Air Force Looks To Laser-Proof Its Weapons

slugo writes "This wired.com article has probably the coolest laser destruction video you have ever seen. The video shows the Israeli and US Air Force working on laser defense systems. The US Air Force is starting to look for ways to laser-proof its bombs and missiles — with spray-on coatings, no less. They think everyone is going to figure this laser thing out sometime and need a defense against what they are already very good at — shooting things out of the sky with a laser."

Comments

It's obvious, isn't it?

[JeremyBanks]

Cover everything in mirrors.

Not so obvious...

[Firethorn]

Doesn't necessarily work as well as it does in scifi. Mirrors aren't perfect, and tend to gather things like dust, which reduce their efficiency even more. Not to mention different mirrors vary in their effectiveness with different spectrum lasers.

Shouldn't matter much, but at the high powers weaponized lasers operate at, they quickly destroy mirrors.

As for working on anti-laser stuff, well, it's best to keep three steps ahead militarily wise - tends to keep your casualties down.

Re:Not so obvious...

[v1]

a simple chrome coating can add a few seconds of protection for a shell, enough to prevent it from being destroyed before it reaches its target. Mirrors are vulnerable because the reflective surface is usually very thin and poorly heat-protected. Chrome a shell and the shell serves as a heat sink to dissipate most of the energy the chrome actually ends up absorbing in the first place. Chrome's a lot hardier than a few microns of silvering.

The lasers weren't blowing holes in the shells, they were cooking them. They aren't nearly as devastating as you might at first believe. Several of their demos required several seconds to detonate the incoming round. If you can buy another 3 seconds of time on a shell, that's probably enough to beat the laser. You only have to survive the heat from the time you are acquired to the time you pass out of view of the laser.

I'm more interested in how they are generating that much laser energy. Most lasers of that calibre are chemical, and I didn't see what I would expect of a chemical laser. Being able to engage several targets one after another rapidly is a big plus over traditional chemical lasers, which require large amounts of chemicals which have to be pumped in, triggered, and vented to be replaced with more chemicals to fire again. The large flying laser beds work this way and I don't even know if they can fire more than once without landing and refueling with more chemicals. (though they are certainly more powerful than the one demo'd here)

They also demo this in the desert every time I see it. No clouds, low humidity, line of sight. Guess what laser weapons don't do well in?

Re:Not so obvious...

[Firethorn]

Last time I saw a specification for the laser mounted in a modified 747, it had 30 seconds of firing capacity, and was capable of being turned on and off at will.

That 30 seconds was considered sufficient to engage something like 5-15 targets.

That's why you need the friggin' sharks!

[Biff Stu]

That's why you need sharks to go with your lasers. You think you can defend yourself with mirrors, do you? Don't you know that sharks like to eat shiny things?

Simple business plan.

[Chairboy]

1. Buy all the Krylon 'Chrome' spray paint.
2. Relabel it and sell it to the government as 'Anti-Laser Shielding'.
3. Profit!

Ha ha h- wait... there's a step #2. There's never a step #2. wtf

well that was a waste of money

[Brain Damaged Bogan]

my sharks-with-freaking-laser-beams missile defense is useless now

Armour them and spin them.

[khasim]

The problems with lasers is that the need to punch through the armour in the time they can stay on target.

#1. Spin them. If the laser cannot hit the same spot for X fragments of a second then it cannot burn through (unless you get a bigger laser).

#2. For when the enemy gets a bigger laser, you coat the missile in a nice insulator. Something like carbon.

So now the laser has to punch through the carbon armour before the missile rotates new armour into sight.

Re:Armour them and spin them.

[davester666]

Instead of carbon, how about that magical substance known as: Tin Foil.

If it's good enough to stop the beams entering my head, it should be good enough to stop the beams from entering missiles!

Re:Armour them and spin them.

[rtb61]

Time to stop thinking of lasers as light and start thinking of them as particle cannons. So it all depends on the type of particle you a firing at the target, whether it passes right through the armour to target the components you a particularly after, or even if it actively targets the armour as part of the destructive affect.

