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Navy's New Laser Weapon: Hype Or Reality?
Lasrick writes: MIT's Subrata Ghoshroy deconstructs the Navy's recent claim of successful testing with the Laser Weapon System. It seems the test videos released to the press in December were nothing more than a dog-and-pony show with scaled-down expectations so as to appear successful: "When they couldn't get a laser lightweight enough to fit on a ship while still being powerful enough to burn through the metal skin of an incoming nuclear missile, they simply changed their goal to something akin to puncturing the side of an Iranian rubber dinghy." Ghoshroy is an entertaining writer and an old hand in the laser research industry. He gives a explanation here of the history of laser weapons, and how the search for combat-ready tech continues: 'At the end of the day, good beam quality and good SWAP—size, weight and power—still determine the success or failure of a given laser weapon, and we're just not anywhere near meeting all those requirements simultaneously.'
Professor Hathaway was apparently foiled again
I don't think the goal has changed, only the writer of the article is saying that. This test is basically a status report, which tells us they still have a long way to go. The real question is how much $$ and effort should they keep putting in?
But I will settle for space lasers.
Your mirror would cease to be a mirror in very short order by either sheer ablation or the formation of oxides, reducing its ability to reflect, causing the absorption of more energy, at which point your mirror ablates. HTH.
No mirror is 100% reflective; a fraction of light energy is absorbed by the material making up the mirror. The reflective portion of a mirror is a metal film. A high-energy laser will overcome its reflective properties and burn the metal film. There are metals (like beryllium) that will reflect up to 98% of light energy, but the cost to cover an entire vehicle or structure in thick enough beryllium to negate the effects of the laser would be stupendous (and you would have to cover everything; lasers are intended to be surgical weapons; an operator would strike un-mirrored targets when possible, assuming mirror armor becomes a real thing).
The power to destroy an Iranian rubber dinghy is insignificant next to the power of the Force.
LaWS is rather unique. Its just a proof of concept test to see if what they will encounter when they put a laser weapon on a ship operationally. This is a step past what they are doing with the X-47b. However, there are no 'X Planes' for lasers, really. LaWS ought to be viewed from that POV. OTOH, HELLADS is a step or two (or more) further along the technology curve than LaWS. Under current Pentagon procurement law, we'll have a laser weapon for ships and/or aircraft by 2020. If we didn't have to go through the insanity of that system, we could have one in a couple years. 2nd, I used to work at HELSTF. I regularly watched pundits claim things we did /that/ day were impossible with the current technology or that there was an easy counter to what we'd done (as if we hadn't tested that first). Talking heads, even ones which have some background in a subject, ought to be taken with a grain of salt. In fact, the BoAS has an axe to grind. Opposition to SDI-like weapons is historical at this point and ought to be taken in that light. Likewise, anything put out there by a defense contractor ought to be taken with an equally large grain of salt, especially one of the beltway bandits.
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Sure, but the laser beam itself is less than ideal too, as it its targeting. We're talking about hitting a moving target from another moving target with a less than perfect beam dispersed through whatever's in the atmosphere between them. Adding reflected waste energy to that equation and mirroring might not be perfect protection, but I'd bet it could make the attacker's job a lot tougher.
I have no doubt that at short range under laboratory conditions lasers can burn through any mirror conceived by the mind of man. In real world conditions I suspect it'd be a lot harder to get to work even without an intelligent enemy dreaming up countermeasures.
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If you have a reflectance of X% for the wavelength considered, that means 100-X% is absorbed. Granted I am not sure how the reflectance of materials is at short wavelength but the weapon considered are at long wavelength compared to visible (the weapon considered seems to be around 1 to 2 micrometer in the near infrared https://fas.org/sgp/crs/weapon...). Source cite a reflectance of 94% to 98% for that wavelength for some type of mirror (silver mirror among others).
At such a 50kW Laser at 95% reflectance would mean 5% absorbance or only 2.5 kW. That means to give the same amount energy at the same distance for the same surface you need 20 time the same time. Or put in another way if you need to give 10.000 Joule to ablate that surface , you would need 4 seconds exposition rather than 1/4 of a seconds for a non reflective surface.
So where do I make an error ? Where do you see that the mirror would quickly lose the ability to reflect compared to exposure time ? Keep in mind that in the case of a balistic projectile, you only need to make sure the laser do not pierce the skin long enough that targeting would be hard. I do not see why you keep telling reflectance has no impact on such laser. It certainly has an impact on how much kW will the target absorb.
