Laser weapons are getting closer to reality


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Preacherman
October 20, 2003, 12:13 AM
From the Oakland Tribune (http://www.oaklandtribune.com/cda/article/print/0,1674,82%257E1865%257E1709759,00.html):

Warfare at the speed of light

By Ian Hoffman
STAFF WRITER

Sunday, October 19, 2003 - DOWN THIS tiled corridor, light does muscular, noisy work. Lasers dig dirt and weld metal. They pound aircraft parts into shape.

In Bob Yamamoto's lab, light devours.

He straps on emerald green goggles. A technician stabs a fire button and calls out the computer countdown. "Three ... two ... one ..."

Then ... nothing. Just a buzz of electronics and an ephemeral glow in this darkened room at Lawrence Livermore Laboratory. But inside Yamamato's target chamber, a block of steel spits flame and molten metal.

In those two seconds, 400 blasts of light poured into slabs of clear, manmade garnet. Swollen in energy, the crystal's atoms then unleashed torrents of infrared light to ricochet 1,000 times between two mirrors and multiply, finally escaping as 400 pulses of pure, square beam.

Kilowatt for kilogram, this is the world's most powerful solid-state laser. Its invisible beam drilled Yamamoto's inch-thick steel plate in two seconds. Add larger crystals and it will eat steel a mile or more away.

"What we're building," Yamamoto explains, "is a laser weapon."

After sinking 40 years and billions of dollars into beam weapons, defense scientists are on the cusp of what could be a military revolution -- warfare at the speed of light.

"We've made a quantum leap here," said Randy Buff, solid-state laser program manager for the U.S. Army's Space and Missile Defense Command. "We're anxious to get out there and do something."

No longer are laser guns the stuff of Hollywood and Strategic Defense Initiative fantasy. Instead of laser-guiding bullets and "smart" bombs, the Pentagon inside of a decade could be armed with a beam weapon that is near-instantaneous, gravity-free and truly surgical, focusing to such hair-splitting accuracy that it could avoid civilians while predetonating munitions miles away.

A laser arms race already is under way, chiefly in California. The prize is billions of dollars. Three families of high-energy beams -- powered by combusting chemicals, electron accelerators and crystals, such as Yamamoto's -- are vying for the Pentagon's eye.

Defense contractors are sniping at each other's designs, and corporate alliances are shifting. But no one seems to doubt that battle lasers -- perhaps mounted on Humvees, jet fighters and unmanned aircraft -- could knock down previously untouchable targets such as artillery shells, mortars, surface-to-air missiles and even cruise missiles at ranges of up to dozens of miles in good weather. In clear air above the clouds, a high-powered laser could lance out 500 miles to destroy rising ballistic missiles.

"If we had them today, they'd be at the former Saddam Hussein International Airport, making sure no one gets off a shoulder-launched missile at an aircraft," said Mike Campbell, a laser expert at General Atomics in San Diego.

By coaxing a huge power boost out of tiny laser diodes like those in CD players, scoreboards and supermarket scanners, scientists are squeezing unprecedented power out of lasers made of exotic crystals -- distant cousins of the world's first laser, which Theodore Maiman fashioned from a ruby cylinder in 1960.

The latest breed of solid-state lasers now are poised to break the dominance of giant, chemical gas-powered beams with compact, mobile weapons that can run off a Humvee's diesel engine or a jet fighter's turbine.

Experts liken this evolution to the shift from 1950s vacuum tubes to the solid-state transistors now driving everything electronic.

"We think the whole thing's going to go solid state," said Lloyd Hackel, chief of laser science technology at Livermore Lab. "Gas lasers are sort of the vacuum tubes of lasers. They work, but in terms of density, intensity and reliability, it's going to go solid state."

No coherent military plan

The Pentagon's economic power places the military at the decisive center of this transition. So far, however, experts say the Defense Department has no coherent plan for speed-of-light weapons research, scattering projects among the Air Force, Army and Navy.

As an offshoot, few in the Pentagon are grappling with the implications of highly mobile laser forces:

Are military computers and commanders ready for entirely automated weapons that deliver instant, lethal blasts of energy and can be retargeted in seconds? Lasers under testing for air defense already offer that capability. Fully automated firing on offensive targets is a short step behind.

