Laser Takes Out Truck Engine From a Mile Away

MutualFun (1730480) writes Aerospace company Lockheed Martin has used a laser to obliterate the engine of a small truck from more than a mile away. (Finally, Star Wars is making a comeback!) The company says, "The demonstration marked the first field testing of an integrated 30-kilowatt, single-mode fiber laser weapon system prototype. Through a technique called spectral beam combining, multiple fiber laser modules form a single, powerful, high-quality beam that provides greater efficiency and lethality than multiple individual 10-kilowatt lasers used in other systems."

Comments

One million dollars

[danbert8]

But can they be mounted on sharks? That is the real question...

Re:One million dollars

[Anonymous Coward]

Please shut up.

Re:One million dollars

[Megane]

Sharks, hell, where's the popcorn?

Re:One million dollars

[The Fifth Man]

Sorry man, the thing is, he wants /. to be like it was and not how it is now, which is like reddit, with movie quotes and in-jokes. Don't be too hard on the old timers. I get that we need to evolve and talk about Pokeyman and make references to '10 era teen comedies or whatever but we have a hard time with that :-/

Re:One million dollars

[Anonymous Coward]

I hate popcorn - get it away from me!

Re:One million dollars

[RyuuzakiTetsuya]

This is Jesus.

Stop playing with yourself.

Re:One million dollars

[Tyler Durden]

Right. Because everybody wants to rule the world...

Re:One million dollars

[design1066]

Please lighten up.

Re:One million dollars

[design1066]

Yes, as soon as we can clone this Megalodon.

Re:One million dollars

[boristdog]

Local man passionate defender of what he imagines Slashdot to be.

Re:One million dollars

[minchazo]

You mean one... hundred... billion?

Re:One million dollars

[Gr8Apes]

.. talk about Pokeyman and make references to '10 era teen comedies or whatever

Not Pokeyoureyeoutman!!! I was hoping that died out with the now over 30 crowd. As for '10 era teen comedies, did they make any? Scott Pilgrim, for example, is not a comedy even on beer binge day.

Re:One million dollars

[K. S. Kyosuke]

Said the laser to the truck?

how much it took

[cachimaster]

Maybe it took a week to make a small hole, that's an important detail.

Re:how much it took

[Carewolf]

Maybe it took a week to make a small hole, that's an important detail.

And what did it cost compared to firing a single armor piercing bullet?

Re:how much it took

[pr0fessor]

The article said "The ground-based laser prototype burned through the engine manifold of a mounted truck in mere seconds." so at least two seconds and less than a minute, but you are correct the longer it takes the less practical it would be to use it against a moving target.

Re:how much it took

[itzly]

0.1% of the kill rate of an A10 Warthog, for only 1000 times the cost. But hey, somebody's making a lot of money here, so we can't complain.

Re:how much it took

[meta-monkey]

They should do some tests to see how many seconds a 120mm shell fired from an M1A1 at ~1700m/s needs to be in contact with the truck to disable it.

Re:how much it took

[NatasRevol]

Don't forget the uranium in the bullets it sprays all over the place.

Re:how much it took

[by (1706743)]

... the longer it takes the less practical it would be to use it against a moving target.

Certainly true, but given that light is (near as makes no difference) instantaneous in this case, having the target in your sights and hitting it are the same thing. If the range is increased enough, I suspect that this would be a much easier weapon to use than, say, projectiles, as there's no possibility of evasion.

Re:how much it took

[itzly]

And how many billion for development of this laser ?

Re:how much it took

[itzly]

It's not going to be easy to keep a target in sight, when both yourself and the target are moving and vibrating. And by the looks of the burn marks on car, the laser spot is less than a few inches wide, so you'd need to be really accurate. And while the laser is near instantaneous, your targeting system still needs some time to identify the movement and compensate for it.

Re:how much it took

[Richard_at_work]

How many billions of dollars of development for the A-10 and the cannon it carries?

Re:how much it took

[Entropius]

It took "mere seconds" to burn through the engine manifold.

Paint it white (specifically, something with high albedo in whatever frequency range the attacker favors) and you can probably increase that time by a factor of ten. Paint it with that retroreflective paint that they make street markings out of and you've blinded anyone near the firing station.

Laser weapons look effective now because nobody's taking rudimentary countermeasures against them (because they don't need to). But if these things start appearing on battlefields, there are some simple countermeasures that will make their life a lot more difficult.

Re:how much it took

[avandesande]

Hardly billions. The technology that goes into fibre lasers is very cheap and efficient. My guess is that this was made form mostly off the shelf components.

Re:how much it took

[BCGlorfindel]

They should do some tests to see how many seconds a 120mm shell fired from an M1A1 at ~1700m/s needs to be in contact with the truck to disable it.

It'd be much like comparing a musket loading firing line to guys with long bows and seeing who had a better firing and kill rate. You could get off a lot more arrows for a long time before guns were improved to the point that the bow was only valuable when you couldn't get your hands on a gun.

If lasers can be improved to parity in damage, they will be immeasurably more useful when attached to something a like a naval nuke. You get a firing rate only limited by your cooldown, and never need ammo for the years it takes the reactor to need a recharge. Meanwhile a gun battery with gunpowder would run out of rounds in very short order and need to get more shipped out to it.

Re:how much it took

[celtic_hackr]

There are two real questions to ask here:
1) is if the laser is in visible light or not. If you can't see the red dot source a mile off, you can't evade it.
2) what is the range of the weapon. The range matters mostly inside the atmostphere. This weapon mounted on a spacecraft (satellite, etc) would have almost unlimited range, since the density of space is so minimal. Inside the atmosphere is another issue.

Let x = number of seconds to disable a target.
Let x > 2.
Let y = range of laser in miles.
let y > 1
Ergo y/x is less than or equal to 1800mph

So the weapon would only be effective against something travelling less than 1800mph, given the internal tracking system of the weapon can keep the laser position in the same area. If the range of the weapon is say 5 miles then you could take out something going very fast indeed, and if the device couldn't see the beam, it wouldn't know it was under attack until it was too late. Ultraviolet lasers have higher powr ratings than visible light. The weapon is likely in the UV range. Hence any defensive protocol would require having a UV detector. You'd have to be able to detect the beam from any location. Since this laser is a fiber laser, and those are metal doped fibers, it is almost certainly a UV laser. Hence notihng to see with the naked eye even staring straight into it, for that brief time before you die.

Re:how much it took

[cdrudge]

If lasers can be improved to parity in damage, they will be immeasurably more useful when attached to something a like a naval nuke.

Finally naval warships will be able to attack and defend itself from the armadas of pickup trucks that might attack it on the high seas...

Re:how much it took

[Dins]

Hardly billions. The technology that goes into fibre lasers is very cheap and efficient. My guess is that this was made form mostly off the shelf components.

Maybe it *could* be made from off the shelf components - I have no idea. But I bet the government spent 100x that to develop their own customized (expensive) stuff...

Re:how much it took

[celtic_hackr]

I should have noted, that these lasers would make a suitable defensive grid against ICBMs, which reach into space (at least according to unclassified knowledge). Effectively neutralizing trillions of dollars and ruples of the US and Russian military equipment.

Re:how much it took

[geekmux]

The article said "The ground-based laser prototype burned through the engine manifold of a mounted truck in mere seconds." so at least two seconds and less than a minute, but you are correct the longer it takes the less practical it would be to use it against a moving target.

...until they develop an equally impressive tracking and targeting system...

...unless they already have...(yes, this would likely be the classified part you're not supposed to be thinking of)

Re:how much it took

[amicusNYCL]

Do you have any idea what the actual cost of development of this program is, then the cost of actually operating the laser, or are you just going to assume it's in the billions and then try and compare it with the A10 program? Have you made any attempt at research? Or are you "just asking questions?"

I love the A10 as much as anyone, but it's pretty difficult to compare a laser program with the A10. The A10 does not exactly excel at shooting down rockets in flight, and the entire purpose of the laser program is not to develop a laser that can disable trucks. It's to develop a general-purpose laser system that can track and engage targets, and this test is a demonstration that the power output is sufficient to disable a vehicle. That gives us a frame of reference for the power of the laser.

