Army Laser Passes Drone-Killing Test

Nerval's Lobster writes "Commercial package-delivery drones such as those revealed by Amazon and DHL could face danger from more than shotgun-toting, UAV-hunting yahoos following the successful test of a drone-killing laser by the U.S. Army. Though it's more likely to take aim at enemy observation drones than Amazon's package-deliver 'copters, the U.S. Army's High Energy Laser Mobile Demonstrator (HEL-MD) did prove itself in tests last week by shooting down 90 incoming mortars and a series of Unmanned Aerial Vehicles (UAV). The original goal during the test at White Sands Missile Range in New Mexico was to burn out or blow up mortar rounds and blind the cameras or other sensors carried by drones. The laser proved capable enough to damage or slice off the tails of target drones, which brought them down, according to Terry Bauer, HEL MD program manager, as quoted in the Dec. 11 Army announcement of the test. The quarter-sized beam of super-focused light set off the explosives in the 60-millimeter mortars in mid-flight, leaving the rest to fall 'like a rock,' Bauer said. The laser could target only one mortar at a time, but could switch targets quickly enough to bring down several mortars fired in a single volley. The laser and its power source are contained in a single 500-horsepower, four-axle truck but was directed by a separate Enhanced Multi Mode Radar system. The next step is a move from New Mexico to a testing range in Florida early next year 'to test it in rain and fog and things like that,' according to Bauer."

Comments

Reflective Armor

[Kagato]

Laser, neat. Couldn't you just wrap the UAV in Mylar to deflect it?

Re:Reflective Armor

[stewsters]

If you paint them red they go faster. If you paint them reflective, they don't get destroyed by the laser.

Re:Reflective Armor

[MyLongNickName]

I'll give you two answers, feel free to pick the one you like.

1) When you are fighting a less-advanced army, they won't have the technology to implement your suggestions.
2) Defense (haha) contracts are written based on what will sell with congress, not necessarily what is useful

Re:Reflective Armor

[alen]

i bet this will do wonders for its radar reflectivity as well

Re:Reflective Armor

[Sique]

Ad 1)

Giving a surface a reflective coating and polish it is a craft humanity knows since at least 2000 BC (that's about the age of the oldest mirror ever found). So I don't expect 1) to be valid in any sense.

Re:Reflective Armor

[iggymanz]

No, reflection from a plastic with aluminum powder embedded in it is only partial, the remainder of the energy is turned to heat. These high powered lasers can bore a hole through a normal household mirror, by the way, for the same reason.

Re:Reflective Armor

[jmichaelg]

How well a reflective surface would work would depend on the laser's power and frequency. Mylar doesn't reflect all frequencies of light and is imperfect at reflecting the ones it does. Pour enough joules onto the target and you don't care that 90% of them are being deflected - the remaining 10% will do the job.

I've always thought that the ideal anti-mortar device would be a radar that told you exactly where the mortar round came from. "You shooting at us? Here, have a little present in return."

Re:Reflective Armor

[seven of five]

1. No mirror is perfectly reflective; they all absorb some light. 2. Any crud on your mirror makes it even less reflective.

Re:Reflective Armor

[ShanghaiBill]

I've always thought that the ideal anti-mortar device would be a radar that told you exactly where the mortar round came from. "You shooting at us? Here, have a little present in return."

This is know as counter-battery radar. It has been around for at least a few decades. I was in the Marines during the 1991 Iraq War (the one that made sense), and we had counter-battery radar then. When an Iraqi mortar fired, our 155mm howitzers would back-trace the trajectory and return fire before the mortar round even impacted.

Re:Reflective Armor

[cayenne8]

Hey, I'd pay GOOD money if we could get a civilian version of this thing...that would target the fscking stoplight/speed cameras in the city. And of course, the soon to be coming to your town, speed limit drones as yet another method to collect revenues.

Re:Reflective Armor

[iggymanz]

a good aluminum mirror is 90% reflective, your bathroom mirror less so, and reflective mylar (with aluminum powder) even less and a bronze one of 2000 B.C. even less 80% of a 50 KWatt beam in the area of a quarter.....thank you for playing.

Re:Reflective Armor

[AdamHaun]

You're not going to be wrapping an optical sensor in Mylar, so the laser can still blind the UAV.

