The interesting bit is that folks realized that you can combine lasers without having them be coherent and still get decent amounts of power on target. That made a lot of off the shelf lasers much more viable.
The key though is the $10 a shot versus $100,000 a missile. That is what will change the equation permanently. If the price of operation of a PATRIOT type missile battery (or Israel's IRON DOME) goes from $1M/day in combat to $100/day, you will see them deployed a lot more frequently.
While that was designed in 1984, the US DoD had successfully tested laser weapons over a decade earlier:
'The first was in 1973 when the USAF shot down a winged drone at their Sandia Optical Range, New Mexico, using a carbon dioxide GDL and a gimballed telescope. Subsequently, in 1976, the US Army employed an electrically pumped HEL to destroy a number of winged and helicopter drones at the Redstone Arsenal in Alabama. The USN, in March 1978, then engaged and destroyed an Army TOW missile in flight' [1]
The first targets destroyed from an airborne platform (KC-135) were in 1979.
I think this one would be an even better reference point to show the gulf of effectiveness between where we were and where we are now: http://en.wikipedia.org/wiki/NES_Zapper
Yes, a US soldier was blinded by an Iraqi in Desert Strom [0]. The article doesn't cover it, but as I remember it, the laser was part of a tank laser range finding system - not a purpose build blinding device (the Chinese were openly producing such weapons at the time). Another class of weapon would be a dazzler [1], and those are used frequently.
Another Pentagon budget cycle has begun. Seemingly forever US companies have put out puff pieces about technology which are then regurgitated by the media. It's all about getting the public to support the ever increasing US military budget.
A surprising limitation on these systems is how short range they are. Ships and Aircraft regularly fire on targets that are over the horizon, but lasers are pure line of sight.
Besides those are just weapon delivery systems. Those same systems can be used to transport a laser weapon system to the area they want to attack (e.g. missile + laser, aircraft + laser)
not really - 10kw laser diode pack is something like laptop size. 35kw (as we have 30% electric to light conversion efficiency) light-duty generator with small motorbike engine - like another 70 kg. Add some other pieces - total will be under 100Kg.
In October 2012, the firm successfully used its 40-kW combined fiber-beam system. Not 10-kW and 40kw is on the low end of what you want. Worse, 100kg per 10kw seems optimistic.
Anyway, as a first approximation if you’re dumping X energy on target with a 30% efficacy laser using a 30% efficient generator your net efficiency is at most 9%. So, you need to dump 11 times as much energy as you can get on the target. This is why most early designs focused on chemical lasers.
Probably a silly question, but would it be even remotely feasible to bounce a ground- or ship-based laser off a drone-mounted mirror?
Pretty sure the obstacles to positioning the drone/mirror precisely enough (and keeping the mirror clean enough) would be insurmountable, but couldn't help wondering.
The article states that the firm MBDA in Germany had helped to show that reflective armour, at least with mirrors, is not a good defense against lasers, as
>any dust on the mirrored surface would get burned in, and lead to the destruction of the target even faster than with a non-reflective surface.
Only in the rube Goldberg sense of a ridiculously inefficient system.
Also, if you can build a mirror to bounce the laser you can use that same mirror to protect the target. But, N beams and N mirrors sidesteps this issue.
PS: An amusing idea is to use a fleet of drones with mirrors to cook the target using sunlight.
Also, if you can build a mirror to bounce the laser you can use that same mirror to protect the target.
Not necessarily. The attacker controls the focal distance of the laser. If they are using a mirror offensively, they can adjust the focal distance to ensure that flux is not destructively high at the location of the relay mirror, but is at the target. If you are trying to use the same mirror defensively, the attacker can simply consider that mirror to be a new armor target that needs to be destroyed before they can get at you, and adjust their focus to create unsurvivable flux at the mirror surface.
To be clear, I did not mean that as a total defense. Still mirrors can be useful in combination with other things.
For example the target can use a high deflection angle to disperse the beam. AKA you beam's intensity is sin X and as it covers 1 / (sin X) area. So full intensity = 90 degrees, and at 10 degrees your down to 17.4% intensity. For something like a Mortar rotation can also be a significant benefit.
I would imagine the laser loses energy quickly going through the atmosphere as the distance increases. Cloud, mist, rain, and dust all absorb the energy.
Reflective paint is surprisingly ineffective. In order to work at all, it needs to be tuned to the frequency of the attacking laser, and not get dirty, or scratched up, or otherwise gain significant imperfection in the finish, which is rather difficult to achieve when firing out a cannon and flying through the air.
Even if those conditions are met, however, mirrors still make for surprisingly bad defense against weaponized lasers, simply because no mirror is 100% efficient. The 0.1-ish% of a well focused, high-powered weapons laser that doesn't get reflected by a ridiculously high quality mirror on initial contact will still damage and deform the mirror, thus allowing more and more of the laser's power to be deposited in the target with increasing dwell time.
Laser weapons avoid destroying their own optics by, first, using optics tuned exactly to the specific frequencies the weapon is designed to fire, and second, by using relatively large focusing mirrors / lenses which keep the power/area on the weapon optics below dangerous levels. Even so, real laser weapons have ridiculous cooling requirements to keep from destroying themselves with waste heat, which keeps their efficiency rather low.