"When you develop the capability to track, target and destroy something in a second, then the temptation to remove humans from the decision cycle becomes very great," said Loren Thompson, chief operating officer at the Lexington Institute, an Arlington, Va.-based defense think tank.

Will U.S. forces fire lasers on humans? International treaty forbids the use of lasers for blinding people. But there is no legal ban on striking humans. U.S. Special Operations Command wants to load a medium-power laser alongside artillery and miniguns on a future version of the AC-130 gunships that since Vietnam have been a mainstay of special forces attacks on ground targets. The laser's power could blow tires and ignite gas tanks, but wouldn't be lethal for tanks or armored vehicles.

"It would be a very long-range, ultra-accurate sniper rifle," suggests John Pike, a weapons expert and director of GlobalSecurity.org.

The likely targets, Thompson said, "would be some sort of lighter vehicle or combustible structures or it could be people. Remember we're talking about a system that can be instantenously retargetable."

Will the payoff of battle lasers sufficiently outweigh their huge drawback -- loss of power and range in bad weather, fog, dust and smoke -- that the U.S. military will shift toward fair-weather operations?

Is the United States willing to defend or attack satellites with lasers? The Air Force's Airborne Laser is to start test-firing against missiles in 2004. But the longer range of its laser in the thinner, upper atmosphere brings space vehicles within targeting.

How will other nations respond? Experts believe the United States could enjoy a near monopoly on battle lasers for years. But under what circumstances will it justify their use in the face of likely international opposition?

Well before the end of the Cold War, Pentagon technocrats talked of "transformation" of the military -- a fusing of electronic eyes, fast communications and data crunching with precision weapons to wage war at hyperspeed and high efficiency.

But despite compressing the time to identify and attack adversaries, U.S. weapons are still chained to the slow, Newtonian physics of explosives, chemical propellants and metal projectiles, and are still restrained by gravity.

Ballistic warheads can strike at speeds greater than Mach 20. But readying them for launch takes several minutes at least and delivering them several more. Lasers race to target at roughly Mach 860,000.

"There's no problem with dodging the bullet," said the Lexington Institute's Thompson.

With that allure, the Bush administration has specified that the signature vehicles, aircraft and vessels of the next-generation military accommodate futuristic weapons.

Defense contractors are shoehorning laser bays into future fighters, tilt-rotor aircraft and helicopters. Humvees are going to hybrid diesel engines, and the Navy's new DDX destroyer to all-electric drive. The military wants to cuts its logistical burden of fuel supply, but a secondary reason is extra electrical power for energy weapons.

"They would have substantial surplus capability for some power-hungry weapon of the future, and whether that would be a laser or a microwave gun or a rail gun isn't certain," said GlobalSecurity's Pike.

The era of battle lasers began in the mid-1990s, when military scientists in New Mexico burned a hole in a Scud missile standing miles away. Soon after, a powerful chemical laser funded by the Pentagon and the Israeli Defense Force began blasting rockets and artillery shells out of midair. Scientists think such lasers have promise for knocking down mortar shells.

Mortars and artillery are so lethal for infantry that they account for nearly half of U.S. combat deaths in Iraq. But no effective defense exists.

'Let your imagination go'

"Nobody thought that could be done," said Josef Scwartz, program manager for the Mobile Tactical High Energy Laser at Northrop Grumman. "Everybody thought you'd just hide in a hole. Now you have the ability to shoot it out of the sky. And if you can do that, you can let your imagination go."

Defense theorists already are performing computer simulations of laser battles. "What it does is change the battlefield," said Thomas McGrann, a military operations analyst who runs battle simulations in Livermore Lab's Q Division. "What we're seeing is, he fires something at me, I knock it down. Anywhere from one to three kilometers out, I'm going to suppress his fire. And when he sends his UAVs (unmanned aerial vehicles) up -- and they're hard targets to kill -- I can take them out. An Army guy says he's taking fire from a wooded hillside. We start a fire there."

But forget about "Star Wars" and blaster pistols knifing the air with multi-colored beams. Visible lasers so far don't pack sufficient punch over distance to be useful weapons.

The laser battlefield will be largely invisible. Targets will explode, break apart in midair or burst into flame without apparent cause.