Re:Reflective Armor

[DM9290]

No, reflection from a plastic with aluminum powder embedded in it is only partial, the remainder of the energy is turned to heat. These high powered lasers can bore a hole through a normal household mirror, by the way, for the same reason.

1. they don't fire the laser at the reflective side of the mirror. the non-reflective side of a mirror is usually tarnished and pretty dark colored.
2. the metal in a mirror is very thin.

not saying it is impossible, but it strikes me that the development cost of a laser resistant mortar would be far far less than the cost of a laser system that can reliably destroy such a mortar.

I don't think mylar is a good material to use either.

Re:Reflective Armor

[lgw]

As others have pointed out, nothing is perfectly reflective. But that somewhat misses the point: a reflective surface only helps against a low-energy laser: one that only damages through radiant heating.

A high power laser weapon in the atmosphere is not a "beam of light" so much as a "column of exploding plasma". If you dump enough energy into the immediate environment of the target, it becomes very difficult to armor against.

Re:Reflective Armor

[techno-vampire]

Back in '72, when I was in the Navy, I worked on a radar-guided anti-aircraft missile. (Never mind which one.) Its on-board guidance was designed so that if you jammed the signals, the missile would home on the jammer instead. Not quite the same as what you're talking about, but similar.

Re:Reflective Armor

[iggymanz]

there are "optical mirrors", probably this system has them. turning a missile into one is left as excercise for the student, they require a special substrate and a vapor deposition process

Re:Reflective Armor

[anzha]

answer is no. HELSTF did a bunch of tests during the 1980s with spinning reflective cylinders against different laser powers. The results were surprisingly negative for protection: the battlefield is dirty/mirrors like to be clean and mirrors for lasers tend to be VERY wavelength sensitive.

Re:Reflective Armor

[Sique]

Yes and no. The 90% are only valid if the laser beam hits the object nearly at 90 degrees. Then indeed, the reflection will cause 90% of the energy to be reflected and 10% will be heating the surface. But still, this means we need to have a 10 times larger laser to have the same effect than on a non reflective (black) object.

But in general, the beam will hit the surface at lower angles, and then we have to multiply the energy with the sinus of the angle. So if it hits the surface at 45 degrees, only about 71% of the energy will be transferred, and we need to increase the laser beam another 40%. And at lower angles, there is total reflection, and 0% of the laser will be able to heat the surface, as 100% of the energy is reflected. In general: if we build a drone like a stealth bomber with a shell of plane, mirroring facettes, laser beams will be rendered totally ineffective except for the seldom case that they hit the drone's surface at 90 degrees with 10 times the necessary energy.

Re:Reflective Armor

[LordLimecat]

3) reflective surfaces become markedly less so when flying in the real world, what with dust and such
4) no surface is 100% reflective, and will rapidly char as it absorbs heat, bringing its reflectivity down.

Re:Reflective Armor

[Tuidjy]

> If you paint them reflective, they don't get destroyed by the laser.

You wish.

Polished metal mirrors reflect about 90%. if you use some really expensive metals, you can push it to 95%. Milar, dielectric coatings, etc. can go up to 99.99%, but only in specific wavelength.

Sounds great? Well, no. That's the reflection you get in vacuum, when the mirror is pristine. Now fire it from a mortar, have it heated by the air rushing past, and then apply even 1% of the output of the laser we're talking about. Your nice upper layer is gone, and your reflection drops like a rock... followed by the rest of your round, once the payload overheats and blows up.

Very expensive reflective coating may buy you a fraction of a second, maybe even a whole one... but mortars are (1) cheap (2) slow to get to the target. So you just made each round a lot more expensive, and you still may not have bought enough time for it to get to the target.

Re:Reflective Armor

[LordLimecat]

Plus you only need to apply enough energy to kill the reflectivity: a charred mirror isnt terribly reflective anymore.

Re:Reflective Armor

[Noughmad]

These high powered lasers can bore a hole through a normal household mirror, by the way, for the same reason.

I would really like a citation on that, especially on the part how they don't get burned by the reflected light.

Re:Reflective Armor

[Anonymous Coward]

While the idea of "Cover yourself in mirrors to protect against lasers" deserves a correct rebuttal, in this case I believe you've missed a joke.

Re:Reflective Armor

[CanHasDIY]

OK, so mirrors are obviously not a serious counter-measure.

What about some sort of prismatic lens?