It is all about how much energy you want to get on target, the nature of that energy and the affect you wish to achieve.

So, minimal amount of energy solution, target CPUs and get all the 0s to be 1s and those smart weapons go stupid and don't target targeting anything ;D.

Re:Armour them and spin them.

[Anonymous Coward]

target CPUs and get all the 0s to be 1s and those smart weapons go stupid and don't target targeting anything

I see they got to yours already.

Re:Armour them and spin them.

[budgenator]

yup the 81MM mortar is a smoothebore but it's round has fins at the base that are canted so the projo spins in flight. 81's are slow too, after you drop one down the tube you can look up and see the round about 100m down range and watch it going until after it's a little past it's max ordinate and it disappears. Howitzers have a rifled barrel so the round spins. All artillery rounds that I know of have a fuse that doesn't arm until the round has spun so many times, this prevents most barrel bursts. Shooting one 81 doesn't impress me, shooting 3 fired in a ripple that's getting interesting; shoot down 3 fired at the same time I'm impressed, but remember real world is going to be somebody see all the loud IR energy pointing at the laser source and they are likely to answer with 3 81mm;s in flight, backed up by three salvos of 3 60mm mortars all taking the high trajectory while 6 more 155mm howitzer rounds are coming in low and fast.

It seems to slow for mortars.

[doublee3]

Judging from the video it seems to be able to shoot blow up 9-10 mortars per minute. But a quick google search showed that the M224 60mm Light Mortar can fire at 8-20 mortars per minute indefinitely or 18-30 mortars per minute for 1-4 minutes. Seems like you'd need a lot of these lasers to make an area 100% protected from mortars.

Re:It seems to slow for mortars.

[greyhueofdoubt]

We already have this. It's called the Phalanx sometimes, or just CIWS (close in weapons system). It features a 20 mm vulcan cannon, multiple radars, autonomous operation, and on top of that it can track multiple (dozens) incoming targets as well as its own outgoing projectiles. They can also network together to form a basewide protective shield. They are loaded with a tracer every 20 or 30 rounds and at night the bullet stream looks like the world's most powerful and accurate garden hose- one continuous stream of projectiles. The sound and feeling even from 200 yards is something you'll never forget, especially after you clean your pants the first time they fire without warning. Watching 5 of them fire in synch during a test is awe-inspiring (in good and bad ways, I guess).

Yeah, lasers, great... But in a deployed area, the CIWS provides early warning and interception of incoming mortars and missiles and doesn't require anything more than a generator and a full magazine. Someday lasers might provide an even better shield but until then we could use a few more CIWS in the field.

http://www.youtube.com/watch?v=cgpQBZF2sZQ

You should watch that video- dove or hawk, any geek has to admit that the phalanx is one bad ass mutha.

-b

Re:It seems to slow for mortars.

[Dun Malg]

Three words: Counter Battery Fire :)

Heh. Reminds me of a story about a sort of makeshift counterbattery fire someone once told me. Small Lebanese army military camp in Lebanon during the civil war, and every afternoon they'd go outside and play volleyball. Local shia militia jerks noticed the pattern and started dropping mortar rounds in the middle of their volleyball game every day. Immediate patrols trying to find them turned up nothing, as the shia militia jerks simply drop a few rounds, picked up the mortar tube, kicked sand over the base plate, and ran. Tiring of this, the Lebanese army guys measured the angle of the holes at the bottom of the impact craters made by the fuse assemblies being blown into the ground and used trigonometry to figure out where the rounds probably came from--- about a quarter mile away. Based on the size of the rounds, they knew the shias weren't taking the heavy base plate with them when they ran. They went out there in the middle of the night and, sure enough, right where they calculated, they found the mortar base plate. They picked it up, buried a big antitank mine underneath, and carefully concealed the plate just as they found it. Next day, they went out to play volleyball. Five minutes into the game, they head a loud explosion from the direction where the plate was. No mortar rounds ever interrupted their game after that.

