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  (Source: Atomic Gator)
Goal is to reach a 50 KW blast sustainable for 2 minutes

Currently, U.S. Marine Corps' Humvees or trucks typically pack a light, mounted machine gun.  While good against ground based troops, that weapon is in danger of becoming obsolete in this era of modern drone based warfare.

I.  Navy's New Laser Project Takes Aim at Land-borne UAVs

Whether its captured U.S. drones that fall into the wrong hands or home-grown varieties under development in hostile nations like Iran, the Pentagon is concerned that UAVs may be used in future conflicts to spy on or attack U.S. troops.

Its current plan is to counter drones with high-energy lasers.  The U.S. Navy's Office of Naval Research has published details about its plan to award up to $400,000 for contracts to build a so-called "Ground-Based Air Defense Directed Energy on the Move" (GBAD-DE-OTM).

Lengthy name aside, the vehicle is basically an anti-UAV laser war wagon.  The goal is to build it up from pre-existing vehicles like military trucks or Humvees.  The ONR has ambitious plans for the power of the laser and duration of the blast.

The laser will replace the M60 (currently being phased out), M240G, or similar mounted projectile cannons.  The Navy's laser efforts are reportedly ahead of schedule, which is a bit of surprise given their ambitious goals.

II. From 2.5 kw Towards Megawatt "Superlasers"

Early efforts involved 2.5 kw trailer-mounted lasers being used by the U.S. Air Force to shoot down lightly armored UAVs.  A 2009 test at the Naval Air Warfare Center, China Lake, Calif. saw five successful kills.  The U.S. Navy has since fielded a more powerful 15 kw laser at sea, which can cut through 20 ft of steel per second.

The seaborne laser is used in the Navy's laser weapons system (LaWS), which is an upgrade to the projectile based MK 15 Close In Weapon System (CIWS), a.k.a. the Phalanx gun, a radar-guided autocannon.  Raytheon Comp. (RTN) is looking to replace current projectile Phalanx autocannons with either missile or laser-based varieties.


The Navy is also working with another defense contractor -- Northrop Grumman Corp. (NOC) -- on the boxy Maritime Laser Demonstrator (MLD), which is meant to target ships.  Several prototypes have been delivered, bumping the beam power, and the laser successfully braved choppy surf to sink a lightly armored boat target.  

MLD system
The Navy will field the MLD at sea on an active surface vessel for the first time later this year.
[Image Source: US Navy]

The $98M USD MLD project's goal for the next several years is to reach 100 kw using advanced solid-state lasers, then bump the power to megawatt-class designs with electron-injection lasers.  The Navy expects electron-injections lasers to be ready by the 2020s; a megawatt beam could theoretically damage enemy cruisers and other armored vessels.

III. Navy Wants 50 kw Laser War Wagon

On land, the Navy wants its wagon laser to weigh less than 2,500 lb and achieve a "minimum" 25 kw beam strength, capable of shooting down modestly armored enemy UAVs.  The long-term goal is to sustain a 50 kw blast for 2 minutes with optics capable of adjusting to "all environmental conditions" (humidity, smoke, etc.).  The beam is also expected to have a fast turn-around time -- ""a 20 minute recharge to 80% of total capacity (power and thermal)."

To get there the Navy will need to carry a lot of batteries and/or powerful chemical charges, likely.

The Navy solicitation does not constrain the users to the type of laser used.  That leaves two primary possibilities [PDF].  Modern fiber-lasers are typically around 25 percent efficient at converting DC current to light.  Thus a 50 kw, 2 minute blast would require over 6 kw-hours of juice -- or roughly 10 car batteries worth of power (car batteries are typically around 1.2 kw-hour theoretical capacity, 50% efficient in the real world).  However, fiber lasers are bulky so may not be applicable to a vehicle setting.  Chemical lasers (aka "solid state lasers") are perhaps a more likely possibility, but are expensive on a per-shot basis.

The biggest problem will likely be the cooling.  The Navy's seaborne 15 kw lasers already need heavy advanced cooling systems.  That will suck down yet more power, while increasing the system size and weight.

III. Laser Weapons Have Their Advantages

It's hard to say just how soon the GBAD-DE-OTM laser wagon will hit the battlefield, but it appears to be top objective for the Navy and the Marines, as military rivals like Iran race to develop war-ready UAVs.