Re:Reflective Armor

[Kookus]

How about aerogel? Then use rf/ir or lasers instead of wires to control motors. Then there would be absolutely nothing to hit in the tail except motors and battery packs and a few other odds n ends in the electronics department.

In the end there's probably always something that's target-able by a laser to disable the uav enough to make it worthless, so I'm sure something that can either reflect or bend the laser beams enough to protect those parts is the better approach.

Re:Reflective Armor

[asylumx]

Interesting predicament though -- do you want something reflective to protect against the laser, or do you want something absorptive to help hide radar signature?

Re:Reflective Armor

[NatasRevol]

Or shoot the mortars out of range of the TRUCK holding the laser.

Re:Reflective Armor

[Kuroji]

Most mirrors are not perfectly reflective surfaces, despite how it might appear to the naked eye. The amount of light striking the mirror also causes heat build up, but the imperfections will reflect the light imperfectly if at all and your mirrored surface will now have larger imperfections for the laser to screw up. As this happens on a time scale of next-to-instant, well... you know.

For the laser itself to be burned by the reflected light, you would need a mirror that is pointed specifically at the laser and at nothing else.

Re:Reflective Armor

[EvilSS]

No no no no. Did you learn nothing from the import fad of the last decade? If you want it to go faster, you have to paint it primer-gray and cover it in stickers for aftermarket automotive component manufacturers. Shez, everyone knows that.

Re:Reflective Armor

[iroll]

And before that, there was sound ranging!

Re:Reflective Armor

[DigiShaman]

Or just fire 10 times as many mortars! Sometimes more is better.

Re:Reflective Armor

[Smauler]

My energy saving idea as a kid was a room with perfectly reflective surfaces. You could just turn a light on for a millisecond, and the room would be perpetually light. Then I realised everything in the room would need to be perfectly reflective too. Not a problem, a cool suit could do that, I thought... but you'd have to have a gap for the eyes, so it would lose its efficiency. I also realised that although the room would be pretty energy efficient, it would not be very practical, and if the surfaces reflected more of the electromagnetic spectrum, a slightly nasty side effect would be that it would actually cook your eyes. I gave up on the idea.

Re:Reflective Armor

[BRGeek]

Now it makes sense why Queen Amadala's starship was polished and shiny!!!

Re:Reflective Armor

[iggymanz]

but this is not mirror we're talking about, missile or aircraft is not optically smooth nor anything like 90% reflective.

no need to increase anything, they're using 50 KW for this test and going to roll out 100 KW in production, doesn't matter what the fraction is, on 3 sq cm of area the flying thing will be toast

Re:Reflective Armor

[HornWumpus]

Grey primer?

Based on the import fad, it appears huge trunk wings, under-body neon and graphic wraps make a car faster.

Grey primer cars (with or without stickers) are often actually fast. Limited dollars and all.

Re:Reflective Armor

[CanHasDIY]

Maxim 37: There is no 'overkill.'

There is only 'open fire' and 'I need to reload.'

Re:Reflective Armor

[iggymanz]

lasers use an optical mirror at one end and partially reflective one at the other. you will be helping the "stimulated emssion" process with your hypothetical mirror.

lasers of "mere" hundreds of watts under CNC control are in fact used to cut ordinary mirrors at many factories. note this article is about 50KW rig that will be upgraded to 100KW

http://www.youtube.com/watch?v=9xQxh8XvXdU

Re:Reflective Armor

[jafac]

simply replace the explosive payload of the mortar round with semtex or similar plastic explosive. Detonates from electrical charge, not shock or heat, like TNT. (also much more expensive - but with our defense budget, no expense is spared, right?)

Re:Reflective Armor

[hairyfeet]

Besides it really wouldn't be worth the bother as you could either spam the site from multiple directions, thus giving the tracking a lot harder time, or you could just use IEDs or suicide bombers which of course wouldn't be affected by your fancy laser.

Every time I see new "super tech" like this all I can think of is Vietnam, the USA had tech light years ahead of the enemy...who then proceeded to make it so messy that the USA gave up and pulled out.

Re:Reflective Armor

[iggymanz]

for that matter ordinary transparent glass is often cut by laser too.

Re:Reflective Armor

[EvilSS]

Most of the imports around me had (thank god it's mostly a dead fad) grey primed wings, fascias, "aero kits", and fenders. Same reason though: bought parts but didn't factor in the cost of painting them.