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I would also expect that there is quite a few details to work out when it comes to mounting any new weapon on a ship and integrating it into the CIC. There is no reason to wait until you have a planet buster to get all that going and in place.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
That makes no sense.
Cover everything with mirrors?
Liberace called, he wants his mirror encrusted missile cruiser back.
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Simply engineer a heat shield for the warhead that is ablative and outgasses enough to provide a protective layer around the object. The advantage of this over a mirror is that the laser's heat is carried away by the emitted gas.
For countries with MIVR'ed ICBM's, the dummy vehicles can be replaced with some sort of defensive weapon. In the case of Russia, you could have two warheads with four defensive vehicles per warhead on each ICBM, or the US could have 3 warheads with 3 defensive vehicles each per ICBM. Since they can be independently targeted, the defensive vehicles could arrive ahead of the warhead between the line of site of the laser and the trajectory of the active warhead. A nice thick cloud of opaque smoke could do the trick. And be cheaper than reflective/ablative armor.
There never was a mission for the navy to shoot down nuclear missiles. there may have been a mission to shoot down anti-ship missiles. But they already had the Phalax and it is probably as effective as laser would ever be for that mission.
Phalanx and other gun based CIWS are being depreciated in favor of missiles like the Rolling Airframe Missile. Guns can't deal as effectively with supersonic missiles and/or those that undertake terminal evasive maneuvers. They've also got a stopping power problem; breaking apart an incoming missile doesn't negate its kinetic energy and the inbound pieces retain the ability to do significant damage to modern warships even without a warhead detonation. The British lost at least one warship -- HMS Sheffield -- in the Falklands to a missile strike without warhead detonation. Mission kills are even easier; take out a few radar antennas (highly exposed targets that can not be armored or otherwise protected) and the ship is rendered combat ineffective.
But the drone situation changed everything.
Drones aren't new to naval warfare. A missile is essentially a drone with a different name. One might even argue that a kamikaze is the same thing, at least from the perspective of the target. :)
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
A nice thick cloud of opaque smoke could do the trick.
How do you lay a nice thick cloud of opaque smoke at hypersonic reentry velocities?
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
Designs for Navy vessels now have to focus more and more on supplying power (as in electricity).
I believe the DDG-1000 series was supposed to address that, I remember reading about the power system and how it was modular enough to allow virtually all power to be directed to any particular system. "All power to weapons."
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
It cannot deal with non-lethal modes of attack (rubber dingy)
If the guys in the dingy are trying to kill you why would you limit your response to the non-lethal? You can defend against that shit with something that's nearly as cheap as the laser, which has more than a century of proven effectiveness in combat.
We don't need to spend millions (billions?) of dollars on laser technology to deal with small boat attacks. Some people like to talk a big game about swarm attacks but there's no where to hide on the open ocean; going after any modern warship on the high seas in speedboats is a fast way to meet your creator without taking any of your enemies along for the ride.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
Only if that target is the Flash.
The posted advantage of a railgun is it's range. At the extremes, time of flight for the projectile is probably long enough that it can be evaded. Of course, those extremes are beyond what you could even fire the laser at in the first place. If i've learned anything from Eve though, it doesn't hurt to have railguns AND lasers.
I'll add that maybe what is most impressive is not the laser power, but the control system required to keep the beam on a moving target at a mile away. The author seemed to miss that part of the technology.
That's actually rather easy. The navy solved that problem decades ago for ballistic trajectories which substantially more complicated computationally. Line of sight targeting is FAR easier with modern computers. That is why they use lasers to paint targets for missiles to home in on a target. It's much easier to target something with a laser which is not meaningfully affected by gravity or wind or time to intercept.
I think the really impressive bit would be how they could keep the laser operational in an environment as hostile as the ocean. I would think that the ambient salt water would be seriously challenging towards keeping a laser functioning optimally.
I think currently demonstrated ship-mountable railguns can emit a 7+ pound projectile at Mach 7. More to the point, these can be kinetic projectiles, meaning no explosives required, and there's more room for other things like, oh guidance systems.
Good luck evading that.
-Matt
This is the only realistic protection. Rotation and ablative shielding. Reflection is folly.