Boeing's Enormous Navy Laser Cannon 291
An anonymous reader writes "Boeing is working to build a huge, incredibly powerful, soon-to-be-seafaring laser for the US Navy. This free electron laser can produce light of any wavelength (ie, color) directly from an electron beam, and gets an energy boost from a superconducting particle accelerator. Once it's onboard ships, the laser could be used to shoot down cruise missiles and artillery shells."
Does it make (Score:3, Insightful)
Re:Wow! (Score:4, Insightful)
And still just as fresh as the day it was first memed.
Re:The laser (Score:4, Insightful)
Fire rapidly is key here. Time to first shot is pretty important, but time to second shot is even more important.
Too often in the prior generations of this device the time to subsequent shots was way too long. Because nobody attacks with only ONE anti-ship missile, and even gunnery sends more rounds down range than can be hit with a slow resetting laser. The power needed for this is enormous, it needs to be instantaneous and repeatable for long periods of time, especially if you intend to make good on your promise of shooting down artillery shells.
With a dispersed battery of HAND LOADED field artillery you can send down range on average 1.5 rounds per minute per gun or better. With 5 to 8 pieces to contend with, you better be prepared to absorb some hits while you skedaddle out of range.
Luckily, no navy has gun boats like those in the past:
From James Grace's "The Naval Battle of Guadalcanal", the Helena is described during its initial firing that night.
"Officially the Helena's fifteen six-inch guns fired at a rate of ten rounds per minute at rapid continuous fire, but the ship had reached seventeen. To Lieutenant Luehman, the shooting resembled fifteen fireflies converging on the same spot, or fifteen streams of liquid fire."
Re:The laser (Score:4, Insightful)
Erm. Both your claims cannot have been made by anyone who has had any real contact with ship based weapons. First, in measure of rapid fire, kinetic guns absolutely destroy everything else. One of the main advantages of the anti air gatling CIWS is that it puts up a wall of small projectiles, which can be tracked by radar, which can auto-correct direction of the stream based on target's relative location to the stream. Which can then retarget near-instantly as kinetic gun turret is also light.
Energy is another huge problem on modern ships. Zumwalt-class was long considered for a nuke to power it because gas-turbines are simple not powerful enough to feed a modern AEGIS destroyer/cruiser anymore. Modern fire control radar going on full power trying to burn through interference generated by the target consumes several tens of percent of total ship power output nowadays - this is something you can find on navy's own website (.mil), sourced to their generals. I linked one such source when this topic came on slashdot before. Energy is in EXTREMELY short supply on a non-nuclear powered ship in a combat situation.
And sure, laser can fire for long distance in many conditions. It just won't hit anything meaningful in heavy rain or fog, or even if it does, it will cause minor burns to biological unshielded targets at worst. Good thing it never rains and is never foggy above large masses or water. Even better that there are never large temperature changes over the ocean surfaces causing various optical distortions. Nosiree!
Re:umm... reflection (Score:5, Insightful)
It's difficult to make a reflective coating that reflects well enough at a broad range of frequencies. The mirrors in the laser usually only work that well at one frequency, and they have cooling systems built into them. They also aren't moving, don't have weight limitations and don't have to deal with weathering and dirt.
It's also hard to make a reflective coating that reflects well enough in all directions that the laser can hit from. Your missile has to be able to home in some way. If you have IR windows for a seeker, that's an area that isn't very reflective.
You just have to get a tiny area burnt through and then the energy from the laser will heat what's behind it so much that it'll blow the rest of the coating off or mechanically disrupt whatever the coating is on.
It can help. A little. And it adds weight and problems to the missile. It's been looked at for some time and found not to be a cure all by any means. It sounds like a good idea, but turns out to not be terribly practical.
Same for the old idea of spinning an incoming missile to distribute the energy. That one is about like pirouetting in front of a shotgun. The energy comes in way faster than a mechanical movement.
Re:The laser (Score:4, Insightful)