Re:Reflective Armor

[Guspaz]

Beyond that, even if you managed to mitigate the current military lasers enough to survive them with some reasonable reflectivity, the lasers will only continue to get more powerful and more compact over time. Reflective armour would buy you a few years, nothing more.

Re:Reflective Armor

[HornWumpus]

If they spent the money on better brakes, I'm good with their choices. But I doubt that.

Re:Reflective Armor

[ImprovOmega]

Yes and no. The 90% are only valid if the laser beam hits the object nearly at 90 degrees. Then indeed, the reflection will cause 90% of the energy to be reflected and 10% will be heating the surface. But still, this means we need to have a 10 times larger laser to have the same effect than on a non reflective (black) object.

I suppose that would depend on how well your reflective surface withstands the raise in temperature. Even if only 10% of the energy is absorbed it can pretty quickly cause a cascading effect of reducing the reflectivity of the device until the whole reflective layer ablates away. With mylar this would hardly take any time at all, with highly polished mirrors the first tiny scorch marks would melt the glass away in seconds. The laser doesn't have to be 10x as strong, it just has to be strong enough to wreck the reflective armor and still punch through the vitals before the payload can get to the target. When you're playing with 10's of thousands of watts, this is not a huge bar to meet.

Re:Reflective Armor

[lgw]

All good points, which is why I tried to qualify with the handwavey "high power". For a few kW, I'm sure (IR) reflective coatings would help. For a few MW, I'd say it's pointless.

You can still try to focus a laser such that it breaks down right before the target, but this is really difficult and unreliable, especially in a real atmosphere.

The airborne laser program did some amazing things with dynamic lenses to compensate for turbulence in real time. I don't know the details (presumably they're classified), but I've wondered whether some game like you describe wasn't part of the reason for the fancy lens.

Re:Reflective Armor

[Dahamma]

IEDs and suicide bombers don't work very well when there are large-barbed wire fences between the two sides. Besides, these are all basically the same things (explosive objects) and the only real difference is the delivery mechanism. In this case mortars are by *far* the cheapest (in terms of cost/resources/risk/etc) delivery mechanism, which is why they are used by Hezbollah, etc against Israel.

The proper counter to that is to find a cheap way to destroy them (in terms of recurring costs - sure, the NRE for this project was probably *huge*). Iron Dome costs almost $50k per missile vs. what, like $300-$400 for a mortar round. A big diesel truck with a laser would seem to be a much more cost effective solution in the long term.

Re:Reflective Armor

[cavreader]

The US government screwed the armed services in Vietnam and Iraq. The military successfully killed everything that they were pitted against only to have the politicians come in and stop the military right before they finished the job. In the first Iraq war the military was stopped from marching into Baghdad and finishing the job which resulted in the US having to go back 10 years later to do what they should have done the first time around.

Re:Reflective Armor

[gl4ss]

well, a laser to shoot the laser that is shooting, duh.
or use prisms to mirror it back.

all very expensive of course.

I wonder how well it fares with volleys where the mortars are due to land at the same instant.

though, maybe just shoot first a mortar with smoke & chaff that explodes when hit by the laser... (SOMEONE PATENT THIS QUICK!) so put every 10th mortar or so of full of shredded foil and waste oil.

Re:Reflective Armor

[flyneye]

I think I'd go with a glass microbead coating to diffuse the beam and take most of the punch out of it. A nice baked aluminum wrinkle finish beneath that might fuzz it up on the radar enough to get shots to go wild, maybe not. Either way it'd look like a flying disco dildo that would show up under low light sources like projecting a movie on a blimp. Maybe the Military could shoot it down with a slingshot.

Re:Reflective Armor

[AmiMoJo]

Expect to see stealth mortars soon. Nothing too special, just the right shape to screw up the tracking radar and perhaps with some chaff on a timer.

Re:Reflective Armor

[ShanghaiBill]

And before that, there was sound ranging!

It is difficult to locate a mortar position with sound. Mortars aren't that loud when they fire, and they can fire from deep defilade. Also, sound propagates slowly enough to give them critical seconds to "shoot and scoot". Even with radar, we would fire our 155s not only on their firing position, but also on likely routes of egress. The Iraqis had mortars mounted in the back of BMPs so they could move as quickly as possible after launching a volley, as well as having some armor to protect them from shrapnel while they were moving.