The Navy does plan to deploy a seaborne laser aboard the U.S.S. Ponce later this year, according to Rear Adm. Matthew Klunder, the Navy’s chief of research.  The deployment will be the first time a laser weapon is actually tested on a mobile navel vessel -- the MLD test attack on the ship was performed by a weapon mounted to the stationary decommissioned destroyer USS Paul Foster, albeit performed at sea.

USS Ponce
The U.S.S. Ponce [Image Source: US Navy]

While expensive, finicky, and hard to reload, and constrained by line of sight, laser weapons do have some unique advantages.  On the ground they remove the friendly fire danger of a "shower" of unexploded rounds that miss the target and hit the ground, detonating. They also are faster allowing them to target fast moving targets like UAVs with precision strikes.

Nevin Carr, a retired two-star admiral and former head of the ONR, describes to Wired, "It’s a good capability for softer targets like UAVs [unmanned aerial vehicles] and boghammers — small, fast-swarming boats."

He says the costs may eventually become an advantage, given that the laser is powered by generated electricity.  He describes, "In a sense, it’s more economical — but more than just theoretically economical, it’s a way to have deeper magazines, because your fuel tanks become your mags. “Now that refueling becomes rearming, it changes the logistics trail.  Think of all the ships that carry weapons."

In addition to ground-vehicle and ship mounted lasers, the U.S. Air Force is also testing out airborne lasers.  The armed forces are also looking towards a variety of other future weapons like a locust-like swarm of small autonomous killing robotslightning gunsmicrowave Humvee cannons, and the ever-popular rail guns.

Sources: U.S. Navy via FBO, Wired, FAS



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expensive
By Jeffk464 on 3/29/2013 5:37:02 PM , Rating: 5
quote:
While expensive, finicky, and hard to reload, and constrained by line of sight, laser weapons do have some unique advantages.


Pretty sure the expensive part is one of the advantage. No doubt some well connected defense contractor will make a ton of money.




RE: expensive
By Jeffk464 on 3/29/2013 5:38:59 PM , Rating: 1
Isn't the easiest way to shoot one of these things down with an off the shelf stinger missile? Or here's a concept, use an f15 that's already up flying fighter cap.


RE: expensive
By Solandri on 3/29/2013 9:02:24 PM , Rating: 2
Stingers have a range of about 3 miles and a ceiling of about 25,000 feet. And that's if it fires straight up. If it flies diagonally, both the range and altitude ceiling are reduced considerably. (That's what killed the stinger missile theory for TWA flight 800.)

While an F15 would probably be easier today, I think the point here is to research the technology for broader future use.


RE: expensive
By Jeffk464 on 3/29/2013 11:32:34 PM , Rating: 2
Yeah I got thinking it might be for the extremely small spotter UAV's instead of something like the predator. But then you don't need that powerful of a laser.


RE: expensive
By Jeffk464 on 3/29/2013 11:34:03 PM , Rating: 1
Predators fly slow and at like 10,000 they should be really easy to knock down.


RE: expensive
By Ramtech on 3/30/2013 5:09:48 PM , Rating: 2
True but lasers are nearly useless in aerosol(weather,aerosol dispensers) also ablative coating can reduce UAV vulnerability to lasers


RE: expensive
By half_duplex on 3/31/2013 6:24:30 PM , Rating: 2
You mean if the UAV were coated with left over NASA space tile?


RE: expensive
By Gondor on 4/2/2013 10:58:53 AM , Rating: 2
They could be coated with anything that that has high solid-to-vapor transition energy and doesn't weigh much. Energy of the beam would be dissipated by the ablative armor, which would protect the drone until it is completely removed (in one spot, this is assuming laser can target same spot all the time while the drone is moving).


RE: expensive
By ShieTar on 4/5/2013 4:10:32 AM , Rating: 2
Even more trivially, if you know the enemies laser wavelength, a drone with a decent mirror coating can pretty much reflect 99.5% of the incoming laser beam and go on unharmed.

Lasers in Warfare have been a running joke since Reagan brought up his Star-Wars Ideas, I guess now finally some generals and engineers came into relevant positions who did not get the joke and take it seriously.