Soldiers won't buckle themselves into a laser cannon. The earliest battle laser systems are designed to defend U.S. troops and aircraft against airborne shells and missiles. That means computerized systems for tracking, targeting and firing faster than humans can react.

And the world's first laser weapons won't be worn on the hip: The most technically mature candidates are sprawling monstrosities weighing 50 tons and filling the better part of a Boeing 747 or, in the case of Northrop's MTHEL, a full-sized drug store, backed by chemical tanks or factories to recharge the lasers.

That's been the story of laser weapons for years. Chemical lasers are proven at delivering high-powered beams at great distances -- if they have enough chemicals. Scwartz' challenge is shrinking its laser by a fifth, to fit inside two cargo containers, packed inside a C-130 cargo plane.

"Can we do it?" he said. "We think we can."

But some Army officials are wary of hauling tanks of flammable, toxic chemicals into a war zone. A former Pentagon official noted that a .50-caliber armor-piercing/incendiary bullet could ignite a toxic explosion.

Once the laser stops firing, it must vent hot chemicals. That chemical and thermal signature could make a weapon traveling in two tractor trailers a conspicuous target.

Ultimately, battlefield lasers will have to be more compact, mobile enough to fit in the tail of the helicopter, in the belly of a jet fighter or in the backseat of a Hummer.

"Solid-state lasers seem to be the ideal for laser weaponry," Thompson said. "The basic design seems to be less complicated than either free-electron or chemical lasers and it seems to be more easily incorporated, say, into a fighter. They have more potential over the long run because of their potential compactness and the flexibility of their power sources."

The most powerful electric laser is taking shape in Yamamoto's lab at Lawrence Livermore, where pursuit of hydrogen fusion has produced two generations of laser jocks and the world's most powerful solid-state lasers.

"If you want something small enough and light enough to put on a Humvee or the back of a copter and have enough oomph to do something, the way to do it is a solid-state laser," Yamamoto said.

Experts agree battle lasers need at least 100 kilowatts of power. The Pentagon wants to see who will get to 25 kilowatts first in 2004.

Yamamoto is a veteran builder of lasers and atom smashers. Next to those, the laser weapon sitting on his lab bench is easy: It's modular. He just adds another 4-inch slab or two of manmade garnet and surrounds it with diodes. He expects to beat 25 kilowatts by Christmas and double it early next year. To reach 100 kilowatts will take more and bigger slabs.

Yamamoto's problem is heat. Lasing makes the crystals warm inside and corrupts the light beam. Eventually, the slabs can crack and shatter. They're thick and don't cool well in chilled water or gases. Livermore's laser designers had a simpler idea: Build two or more of the compact lasers in cassettes and rotate them when hot.

A leap in efficiency

But the real innovation that makes solid-state lasers worthwhile for defense are high-power diodes. Instead of using flashlamps like Maiman's ruby and the National Ignition Facility, Yamamoto's laser is pumped by more than 8,000 diodes. They're 10 times as efficient.

In theory, that means a liter of everyday Army diesel fuel costing as little as $1 will generate enough rapid-fire laser pulses to destroy a standard airborne missile. The job now falls to Patriot missiles costing $3 million apiece.

The question is, will solid-state lasers that today resemble science projects, full of glass, mirrors and banks of sensitive electronics take the beating of battle?

"You have to get these lasers out in the field to see if they work. If you hit a bump in the road, do they hold up? Do you need five Ph.D.s to make them work?" said General Atomics' Campbell.

Moreover, all laser guns will, for the forseeable future, remain fair-weather weapons. Airborne particles and vapor diffuse the beam and cut its range enormously. Smart adversaries will attack under cover of smoke or inclement weather.

"In the first order, lasers are not going to work on bad days," Campbell said. "They're just not."

But then, neither do so many of the optical sensors on which U.S. forces depend for information-accelerated warfare.

"I'm sure there will be many games to be played in measures and countermeasures and counter-countermeasures," said Northrop's Scwartz. But the rule of thumb is "if you see a target, you can kill that target."

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Devonai
October 20, 2003, 12:46 AM
This is beyond cool.

If we can go from computers the size of a room to the one I'm typing on now in less than 40 years, who can doubt that these weapons will soon be combat effective?