But apparently you want to scrap the laser program and instead have fleets of A10s just flying around Israel or aircraft carriers or any other place where a laser defense system might come in handy? Yeah, that sounds a whole lot cheaper than having a trailer with a laser and radar sitting there waiting for targets.

Re:how much it took

[amicusNYCL]

Paint it white (specifically, something with high albedo in whatever frequency range the attacker favors) and you can probably increase that time by a factor of ten.

Well won't you be embarrassed when you actually click on the article and note the color of the target vehicle.

Re: how much it took

[fnogxpto]

I'm almost sure a regular mirror is completely impotent to avoid a laser of this calibre.

Re:how much it took

[duck_rifted]

Its effectiveness against a moving target depends entirely upon how quickly it aims itself. And... you know, whether it aims itself.

Re:how much it took

[afidel]

$159,279,888 in 1973 or ~$837M is 2015 dollars for the A-10. The GAU-8A develop cost was $49.7M in 1974 or $235M in 2015 dollars for a total system development cost of just over $1B.

Re:how much it took

[afidel]

Even near perfect mirroring makes damn near zero difference to a cutting laser so I doubt this attack laser would be any different.

Re:how much it took

[Rich0]

0.1% of the kill rate of an A10 Warthog, for only 1000 times the cost. But hey, somebody's making a lot of money here, so we can't complain.

Speed-of-light weapons that have virtually linear trajectories certainly have the potential to change warfare though.

Put it this way - if you pointed that A10 cannon upwards at an aircraft at 70k feet, you'd be hard-pressed to hit it at all. On the other hand, a laser would have relatively little difficulty hitting the aircraft even if it were in geosync orbit, or even on the surface of the moon.

Stick something like this on a plane and you could use it to shoot down incoming missiles, shoot artillery shells in mid-flight, shoot aircraft, and so on.

Sure, the technology is immature, but it certainly is a capability that is valuable for a military to posses.

Re:how much it took

[avandesande]

Similar system for 40 million dollars.
http://www.industrytap.com/40-...

Is it just me or are /. passive aggressively feigning stupidity today?

Re:how much it took

[Rich0]

They should do some tests to see how many seconds a 120mm shell fired from an M1A1 at ~1700m/s needs to be in contact with the truck to disable it.

Perhaps a more important question is how long the laser has to be pointed at the 120mm shell in-flight from the M1A1 at 1700m/s before the shell does nothing on contact with the target.

Blowing up targets sitting still on a range has been a solved problem for centuries. That doesn't mean that an Aegis air defense system has no more value than a medieval cannon.

Re:how much it took

[nehumanuscrede]

You're limiting your thinking to the short term. Expand it out a decade or two and try to picture what the tech can evolve into.

Imagine a satellite ( or something like the ISS ) based weapon that will fire an invisible high-kilowatt ( or even megawatt ) beam on any target it can see from orbit. Maybe combine a few of these satellites onto the same target for even more power output.

Then realize you can pretty much incinerate any human target on the planet, instantly. From orbit. Crank the power output up enough and you can do the same with aircraft, other satellites, light vehicles, ICBM's, etc. The puppet you installed during your regime change a decade ago giving you shit ? No problem. Hope they remember to wear their SPF-10000 today . . . . :| Those pesky whistleblowers taking refuge in a non-extradition country ? Pffft. No problem. Start some wildfires, disable power grids, use your imagination.

On the ground, the target will just heat up, catch fire and die horribly. No collateral damage, nor explanation as to wtf just happened.

Is the tech clumsy today ? Sure it is. All tech starts that way. Compare computers from 20-30 years ago with what is common today if you want to see tech evolution in action.

Re:how much it took

[Bugler412]

the Navy is interested in this because they would really like to get out of the carrying and storing lots of explosive ammunition on warships in hostile areas business. If all they need is bigger generators and this device to have essentially unlimited shots, and not carry ammunition, some reduced capability of the individual shots is likely acceptable.

Re:how much it took

[avandesande]

A similar system was developed for about 40 million

http://en.wikipedia.org/wiki/L...

So the answer is ~.04 'billions'

Re:how much it took

[Ralph Wiggam]

Keeping the 300 A-10s operational costs over $800M per year. That's a lot of money for a plane that can only do one thing under specific circumstances. Newer, more flexible systems can take over those missions at little additional cost. The Air Force has been trying to get rid of the A-10 for years, but Congress won't let them.

Yes, the A-10 appeals to the inner 12 year old in all of us. But the days of a pilot flying slowly in a straight line directly towards its target are behind us.

Re:how much it took

[Pinky's Brain]

Because plasma doesn't mirror very well ... but if you have say a rotating rocket this effect is going to be much reduced with a continuous wave laser, you probably won't get to the evaporation temperature necessary to really get the ball rolling.

I think for use against rockets you're going at the very least need a hybrid pulse/continuous system ... with the pulses doing only superficial damage but destroying the mirroring properties of the metal shell so the power from the continuous laser will actually be absorbed.

Re:how much it took

[vux984]

Imagine a satellite ( or something like the ISS ) based weapon that will fire an invisible high-kilowatt ( or even megawatt ) beam on any target it can see from orbit. Maybe combine a few of these satellites onto the same target for even more power output.

If any nation had one and started using it in the ways you suggest, how long before opposed nations would knock it down.

After all, what is its defense against a ground based laser shooting back at it?

Re: how much it took

[DigiShaman]

If it scales, certainly you can put an orbital weapon system in space, right?

An assassin in space kills at the speed of light?

Re:how much it took

[drinkypoo]

Paint it white (specifically, something with high albedo in whatever frequency range the attacker favors) and you can probably increase that time by

Basically nothing.

Paint it with that retroreflective paint that they make street markings out of and

Basically nothing special will happen.

Re: how much it took

[Redmancometh]

What if they gain the ability to change the wavelength/frequency on the fly in the future?

A targetting computer gets the color of the target, decides what type of laser is most effective, target destroyed.

Granted I assume that would be highly complex..but certainly possible. Especially since it uses multiple beams.

Re:how much it took

[davesays]

It also says "The vehicle, hoisted onto a test platform, was running its engine and drive train, simulating a real-life military scenario." I have NEVER seen a vehicle in combat on a test platform OR tilted 45deg to improve the angle of incidence of the enemy weapons systems...

Re:how much it took

[rossdee]

" a plane that can only do one thing under specific circumstances."

But it is the best at doing that one thing , and that one thing (supporting ground troops) is something that we still need to do in the esrs we are hoing to be fighting (against ISIS and Al Qaeda who do not have an air force.) we don't need fast, stealthy fighters like the F35 aginst terrorists.

And we are not going to be fighting a conventional war against China or Russia where we would need the F35.

Re:how much it took

[umafuckit]

On the other hand, a laser would have relatively little difficulty hitting the aircraft even if it were in geosync orbit, or even on the surface of the moon.

Are you sure about that? Laser beams diffract. The tighter you make it the more it diffracts. There are limits, therefore, as to far away it will work. I don't know how the numbers work out, however, or to what degree you can get around this with collimating lenses.

Re:how much it took

[Ralph Wiggam]

The reality is that the Air Force, Army, and Marines want the A-10 kept alive

You should talk to the Secretary of the Air Force. They're saying otherwise.

http://thehill.com/policy/defense/213844-ayotte-rips-air-force-for-defending-a-10-retirement

Re: how much it took

[fyngyrz]

I"m pretty sure a regular mirror would not be employed.

But here's some hand-wavy math.

If a mirror reflects 99% of the light that hits it at the laser frequency (remember, there's only one frequency to be covered), and the light that hits it can heat proportional to 30 kw (however one figures that), then the mirror is absorbing a 300 watt equivalent and reflecting the rest unless the reflective surface fails.