RE: expensive
By MrBlastman on 4/1/2013 2:34:55 PM , Rating: 2
Whoa, good luck seeing a MANPAD, especially a 2nd/3rd generation one like a Stinger breaking 25k feet. The general rule of thumb is 13k (feet) max altitude for most MANPADs being effective. They just don't possess enough energy beyond that to maneuver/hit anything due to gravity. Remember, the chemical motors burn for a very short time.

Now, I'd say it is plausible a UAV might be hit at the outer edge of this envelope but a fast-mover, provided the pilot is dumping flares during his brief dip to low altitude, has sufficient speed (500+ knots) and is pulling back up or begginning to while minimizing airspeed loss--well, the odds are pretty low they're going to be hit. Violate 8k feet and you're just asking for serious trouble.

There are some newer ones that can go a bit higher but their maneuverability envelope is limited.


Collateral damage?
By chmilz on 3/29/2013 10:10:11 PM , Rating: 2
With lasers cutting through materials so fast, what kind of collateral damage can we expect from future laser-based weaponry? If the laser operator is poorly trained or over-estimates the shot needed, isn't there significant risk it could cut through the target and wreak havoc on whatever is behind it?

Consider my question in an urban setting full of civilians. Also keep in mind I said future, as laser weaponry becomes more ubiquitous.




RE: Collateral damage?
By StormyKnight on 3/29/2013 11:31:32 PM , Rating: 3
No different than ballistic weapons that have ranges from 25 yards to 250 miles.


RE: Collateral damage?
By Jeffk464 on 3/29/2013 11:35:19 PM , Rating: 3
Yup, it would be embarrassing to accidentally destroy the international space station.


RE: Collateral damage?
By FaaR on 3/30/2013 5:33:51 AM , Rating: 2
Biggest risk of collateral damage is blindness, I would think. 50kW lasers would annihilate every retina in sight if fired in an urban setting, not to mention what havoc even more powerful megawatt-class lasers would wreak...


RE: Collateral damage?
By MrBlastman on 4/1/2013 2:36:34 PM , Rating: 2
d00d, they might turn the moon into Swiss cheese!

(wait, isn't it already a variation of muenster or did we inject a compound into it during the Apollo missions turning it into American Cheddar?)


M60 Cannon?
By Mozee on 3/29/2013 4:19:38 PM , Rating: 3
Now those that have served please correct me, but that picture of the "M60 Cannon" mounted on a Humvee looks an awful lot like the Mk. 19 40mm Grenade Launcher to me.

You may want to double check your sources next time, considering an M60 is much smaller, fires a 7.62mm round (.30 caliber) and has a butt-stock so you can fire it from your shoulder.




RE: M60 Cannon?
By stm1185 on 3/29/2013 6:29:11 PM , Rating: 2
Yeah the author needs to play some more CoD and BF. Clearly not an M60.


RE: M60 Cannon?
By kypd275 on 3/29/2013 7:12:00 PM , Rating: 2
Yes, that is indeed the Mk. 19, the M60 for the most part has been replaced by M240s for general use.


RE: M60 Cannon?
By kypd275 on 3/29/2013 7:15:46 PM , Rating: 2
also, I find it amusing that the article seems to imply that the laser would be something that would replace the machine guns, when it would be rather useless against anything other than those drones, I doubt the laser turret will be able to lay down suppressive fires.


I doubt that
By bug77 on 3/30/2013 10:31:19 AM , Rating: 4
quote:
The U.S. Navy has since fielded a more powerful 15 kw laser at sea, which can cut through 20 ft of steel per second.


6m of steel per second? With only 15kW? I doubt you can concentrate the beam enough even under lab conditions.




RE: I doubt that
By Integral9 on 4/1/2013 11:41:46 AM , Rating: 2
Does sound a bit low, but I'm sure the Navy is holding back. Do you know how many watts it does take to melt through steel of a given thickness in 1 second?


RE: I doubt that
By Iuconnu on 4/3/2013 5:13:47 AM , Rating: 2
Assuming:
- 2mm diameter vaporization.
- minimal heat bleed into surrounding structure
- properties of steel are similar to iron

Mass of 1m x 2mm diameter steel rod, m = ~0.025kg
Specific heat of iron, Cv = 450 J/kg/K
Heat of melting or iron, Lm = 240 kJ/kg
Heat of vaporization of iron, Lv = 6 MJ/kg
Vaporization temperature of iron, Tv = 3133 K
Starting temperature of iron, Ti = 300 K

Power required to vaporize 0.025kg of iron in 1 second:

P = (Tv - Ti)*m*Cv + m*Lm + m*Lv
= 32 kW (heat up) + 6 kW (melt) + 153 kW
= 191 kW

For 1m/s. For 20 m/s, just multiply, i.e. ~ 3.8 MW.