Moparmike
October 20, 2003, 01:06 AM
I still want my 16-setting phaser. :D

And a flip-communicator. And my own ship. And a Scottish Engineer. And a Vulcan science officer. And hordes of green women....:scrutiny: :scrutiny:


:D :cool: :rolleyes:

madmike
October 20, 2003, 05:55 AM
You'll probably never see one that's man portable.

Lasers are inefficient--less than 15%. The rest is wasted heat that has to be cooled. Even tank-mounted ones are not close to reality. The USAF IS about to fly an airborne COIL laser...mounted on a 747--nine units are scheduled.

And there are times when indirect fire is JUST what you need. Sure, lasers are cool, but they aren't the be all and end all.

Good old fashioned bullets have been around for 800 years. It'll be a long time before they're done away with.

4v50 Gary
October 20, 2003, 11:08 AM
Good for "Star Wars" defense of incoming warheads. It'll take a long time before we reach the portable small arm variations are available. In the meantime, we'll lob shells, bullets and mortar rounds as we have traditionally done for all these centuries.

KMKeller
October 20, 2003, 11:16 AM
You'll probably never see one that's man portable.
True, unless we see a breakthrough in room-temperature superconducters. Then all bets are off.

Kharn
October 20, 2003, 11:23 AM
I bet a pulsed laser would be the only way to go for taking out a human, as a single beam would be like shooting a needle through a person. You might hit them, but they'll never bleed out if the laser cauterized the wound. Fifty thousand needles all passing through a person in under a second would likely do the job.

Kharn

AJ Dual
October 20, 2003, 12:16 PM
It'll take a long time before we reach the portable small arm variations are available.

Don't be so sure about that.

http://www.defensereview.com/352003/TIS1.pdf

It's energy delivery in Joules at over 1000 meters is comparable to a .44magnum at the muzzle. And it can fire 170 rpm (technically bursts per minute)

The main drawback if they actually try and produce the thing, is that the polonium rod that ionizes the gas with it's beta emissions (kind of like a gigantic tritium sight capsule) only lasts about 60 days. And any reload tanks only last 60 days from time of manufacture, not use, as well, due to the polonium's half-life.

Still, it's a start. I looked up Stravatti on the web, and some of their stuff had me initially convinced they were really just a cleverly done futuristic company for a sci-fi or RPG game. They've designed fighter prototypes that make the F-22 Raptor look antique. Crazy stuff with 4 wings and variable gemoetry that looks like it's right out of Robotech cartoons...

But they're listed in defensereview and Jane's. They're for real... :eek:

Penforhire
October 20, 2003, 01:42 PM
The main drawback I see is how easily you can defend against a light beam. Take a lightweight leaf of copper. As soon as an incoming beam heats the surface to a molten state you have an extremely efficient mirror, depending on frequency. So if laser weapons become popular, so will lightweight reflective clothing.

Particle beams? Different story.

Deadman
October 20, 2003, 07:09 PM
Assuming that a small-arm sized laser weapon is produced, how effective would laser energy be at penetrating trees, brick walls, earth mounds etc.?

Nightcrawler
December 11, 2003, 01:07 AM
Assuming that a small-arm sized laser weapon is produced, how effective would laser energy be at penetrating trees, brick walls, earth mounds etc.?

Unless I'm mistaken, they'd be grossly ineffective. The laser pulse would expend all of its energy on the first thing it hits. Basically, you couldn't tag a guy hiding behind a sheet-metal fence.

As was said, particle beams would be another story altogether.

thefitzvh
December 11, 2003, 01:42 AM
What!?!?! LASER WEAPONS!

You mean you can kill someone with light!?!?

:what:

That's it... no more laser pointers. Those evil "assault pens" have no place in a civilian's hands

and kids shouldn't be allowed to play with flashlights. It'll make them grow up wanting more powerful light to injure and maim people with. And we're removing star trek from TV.

It's for the children!

:neener:

James

MrAcheson
December 11, 2003, 08:44 AM
That's it... no more laser pointers. Those evil "assault pens" have no place in a civilian's hands and kids shouldn't be allowed to play with flashlights. It'll make them grow up wanting more powerful light to injure and maim people with. And we're removing star trek from TV.