If the reflective surface is highly heat conductive and the beam isn't all that tightly collimated, likely it won't flinch at all. Like any impact, the effect is all about how much energy you can shoehorn into the smallest possible area. If the beam is ~1/3 of an inch on target, then given 99% reflectivity, it's effectively 1 kw / square inch. If the beam is 1/30th of a square inch on target, it's 30 kw/square inch absorption after reflection. So it makes quite a difference. I think.

Anyone who works with lasers and mirrors, feel free to step in and correct or expand.

Re:how much it took

[fyngyrz]

CIWS targeting is, as the acronym hints, "close in." You should think of the distance between the shooter (of anything) and the target as a lever. A tiny pivot at one end of the lever (the weapon's aim) translates to a "much" larger motion at the end of the lever (the point of impact.) Tolerances that will work at 100 yards aren't anywhere near close enough to work at many miles, or hundreds of miles in the case of missiles not aimed particularly at you (so you can be sure they will get close enough to hit.)

Re:how much it took

[pr0fessor]

They are talking about putting these on trucks and air craft. The real world is full of hills, valleys, trees, buildings, vehicles, road signs, and any number of other obstructions that can come between you and a moving vehicle. Even if you can't see the weapon's laser the possible obstructions would still make the operation impractical in some situations if it doesn't do it's damage fast enough and you just end up leaving scorch marks and catching stuff on fire.

Re:how much it took

[painandgreed]

It took "mere seconds" to burn through the engine manifold.

Paint it white (specifically, something with high albedo in whatever frequency range the attacker favors) and you can probably increase that time by a factor of ten. Paint it with that retroreflective paint that they make street markings out of and you've blinded anyone near the firing station.

Laser weapons look effective now because nobody's taking rudimentary countermeasures against them (because they don't need to). But if these things start appearing on battlefields, there are some simple countermeasures that will make their life a lot more difficult.

First, it has to be reflective to the wavelength of laser they are using. Just because it's white in the visible doesn't mean it's not "black" in the spectrum of the laser. Even then mirrors are only good for a percentage of the power put out by the laser. That percentage that gets through turns into heat which quickly changes the properties of the material, usually making it not reflective any more. Even then, that would require lab type clean conditions, otherwise the laser will heat up the dust an dirt on the reflective surface which will do the work for it. I doubt that military targets would be able to be kept that clean.

Smoke might work, but that's already an option. It just might be more of an option if it actually stops some munitions.

Re:how much it took

[dpidcoe]

The trick is keeping it on target for long enough to do damage. A glancing hit or two from the cannon of an A10 is going to do a lot more damage than a glancing hit or two from a laser that takes a few seconds to heat up the target to damaging levels.

Re:how much it took

[dpidcoe]

Lasers aren't quite as infinite as you make them out to be. There's still the matter of upkeep (all that supporting hardware is much more delicate and complex than a big gun), and often the optics and/or bits of the cooling system are expected to be replaced as wear items.

Re:how much it took

[Rujiel]

But they have to get rid of it somehow, and given the US' recent record of irradiating Iraqis (see: fallujah), i wouldm't be surprised.

Re:how much it took

[Ol Olsoc]

Keeping the 300 A-10s operational costs over $800M per year. That's a lot of money for a plane that can only do one thing under specific circumstances. Newer, more flexible systems can take over those missions at little additional cost. The Air Force has been trying to get rid of the A-10 for years, but Congress won't let them.

Yes, the A-10 appeals to the inner 12 year old in all of us. But the days of a pilot flying slowly in a straight line directly towards its target are behind us.

I envision you reading this as a computer animation of the "New F-300 Destructagator swoops down to deliver a cost effective, high reliability, and multi-mission multi- platform fighter/bomber built expressly for the modern asymmetrical warfare environment, providing cost effective and decisive air and groundspace superiority for the warfighter of tomorrow, - today!

Re:how much it took

[Ol Olsoc]

The reality is that the Air Force, Army, and Marines want the A-10 kept alive

You should talk to the Secretary of the Air Force. They're saying otherwise.

We're always ready to fight the last war.

Re:how much it took

[Ol Olsoc]

Hardly billions. The technology that goes into fibre lasers is very cheap and efficient. My guess is that this was made form mostly off the shelf components.

Mirrors are pretty cheap too. I suspect the next war we're in will be very bright and shiny.

Re:how much it took

[DamnOregonian]

You'd perhaps be surprised how difficult it is to mirror 40kW of coherent light without liquid nitrogen.

Re:how much it took

[DamnOregonian]

I imagine not very long before it causes enough damage (melting?) to make the shell's formerly ballistic trajectory no longer a threat to you

Re:how much it took

[DamnOregonian]

No, because it's only white for a fraction of a millisecond at that energy.

Re:how much it took

[guises]

That one thing is not supporting grounds troops. That one things involves supporting ground troops. There's a big difference there. If the A-10 really was the best at the very broad category of supporting ground troops then there would be plenty of reason to keep it around, but the fact that it's only effective under specific circumstances is why people want to get rid of it.

Re:how much it took

[Ralph Wiggam]

We're always ready to fight the last war.

That may be true. But the statement "The reality is that the Air Force, Army, and Marines want the A-10 kept alive" is clearly false.

Re:how much it took

[Rich0]

Of course. I'm not saying that it is a solved problem. I'm just saying that there is a reason people are interested in solving it.

Re:how much it took

[angel'o'sphere]

A geo synch orbit is about a tenth of a light second away (actually a bit more).
The object in such an orbit is moving with ~3km/sec, that is over 300m in the time a laser beam needs from the ground towards it.
So: hitting it with a laser without artificial aiming/tracking aids is impossible.

Re:how much it took

[peragrin]

Name one thing the A-10 can't do in support of ground troops the F-35 can? The A-10 can loiter longer, fly lower, stay on target longer. It can fly from forward unimproved airstrips. It has longer range. It can carry far greater number of missiles and bombs.

So just where is the A-10 deficient in support of ground troops? The F-35 is an expensive fast moving, carries less weapons, can only stay on target for a limited time. The only plane better than the A-10 is the AC-135, and the AC-135 isn't as effective against heavy armor.

Re:how much it took

[weilawei]

GP probably won't be, seeing as there is a long-standing tradition of not reading TFA, TFS, and often, TFC.

I'm mostly here for the comments.

Re:how much it took

[guises]

So just where is the A-10 deficient in support of ground troops?

Well... any time there's a target which isn't directly in front of it.

I don't know why you're talking about the F-35, either in this post or the one above. That isn't the topic at hand. Yes, the F-35 is an even bigger waste of money. This fact is irrelevant.

Re:how much it took

[Sardaukar86]

So: hitting it with a laser without artificial aiming/tracking aids is impossible.

Sure, but that's not really the argument, is it? I may have missed something but I've never seen a laser system without sophisticated target tracking capabilities.

Hmm, think I might have already proven myself wrong with this 104KW polonium-210-powered laser rifle [PDF warning]. Think I've finally found what I want for my birthday!

Re:how much it took

[sumdumass]

It appeals to the soldiers in the field who are relying on the A-10 for support. I've read stories that claim nothing can replace them as they are the most effective close combat support unit in service at this time. Of course others might disagree, but if you look around, you will find a lot of service members grateful it was there.

Re:how much it took

[angel'o'sphere]

Sure, but that's not really the argument, is it?
I thought it was.
Because with a tracking/aiming system every weapon can hit anything which is not fast enough to escape.

Re:how much it took

[Sardaukar86]

I thought it was. Because with a tracking/aiming system every weapon can hit anything which is not fast enough to escape.

Well, I think now I'm doubly-confused because I didn't see anyone posting something that disagreed with this position of yours, nor was anyone positing an argument that in some way suggested that a sophisticated tracking system wouldn't be used, at least that I've seen. I guess I just don't quite see the link between what they were saying and what you appear to be countering with. :)

Re:how much it took

[gwills]

lol

Re:how much it took

[vux984]

let's think about this for a moment... something that reflects photons... hmm...

I cannot think of a single thing.

What would happen if you fired a laser gun at a mirror?

Some energy would be reflected. Some would be absorbed.

Throw enough energy at it, it still burns up. Elementary physics.

