Record-Breaking Laser Burns Through 200 Feet of Steel per Second

[Bren]

http://www.foxnews.com/scitech/2011/02/18/navy-breaks-world-record-futuristic-laser-getting-real

[ANS Kamas P81]

Considering your average USN ship, say a Tico or a Burke, the size constraint isn't anything all that significant.  You only need to get it to fit in a volume roughly equivalent to a good-sized house, for a laser-based air-defense ship.  Of course, range, blooming, and other such is a major consideration, but if you're putting enough energy through the thing that you can kill the target before the destabilized air can distort your beam then you're good to go.  High-energy low-discharge-time pulse system would work the best, and considering most missiles and aircraft tend to be remarkably thin-skinned well...cutting through three inches of steel in a 1/800 of a second pulse should do the job nicely.

One wonders what this might do for ship construction, though.  Cut prop shafts in one pass?  Or run enough of a beam splitter that you can laser-cut a bulkhead or hull plate almost instantly...think of something like a giant CNC cutter, and scale way the hell up.

[Winterborn]

Could this be the prototype for Mech based DE weapons, or what started it all.

[Peter Smith]

Cut prop shafts in one pass?

You comment about bloom, then propose cutting through a target that's below water? ;)

[Stormlion1]

I wonder what this will do for shore bombardment?

[Jackmc]

You comment about bloom, then propose cutting through a target that's below water? ;)

That's such an obtuse viewpoint that it has to be post-whoring.  Not that I have room to talk!   ;D

-Jackmc

[Taurevanime]

I wonder what this will do for shore bombardment?

Nothing. Lasers tend to travel in straight lines. Unless you can use a high enough gravity well to curve it. So unless the ship has direct line of sight to it from the weapon system, then it won't be able to shoot it.
The main focus for weaponised laser systems now is for anti-aircraft and anti-missile systems. Since those might be flying high the possible engagement range is a lot longer.
It won't have an unlimited range though. Beam divergence will occur and will do so a lot quicker depending on enviromental conditions. But even if this thing only has an effective range of a kilometer, that is still enough for use as a close in weapons system. (Think Laser AMS)

[ANS Kamas P81]

You comment about bloom, then propose cutting through a target that's below water? ;)

You saw the two words just before that sentence, right...?  ???

[Peter Smith]

I did. From my read it looked like you were assuming the ships are built in a manner than the shafts are facing the open seas and are exposed. I can't think of many shipyards that are even exposed in that manner (most tend to be inland a bit to save themselves from direct exposure), nor can I think of many ships of note that are not built in an enclosed drydock.

Now couple these facts with the size of ship required to even house such a laser and I think you'll find that the risk of an enemy ship rushing up to a shipyard and cutting the shafts off of ships in for service is rather low on the scale.

[ANS Kamas P81]

...I wasn't talking about using it in combat in that manner at all.  SHIP CONSTRUCTION.  As in get yourself a nice big chunk of steel and instead of taking days to cast, lathe, and weld it down like they do for current prop shafts, line it up lengthwise and just make a clean circular cut with the laser.  Noone said anything about attacking prop shafts or construction facilities or enemy ships; I'm talking about making things.

[cray]

I don't see where the "200 feet of steel per second" value came from. I mean, the target of this system - due in the 2020s - is a 1-megawatt laser, while this is only a fraction of that (not knowing the amperage behind the 500 kilovolt operation I couldn't say).

1 megawatt is not a lot of energy to be melting large targets.

The Boeing Airborne Laser is a 1MW unit that needs several seconds of dwell time to break up a lightweight liquid-fueled ballistic missile (i.e., Scud). It wouldn't take a lot of ablative material to protect a seaskimming missile for a few seconds against the laser (its optical sensors are another matter). It takes quite a bit of time to carve up steel with 1 megawatt.

I wonder if they got the 200 feet from a welding/cutting website that talked about, like, a 1-megawatt torch being able to cut or weld 200 linear feet of steel sheet per second.

Regarding shore bombardment:

If you put the emitter turret high on a ship's mast, then you can get a decent range. About 11 miles for a 100-foot mast. I'd expect the greater limitation would be trying to get the beam to bull through all the atmospheric crap near sea level. The laser, though, would primarily only be useful against soft targets. You might dazzle a tank, but it's only going to be moderately irritated about its scorched paint.

