Mirror, mirror on the missile...
Er, wouldn't a nice shiny finish to the missile render any laser-based weapon useless?
The Pentagon's astounding flying raygun programme has passed its penultimate technical milestone, according to makers Boeing. The Airborne Laser (ABL) project is intended to deliver a fleet of aircraft armed with high-powered energy weapons. The idea is that such aircraft would patrol up to 400km from the launch sites of enemy …
Could someone explain why these planes can't shoot down ICBMS with missiles, or even projectile weapons (= "a big gun")?
I know it's a difficult target to aim at, but doesn't that sort of argument go double for a laser, which attenuates quickly at range?
Assuming that the US needs them at all, that is.
Corner-cube reflectors would be even better.
I suspect that getting the angles at exactly 90 degrees would be tricky. You wouldn't need much error over a few hundred kilometres to miss your attacker altogether. On the other hand, if you could build the reflector out of single crystals (cubic-close packed, I suppose) then you could sit back and let mother nature get the angles right for you.
One way or the other, you can be sure that if this weapon is remotely functional then some serious effort will be expended in Russia and China to defend against it.
They are looking at 400km intercept ranges. The boost phase for an ICBM is only quite short; even hypersonic missiles (1500ms^-1) will take 4-5 minutes or so to reach them. I think the current standoff Air-to-air missiles have a range of under 200km and they don't travel at quite that speed. It's much easier to hit a small, fast target with a transit time of tens of microseconds than try and manage a terminal intercept by a missile on a receding, accelerating target.
Says the iodine laser's wavelength is well-absorbed by metals, so brass would be no good. Silicate glitterball effects could be tried though...
I've come up with a great way of sneaking your nukes past the ABL. Forget about ICBMs - as pointed out, those hot exhaust plumes are easy to spot (although probably a satellite would spot the launch first and alert the ABL). ICBM delivery systems are, in any case, difficult to procure, expensive to develop and hard to maintain.
Instead, why not buy a small fleet of executive jets or turboprops, develop a simple remote control for it, rip out the seats to make space for the bomb, and fly it - subsonically, on regular commercial routes, getting proper clearance from ATC as you go - to your target.
Of course, if you're a fundamentalist organisation with access to nuclear warheads, you don't even need to do the remote control bit.
Mirrors won't protect against a sufficently powerful laser. There's no such thing as a perfect mirror, so the surface would absorb a small amount of the radiation, heat up and eventually blow the booster apart.
How much laser energy you'd need is a matter for someone better qualified in physics; I got bored with the subject just as soon as my GCE teacher, Mr. Sampson, said we couldn't use the cobalt 60 source to develop our own superpowers. No sense of fun that man.
why lasers? because a high speed moving target is very difficult to hit unless your ordnance is moving much faster. Once fired, the laser will hit the target before it has move little more than a few centimeters.
If the laser is of sufficient power (500kw), Mirrors or shiny surfaces will still adsorb enough energy to be blown to small shiny pieces (from thermal shock) or melt. This is also one of the problems with using high powered lasers, trying to focus that amount of energy can lead to problems for the optics.
What would be interesting is how fast the weapon can cycle? Or else you (or whoever is attacking) can just throw up loads of missiles and cheap decoys at the same time.
What should worry us more than wether these idiots can't figure out they can fire a heat seeking missile at the ICBM's instead of using a laser is what they could be used for.
If you think about it logically once a launch was detected to scramble one of these birds to incepet is going to be much longer than the time it would take the missile to reach low orbit and therefore be out of range.
The only use is if you knew they were going to launch and then use them as a defensive measure to prevent your own boarders being hit - and when would we know they were going to launch, why it's simply straight after U.S.
The laser in question is more about heat than light (it's an infrared laser). The sheer amount of heat (or vibration, depending on how you want to look at it) produced would crack even the hardiest heat-reflecting mirror. A shiny surface would certainly be unable to reflect enough heat to not be compromised, these lasers can achieve several megawatts of continuous flow.
EVERY time this boondoggle is reported someone says 'well just put mirrors on it'. See above: won't work. Chances are, you wouldn't need any putative countermeasures beyond waiting for the bloody thing to fall out of the sky anyway. If it's ever capable of doing anything more than changing the channel on your TV that is. Possibly it will be ready in time to be mounted on a Moller flying car...
You know it's almost as if the person who wrote that comment didn't read the article.
From the first main paragraph: "The idea is that such aircraft would patrol"
So no "scrambling" needed. Even if the plane were on the runway with its engines running, the world is a big enough place (and IIRC the nukes fly fast enough) that the airbase would be smoked before the plane got to the nuke's launch site.