And that's assuming you shoot a laser at a mirror. An orbiting laser weapon platform is NOT a mirror. Its not even slightly plausible that you could make the entire surface -- from the weapon itself to the communications antennae to the maneuvering thrusters all sufficiently reflective that you'd be immune from a ground based laser attack.

Worse the energy getting absorbed would heat, distort, discolor etc the relfective finish making it increasingly less effective.

Not to mention the reflective surface would degrade over time from micro-debris impacts.

Meanwhile ground based opponents wouldn't even be limited to one laser -- they could concentrate their entire arsenal at it.

Care to try again?

Re:how much it took

[angel'o'sphere]

Sorry, then. Perhaps I clicked reply on the wrong post :D

Re:how much it took

[Rich0]

That's what airburst grenades are for. :) I'm not saying the laser is the solution to EVERY problem. I don't really see them as being replacements for hand-held rifles. This is something that would be combined with an automated control system.

Also, when somebody else throws a grenade at your wall, then your laser turret can blast it out of the air.

Re:how much it took

[NatasRevol]

Can. But aren't.

Re:how much it took

[BevanFindlay]

Also, lasers don't tend to explode when say, hit by enemy fire. /. talked about this point recently - the navy want to get away from gunpowder.

Re:how much it took

[Rich0]

Sure, but that's not really the argument, is it?
I thought it was.
Because with a tracking/aiming system every weapon can hit anything which is not fast enough to escape.

If the target is maneuvering, the speed of the projectile makes a HUGE difference. If your target is 20 meters away, it is much easier to shoot it with a gun than to hit it with a water balloon, even if the balloon is thrown perfectly. Lasers travel at the speed of light, making target maneuvers almost negligible. Granted, at a distance like my geosync orbit example, a maneuvering target could evade attack unless you can direct enough energy in its general vicinity to make maneuvers unimportant (ie fire many beams over an area of space).

Lasers basically push the potential engagement ranges MUCH further out.

Re: how much it took

[Neil Boekend]

Space still has trouble with dumping the heat from a high powered laser.
30 Mw at 30% efficiency means 21 Mw of heat needs to be dissipated. That's a lot.
The ISS heat dissipation system EATCS can dump up to 70 Kw.
In short, you'd either only be able to fire short bursts before the sat overheated or you'd need massive radiators (which makes it easy for your enemy to hit it back)

Oh and of course that 30 Mw is going to have to be generated somehow.

Re:how much it took

[angel'o'sphere]

Lasers basically push the potential engagement ranges MUCH further out.

That is obvious :D but one of the parents claimed you easy could hit stuff in a geo synch orbit, while I pointed out: that is more than 1/10th of a light second distance.

Re:how much it took

[Rich0]

Lasers basically push the potential engagement ranges MUCH further out.

That is obvious :D but one of the parents claimed you easy could hit stuff in a geo synch orbit, while I pointed out: that is more than 1/10th of a light second distance.

How much is a target going to maneuver in 1/10th of a second? To evade the laser the target would need to change velocity such that it wasn't anywhere near where it was going 1/10th of a second prior, and then continue to do that every 1/10th of a second as the laser continues to fire at it. That would be thousands of Gs of continuous acceleration unless the target was the size of a speck of dust, which would require incredible amounts of fuel unless the target was the mass of a speck of dust.

Now, hitting a target out by Mars is a different story - light travel delay is going to make that very hard unless you take a shotgun approach (blanket an entire region of space with enough laser fire to hit the target eventually no matter what it does).

Re:how much it took

[angel'o'sphere]

You forget that the tracking system has a 1/10th of a second delay as well, or if it is radar like 2/10th of a second.

Obviously the target can not start maneuvering as soon as it realizes the it is hit, as that is to late.
However your idea of 1000nds of g's is wrong.

A laser at that hight has perhaps a diameter of a meter. So sidestepping a meter is enough.

Even a human can step 1 yard/1 meter to the side in a 1/10th of a second.

A car accelerates in perhaps 6sec from 0 to 100km/h, that is roughly 2m/sec^2

So in 1/10th of a second a car would approximately accelerate 20cm/sec and move something like 20cm - 40cm (to lazy to calculate, assuming the car is at rest ofc.)

So bottom line, you don't need absurd accelerations to sidestep by a single yard and make a shot miss.

If you can in anyway measure the "build up" of energy in the laser over a distance and estimate the moment of fire, you only need to move just before that.

Re:how much it took

[Rich0]

You forget that the tracking system has a 1/10th of a second delay as well, or if it is radar like 2/10th of a second.

Agree - the round trip time matters from a tracking perspective.

Obviously the target can not start maneuvering as soon as it realizes the it is hit, as that is to late. However your idea of 1000nds of g's is wrong.

A laser at that hight has perhaps a diameter of a meter. So sidestepping a meter is enough.

Even a human can step 1 yard/1 meter to the side in a 1/10th of a second.

First, it isn't enough to move a meter in 1/10th of a second. It has to accelerate such that ends up a meter away from where it would otherwise be.

That is an acceleration of 200 m/s^2, assuming we stick with a meter and 0.1 seconds. That is quite a bit of acceleration. It isn't actually enough to evade the fire though even with your numbers.

What happens if the laser misses? The computer fires again. It would fire in a random pattern around you, so it would hit if your RNG maneuvered you into the same place the turret's RNG picked to shoot at. Maybe it would take 5 shots to hit you, maybe 15. You're constantly accelerating at 20G the whole time in random directions to try to avoid it.

To really evade fire you'd need considerably more acceleration so that you're not just a meter away from your last predicted position when the laser arrives.

I actually outlined this on slashdot before, though it was probably years ago. Basically armor and acceleration are both forms of defense in space combat at long range, since both increase the total amount of energy an attacker has to expend into space in order to destroy you. If I can be anywhere in a circle a mile across by the time the laser arrives, you have to put enough energy into every point in that circle to destroy me no matter where I'm at. As range closes, the error in my position drops until I'm dead, or vice-versa.

Keep in mind that uniform motion is no defense at all, since the laser would be leading you. You need continuous random acceleration.

Re:how much it took

[angel'o'sphere]

Well, ofc you need a random acceleration pattern to avoid the laser for a longer period.
My point simply was that having a laser alone is not a guaranty for a hit. Especially if the laser has no continuous beam but can only fire a pulse every few minutes.

Re:how much it took

[Rich0]

Agree. Basically at ranges where speed of light is a factor the battle is the attacker expending a lethal amount of energy across as much space as possible, with the defender trying to be able to either withstand shots or not be inside that area of space. As range closes, the advantage moves towards the attacker.

And of course hollywood never gets this. The only place I've seen it done right is a Charles Stross novel (where speed of light delay in long-range tactics is accounted for both in terms of detection and fire).

As Stross also exhibits, a guided weapon is of course much slower, but doesn't suffer the same problems since as it approaches the target the position uncertainty drops.

Re:how much it took

[angel'o'sphere]

Do you remember the book?
I only have Glasshouse and Accelerando, and a follow up, I believe.
I should look around and get his other works, I think ;)

Re:how much it took

[Rich0]

It was Singularity Sky.

Retro-mirrors anyone?

[cpotoso]

Retro-mirrors anyone? Then it bounces off me and sticks to you!

Re:Retro-mirrors anyone?

[elfprince13]

Rather: overheats, stops functioning as a mirror, and burns like everything else.

Re:Retro-mirrors anyone?

[itzly]

But it will take longer... it's already taking seconds. If you reflect 95% of the incoming beam, it's going to take a minute of careful aim.

Re:Retro-mirrors anyone?

[elfprince13]

Which is why the target power for most military lasers is orders of magnitude higher than this. This is a research milestone, not a finished project.

Re:Retro-mirrors anyone?

[jeffb (2.718)]

Probably not.

First of all, the target wasn't matte black, so it was already reflecting a good bit of the incoming beam. I don't know what the IR reflectivity of the hood paint and underlying steel was at the laser's wavelength, so I don't know how much.