Ever read Ringworld by Larry Niven? Long story short, one of the main weapons the heroes use are flashlights. In his future, you can focus the beam and turn up the power on a flashlight so much that it becomes an anti-personnel laser weapon.

HankB
December 11, 2003, 09:44 AM
No coherent military plan :D A little laser humor there, eh? (One of the characteristics of laser light is it's temporal and spatial coherence.)Instead of laser-guiding bullets and "smart" bombs, the Pentagon inside of a decade could be armed with a beam weapon Laser weapons WILL appear in the future. Laser weapons WILL NOT replace conventional explosives, smart bombs, etc. in 10 years.

And JUST WAIT until someone realizes that even diffuse reflection from a high powered laser can damage eyesight!

Daniel T
December 11, 2003, 10:28 AM
But some Army officials are wary of hauling tanks of flammable, toxic chemicals into a war zone. A former Pentagon official noted that a .50-caliber armor-piercing/incendiary bullet could ignite a toxic explosion.


It seems to me that we already haul explosives into combat zones. Sounds like foot dragging.

The main drawback I see is how easily you can defend against a light beam. Take a lightweight leaf of copper. As soon as an incoming beam heats the surface to a molten state you have an extremely efficient mirror, depending on frequency. So if laser weapons become popular, so will lightweight reflective clothing.

I don't think it'd work quite that way. More likely, the thin copper surface would vaporize before it'd have a chance to melt and get shiny.

fourdeuce82d
December 11, 2003, 10:36 AM
"Take a lightweight leaf of copper. As soon as an incoming beam heats the surface to a molten state you have an extremely efficient mirror, depending on frequency. So if laser weapons become popular, so will lightweight reflective clothing."

<p>
Depending on how wide/powerful the beam is, you might get something like an explosion, as the copper vaporizes violently...perhaps not a high-order explosion, more like a pressure cooker letting go, splattering molten copper hither and yon!

we'll have to wait and see.

benEzra
December 11, 2003, 01:13 PM
In one of the more recent "Bolo" books (based on Keith Laumer's original stories on that theme), there is a comment that high-powered beam weapons changed the nature of (future) warfare by making vertical envelopment no longer practical--anything light enough to fly could be easily taken out by a ground-based beam weapon as soon as it entered line of sight. Ground vehicles (e.g., really large tanks) again became dominant because they could carry far heavier armor, the most powerful direct- and indirect-fire weapons, and were not susceptible to long-range direct fire because of the curvature of the earth . . .

Interesting thought . . . I wonder if it will turn out that way. Aircraft are EXTREMELY susceptible to beam weapons compared to, say, a missile RV . . . or a tank . . .

P95Carry
December 11, 2003, 01:35 PM
Hmmm ...... I wonder ....... would the ''silvering'' on the back of mirror glass suffer if hit? Or would the humble mirror in fact be the ultimate protection?

Turn the beam back on the source!?

Penforhire
December 11, 2003, 02:43 PM
It's all about the % reflectance versus absorption at the specific weapon frequency. Some materials that reflect visible light extremely well are transparent to other light frequencies.

We'll just have to see the specifics because the writers who suggest an explosion at the first interface may be right. But I might also be right that a "patio misting" set-up could throw enough water vapor to absorb most of an attack...

benEzra
December 11, 2003, 03:10 PM
To successfully reflect a high-power laser beam, you have to have almost perfect reflectance at that wavelength (for military lasers, typically in the infrared). A typical beam power number I've seen kicked around for current chemical oxygen iodine lasers and deuterium fluoride lasers is 5 megawatts continuous power. That's 5 MILLION watts, or 5 million joules every second. If your mirror reflects only 90% of the light that hits it, your mirror is ABSORBING 500,000 joules of heat every second and will quickly melt.

Herk
December 11, 2003, 03:38 PM
What about all the hoopla of going back to the moon and building permanent structures? Would a moon based giant laser be a sort of death star? Can it reach that far? I know it's hit or miss as far as being aligned with the earth when you need it, etc, but still... could it work?

benEzra
December 12, 2003, 08:11 AM
Not really practical, since light intensity falls off roughly as the square of the distance to the source (not strictly true at very close ranges for a highly collimated source, but a good approximation at greater distances). Hence, a laser in orbit 100 miles away trumps a moon-based laser 240,000 miles away. Also, moon-based equipment would be vulnerable to ground-based lasers based on earth.