The whole requirement of patrolling to be within range at all times is pretty much one of the biggest flaws with this scheme, and was highlighted multiple times in the article. You need to know which of the multitude of countries that hates the US is going to fire first (unless you have thousands of them), and yes I would like to include the UK in that list if I can *grin*.
How on earth do they expect this to work. They honestly think a nation capable of deploying a nuclear icbm is going to miss a bloody great 747 flying overhead?
We can obviously discount surprise as a valid tactic. So how does this cope with multiple rockets? We already know the laser needs refueling, so will a couple of cheap dummy warheads be enough to drain the batteries?
What of the political implications if those 'dummy' warheads were full of legitimate scientific instrumentation?
It's also a damned expensive piece of kit. Can it defend itself against being shot down? Cheaply? Without having to go back to base for refueling? It sounds to me like attacking this may be a better option than launching an icbm. If it can be done with plausible denyability it's a great way to cost the american govenment a fortune.
Best way to tackle these ray-guns is to block them with smoke - launch them through a cloud of finely powdered carbon.
Maybe you could have a pair of missiles, one pumping out smoke and one carrying the nuke travelling just behind it?
Any of you physics boffins care to work out how thick the cloud of smoke would need to be to render the laser ineffective?
To be honest, the comments about making the thing reflective are valid. If it effectively reflected the wavelength of the beam it would protect the missile to some extent. You'd either need to hit the targer for longer, or hit it with more power, to achieve the same effect. A reflective coating WILL reduce the proportion of power absorbed by the missile. It's just a question of whether it will reduce it enough (or a question of "how much power you can hit the missile with", if you prefer)
But, like all armour, there is a limit beyond which the reflectivity would not be able to cope. It's like a bullet-proof vest works again a handgun close-up or something meatier at a distance, but is useless against an assault rifle at close range. But that doesn't mean to say it isn't worth wearing one.
Another plan is to "spin" the missile, thereby denying the laser a nice, constant patch to heat up continually.
Hey, this should do the trick...
A coating of "Laser Gold" http://www.epner.com/laser_properties.ssi
"Laser Gold plating reflectivity is greater than 97% at 0.7 microns and greater than 99% at 10.6 microns"
The COIL laser operates at about 1.3 microns so the gold plating should reflect > 97% of the laser energy directed at it.
According to the website, it's easy to clean too.
@Gordon-- I think the Russian ICBMs already spin as they fly, increasing ballistic stability. Not sure about others.
My thought, though, as similarly voiced by myxiplx a few comments up, is that, wow, can you imagine a more vulnerable plane to carry this thing than a 747? The jumbo is extremely easy to shoot down with virtually any type of missile, due to its extremely large size, slow speed, and limited maneuverability.
Since we're not talking about using these to fight Russia or China, some arguments about symmetrical air war don't apply; but, still, Iran has F4 Phantoms and MiG 21s, don't they? I'd imagine North Korea has similar gear. So, if for some unthinkable reason, North Korea or Iran were to wish to launch missiles at their neighbors or at the US, sending up a squadron of fighters to take out the laser patrol jumbos wouldn't be all that difficult.
The real problem with this weapon system is that it departs from basic strategic theory when you start trying to make up reasons why it might work. Iran and North Korea pose no credible ICBM threat to anyone-- the price of a successful launch by either nation would be a vicious retaliation they would have no hope of evading. Despite grandstanding, the leadership of both nations is not suicidal.
In fact, the only nation which poses a credible nuclear threat to America is Russia, because they have both the warhead stockpile and delivery systems to assure a fairly massive strike against the North American continent. However, for reasons of economics, and, again, basic self preservation, Russia has no reason to ever launch a first strike anymore than America does.
In light of these facts, I'm forced to conclude the laser-on-the-747 plan is yet another example of military contractors making up a solution to a problem which doesn't exist.
How about putting a layer of this aerogel stuff under a mirror?:
it looks like the 2 combined, plus maybe the spinning idea might have a good chance of at least holding off the laser long enough for the missile to get away or the laser to run out of juice.
although, i would have thought they would use it for the heat shielding on the shuttle as well, so maybe there's a good reason not to use it for either.
Carbon: Hmm, so you fly your fiery-tailed ICBM in a cloud of highly reactive powder mixed nicely with air? Who needs lasers?
Laser gold: All well and good but it takes less than 5J/cm^2 to "damage" the coating. The laser is chucking out MegaJoules/s. Even at 97% efficiency, thats tens of *kilo*joules/s. It'd flash vapourise and be rendered ineffective. You might make it thick enough to withstand that sort of energy for long enough to make a difference, but it's *gold* which is a) very dense and b) very expensive... There wouldn't be much payload for a nuke (which are also heavy) and if it didn't go *bang* you just launched half your nation's treasury at your mortal enemy...