Second of all, while a mirror layer would be more reflective, it would also be thinner and less durable than a truck's sheet-metal. So, even if it's absorbing less energy, it's also less able to dissipate it.

It is interesting to consider the conflicting demands of stealth (low reflectivity, high absorbance) and laser-resistance (high reflectivity, low absorbance).

It's fun to imagine a target covered with corner-cube reflectors (which would direct the energy back toward its source), but if the laser emitter is a mile away, I don't know how much difference they'd make.

Re:Retro-mirrors anyone?

[Anonymous Coward]

But it will take longer... it's already taking seconds. If you reflect 95% of the incoming beam, it's going to take a minute of careful aim.

You fail at physics and math. 5% of 30 kilowatts will burn through the super-thin reflective film that makes up conventional mirrors in less than a tenth of a second.

Re:Retro-mirrors anyone?

[Entropius]

Yes, but they're very cheap. They'll melt eventually but, in the meantime, should deliver enough power back to the attacker to screw up eyeballs and sensors.

Re:Retro-mirrors anyone?

[itzly]

The laser defense systems aren't finished yet either. Mirrors can be stacked and cooled.

Re:Retro-mirrors anyone?

[itzly]

Second of all, while a mirror layer would be more reflective, it would also be thinner and less durable than a truck's sheet-metal.

If people are going to design anti-laser mirrors, they're not going to make them super thin.

Re:Retro-mirrors anyone?

[Leuf]

Covering yourself with reflectors is a very good way to make sure you are always the one who is detected first. The one who gets detected first is usually the one who is dead.

Re:Retro-mirrors anyone?

[Mr D from 63]

Retro-mirrors anyone? Then it bounces off me and sticks to you!

How about covering the vehicle with laser rated photovoltaics? Use that energy to your advantage.

Re:Retro-mirrors anyone?

[Admiral_Grinder]

Only if the reflecting angle is exact 0 degrees. Chances are you are going to be moving and bouncing around too. You will end up grilling more birds and grass in your backyard than making them think twice about shooting you.

Re:Retro-mirrors anyone?

[drinkypoo]

Could enough coolant be pumped through a laminated plate armor to dissipate kW per square inch of localized heating?

The only thing that might kind of work is clouds of steam and/or smoke. But a liquid isn't going to help you, this thing can turn solid engine block into vapor, what do you think it's going to do to your magic liquid?

Re:Retro-mirrors anyone?

[fyngyrz]

The surface of the craft can be a mirror.

No useful cooling? At hundreds of miles per hour of atmospheric passage? Hmmm. Not sure I can buy that. A few fins collinear with the forward-back axis of the craft and you'd have quite a bit of cooling.

Re:Retro-mirrors anyone?

[Ralph Wiggam]

You think a military truck is going to drive around covered in perfectly clean mirrors?

I can think of a couple problems there.

Re:Retro-mirrors anyone?

[DamnOregonian]

No, because the material with 95% reflectivity will not have that after it begins to heat up and is destroyed catastrophically. One does not mirror 30kW in a few square inches of area. 99% still wouldn't be enough. It would no longer be reflective in milliseconds, and then it would burn like anything else.

Re:Retro-mirrors anyone?

[elfprince13]

If you want a home* demonstration of how tiny hot-spots spread in glass in a slightly different context: blow torch a redhot-spot onto a glass bottle and then put the glass in the microwave for a few minutes. Whereas before the glass would have been fine in the microwave for an indeterminately long time, it will now turn into a puddle of molten goop in short order.

Different wavelengths and all for the laser stuff, but still.

*Don't try this at home.

No more OJ car chases

[es330td]

Affix one of these to a police helicopter and that will be the end of police chases. Pinpointing the hood of fleeing vehicle for take out will be trivial.

Re:No more OJ car chases

[oh_my_080980980]

"The truck was mounted on a test platform with its engine and drive train running to simulate an operationally-relevant test scenario."

Doubt cars are going to stay still....

Re:No more OJ car chases

[Anonymous Coward]

Until people paint their car chrome, and then who knows what your laser will take out.

Re:No more OJ car chases

[itzly]

You'd still have to have a mechanism to see where the target is going, and keep hitting the exact same spot.

Re:No more OJ car chases

[topology]

The more distance between the "gun" and the "target", the more opportunity there is for both (1) unintended targets entering the field of fire, and (2) minor jostling of the laser mount will create large arcs in the area where the target is. Seeing as the laser fire needs to be durative, collateral damage from these two factors is potentially going to increase.

Re:No more OJ car chases

[hawguy]

Affix one of these to a police helicopter and that will be the end of police chases. Pinpointing the hood of fleeing vehicle for take out will be trivial.

Put one of these in the hands of criminals, and it'll be the end of police helicopters -- it's got to be easier to take down a lightweight fiberglass clad helicopter than a car.

Re:No more OJ car chases

[Moof123]

Helicopters would have insufficient power generation capability without becoming too heavy to take off. So far these laser systems are being loaded up things as bug as 747's or warships where coming up with a few megawatts is not on insurmountable hurdle.

Re:No more OJ car chases

[pla]

Not going to damage the surroundings.

30KW getting scattered doesn't really compare well to accidentally pointing your green laser pointer at something shiny and seeing speckles for a minute - More like "everything even remotely flammable within 50ft ignites".

Re:No more OJ car chases

[Lab Rat Jason]

The concerns you are citing are equally vexing to traditional ordinance, so not much of a change here.

Point #2 is a trivial concern, considering the fact that current targeting systems can solve parabolic firing solutions thousands of times a second and update the firing solution based on the pitching of a ship. Modern tanks can fire while on the move and their firing solutions have little difficulty tracking that motion too. So how much easier will it be to calculate linear firing solutions? Multi-target tracking also makes point 1 moot, and it could be argued that there is way more collateral damage from traditional methods of disabling a vehicle. This method allows you to capture and interrogate the driver of said vehicle rather than turning him into fertilizer.

For those who are arguing the cost of conventional weapons systems vs the cost of this system, don't forget that this is a prototype! Deployed version will of course be cheaper.

Re:No more OJ car chases

[Entropius]

It won't even ignite things 2m away, assuming uniform diffuse reflections in the half-volume facing the surface:

30 kW / (2 pi r^2) = 1200 watts per square meter = sunlight.

Re:No more OJ car chases

[itzly]

Modern tanks can fire while on the move and their firing solutions have little difficulty tracking that motion too

Tanks don't need 2 inch accuracy over multiple seconds.

Deployed version will of course be cheaper.

Of course. Just like the Joint Strike Fighter.

Re:No more OJ car chases

[itzly]

There are plenty of reflections that aren't diffuse. Also, according to some people the real system will be orders of magnitude more powerful.

Re:No more OJ car chases

[Eponymous Coward]

I suspect the laser light scattered by the hood would just blind the driver anyway. One way or another, the chase would end.

Re:No more OJ car chases

[pla]

Ah, good response! Thank you for the correction!

Re:No more OJ car chases

[Lab Rat Jason]

Tanks don't need 2 inch accuracy over multiple seconds.

Do understand that the reason a tank is less accurate while under motion, it isn't because the computer can't keep up? It takes time between when the computer commands a fire, and the projectile exiting the barrel, and during that time, external conditions or the attitude of the vehicle might change, and nothing can be done to compensate since the projectile is in motion. Tanks also deal with wind, air density, and other factors that are difficult to measure accurately on the move. All non-issues to a laser system. You can poll the target sensors thousands of times a second and change and update your firing solution WHILE STILL FIRING. This all happens orders of magnitude faster than the time it takes a bullet to leave the barrel.

It reminds me of an argument I had with my brother about electric cars and traction control. The ability to change the torque of an electric motor is near-instantaneous compared to the throttle-body actuated traction control of the 90's and 00's. Comparing the two isn't even a fair fight. No gas powered car will ever have a traction control superior to a well designed electric car simply because of the physics behind it. Same with a laser weapons system. It will always be no contest.

Of course. Just like the Joint Strike Fighter.