Re:Reflective Armor

[khallow]

Detonates from electrical charge, not shock or heat, like TNT.

If it can chemically detonate, then it will under enough shock and heat, something a high power laser can readily apply, since that's how you get a detonation rather than a local fizzle in the first place.

Re:Reflective Armor

[khallow]

The problem with your assertion is that the US simply didn't have the political backing in the first war to invade Iraq. "Finishing the job" would create strategic problems such as fighting an insurgency with no support from anyone in the Middle East or the developed world.

Re:Reflective Armor

[khallow]

Very expensive reflective coating may buy you a fraction of a second, maybe even a whole one...

A fraction of a second is a long time when you have a lot of rounds incoming.

Re:Reflective Armor

[davester666]

where's the "Strap it to a shark, then sent both into orbit." joke?

Re:Reflective Armor

[EvilSS]

If they spent the money on better brakes, I'm good with their choices. But I doubt that.

That depends on if you consider spray-painted brake calipers an improvement.

Re:Reflective Armor

[LifesABeach]

As for Viet-Nam, the general says, "Please", to the Commander and Chief.

Re:Reflective Armor

[Archimboldo]

It was forever ago when I went through the calculations, but it is indeed an interesting property of lasers that their beam initially shrinks in diameter with distance and then grows. So it could defocus instead of focus, depending on distance.

Re:Reflective Armor

[triffid_98]

The military successfully killed everything that they were pitted against only to have the politicians come in and stop the military right before they finished the job.

When huge swathes of the native population hate you and want you gone, "finishing the job" typically involves carpet bombing the natives back to the stone age. That or keeping a semi-permanent military presence and installing a puppet dictator. Which option were you thinking we should have gone for?

Re:Reflective Armor

[Optali]

And you could paint flames on it, this would add an extra boost!

Re:Reflective Armor

[hicksw]

These high powered lasers can bore a hole through a normal household mirror

Front silvered?
--
There is no mercy, only ashes.

Re:Reflective Armor

[khallow]

With a pulsed laser, you could be talking about the difference between 8 ns and 10 ns for something to fail.

And the subsequent increase in charge time for the next pulse. Don't forget that part.

Re:Reflective Armor

[khallow]

Pulse length of such systems is unrelated to the input energy and charge time to fire them

But it was clear from the original post that the longer pulse length was so that more energy would be brought to bear on the target.

and instead comes down to geometry and basic technique being used

Geometry and "basic technique" has nothing to do with pulse length either.

Re:Reflective Armor

[iggymanz]

actually, the silvering is on the back of household mirror, and it doesn't matter what the color of any coating on that side as it will soon be gone, and the laser will in fact have to burn away the "reflective" material (which is only 70-80% reflective even on the "shiny" side).

Now think about this: those industrial lasers also can cut ordinary "transparent" glass.

You're not going to make a missile or mortar shell an "optical mirror", smooth to millionths of an inch.....

Re:Reflective Armor

[cavreader]

The back to the stone age choice of course. It's a total waste of people and money to end a conflict without any ambiguity as to who one and who lost. If you are not prepared for that course of action you should do nothing. And today the US should have a firm policy that does nothing until someone directly threatens American interests.

Really?

[RightSaidFred99]

The laser could target only one mortar at a time,

In the words of 15 year old sarcasm-meisters from 1989, "No Shit Sherlock?". Though I for one welcome the innovation of lasers which are broad enough to simultaneously detonate a bunch of mortars spread out over several hundred feet in 3D space.

Re:Really?

[barlevg]

Using beam splitters, you could in theory target as many targets as the laser can handle while keeping the beams directed. You wouldn't even need to have multiple targeting systems--I vaguely remember seeing a talk once (where the lasers were being used for optical trapping) where the beam pattern was controlled by a single piece of optics.

Re:Really?

[flaming error]

And using boat rudders, we could in theory target multiple tree-huggers with only one water cannon.

Re:Really?

[VortexCortex]

Though I for one welcome the innovation of lasers which are broad enough to simultaneously detonate a bunch of mortars spread out over several hundred feet in 3D space.

Let me introduce you to my Sun.

Advantages of DEWs

[barlevg]

Considering drones should be susceptible to conventional means of destruction (read: bullets, missiles), I was wondering why bother with directed energy weapons? The answer appears to be (1) discretion (because a drone dropping out of the sky is totally not attention-grabbing) (2) the ability to shoot through walls (okay, that's pretty cool), and (3) lower "cost per kill."