As someone who works for Mr. Lars, Incorporated, I really got a kick out of your reply.
I'd like to say that the recent speculation that our country's latest weapons systems are non-functional boondoggles inspired by 'comic-books' is utterly false, though (of course) we cannot speak for Peep-East.
@ anonymous boffin...
I'm sure there's something inert that could be used to create a suitable smoke / fog if the carbon particles would ignite. Water vapour perhaps?
As for the laser gold, the laser may be producing MJ/s worth of energy at source, but a lot is absorbed by the atmosphere between the plane and the missile. How much energy is delivered at the target 400Km away? Surely the gold plating would at least about half the effective range of the laser since it would have to be delivering nearly twice as much power as the theoretical minimum to destroy the missile. Regarding the mass of the gold, the laser gold plating is used in lots of aerospace applications, so it's probably relatively light.
"From the first main paragraph: "The idea is that such aircraft would patrol"
So no "scrambling" needed. Even if the plane were on the runway with its engines running, the world is a big enough place (and IIRC the nukes fly fast enough) that the airbase would be smoked before the plane got to the nuke's launch site."
And they were insane enough to do it with the B-52's ... so really keeping a bunch of 747's flying around 24/7/365 ain't gonna be a big deal...
http://en.wikipedia.org/wiki/B52 - under the Cold War section.
"...if it didn't go *bang* you just launched half your nation's treasury at your mortal enemy..."
Oh, so you're saying it's something only the U.S. would use, then?
On a more serious note, three things pop up in my mind: 1) imagine the kind of damage if this thing malfunctioned and *didn't* hit the target; 2) how can the 747 tell the difference between the hot exhaust of a nuclear projectile and a space-bound rocket (putting up a satellite, for example); and 3) you're stupid if you think the U.S. will only use this for shooting down enemy missiles (they'll use it to shoot down space rockets as well as anything *in* space they feel like, not to mention anything on the ground).
Every time I watch "Real Genius", it seems we're getting closer and closer to it.
I might be wrong, but I suspect the B747-based system is really just a prototype that could become an operational limited-run prototype. Given the speed of minaturization these days, it will end up small enough to be mounted on a fighter one day in the none-too-distant future. If you consider it a laser is generally superior to a machine gun or missle. Provided you're on target when you shoot, the chances of the weapon being obstructed are pretty small. Unlike a missile things like chaff, flares, emc and evasive will not help (although they COULD make targetting harder). In clearner air (eg that at higher altitudes) they have a massive range. There is no way for the target to KNOW they're being targetting until they are hit.
While its very interesting watching the debate about how useful/ vulnerable this 'weapon' is likely to be, personally I doubt it will ever see anything more than token active service. It all just smacks of Ronnie Ray-Guns Star Wars all over again. Another excuse for the contractors to feed at the trough and deliver a defense for a problem that doesnt exist. While it may make (some of) the American public proud that they have such inventive weapons I doubt it will make the average grunt in Iraq/Afghanistan/<insert next victim here> feel much safer while he runs the daily gamut of snipers and car bombs. Unless of course they develop an air-support version of course....
' This is Black Hawk, please get the Big Bird to vapourise the building in front of us...'
Now Im scared !
Tales of the bogeyman are, as they have always been, designed to manipulate the gullible and/or nincompoops into behaving a certain way desirable to the teller of said tale. Nowadays it appears to be a transfer of wealth & power, from the workers to the fat cats who make trillions out of manufacturing arms and the ensuing suffering.
In this case, "Mission accomplished". If I may borrow a quote from a certain someone. The money has shifted, a tiny group of people are more wealthy than they were before and the majority poorer, irrespective of whether it works or not ?
Wow, this is probably the dumbest comment ever posted on The Reg. and that takes some doing:
"So what happens when one of these aircraft crashes and their "dangerous hazmat fuel" spills all over the place...
I suppose no Terrorists would ever think of hijacking a plane and using it as a weapon..."
I'm not sure that the intention is to sell these particular 747s to British airways you know or are you suggesting that hijacking a top secret, rediculously well guarded aircraft is somehow as easy as walking onto a plane with next to no security as was the case before and on 9/11?
I really do not believe that most of these "rogue" states will launch their missiles on a nice day with only thin layers of scattered cloud. This boondoggle (or white elephant) is almost certain not to be able to burn it's way through several hundred tonnes of water vapour. This project is pure US pork
No one seems to have raised the issue of cost-benefit clearly. The cost of this system would be astronomical compared to the cost of the threat it is supposed to counter. On top of that, the various countermeasures would increase the costs beyond astronomical. Two very cheap countermeasures that haven't even been mentioned: Cheap SAMs that can easily take out a 747 to create a launch window, and waiting for nice cloudy day for your launch. You could even wait for a convenient front of clouds to move between the laser planes and your missiles.