You think the technology of the JSF is the reason it costs so much? The reason it costs 10 times what it should is because each service in the armed forces wanted something different and nobody wanted to tell them no... so instead we got "the Homer" aircraft with a bubble in the back to keep the kids in. That's a straw man argument. If they ever add missiles and torpedoes to this laser weapons system, then you can compare it to the JSF.

Re:No more OJ car chases

[Agripa]

Affix one of these to a police helicopter and that will be the end of police chases. Pinpointing the hood of fleeing vehicle for take out will be trivial.

And when the driver, passengers, and bystanders have their retinas damaged from the reflections, they can take pride in ownership of the law enforcement agency responsible. Or not since law enforcement has qualified immunity but permanently blinding citizens sure looks bad in the news.

Re:No more OJ car chases

[Agripa]

I suspect the laser light scattered by the hood would just blind the driver anyway. One way or another, the chase would end.

The driver, passengers, and bystanders would be at risk of eye damage. People who work around unshielded hi power lasers wear eye protection to protect against reflections.

Vid or STFU

[richy freeway]

Words are cheap, we wanna see shit BURN!

Re:Vid or STFU

[K. S. Kyosuke]

we wanna see shit BURN!

Like this?

Obliterate?

[ei4anb]

You keep using that word. I do not think it means what you think it means.

Defense?

[MagickalMyst]

I think that an important question here is how does one defend oneself against this?

Of course, I don't expect to have the local police or military shooting at me (although we do seem to be moving towards a police state); but thugs and gangsters are always able to get their hands on powerful, illegal weapons.

What can the average person do if some whackjob starts running around the city or a shopping mall with one of these things targeting innocent people?

Do we start wearing fire-resistant foil suits?

Re:Defense?

[itzly]

I don't think you have to worry about people wielding such powerful lasers. One little mistake where you aim the laser at something reflective, and you'd blind yourself.

Re:Defense?

[Coren22]

Plus, carrying around the house sized power supplies would make you a bit conspicuous.

Re:Defense?

[MagickalMyst]

"...someone eventually shoots / tackles / pepper sprays them"

Bulletproof vest/self defense training/protective eyewear for protection against those types of attacks - although I think that you were referring to the laser wielding whackjob being attacked in that case.

Re:Defense?

[Anonymous Coward]

Just carry your own airliner sized laser.

Re:Defense?

[pla]

I think that an important question here is how does one defend oneself against this?

Ordinary mirrors just don't work against that sort of power - they still absorb a small fraction of the energy of the light hitting them, which at 30KW would vaporize anything wearable in milliseconds.

Realistically, you'd need some sort of ablative armor, but anything you could actually carry would only buy you a few seconds at best - And keep in mind that whole "equal and opposite reaction" thing - Blocking a 30KW laser through ablation would hit you with the same force as a .45 caliber bullet 60 times a second.

Re:Defense?

[SillyHamster]

Of course, I don't expect to have the local police or military shooting at me (although we do seem to be moving towards a police state); but thugs and gangsters are always able to get their hands on powerful, illegal weapons.

So when's the last time you were pinned down by machine gun fire from a thug/gangster? How much body armor do you wear for that?

How about a drone attack with a Hellfire missile? 155m artillery round? 500 pound bombs from an aircraft? Battleship 16" shell?

Re:Defense?

[geekmux]

What can the average person do if some whackjob starts running around the city or a shopping mall with one of these things targeting innocent people?

Probably the same damn thing you're going to do if some whackjob starts running around shooting an AR-15 rifle.

Duck and run.

Sorry, but even most bulletproof vests don't stop high-powered rifle rounds, so you've no more defense today against a 40-year old AR-15 platform than you do this brand-new thing.

Re:Defense?

[celtic_hackr]

One little mistake where you aim the laser at something reflective, and you'd blind yourself.

One little mistake where you hit something reflective, and you'd kill yourself. A 50 KW laser may take seconds to burn through a iron engine block but will burn through soft flesh and bone MUCH faster. TFTFY

Re:Defense?

[Adriax]

Right...

*bad mobster accent" "No sir officer, nothing illegal here. We're just three guys going for an afternoon drive in our truck.
Oh, the trailer? The one with the 30kw laser assembly and diesel generator to power it? The 30 foot long double wide trailer that weighs 20 tons? Oh, that's my grandma's. We're just delivering it for her. Why, is a tail light out?"

Re:Defense?

[Justpin]

There's something called smoke? Smoke grenades, or simply injecting diesel into hot gas streams like exhausts, pump it forward and smoke particles absorb a tiny bit of energy each but since you're pumping out tons of it this doesn't matter as the smoke particles are replaced with more smoke particles pretty much instantly. Most tanks even from WWII can create smoke via exhaust injection.

Re:Defense?

[drinkypoo]

What can the average person do if some whackjob starts running around the city or a shopping mall with one of these things targeting innocent people?

Absolutely nothing. That guy is a goddamned superman, and he could crush you into a thin paste with his bare hands. Make peace with your maker, you're coming to meet him.

Re:Defense?

[BevanFindlay]

This is an interesting point, and much more insightful than the myriad "What if I put up a mirror?" nonce comments here. I don't quite know enough laser physics to answer your suggestion, but I think it would probably work - as long as you knew to deploy it before you got hit. It would probably not stop you from getting blinded and skin burns (would probably make those worse), but it could be enough to stop your truck being disabled. I'd mod you up if I hadn't already commented.

However, the effect of vaporisation/ionisation (conversion to a plasma) would need to be considered - most likely, the beam would clear its own path through the cloud in a fairly short time, so it would tend to be a "mitigation" not a "prevention" technique, unless the cloud also managed to "distract" whatever was maintaining the targeting lock long enough for you to move out of the way (e.g. a shallow gash down the whole side of the truck would be better than having no engine).

However, to answer the GP: think about the power requirements. This sort of laser is not something you would just carry around in your hand or conceal in a trenchcoat. It's the kind of thing you mount to a nuclear-powered ship, or on something like a 747. At best, you might be able to get it powered from a small truck, but effective anti-materiel laser weapons are still in the realm of "bigger than a tank".

Re:Defense?

[BevanFindlay]

The person using a laser weapon would be wearing something to protect their eyes against the specific wavelength of the laser. If they weren't, then they're too stupid to deserve to keep their eyes. As noted elsewhere though, bystanders and burns are a little harder to deal with (though, if you're picking your targets right, if you get a stray reflection back to where you're standing, it should be diffuse enough to be little more than sunlight, or perhaps very minor skin burns - seeing as we would be talking about extremely short exposure times before it toasted the reflective surface). If you happened to walk in front of the beam however...

It is interesting seeing how even with an educated audience (ok, making assumptions about /. here... ;-), there is still little understanding about the actual technical aspects and limitations of real laser technology - /. seems more informed by sci-fi than by science (not necessarily your comment, but this discussion in general). No, mirrors aren't going to work. No, we can't carry around a handgun-sized laser with current energy storage tech. Yes, it's going to cause partial blindness to anyone nearby, but no, it's not going to set everything around it on fire due to scattering.

This is a good read for anyone interested in the science side of laser weapons: Atomic Rockets - Sidearms.

Terminator at gun shop...

[tekrat]

Terminator: Phased plasma rifle in the 50-watt range.
Owner: Hey, just what you see here pal!
Terminator : Uzi 9 millimeter
Owner: You really know your guns, this baby is perfect for home defense....

Re:Terminator at gun shop...

[karlandtanya]

Forty watt range

One good thing about star wars weapons

[140Mandak262Jamuna]

The regular lead bullets from even a small caliber short barrel weapon is too fast for eyes to see. But the speed of light phasers being fired by the storm troopers leave a neat clean visible tracer lines. That leads straight back to the location of the gun which helps Harrison Ford ample time to find good spot to dive into, no antique plane needed.

Re:One good thing about star wars weapons

[avandesande]

Actually phasers leave a trail so moviegoers can follow the action in battles.

Re:One good thing about star wars weapons

[samwichse]

Farscape did this best:

Crichton: "Don't move! Or I'll fill you full of....little yellow bolts of light!"