[Solarmech]

I don't see where the "200 feet of steel per second" value came from. I mean, the target of this system - due in the 2020s - is a 1-megawatt laser, while this is only a fraction of that (not knowing the amperage behind the 500 kilovolt operation I couldn't say).

It's FOX News. Facts don't matter! (Joke!)

If you put the emitter turret high on a ship's mast, then you can get a decent range. About 11 miles for a 100-foot mast. I'd expect the greater limitation would be trying to get the beam to bull through all the atmospheric crap near sea level. The laser, though, would primarily only be useful against soft targets. You might dazzle a tank, but it's only going to be moderately irritated about its scorched paint.

Lasers on whips not so good for hitting land targets. That's what the rail guns are for. But if did hit a tank, you could disable some of it's sensors (degrading capabiliites) or damage the barrel. Tank is still alive, but useless. sm

[Peter Smith]

...I wasn't talking about using it in combat in that manner at all.  SHIP CONSTRUCTION.  As in get yourself a nice big chunk of steel and instead of taking days to cast, lathe, and weld it down like they do for current prop shafts, line it up lengthwise and just make a clean circular cut with the laser.

If it were just a matter of speed then you would see molds being cast and molten metal poured in, like an engine block. No, prop shafts are extremely balanced, very precise machined pieces of equipment. One of the reasons for slowness in the process is to let things cool down, that's why the process is what it is.

[cray]

Lasers on whips not so good for hitting land targets.

And, yet, ships have been putting optics high on their masts for a century. The problem of stable optics is solvable.

or damage the barrel.

I doubt it.

[Jackmc]

And, yet, ships have been putting optics high on their masts for a century. The problem of stable optics is solvable.

I used to point to the main guns on tanks to illustrate that but heck even now your average camcorder seems to have built in gyro stabilization.  And if you can get 2 axis stabilization on a $300 piece of home electronics, do we even need to stop to ponder the possibility on a multi-million dollar piece of military hardware?

-Jackmc

[Nanaki]

I don't see where the "200 feet of steel per second" value came from. I mean, the target of this system - due in the 2020s - is a 1-megawatt laser, while this is only a fraction of that (not knowing the amperage behind the 500 kilovolt operation I couldn't say).

It is there, although the OP made a typo, it is 20 feet of steel per second, not 200.

saw scientists blast unprecedented levels of power into a prototype accelerator, producing a supercharged electron beam that can burn through 20 feet of steel per second.

[ANS Kamas P81]

Now that's a more reasonable level.  And yeah, as far as mounting the thing, a hundred feet at the top of a mast is pretty doable, for a final director of some kind (mount the emitter in the ship, and a mobile targeting mirror high as you can) - and yeah, you're still gonna be limited to soft targets.  Still, that includes missiles and aircraft, and an eleven mile radius of control means you get some great fleet protection.

I wonder if this might invite a return to naval gunfire, in a few decades?  Thick walled, mostly solid rounds that won't get popped in a half-second or three of interception...then again if that was the case against missiles then noone would use them either.

[cray]

It is there, although the OP made a typo, it is 20 feet of steel per second, not 200.

The news article does say 200fps. Even at 20fps it doesn't make sense unless you're welding/cutting sheet steel.

I wonder if this might invite a return to naval gunfire, in a few decades?  Thick walled, mostly solid rounds that won't get popped in a half-second or three of interception...then again if that was the case against missiles then noone would use them either.

You'd need a few more tens of megawatts to quickly burn down any shells or missiles. Ablative plastics provide enormous protection against heat.

[Solarmech]

And, yet, ships have been putting optics high on their masts for a century. The problem of stable optics is solvable.

I was not talking about stability/targeting issues, but effectivness issues. For example what would the laser due to bunker or a concentration of troops. Also at 11 miles, the range is greatly below what a WWII battleship could do much less the railgun is supposed to be able to do. sm 

[ANS Kamas P81]

That's 11 miles to the surface.  What about to an altitude of 30,000 feet, shooting across the horizon at something at that altitude?

[cray]

For example what would the laser due to bunker

Blind it.

or a concentration of troops.

Kill them. 1MW would make people into steaming chunky salsa. Or maim them pretty badly.

That's 11 miles to the surface.  What about to an altitude of 30,000 feet, shooting across the horizon at something at that altitude?