The answer is mirv

[moteyalpha]

mirv already exists and so does flack. You can't hit what you don't know is a target. There are always limits to energy per unit time per unit area and since we are already 10 trillion dollars in debt destroying things, perhaps that money would be better spent on a plan to grow some crops to eat.

Re:The answer is mirv

[Dun Malg]

perhaps that money would be better spent on a plan to grow some crops to eat.

We already grow enough crops. Hunger is a politically created distribution problem, not a problem of lack of food.

Once it discovers it, security becomes an issue

[CrazyJim1]

Hopefully the guy making the decisions weighed espionage. You can really shoot yourself in the foot if you find a counter to your own missle defense and then someone publishes the counter. Do you really need an anti missle defense technology so bad that it is worth endangering your own missle defense?

Dragged along for the ride

[Un pobre guey]

1. Create an expensive and ostentatious weapons system on which other nations were not willing to squander billions of dollars
2. Make a cool video about it and circulate it widely. Conceal the real, practical day-to-day performance results.
3. If a global arms race fails to start, announce that you are also developing a handy-dandy, sure-fire defense against the weapons system only you possess. Caution: increased risk of scam backfiring.
4. ???
5. Profit!

Yet another defense industry scam, and all of us are dragged along for the ride.

Environmental Impact

[DougF]

of chrome would probably rule out using it as a coating/shield. Its tough enough getting EPA approval to use chromium coatings on stuff that isn't going to go BOOM (such as bearings/anti-corrosive coatings, etc), let alone a proposal that says "We'd like to put chrome on artillery rounds so there are lots of opportunities to leach into water supplies, cause cancer, etc."

Re:Laser-proof first post

[Arthur Grumbine]

Your first post is in as much danger from lasers as anything else. Which is none at all. It's been 25 years and untold billions of dollars secretly(gotta love the Cold War) pumped into viable military applications for lasers. What do we have to show for it?!? An entirely-useless-chemical-laser-carrying 747 that:

1) Has gotten so far in that last 12 years of focused development that it has finished "target illumination" testing.
2) Has 40 shot maximum payload (according to the entirely optimistic marketers of this project). They admit that it is only really specced for 20 shots now, though.
3) Does NOT have any variety shark attached to it.

I think Northrop Grumman, Boeing and all the other defense contractors had the following plan when they met with Reagan:
1)Convince The Gipper that Green lasers is just what's needed to kill the Red Communists. ("It'd be just like that recent film by that young George Lucas, and we know how much you love movies, Mr. President."
2) (optional) ???
3) Profit!!!

As a former artilleryman...

[gillbates]

I say, good luck!.

Even a modest artillery battery, on a bad day, with the hot, dusty wind in their face and half their crew asleep, can manage to put 18 rounds downrange, per minute. With a 30 second flight time (hey, it varies with range), you've got less than two seconds per projectile if you're going to destroy them all. And the laser takes several seconds per round to destroy it. And that's without the coating.

So here's what you do: you fire a 'smurf' round - that is, a hollow steel round as your first projectile. Because it doesn't have any explosive, the laser will track it and burn it until it hits the ground, paving the way for the remaining rounds to come through without any problem.

Granted, I think lasers are cool and all, but we already have anti-rocket systems like the Navy's phalanx which seem to be much more effective. The problem is that something like a 3000 rpm chain gun can put more energy on the target than most tactical lasers. Even more embarassing, a .50 cal round can pierce 2 inches of solid steel at ranges greater than 3 kilometers. A single .50 cal round impacting nose of an artillery shell would detonate it instantly. Why not use those precision servos to direct a weapon with real takedown power? Ballistic flight trajectories aren't that hard to calculate.

And unlike the laser, artillery can hit things beyond visual range, in places obstructed from direct line of sight. Put yourself in a valley, and your laser defense system might not even track the round until its already too late. I think it's a step in the right direction, but they clearly need much more powerful lasers to be practical.