Alan Fud
December 12, 2003, 08:42 AM
" ... particle beams would be another story altogether ... "

What's the difference between a laser and a particle beam :confused:

benEzra
December 12, 2003, 09:10 AM
A high-power laser is a very, very, very intense beam of light. A particle beam is a stream of ions or subatomic particles (i.e., electrons, protons) moving at extremely high speeds (e.g., millions of miles per hour, or a major fraction of the speed of light). So a particle beam is a high-speed stream of matter, whereas a laser beam is not.

BTW, here are some photos of one high-energy laser in development, the Tactical High-Energy Laser (THEL):

http://www.st.northropgrumman.com/mediacenter/page.cfm?PageID=5508&SiteSectionID=0
http://www.st.northropgrumman.com/mediacenter/page.cfm?PageID=5509&SiteSectionID=0

The Airborne Laser aircraft (which may be designated AL-1A):
http://www.airbornelaser.com

iapetus
December 12, 2003, 02:24 PM
I heard about a "non lethal" laser weapon that was being developed or proposed (no link, unfortunately).

The idea was that when the beam hits someone, it vapourised the top milimeter or so of clothing/ skin etc. This expands rapidly and explosively, creating a long bang and knocking the target over.

I think the expanding gasses also interfered/ blocked the beam, preventing any deeper penetration. So this could be a problem for non-non-lethal lasers.


Also, if the mirror "armour" on your troops or tanks etc absords 10% of the laser and melts, that still means there's 90% of the laser reflected back at whoever fired it (or his buddy, or the bridge he's trying to secure, etc), so could be too much hassle for normal military use.

Could be good for sniping, though (if you could make one small enough). No recoil, instant-hit, perfect straight trajectory, no bullets blown of course by wind, etc.


Iapetus

fiVe
December 12, 2003, 03:30 PM
So, hypothetically, we could one day (maybe) be debating who makes the best laser--Surefire or Maglite?

CMcDermott
December 12, 2003, 04:25 PM
benEzra - the coherant nature of a laser means that it's power doesn't fall off porportionally to the square of the distance - the light stays together and spreads very little so it retains all of it's energy. On the moon, in orbit or on the next ridge over, the same laser would deliver the same amount of energy (except for what the atmosphere absorbs/reflects etc) to the target. A much bigger problem for a moon based laser would be getting it aimed precisely enough to be sure of what it was going to hit 400,000 kilometers away. Thats roughly 0.0000005 minutes of angle for an 8 inch target zone at that distance,

I can see a laser CIWS type system for ships, and a version for vehicles to protect against missles and shells. But you will still need the current bullet ammo systems for use in fog, rain, snow, dust/sand storms etc where the laser becomes useless. Current smoke screens wouldn't greatly reduce the laser since it works in the infrared region of light, and that goes through todays smokescreens fairly well. Of course the camaflauge people are already working on smoke that is opaque to infrared to hide from todays infrared goggles - and this new type of smokescreen will work against infra-red lasers as well.

HankB
December 12, 2003, 07:51 PM
if the mirror "armour" on your troops or tanks etc absords 10% of the laser and melts, that still means there's 90% of the laser reflected back at whoever fired it Angle of reflection = angle of incidence, so unless the reflective surface is perfectly normal to the input beam the reflected ray will go off in some random direction. The way around this is to use some sort of retroreflector, such as a cube corner mirror or prism array. Of course, such an array wouldn't make for good camouflage . . . Would a moon based giant laser be a sort of death star? Can it reach that far? In principle, yes. The problem is, for maximum effectiveness, you want the beam waist at the target - that produces maximum energy density. Now, single mode lasers (the kind you want, for minimum beam spread) are basically gaussian beams, so if you want a small beam waist down around the Earth or in low earth orbit, you need a really BIG aperture on the moon, along with the appropriate beam-shaping optics. This is actually pretty easy to compute, not so easy to fabricate.

Aiming at a moving target on earth from the moon will be difficult - the time between observation, firing, and verification of a hit (or miss) would be around four seconds, even with things moving at the speed of light.

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