Potentially quite a bit further than 11 miles. The USAF's Airborne Laser is citing a range of hundreds of miles to airborne or space targets. The hard-to-predict limit of ground targets is how much beam strength you use lose to atmospheric absorption. Even if the beam can reach 100 miles from 30,000 feet, can it even cook a bag of popcorn at that range?

[Solarmech]

Blind it.

In other words, not much. 

Kill them. 1MW would make people into steaming chunky salsa. Or maim them pretty badly.

You take out one or two guys and the rest hunt cover. Not overly effective. sm

[Jackmc]

You take out one or two guys and the rest hunt cover. Not overly effective. sm

If the unit is hunkered down in cover, they are not a fighting force.  Sounds like a heck fo lot more than "not much" to me.

-Jackmc

[Scotty]

In other words, not much. 

You take out one or two guys and the rest hunt cover. Not overly effective. sm

Oh, just like with artillery, right?

[Solarmech]

If the unit is hunkered down in cover, they are not a fighting force.  Sounds like a heck fo lot more than "not much" to me.

-Jackmc

Oh, just like with artillery, right?

Wow. Those are really bad. The job of arty is not to keep the enemies head down, it's to destroy them. Destroy building, rip up tanks kill people, crater roads. Arty being used for suspression means that your fire is mostly ineffective (an expensive way to plow a field). Also there is a little thing called Line of Sight with lasers. In other words you will not be able to hit anyone on the other side of a hill, building or even a small grove of trees! A cheap WWII era 6 incher would be more effective by orders of magnatude over a ship born laser weapon for targeting land targets. sm

[cray]

Also there is a little thing called Line of Sight with lasers.

Much like artillery. Simple expediencies like fox holes interrupt lines of sight between bursting shells and soldiers.

The ability to point-and-zap with lasers can make them deadly in ways that artillery is not. Artillery has its advantages, but so do lasers.

[Solarmech]

Much like artillery. Simple expediencies like fox holes interrupt lines of sight between bursting shells and soldiers.

Have you ever heard of airburst rounds? A foxhole does little to protect you from attacks from above and airburst rounds have been in use for well over a century.

The ability to point-and-zap with lasers can make them deadly in ways that artillery is not. Artillery has its advantages, but so do lasers.

Your making this weapon into a multi million doller sniper rifle. There are a lot better uses for it. sm

[HobbesHurlbut]

Have you ever heard of airburst rounds? A foxhole does little to protect you from attacks from above and airburst rounds have been in use for well over a century.

Yet that's if the shell burst *directly over* the foxhole.

[Jackmc]

Have you ever heard of airburst rounds? A foxhole does little to protect you from attacks from above and airburst rounds have been in use for well over a century.

???  Virtually everyone I know who's been infantry says that the first thing you go after you dig your fox hole, time permitting, is to hollow an alcove in it to protect against such attacks.

-Jackmc

[Von Jankmon]

Weaponized lasers exist, or more fairly are developed in two different ways. This excludes range finding communications and targeting lasers. The first is what we read about here, shooting down missiles etc, the second more alarming use is for blinding people.  A laser beam can be used to sweep an area causing permanent retina damage to large numbers of people. The US has this technology, and it is believed the Soviets did also, it was successfully banned globally by pressure from the Red Cross in the early 90's.  The only nation believed to be still with an active blinding laser program is Israel.

Large missile defence lasers are a decent step forward, but remember that the age of the laser weapon is already here and has been for a while and it's pretty ugly tech.

[cray]

Have you ever heard of airburst rounds?

Yes. And when they burst directly over the fox hole, you've got a readymade kettle for the resulting chunky salsa. In the mean time, you've got a dandy shelter for all the airbursting rounds that did not explode overhead.

Your making this weapon into a multi million doller sniper rifle. There are a lot better uses for it. sm

I don't recall saying, "This weapon should be limited to shore bombardment."

[worktroll]

One thing to my mind that's being missed in all this is that you're not going to be mounting your laser on the tip of the mast. At best, it'll be an aiming mirror. That's sensible - you only expose a replacable component, and bury the actual lasing mechanism safely in the hull, and keep the bit that needs to move as small as possible (eg. easier to aim and stabilise). This has its own challenges - maintaining an optically clean surface (dirt on the mirror absorbs laser light, causing a small explosion), and probably cooling.