Re:Advantages of DEWs

[X0563511]

Also, you don't have projectiles flying off past the target if you miss or pass-through. If there's a friendly base, city etc beyond the drone, you most probably don't want to light it up with bullets or missiles.

Re:Advantages of DEWs

[C0R1D4N]

I don't think the laser beam has an arc and return trajectory.

Re:Advantages of DEWs

[barlevg]

Several things wrong with this.

-More like cooked--these beams aren't visible spectrum.
-Yes, I'd rather be blind than have a bullet to the head.
-Cities and buildings shouldn't be in the linear line of fire of these beams (which will mainly be shooting up). The issue that X0563511 brought up is based on that obscure sciencey concept that things that go up usually come back down.

Re:Advantages of DEWs

[Sarten-X]

Directed energy also has the advantages of a high rate of fire, easier reloading, and no recoil, and it travels at light speed. It's a better replacement for bullets in many situations, effectively firing as long as there's electricity, and burning a hole through practically anything, without needing to worry about travel time.

Re:Advantages of DEWs

[SirGarlon]

Actually, discretion can matter depending on who the adversary is. Radar can theoretically track a missile or even a bullet back to its source; a laser is not traceable in that way. If, for example, one envisions fighting another well-equipped industrialized country, that could matter considerably. Air defenses that could fire without revealing their locations would have a an edge. (Unlike in science fiction movies, lasers do not make a visible beam unless there is smoke or dust to scatter them.)

Since lasers propagate at the speed of light, there is by definition no way to know one is incoming before it hits. That's another advantage.

Re:Advantages of DEWs

[bob_super]

Yes but that random airliner doesn't have wings designed to resist laser cutting.

What? You mean I have to check behind the target just in case? That's against SOP.

Re:Advantages of DEWs

[barlevg]

Assuming the laser platform wasn't firing through some complicated Rube Goldberg-style mirror setup, wouldn't you be able to figure out where it was fired from based on where on the drone was hit / angle of incidence? If I get shot in the back, my buddies aren't going to look in front of me for my shooter.

Re:Advantages of DEWs

[barlevg]

I haven't done the calculation, but I'd imagine that the odds of an airliner getting hit by a stray beam are much less than the odds of a civilian being hit by a stray bullet. Basing this off of the lower density of airliners in the night sky vs. people in a city. Also beams are a bit more predictable (unless reflective-material ricochet is indeed a concern).

Re:Advantages of DEWs

[Ferrofluid]

I'd rather be blind than have a bullet to the head.

Funny, I'd rather the opposite.

Re:Advantages of DEWs

[RivenAleem]

I see you've never fired a laser at a black hole!

Re:Advantages of DEWs

[bob_super]

I have to ask: according to current US policy, where is NOT an "active warzone"?

Re:Advantages of DEWs

[volxdragon]

Actually, I believe in that case the trajectory does not change - space-time is distorted such that it appears the beam would bend toward the black hole...

Test it in ran....lol

[Notabadguy]

They're going to move it to Florida to test it in ran and fog.

RAN = Japanese pronunciation of "rebellion."

Tomorrow's headlines: US ARMY DEPLOYS JAPANESE LASERS INTO FLORIDA TO QUELL REBELLIOUS FLORIDIANS!

Targeting and Speed of Light ...

[perpenso]

I was wondering why bother with directed energy weapons?

With speed of light weapons the target does not move very far between firing and impact. Point of aim is basically point of impact, unlike bullets. No guidance system required, unlike missiles.

Ammunition is unlimited as long as you have power.

And because sci fi fans have been waiting for this since 1898. The War of the Worlds, H. G. Wells.

Re:Targeting and Speed of Light ...

[Anubis IV]

Not to mention that pesky problem of missiles and bullets raining down on people below being a problem of the past with DEWs.

Re:Targeting and Speed of Light ...

[bobbied]

I was wondering why bother with directed energy weapons?

No guidance system required, unlike missiles..

Actually, the guidance systems are going to be pretty sophisticated and darned difficult to get right. You have to fix the target's position and then get the laser beam headed in the right direction when the energy is being emitted, while keeping the adaptive optics to maintain focus working long enough to transfer enough energy to cook the target. If it take more than a small fraction of a second to transfer enough energy, you are going to have to track the target too, which could be a guidance problem that's pretty hard, for ballistic objects or really hard for fast maneuvering objects. As the object gets further away, your ability to be as accurate in absolute distance will diminish as will your ability to transfer energy, so you will have to track longer and better.