Of course, if you're really a low-budget operation, say like North Korea, you aren't going to risk one of your precious nuclear bombs on an unreliable missile. You're just going to stick it in a cargo container and ship it to your target the cheap and reliable way.
I concur with the previous suggestion that this only makes sense as an assassination weapon. All you need is one solid sighting on your target, and you can smoke him instantly. However, still not cost-effective compared with the current Predator missiles. The missiles aren't instant, but they're fast enough for government work.
However, as a target for a terrorist, these things do sound very attractive. All you would need to do is down one as it passes over any place where people live.
The fact that so many people who know zero about lasers or aeronautics didn’t hesitate to shoot off their stupid opinions into this forum says a lot about the egos & ignorance of IT people, who are the overwhelming majority of readers here.
Anyone who does know about lasers & aeronautics knows that making this scheme work is only a matter of money. Are there alternative technologies? Not with a 400km standoff capability. Will it come in on time and on budget? I doubt Boeing knows. Is it worth it? That’s for the US tax payers to decide.
they will just kill this project anyway it's
not the initial outlay our government has
trouble comitting to long term upkeep
of unused assets so there will be ten
of these things sitting in the boneyard
and we of the US will have paid for them
it's our way of subsidizing our aerospace
industry it seems to work at least we have one.
The lasers are more effective in thin atmosphere, therefore will only fire once the missile is above the clouds.
I think that it is right to think of this as just a load of pork, but if the tech is useful it could lead to all sorts of developments outside defence. Having a high powered lasers on a plane sounds ideal for a propulsion system, even better if the research can lead to making it a bit more compact and reduce the reliance on hazmat.
re: M.Burns "release the hounds"
re: DeFex: lol, I guess the guys with tin foil hats had the same idea.*
*shiny surfaces and mirrors won't help, guys.
@Mr (e?) P E Dant
"I'm sure there's something inert that could be used...Water vapour perhaps?"
Maybe. Don't know how good water is at absorbing IR though. Every litre of water you have to carry as anti-laser measure reduces your payload or your range, though, and a nice thick barrier of vapour would take a lot of sustaining until the missile got out of the intercept envelope of the laser. A reason it needs to be airborne is to be above the weather and in thin air to mininise attenuation by pesky natural phenomena.
"As for the laser gold, the laser may be producing MJ/s worth of energy at source, but a lot is absorbed by the atmosphere between the plane and the missile."
I really don't know how much a laser will be attenuated by the clear, thin air that the platform will be operting in. If they want a quick kill, it'll have to be "most" of it.
"Surely the gold plating would at least about half the effective range of the laser since it would have to be delivering nearly twice as much power as the theoretical minimum to destroy the missile"
"Half" would be in the category of a "guess". It's *energy*, not power that will destroy the booster. If the total energy required to penetrate the thin aluminium walls (sans plating) of the booster and ignite the fuel within is, say (and this is a "for the sake of argument" guess) 10kJ, then a 1 MW source will have to dwell on the target for 1/100th of a second, multiplied by the attenuation factor between emitter and target. It would depend on the size of the "impact area" how much the gold plating would delay penetration. Again, I have no information on how big the "searchlight" would be. The collimator on that Boeing looks pretty large. How big does a telescope have to be to achieve centimetre resolution at 400km? Is that a relevant question, given the power being shoved through the optics and the fact that it's a laser, and therefore coherent in a way that telescopy isn't?
"Regarding the mass of the gold, the laser gold plating is used in lots of aerospace applications, so it's probably relatively light."
Oh, yes. Definitely. But that's "light and fragile"; I was hypothesising about making it thicker and less liable to burn through instantly. That's where the weight would come in.
Corner-cubes also aren't 100% reflective and would burn through so fast that the amount of energy reflected back would be negligible. Unless they were so sturdy that their weight impinged upon range/payload performance.
Stick it in a Liberian-flagged frieghter with plenty of lead lining to defeat radiological inspection. It's safer, easier and cheaper, and most of the US's "valued" cities are coastal.
I don't think the beam will make any sound at all.
Lightning heats the air to create a shock wave, but that is several magnitude more powerful than the laser being suggested here. (1.21 Gigawatts , if back to the future is anything to go by)
Do high powered lasers fire in a medium of air make any sound?
If a missile was faster than a satellite, it would be less useful on terrestrial targets. Even anti-satellite missiles are likely to be slower than their targets, they only need to place a cloud of bits in front of the target just as it arrives, not match orbits.
The interesting thing about a State launching a satellite is it proves that they can throw something that size to any point on Earth.
Have people stopped being embarrassed at displaying ignorance in public?
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