Re:One good thing about star wars weapons

[Walking The Walk]

The regular lead bullets from even a small caliber short barrel weapon is too fast for eyes to see. But the speed of light phasers being fired by the storm troopers leave a neat clean visible tracer lines. That leads straight back to the location of the gun which helps Harrison Ford ample time to find good spot to dive into, no antique plane needed.

I can't believe I'm replying to a joke post but... (a) you're mixing your movies, phasers are Star Trek and blasters are Star Wars. (b) Blasters supposedly shoot charged plasma - you fill them with gas, they excite it to a plasma somehow, and the glowing plasma is what's shot at the targets. Don't ask me about turbo lasers on capital ships.

(Cue a follow-on stream of comments correcting mistakes I've made, lol.)

Re:One good thing about star wars weapons

[140Mandak262Jamuna]

Thanks for the correction buddy. The less informed would just shrug it off. But for true afficianados committing a faux pas like mixing up blasters with phasers would be shameful.

Re:One good thing about star wars weapons

[Hamsterdan]

That show was clever in so many ways, too bad it got canned (same goes for Firefly)

Re:One good thing about star wars weapons

[Vicious Penguin]

The regular lead bullets from even a small caliber short barrel weapon is too fast for eyes to see. But the speed of light phasers being fired by the storm troopers leave a neat clean visible tracer lines. That leads straight back to the location of the gun which helps Harrison Ford ample time to find good spot to dive into, no antique plane needed.

Please remember that it was a long time ago in a galaxy far far away. So....... they hadn't developed fast light beams there yet. Don't judge the past by present standards, you just make a fool out of yourself.

Nerds make the impossible possible.

[Etherwalk]

You can't hit a moving bullet with another moving bullet. It simply can't be done.

What are you talking about? You can't hit it from behind with the same kind of bullet fired under the same conditions, but that's not the same thing. We have the ability to intercept missiles with limited but significant success; intercepting a bullet is a harder problem, but that doesn't mean it's undoable.

Re:Nerds make the impossible possible.

[Gr8Apes]

We already intercept missiles with bullets. A bullet is only a little over an order of magnitude smaller in diameter than at least this anti-ship missile?, and it should be noted that those missiles can change trajectory. Most bullets cannot, although this one can.

oh great

[slashmydots]

What they don't tell you is it doesn't work in the rain, fog, or basically anything else. Luckily most people we'd fire it at are in a nice, thin-aired desert.

There's Star Wars and there's Star Wars

[davidwr]

Star Wars maybe, but it's not quite Star Wars.

Re:Impossible

[Shortguy881]

Oh ye, of little faith.

There is a calculable number of variables in bullet trajectory, so with the correct algorithms one could theoretically hit a bullet with another bullet.

Furthermore, one of these is a laser, which is traveling at the speed of light, reducing the complexity of the formulas involved by almost negating the effects of velocity and gravity on that projectile.

Who said science and math cant be fun?

Scat

[AndyKron]

How many civilians will it blind from the scatter?

Great Success!

[ThatsNotPudding]

[Provided our enemies accommodate us by propping their vehicles up at the optimal 45-degree angle.]

Re:NOT a joking matter: Moths in your pocketbook.

[kilfarsnar]

The government gives big corporations tax dollars to kill people and destroy their property. Since it is done with secrecy, citizens can't have any control. Killing people is the most profitable business in the United States. And... Many of the citizens joke about the killing. Don't they realize that killing people is theft from their pocketbooks?

No, of course they don't. The American people, on average, don't know much. See my sig for further insight.

Re:Star Wars

[GameboyRMH]

Through a technique called spectral beam combining, multiple fiber laser modules form a single, powerful, high-quality beam that provides greater efficiency and lethality than multiple individual 10-kilowatt lasers used in other systems."

Hmm, what does that remind me of...

Re:I know this movie

[geekmux]

Must've taken a Real Genius to build a laser system like that.

Yes, and it's probably a pretty sound assumption that the "spinning mirror" order has been placed as well.

seen this before

[ArsonSmith]

"Through a technique called spectral beam combining, multiple fiber laser modules form a single, powerful, high-quality beam"

this sounds really familiar

Re:Impossible

[morethanapapercert]

I've seen several images of American Civil War bullets being dug up welded together. There were battles where there was so much musket and rifle fire and so densely targeted that a few bullets actually collided in mid air Granted; this was an accidental result, the product of sheer numbers. It invalidates your specific claim without invalidating the point I think you were trying to make about using lasers to down incoming missiles/artillery/etc.

Re:NOT a joking matter: Moths in your pocketbook.

[jellomizer]

But there are other governments/organizations paying other corporations a lot of currency to come up with weapons to kill us.
The nice thing about Lasers is that it is a directed weapon so you can hit your target, and not hurt what is around it.

Careful

[Bootsy]

Careful where you point that thing

Yeah on blocks

[Lawrence_Bird]

maybe next time have it moving? like oh 50 mph? and not in a straight line?

Re:Impossible

[jafiwam]

I've seen several images of American Civil War bullets being dug up welded together. There were battles where there was so much musket and rifle fire and so densely targeted that a few bullets actually collided in mid air Granted; this was an accidental result, the product of sheer numbers. It invalidates your specific claim without invalidating the point I think you were trying to make about using lasers to down incoming missiles/artillery/etc.

Modern jacketed bullets won't stick when they collide, and are generally moving a lot faster than a .51 cal musket ball. So they would break apart instead when they do collide. Modern firefights usually involve more bullets going down range too. They probably are colliding, it's just that nobody notices.

Re:Impossible

[fyngyrz]

Who said science and math cant be fun?

Congress comes to mind.

You need to rethink that.

[Anonymous Coward]

You see the laser works by running a high intensity light beam on an absorbing surface.

By the time the light gets to the moon, it will have spread to a few kilometers across *at best*. Not so intense a beam of light...

This doesn't take into account extinction as it passes through many layers of the atmosphere. Not to mention clouds... All of which remove the ability of the beam to kill or damage.

Then you have the problem of aiming the bastard against a fast moving object. Tracking isn't easy, and errors in tracking will remove the intensity by virtue of the fact of shimmying the light about and giving an area the ability to recover from the thermal stress.

Re:You need to rethink that.

[Celarent Darii]

What is interesting is that this beam is made by several beams interacting at a focal point. What if they changed the difference of the focal point? Sure, one beam would dissipate over 70km, but perhaps they could manipulate intensity of the beam at a certain distance by the interaction....

What you describe are engineering problems. If history is any indication, the military is pretty good at [eventually] solving them. Nothing like the instinct to destroy someone else to get the human intellect working.

...with remaining eye

[fyngyrz]

1) is if the laser is in visible light or not. If you can't see the red dot source a mile off, you can't evade it.

Pretty sure if you "see the red dot a mile off", the location where your eye was is just the steaming, goo-surrounded beginning of a well-cauterized hole that completely transits your head. Assuming tight collimation. With a broader 30 kw beam, your head would explode (steam pressure), and with a really broad beam, you'd turn into a human crisp before you had time to think "Hey! Las..."

Re:Impossible

[techno-vampire]

Modern firefights usually involve more bullets going down range too.

Imagine how rare it must have been for two Civil War bullets to collide and fuse. Imagine how few of those that do ever get found. Now, consider the fact that they've found at least a dozen of them at Gettysburg, and that will tell you how intense the fighting was.

Suitable defensive grid?

[fyngyrz]

There are other issues. That truck was relatively close, between 1 and 2 miles ("more than a mile away"). To hit an ICBM at apogee, even it it goes right over you, you are going to have to spend a lot of energy on atmospheric heating, and you'll lose even more to atmospheric distortion. We're talking 300 to 700 times the distance, depending on exactly what "more than a mile away" actually means. But it is certain that 30 kw at the source will not equate to 30 kw at the target at those distances. So now the problem becomes more than "hit the target", it is also "stay on target for X time", and that assumes that enough energy can be delivered to overcome the missile skin's ability to dissipate it. Because if you can't do all those things, you can't hurt the missile.