You don't have to throw away all the fancy guidance equipment by blowing it up though.

Re:Who gives a fuck?

[Anonymous Coward]

... oppress a bunch of other homeless people in a different country ...

Since when do the homeless have mortars and aerial drones?

Anti-satellite

[perpenso]

Also, you don't have projectiles flying off past the target if you miss or pass-through. If there's a friendly base, city etc beyond the drone, you most probably don't want to light it up with bullets or missiles.

And for a "kill" in space you don't get the debris problem. Just a burned out image sensor on an otherwise intact spy satellite.

Re:Anti-satellite

[volxdragon]

And for a "kill" in space you don't get the debris problem. Just a burned out image sensor on an otherwise intact spy satellite.

Not necessarily....hit the hydrazine tank and methinks things will go boom!

Re:Anti-satellite

[perpenso]

And for a "kill" in space you don't get the debris problem. Just a burned out image sensor on an otherwise intact spy satellite.

Not necessarily....hit the hydrazine tank and methinks things will go boom!

Burning out optics may take much less power than cutting into the tank.

Competition...

[msauve]

"Commercial package-delivery drones such as those revealed by Amazon and DHL could face danger from more than shotgun-toting, UAV-hunting yahoos "

Kudos to Yahoo! for finally figuring out how to compete.

Re:Competition...

[bobbied]

"Commercial package-delivery drones such as those revealed by Amazon and DHL could face danger from more than shotgun-toting, UAV-hunting yahoos "

A shot gun won't do you a bit of good over about 150 feet, unless you just wanted to wake the neighbors. You might hit the thing, but the shot will be moving so slow it will bounce off just about anything. Good luck getting that close. Of course, a GPS spoof/jamer could net you some great stuff that was supposed to go to the neighbors.

Re:2 nd ammendment question

[barlevg]

I'm not a firearms enthusiast. But if I had to be armed, I would choose a "slug thrower" over a ray-gun any day--much less complicated tech that can go wrong. And, as people have pointed out elsewhere, bullets are not stopped (and bounced back) by reflective sheeting.

Approaching useful power levels

[Animats]

This isn't the first U.S. Army laser system that can shoot down mortar rounds. The Tactical High Energy Laser, in test since 2000, could do it. Here it is in action. That took three semitrailers of equipment and tanks for the chemical laser. Each shot cost $3000 in chemicals. Israel wanted to deploy the thing, even though it was expensive to operate, couldn't run for long, and not very portable. It was just too clunky for combat.

The Army wanted a solid-state laser with that kind of punch, and now they have one. This new truck-mounted system uses a 10KW solid-state laser array. Probably a lot of small solid-state lasers. It might just be an array of 1000 standard 10-watt laser diodes. That's enough to take out artillery shells and small rockets. The only consumable is electricity.

Beam weapons are about to become real. The most likely initial user is, again, Israel, which has to deal with small rocket attacks in known areas. Israel's Iron Dome system works reasonably well but uses a pair of $50,000 guided missiles to take out each $800 attacking rocket.

Re:Approaching useful power levels

[sconeu]

C-RAM is exactly where speed-of-light weaponry is needed. You have rapid closing times, and you don't have as much time to track. As has been mentioned before, with DE, you "point and shoot", you don't have to worry about time of flight and evasion.

Re:Approaching useful power levels

[Animats]

Great, except for the fact that, you know, mortar rounds don't slow down in mid-air.

If you can explode their warhead in flight, when they hit, they're just rocks, lethal radius of a few inches.

Re:Approaching useful power levels

[volvox_voxel]

If you dig through the links, you'll find that they're developing a free-electron laser: http://www.boeing.com/assets/pdf/defense-space/ic/des/files/DES_overview.pdf I'm pretty amazed that they can get something like that working in a truck. SLAC was converted into a free-electron laser. http://en.wikipedia.org/wiki/Free-electron_laser. A free electron laser starts as an accelerator and ends up turning into a beam of light; I thought these things had to be huge in order to work.. They were not clear about what they were currently using.. A compact high energy free electron laser opens up a lot of possibilities.

We should worry

[DaveAtFraud]

...

