Navy just 4 years away from laser cannon


From Wired:

The dream of sailors, nerds and sailor-nerds everywhere is on the verge of coming true, senior Navy technologists swear.  Within four years, they claim they’ll have a working prototype of a laser cannon, ready to place aboard a ship. And they’re just months away from inviting defense contractors to bid on a contract to build it for them.

“Subsonic cruise missiles, aircraft, fast-moving boats, unmanned aerial vehicles” — Mike Deitchman, who oversees future weapons development for the Office of Naval Research, promises Danger Room that the Navy laser cannons just over the horizon will target them all.

Or they will be, if ONR’s plans work out as promised — not exactly a strong suit of proposed laser weapons over the decades. (Note the decided lack of blast at your side.) First step in reaching this raygun reality: Finish up the paperwork. “The contract will probably have options go through four years, but depending on which laser source the vendors pick, we may be able to demo something after two years,” says Roger McGiness, who works on laser tech for Deitchman. “Our hope afterwards is to move to acquisition.”

Translated from the bureaucrat: After the Office of Naval Research can prove the prototype works, it’ll recommend the Navy start buying the laser guns. That process will begin in “30 to 60 days,” adds Deitchman, when his directorate invites industry representatives for an informal idea session. Deitchman and McGiness plan on putting a contract out for the prototype “by the end of the year.”…

From a technological perspective, the Navy thinks maritime laser weapons finally represent a proven, mature technology. The key point came last April, when the Navy put a test laser firing a (relatively weak) 15-kilowatt beam aboard a decommissioned destroyer. Never before had a laser cannon at sea disabled an enemy vessel. But the Martime Laser Demonstrator cut through choppy California waters, an overcast sky and salty sea air to burn through the outboard engine of a moving motorboat a mile away.  (Read more)

I thought we’d posted the test video, from last year, but if not:

Hum…. wonder if these will fit on the LCS?

I hear the first deployment is slated for the USS Alan Parsons….

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8 Comments

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8 responses to “Navy just 4 years away from laser cannon

  1. Jeff Gauch

    It looks like it took ~10 seconds to disable one engine, and the better part of a minute to disable the boat. How long would it take a CIWS to disable a small boat?

    When it comes to getting energy downrange I’m not sure a laser has anything on a 20mm Vulcan. At the ranges we’re talking about I don’t think the difference in travel time is significant. I also have concerns about the loads we’re planning on putting on the electrical system, most of our capital ships aren’t designed to move that many electrons around that quickly.

    • Somewhere in the archives here is video of a Block1B shooting at target skiffs. I say “shooting at” rather than “hitting” for a reason. The rounds went ALL over the place. I was appalled. I understand that a pitching, rolling, heaving mount shooting at a pitching rolling, yawing, heaving target is a tough fire control solution, but a LOT of the bursts weren’t even close. If things haven’t improved from that, small boats look like a far more deadly opponent than I’d first figured. You need to be able to service a series of targets quickly. And it’s no guarantee that one round will be even a mission kill.

      But your point on the efficacy of the laser mount is true. Indeed, if a Phalanx had that much trouble staying on target, won’t a laser have the same issue?

    • LT Rusty

      I’ve seen a LOT of CIWS shoots at sea. I’ve seen absolutely zero CIWS HITS at sea. You’re lucky if that POS can hit the water, let alone an incoming missile.

  2. Grumpy

    Bad time to be the central focus of attention, ya think?

    Brad, for something like this, do you think it might easier to make this thing, helmet controlled? You are shooting a beam of light not a projectile.

  3. Jeff Gauch

    OK, just for fun I did the math. (What? Don’t judge me.) I got all my starting numbers from Wikipedia.

    The CIWS has a maximum range of 2.2 miles. A laser’s range is going to be strongly determined by the weather, but let’s assume it’s the same. We’ll also assume the laser is mounted on the same block 1B mount. I’m also going to ignore any delays in the actual targeting software (I’m sure they’re classified and I don’t want to give the Russian, Chinese, and Iranian spies who certainly read this any help) and focus only on the physical capabilities of the mount. The bullets would take around 4 seconds to arrive on target. The laser is, near as makes no difference, instantaneous.

    To dodge the CIWS at maximum range a 20′ target would have to accelerate at 0.03g across the ship’s field of view after the bullet had been fired. To dodge the laser the target would have to move at more than 4 miles per second. How much more would depend on how much energy the laser was able to deposit at that range and how big the target was, but I don’t think it really matters at this point.

    Now, if you look at the math something interesting pops up. The speed needed to dodge the laser falls off linearly with range, but we’re starting from Mach 15 so who cares. The acceleration needed to dodge a bullet, however, is inversely proportional to the square of the range. Add in the fact that CIWS is throwing out around 250MW at the muzzle and I conclude the CIWS is much better close in (duh!).

    So I’m not sure a laser would be a good replacement for CIWS, but it might make an acceptable compliment/replacement for the RAM. It would also be useful in the C-RAM role to eliminate hot chunks of tungsten falling on the locals.

    • LT Rusty

      How do you figure CIWS is putting out 250 MW at the muzzle? I make it something closer to 54 kJ, which works out to 54 kW/s.

      Now, that said, in terms of being able to deliver that amount of power in terms of hundredths of a second … in order to do that with a laser, you’re going to need to be pumping out something like 540 kW/s, but you’re also going to have attenuation, scatter, etc., and in order to deliver that at a range of 4000 yards … it’s going to be a mess. It wouldn’t surprise me if you’d need a dedicated 9140 just for your laser CIWS. A full 2500 kW input, maybe more. That’s a third of a DDG’s power output for a single CIWS mount. That’s going to make it a little difficult to run your illuminators and AEGIS at the same time as you’re conducting a defensive engagement …

    • Jeff Gauch

      It’s 54kJ per bullet x 75 bullets/sec = 4MJ/sec = 4MW. That’s what I get for doing math in my head. I had initially used 50kJ and 50 rnds/sec, and somehow threw in a couple of extra zeros.

      Your argument was what I was referring to when I mentioned energy downrange. From what I can tell laser weapons seem to be on the order of 100MW, so they can probably get a comparable amount of energy to the target. Of course, actually depositing that energy in the target is a whole other kettle of fish.

      The electric plant is definitely going to be the limiting factor for these energy weapons. I know the Fords are being built with a 13KV electric plant to support EMALS and energy weapons, but I doubt there are plans to refit existing ships. Maybe we could put them in LCS if we crammed an S9G plant into a mission module.

  4. shipfitter

    I was working on FFGs back in the early 80s and sailors told me the CIWs was known as the “Hail Mary” gun…and the 76mm wasn’t much worse

    The difference between the CIWS and this little laser is one round of 20mm depleted uranium is going to mission kill that engine first hit. And why in the world would they piss away 30 grand worth of outboards? Didn’t we use to use a towed target at one time? Stupid….