Of course there will be losses, but it looks like it is actually doable provided the beam focus is tight. For comparison, a vaporization tunnel 1cm in diameter will require 25 times more energy.


dude
By Bubbacub on 3/30/2013 6:17:45 AM , Rating: 5
"Chemical lasers (aka "solid state lasers") are perhaps a more likely possibility"

chemical lasers are not AKA solid state lasers. a chemical laser uses the energy from a chemical reaction to generate the beam.

a solid state laser uses laser pumping of a gain medium to produce a beam - the pumping can come from a lamp or even an array of laser diodes - the energy going in is basically electrical.

also a fibre laser is a type of solid state laser - the optical fibre forming the role of the gain medium.

that whole section describing different laser technologies is wrong and needs a bit of rewrite.

sorry.

seriously if you don't know that much about a topic then don't post on it or ask a colleague who does know about it to write for you.

or read a wikipedia article before you do - it only took me 2 minutes after i realised something was wrong with the article and i'm not an engineer.




RE: dude
By chemist1 on 3/31/2013 1:23:34 AM , Rating: 2
Agreed -- it's disappointing to see how many basic technical errors are frequently present in articles written for DT that cover science and engineering -- errors that could be easily avoided if the writer just made the effort to do some basic background research before posting. The problem, simply put, is that the standards here are low.


How Do You Reload a Laser?
By DougF on 4/1/2013 9:09:32 AM , Rating: 2
I've read a lot on lasers, and I'm trying to figure what is meant by "tricky to reload"...help?




RE: How Do You Reload a Laser?
By DougF on 4/1/2013 9:10:24 AM , Rating: 2
Sorry, "...hard to reload"...


RE: How Do You Reload a Laser?
By Bubbacub on 4/2/2013 3:12:44 AM , Rating: 2
well i guess a chemical laser could run out of chemicals, a solid state laser could run of electricity (new batteries???)

its just another poorly worded ambiguous statement in a poor worded misleading article.


Star Wars
By lagomorpha on 3/30/2013 7:03:19 AM , Rating: 2
quote:
The Navy expects electron-injections lasers to be ready by the 2020s; a megawatt beam could theoretically damage enemy cruisers and other armored vessels.


So how long before the US shreds a few treaties and puts satellite lasers into space capable of destroying ballistic missiles before they can launch?

Something like that would spread egg on the face of a few North Koreans...




RE: Star Wars
By FaaR on 3/30/2013 7:14:47 AM , Rating: 2
Lasers in space shooting at targets on the surface of the earth would have huge problems penetrating the earth's thick atmosphere, especially through cloud cover, precipitation and so on. If you wanted to shoot at ballistic missiles it would be far easier to do so when the missile is near the edge or has left the atmosphere.

If you want to target infrastructure from space, kinetic penetrators would probably make more sense.


By 91TTZ on 4/1/2013 2:57:29 PM , Rating: 2
I'd like to see an example where the drone is painted white so it can reflect more of the energy.




By ShieTar on 4/5/2013 4:20:05 AM , Rating: 2
Forget white paint, just let it loose on polished steel and see if it even leaves a scratch. And if the operator still has his eyesight afterwards.


The real question here is...
By Spookster on 4/1/2013 2:10:16 AM , Rating: 3
Can I heat up my MRE with it?




Val Kilmer
By jak3676 on 3/29/2013 4:16:15 PM , Rating: 2
Made it all the way through the article without one mention?




Lasers!
By Apone on 4/1/2013 11:46:28 PM , Rating: 2
"I want five megawatts by mid-May...."




By UncleSane on 4/3/2013 7:47:35 AM , Rating: 2
The writer (Jason Mick) needs to provide proof when he suggests that Iran is a hostile nation. -- Eg: Brainwashing-ly efficient media consumption has the desired effects of making the American populace believe that Iraq actually had 'non-existent' weapons of mass destruction. -- The only hostile nations of any consequence by a very large majority in recent history is the USA (Zionist puppet) & Isarael.




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