Tomorrow's headlines: US ARMY DEPLOYS JAPANESE LASERS INTO FLORIDA TO QUELL REBELLIOUS FLORIDIANS!

You'd be surprised how much it hurts when some little old lady violently runs into you with her walker.

Cheers,
Dave

Re:2 nd ammendment question

[LordLimecat]

bullets are not stopped (and bounced back) by reflective sheeting.

Nor is any laser of any reasonable power. Not sure the exact formula / power, but a quick google search indicates that hobbyists cut things like reflective mylar foil with 3-watt CO2 lasers, which Im sure can be powered by a 500HP generator.

Generally an object in the battlefield will not be dust-free, and anything at all that isnt reflecting light is absorbing energy. Very quickly even a highly reflective surface burns and stops being reflective.

Amazon Drones Not My Main Concern

[the eric conspiracy]

I wants a weapon that I can attach to my phone which will cause instant annihilation of any robocall system that happens to call me.

I've never seen either a mortar round or UAV incoming. However I get multiple incoming robocalls per day.

WORK ON SOMETHING RELEVANT!!

Re:Amazon Drones Not My Main Concern

[VortexCortex]

You can construct one yourself. Simply take a telephone wire and connect the red and green respectively to the black and white of an extension cord. Plug the phone in first, then the extension cord.

Still with the Amazon delivery drone?

[umafuckit]

It's just a pre-crimbo publicity stunt.

Re:2 nd ammendment question

[Anonymous Coward]

"I don't know anything about this, but I'll give you my opinion anyway."

So you can shoot down multiple mortars?

[Hobadee]

So your fancy new laser system can shoot down several mortars in a small amount of time?

Challenge Accepted! ...oh, and BTW, challenge already won; http://www.youtube.com/watch?v=zx_9_RgMPCE#t=82

Re:So you can shoot down multiple mortars?

[PPH]

Yep. Just as fast as they can make the "Pew, pew, pew" sound.

Wrong Light Theory

[pubwvj]

A laser is not a focused beam of light. It is parallel light. Get the details right.

Jammers

[phorm]

So all the bad-guys have to do is put their jammer on top of a hospital or orphanage or whatever. They they get to put out some nice publicity about how the US is killing orphans and sick people.

Hiding behind civilians is a fairly common thing among certain terrorist groups.

Re:Jammers

[phantomfive]

Back in '72, they weren't designing weapons to destroy small-time terrorists. They were designing them to defeat the communists, and it was about military strength, not publicity.

Unless there's Rayleigh Scattering involved.

[fazookus]

I'll pretend that I Rayleigh Scattering is something that I picked up in a physics class and not something I looked up on Wiki when I got a cool new green laser http://en.wikipedia.org/wiki/Rayleigh_scattering

anti-munition / drone?

[Anathem]

And like many an anti-aircraft (I know, anti-drone/munition) weapon before it, I imagine there are some unorthodox anti-personnel uses as well.

Miaow

[easyTree]

you have fifteen picoseconds to comply!!!

Re:when in doubt

[bobbied]

Nice thought but smoke and fog are fairly transparent to IR unless it's really thick. I don't see how you'd get it that dense.

Lasers vs smoke screen final score: 0-1

[TiggertheMad]

Simpler solution: Formulate your explosive to produce a lot of smoke on ignition, so that if a single mortar is destroyed mid flight, you have just deployed a smoke screen that is more difficult for the laser to cut through. Then when you call in a mortar fire mission, the first three rounds are destroyed mid flight, and the laser is then useless to target anything on the flight path until the smoke dissipates.

Lasers vs ceramic final score: 0-1

[TiggertheMad]

Other simple solution: Make outer mortar case out of ceramic. Mirrors and reflective materials don't work, so rather than reflect the laser, just absorb the energy. Ceramic can be made hard, cheap, and is a wonderful heat sink. Common formulas will work, but if needed, you can make ceramic shells out of the same stuff that they put on the space shuttle as reentry tiles.

You're doing it wrong

[Hognoxious]

If the mortars are flying through the air you're doing it wrong.

Yeah but...

[xednieht]

Have you any new developments to report on shark tech?

Heh

[locke.th]

Well, as lasers become more and more practical as weaponry, say goodbye to the age of air superiority. Practical lasers mean point and click anti air weapons, which means ground warfare will be dominant once more.