Also, the odds of it going right over you kind of suck.

Re:Suitable defensive grid?

[DamnOregonian]

I don't know if staying on target is a problem. The RVs are on a ballistic trajectory. However, completely destroying them may be a bit of a trick. I think the best you can hope for is disabling the warhead and having a dirty bomb fall on your head.

Re:Suitable defensive grid?

[fyngyrz]

I don't know if staying on target is a problem.

Oh, it definitely is in the case of an ICBM. Anywhere within the atmosphere, the missile will be shaking. A lot. Randomly. Very likely it will be rotating about its long axis as well, in or out of atmosphere, so you'd have to track across the short axis at the rotational speed, then wait for the spot to come around again (while it is also cooling off, if it isn't in a hard vacuum at the time.) The atmosphere between the emission and the target will be turbulent, both naturally and as a result of incidental heating from the beam, and this will serve as an optical lens, moving the beam off target (high speed laser pulses can avoid this with a very fast double pulse: One to blow the atmosphere out of the way, and one to hit the target through the hole. However, 30 kw isn't enough for that, not even close.) Beam collimation is also very important, and the atmosphere fouls that up as well. The larger the area the beam covers when it hits, the lower the energy per square inch is, and the less local heating occurs (or conversely, the more local heat dissipation can be effective.) So you can't fix this by making the spot bigger (decreasing collimation.)

All these factors work together to interfere with the delivery of energy to one well defined region on the skin.

I suspect that in these cases, a kinetic kill is far easier and more reliable. Blow off a cloud of lead pellets in front of the missile, let it run into them, it's finished. Such an intercept missile can self-guide and actively measure distance to target which can significantly reduce misses, and it can compensate somewhat for its own velocity forward by shooting the cloud backwards so it stays in front of the incoming missile longer. Using a cloud of pellets reduces the need to be spot-on. At ICBM speeds, just one pellet is likely to incur completely fatal damage to the incoming missile's airframe. If you significantly disrupt the airframe's streamlining, it will self-destruct due to structural overload. And at these speeds, "significant" doesn't amount to very much.

Re:Suitable defensive grid?

[DamnOregonian]

Very likely it will be rotating about its long axis as well

I'm sorry, are you saying it'll be rotating with the pointy end down? Why can you not simply keep it pointed at the nose? Or are you saying it will be tumbling? If so, I guess that would make it pretty damn hard to do much damage.

I think maybe you're underestimating the power of a 30kW beam collimated to a few square inches of area when fire through a mile of thick atmosphere, nevermind fired upward into atmosphere of rapidly dropping density? (The test scored the kill in seconds at 1 mile- and I imagine did plenty of damage in fractions of a second. The "seconds" was for complete burn through to disable the engine block)

My understanding is that ICBM RVs are very aerodynamic (sharp cones), entering at a significant enough velocity as to undergo massive friction and compression wave heating, and have quite stable trajectories, atmosphere be damned (Enough momentum and aerodynamic shape should reduce the ability of the atmosphere to move it around much, yes?) and pictures I've seen of MIRV re-entries do in fact look unnaturally straight.

I'm also not sure disrupting the airframe of an RV is much use. Again, it's a small, dense cone, in a high velocity ballistic trajectory. I'm not sure even significant damage to that airframe is going to cause destruction of the warhead even should the airframe come entirely apart.

I still don't think you could hope for much more than disabling the warhead in the RV, dropping a tumbling nuke onto the ground at high velocity, hopefully not spreading too much isotopic matter all over the place, and that applies for ballistic weaponry applied against the RV as well.

Re:Suitable defensive grid?

[fyngyrz]

I'm sorry, are you saying it'll be rotating with the pointy end down?

Up or down. Likely it'll be rotating, because that makes no particular difference to the steering mechanism, it's trivial to see to, and it's a free way to distribute laser energy. Not tumbling.

I think maybe you're underestimating the power of a 30kW beam collimated to a few square inches of area when fire through a mile of thick atmosphere

I'm just assuming there will be a reasonable polish on the surface, good enough to reflect 99% or better of the incoming beam, which leaves about 300 watts applied to the target, which it can't keep steady on, due to atmospherics, target movement (the aforementioned rotation plus vibration unless it's in vacuum) and incidental atmospheric heating / distortion.

Go look at that truck. It wasn't set to reflect much of that energy at all. It also wasn't moving. It also has a decent angle of incidence to the beam. It was also going through 1 mile of atmosphere, rather than 300 to 600 miles of atmosphere, and *that* assumes the target passes directly overhead and you have a *perfect* shot at it. Likely, it won't, and you won't, and the amount of atmosphere will be much greater. 30 kw isn't much in such a scenario. I don't think it'd work.

My understanding is that ICBM RVs are very aerodynamic (sharp cones) ...I'm also not sure disrupting the airframe of an RV is much use.

Oh no, of course not. Not the RV. The rocket airframe, pre-release. If you're going to shoot a laser at a missile, the warhead isn't a reasonable target.

I still don't think you could hope for much more than disabling the warhead in the RV

I don't think that's even remotely possible with a 30 kw laser. You'd need a kinetic kill of some kind if you couldn't deliver at least another couple of orders of magnitude with a laser. You want 30 kw well collimated on target after 99% reflection to almost instantly disrupt the reflective surface (ablate it, most likely), which would take about 3 mw. For 30 kw... who would design an RV or a MIRV or a MIRV/RV with such delicate stuff in front or on the surface? Why would there even be a need to? The barometer could be anywhere (so you'd put it in the rear, and inside some heavy protection), likewise the logic package. You *might* manage to disable guidance fins, presuming that's the tech in use, but even so, you still have a live ballistic incoming that's going to go off as designed, albeit perhaps somewhat outside the predicted CEP.

If you're going to actually stop an ICBM from going off, you need to do so before it drops its last stage and reaches its programmed apogee. Things get pretty automatic and pretty unsophisticated once the thing begins the arming sequence, and all the easy-to-blow-up stuff has been left behind.

hopefully not spreading too much isotopic matter all over the place

Compared to the thing actually detonating (we're almost certainly talking multiple megatons here, quite likely double-digit), a core that doesn't even fizzle is no threat at all. Of course, if it does fizzle you're going to get a low yield nuclear explosion on the order of several tens of kilotons (basically it'll act like a small fission weapon instead of a large fusion weapon.) But the odds don't favor enough of the right kind of compression occurring, and anyway, 10-20 kt is highly preferable to 1-40 mt, so you shoot it down if you can.

Not that simple

[fyngyrz]

You are making a LOT of assumptions. All of these matter: Ability of the mirror to dissipate energy prior to ablation or meaningful distortion. Collimation of the beam. Reflectivity of the mirror at the laser frequency. Ability of the laser to stay on target, and for how long. Distance from the laser. Atmospheric clarity and particulate density. Atmospheric turbulence. Disruption from atmospheric heating.

It's just not as simple as you paint it.

Was it a Toyota?

[jsepeta]

Please tell me we're test-firing on the Toyota models used by ISIS.

Re:Was it a Toyota?

[mjwx]

Please tell me we're test-firing on the Toyota models used by ISIS.

They tried that.

The Toyota Hilux broke the laser. Its the Chuck Norris of vehicles, that's why the 30 yr old models ISIS are using still work.

Re:Impossible

[Ol Olsoc]

Who said science and math cant be fun?

Congress comes to mind.

Don't forget Kansas.

Re:"engine manifold"

[PPH]

or the sight of the hood melting away might be enough to distract him into crashing.

So, ineffective against GM truck drivers. Can't tell if it was a laser or typical operation.

Enough!

[doug141]

That joke has jumped the shark.

Blinding?

[Mattsson]

What I always wonder when I read about laser weapons is how they affect unprotected eyes of people in the vicinity of the weapon or the target.
When laser weaponry is finally deployed in military forces and used in places where you can not be certain that civilians aren't in the area, will said military then be making civilians blind?
If so, laser weapons should be made illegal.

Or is the range at which the laser is damaging to eyes so small that it isn't a problem?