've done research work involving lasers in both physical chemistry and medicine, and I've seen a number of purportedly highly-reflective optical elements get toasted by a powerful enough beam. Also, high-quality optical coatings usually aren't meant to handle the stresses (physical and thermal) experienced by your typical missile (ballistic or tactical).

Re:Not a feasible weapon

[Idarubicin]

Lasers work by creating an inversion of atoms into an excited state and then releasing that exciting energy in a burst. But exciting the atoms obviously takes energy and, by E=mc^2, it takes a LOT. Industrial and scientific lasers can manage this by being plugged in to a dedicated power supply capable of delivering the gigawattage required for even small lasers, but a soldier in the field clearly doesn't have the luxury of an outlet needed to power his weapon.

Okay, I'll bite. Where does E=mc^2 come into this? I've worked with lasers for a number of years, and I have yet to see any of my lasing medium converted directly to energy. Lasers operate by kicking atoms into an excited state (usually an excited electronic state) and then emitting light when excited atoms relax back to ground state.

For the record, small lasers don't require "gigawattage" to operate. I have a laser pointer that runs on one AA battery--I'll be giving a talk using it in a couple of hours. A laser designed for a weapons application would be larger. Still, I could assemble a carbon dioxide laser that could start fires from several hundred feet away and still be light enough to carry--and operate for a while on a moderately hefty battery back.

Granted, I couldn't destroy missiles with it, but the article discussses lasers that are mounted on aircraft or vehicles, or are part of fixed installations. You don't need a large power supply for even an extremely powerful laser if it only fires the very short pulses (microseconds or nanoseconds) that would be most useful for military purposes.

Not Just Lasers

[dscottj]

What is not reported here, but has been mentioned in Aviation Week and Space Technology, is Israel seems to have already fielded a chem-based laser missle defense system, apparently deployed on the Syrian border (at least that's where it was last reported anyway).

Another thing not widely covered in the normal monkey media: Gulf War II will almost certainly premiere our new "directed energy" weapon systems which have quietly been brought out of the labs over the past year or so. From the (admittedly basic) descriptions given to the non-monkey press by those in the know, the systems work with microwaves to zap electronic gear. They're mounted on precision guided bodies (not bombs per-se, but probably shaped a lot like them) and are one-shot items.

The idea is superpowerful microwave radiation can fry anything with transistors in it, even stuff buried deep underground. These things deliver a burst of microwaves that fry things within a (classified) limited range. It's not clear if they can be directed or if it goes off in a sphere like a ghostly bomb.

The reason they aren't already mounting these things on F-16s and just pressing buttons is a) the range is really short right now and b) they aren't directional enough yet and would end up frying the electronics of the shooter, which would be annoying to the pilot.

Re:Just for your information

[KFury]

"A kilowatt is 3,600,000 joules, 10 kilowatts in respect is 36,000,000."

What are you talking about? A kilowatt is a measure of power, and a joule is a measure of energy. The two are not directly comparable without a time factor thrown in. Do you mean a kilowatt hour is 3,600,000 joules?

By your calculation, lightning is 280-2,800 kilowatts (0.3-2.8 megawatts). As we all know, lighting is more in the range of 1.21 gigawatts (humor intended, but general priniciple remains the same). It's not like lightning strikes last for an hour.

------
"To put this in prespective, the adverage person uses 64,800,000 joules a month, or 18 kilowatts... So for every time they fire this baby, they are blowing 50-100 bucks....

They essentially are what cause the blackouts in California."

What the fuck are you talking about? This causes the blackouts in California, not some sergeant flipping the switch on $100 of electricity.

Forget Stealth technology then...

[glesga_kiss]

If you build your aircraft/missle out of reflective materials to counteract lasers, your going to make it a large target for radar.

Stealth material generally works by absorbing the energy. The two defences won't be able to co-exist.