Question to sailors - I assume modern warships have optical sensors mounted around the place exposed to the weather. How often did they need to be cleaned, and did such lenses close to the waterline need more or less cleaning than sensors mounted on the mast? Feel free to answer in generalities if I'm touching on Top Sekrit stuff :)

W.

[cray]

One thing to my mind that's being missed in all this is that you're not going to be mounting your laser on the tip of the mast.

I did say, "If you put the emitter turret high on a ship's mast, then you can get a decent range," referring to a "simple" mirror like the ABL's turret (the laser is in the body of the aircraft, not the turret). However, I can see my statement could be construed to refer to the whole laser.

[worktroll]

Just knowing how fiddly the 90s Star Wars optical surfaces were, I do wonder how easily that'll translate into the field.

W.

[cray]

Desert Storm was a crash course in developing durable military optics. Too many helicopters and fighters had their optics sandblasted to garbage.

Coatings on laser mirrors might be another issue, but there's been steady advances in coating application.

[worktroll]

It'd be interesting to be able to find out the current state of the art. It's all down to the reflectivity - with 99.9% reflection, the mirror for a 5-megawatt laser has to manage 5,000 watts of heat without having the surface degrade.

And I've always wondered how much beam direction you could get by playing with Fresnel lenses. While the low material volume helps with avoiding energy loss, I just can't see how to cool them in any way which doesn't impact on the light path, alas. Where's that force field when I need it?

W.

[I am Belch II]

Thats some firepower.

[Demon55]

Sounds like a good weapon to have.  Spy satellite hunting anyone?

[Solarmech]

???  Virtually everyone I know who's been infantry says that the first thing you go after you dig your fox hole, time permitting, is to hollow an alcove in it to protect against such attacks.

Time permiting and soil conditions permiting. :(  Modern warfare is getting more and more mobile and weapons getting more accurate. If it stays still, it's highly vulnerable. There will always be a place for a foxhole, but it of limited use faceing a modern foe. Against more backwards foes it is of great use as they tend not to have so much heavy arty avaliable.

Yes. And when they burst directly over the fox hole, you've got a readymade kettle for the resulting chunky salsa. In the mean time, you've got a dandy shelter for all the airbursting rounds that did not explode overhead.

Unless you have the alcove mentioned above, you will find a foxhole is vulnerable than you think. You don't need to have the round go off  directly overhead in order to be hit. My estimation would be that at anything less than 40/45 degrees you can still get hit (depending on the dimensions of the foxhole).

I don't recall saying, "This weapon should be limited to shore bombardment."

I never claimed you did. All I am saying is that it is an ineffective and innapropriate for shore bombardment. sm

[cray]

More useful technical information than Fox provided.
http://www.wired.com/dangerroom/2011/02/unexpectedly-navys-superlaser-blasts-away-a-record/

First, it's cutting 20fps, not 200. I'm still not sure how they're gauging that, but they're also giving some handy wattage values that Fox skipped. The current version is way weaker than the chemical ABL, and the final version will still be 1/10th of the ABL (100kW vs. 1MW). Never mind shore bombardment with that.

[Von Jankmon]

First, it's cutting 20fps, not 200. I'm still not sure how they're gauging that, but they're also giving some handy wattage values that Fox skipped. The current version is way weaker than the chemical ABL, and the final version will still be 1/10th of the ABL (100kW vs. 1MW). Never mind shore bombardment with that.

The figures are probably accurate but rather misleading if informative nonetheless.  Stats like that could possiblty tell us more than the designers would want to let out.

I think 20 feet per second is the distance cored as if the weapon was able to be fired for a second. Its like Metalstorm the million rounds a minute gun, that might be its rate of fire, but it doesn't mean it could fire for a whole minute.

It sounds to me like you get a single very intense pulse from this laser measured in fractions of a second in duration unleashing all that energy at once for the desired effect. It's a single shot 'cannon', probably with a long reload time not a ray gun with a 'cutting beam' effect.  Its possible that its effect is subtle enough that unless you are watching a datascreen linked to the weapon or its power support you would be unaware that it had fired.

[OverKill]

So what you are saying is that I won't be mounting one of these on my Mazda 6 any time soon?

[Von Jankmon]

So what you are saying is that I won't be mounting one of these on my Mazda 6 any time soon?

What I am saying is that is has 'ammo' of some sort rather than a power plant and an on switch.