There are other countermeasures that can be used against lasers, to be sure; mirrors just ain't one of them.
You took "reflective" too literally. I just meant more reflective to IR than dark green paint that most military stuff gets painted with. I never meant a mirror surface. Just the IR equivalent of white paint.
White paint (or IR-colored paint, in this case) is worse than a mirror surface; it starts out at a disadvantage already. By assuming a mirror surface, I'm giving you the benefit of the doubt- anything else would be even more useless.
Are you saying that picking a coating with low absorption in the part of the spectrum that the laser is in doesn't matter?
I'm not sure I agree with you, since it makes other strategies (such as rolling the projectile in flight or using ablative materials) more effective if the projectile is slower to absorb energy from the laser.
The whole name of the game is to collect as little energy as possible, disperse it as evenly as possible (in non-important areas), and avoid deep penetration.
It doesn't magically stop the laser to paint it the right color, but choosing the right paint is an important part to penetrating laser based defenses.
For a sufficiently powerful laser weapon, yes, low absorption doesn't matter.
If the attacker is just trying to heat up the bulk of the target until it melts, or is otherwise disabled, then a low-absorption coating would indeed slow them down. Such weapons have been proposed, but they're not especially effective anyway, and that's not how modern experimental military lasers are designed to work.
Weapons lasers are designed to focus as much power as possible into as small an area as possible in order to cause physical damage at the point of impact- blasting a hole in the thing, setting it on fire, etc. Heating the bulk of the target is a mere side-effect.
In that regime, anything less than 100% reflectivity is essentially pointless. Sure, it'll delay penetration, but not by any significant amount. Within a very tiny fraction of a second, the part of the laser energy that you do absorb in the target spot will be enough to destroy the reflective coating, and bring the full beam energy to bear. Unless your projectiles are expected to have flight times measured in milliseconds, the delay provided by a special low-absorption coating is utterly useless.
If you can prevent the enemy from dwelling on a particular spot, then things look much better. If you can screw up their targeting quickly enough, maybe you can actually prevent damage to the reflective coating after all. Even if you can't, maybe you can keep the laser occupied with constantly eating through fresh areas of reflective armor, never absorbing the beam's full power. But at that point, it's not the low-absorption coating that's saving you- it's your ability to screw up their targeting.
Again, I don't think reflective coatings are a lone solution, but I do think that they enhance other tactics, and as such, are a key aspect of defense in depth. However, those contributions are key to those other systems working at all.
For example, the typical bullet rotates at ~200,000RPM. This is about 3,000 revolutions a second, or about 300 microseconds a revolution. Figuring a larger projectile could only rotate about a tenth of the rate, we get about 3 milliseconds per rotation on a shell.
At 3 seconds per revolution, I suspect that we're inside of the timing windows that talking about the efficiency of energy absorption and dissipation in the coating that the laser is striking is relevant, and we can begin to talk about the laser energy being dissipated over more than a single fixed point.
However, I suspect that such tactics (as high velocity spinning) can only mitigate the effects of the lasers and not stop them in isolation. It needs to be tied together with a coherent plan to dissipate the energy that areas do absorb and scatter the beam's focus using ablated coating.
In terms of energy absorption rates, energy dissipation rates, and ablative properties, picking the right coating for your mortars trying to pierce laser defenses is essential.
tl;dr: It's a synergy thing, since the low-absorption coating reduces the demands on screwing up their targeting, and screwing up their targeting reduces the demand on a protective coating.
I think that demonstration was to show that the laser system can be useful against very cheap home-made mortars and rockets. The military would rather use a laser that costs tens or hundreds of dollars per shot to defend against mortars that cost perhaps several hundred dollars, rather than the current conventional methods that cost tens of thousands of dollars per shot.
The military would rather use a laser that costs tens or hundreds of dollars per shot... than the current conventional methods that cost tens of thousands of dollars per shot.
Wait, I thought we were talking about the USA military? When have their weapons systems ever gotten cheaper? The only time they buy something cheap is when there is no more expensive option that does the same thing available (e.g. drones). If the only consideration is cost/shot, lasers will never be deployed. The point of TFA is that the new systems do things that haven't been done before, like stopping a mortar round in flight.
The reflective coating one in particular was explicitly covered in the article. The rest mostly add weight for dubious benefit; I'm guessing increasing laser power will win that arms race decisively. And it doesn't seem like you have to cook off the explosives to beat the mortar round, since they mention that some don't explode when they're destroyed.
yes but most of the mortars this will be facing will be diy ones or at best ww2 era 80 or 120 mm fired by insurgent's who wont have these exotic rounds.
"MBDA's tests have also helped to debunk the science-fiction idea that reflective armour would defend against laser weapons. They found that any dust on the mirrored surface would get burned in, and lead to the destruction of the target even faster than with a non-reflective surface."
gliese1337 also explained it more in details in this thread.
Ah, the sound of lasers in space! I find the way laser rays are depicted in movies interesting (other than the silly "bad guys use red beams" thing). They are generally shown as a "bolt" with a clear beginning and end that travels through space at a low speed (good compilation from Star Wars here: https://www.youtube.com/watch?v=QRJ9Evjm5Xs). This, I believe, is why spaceships have to at such close proximity to each other in battles, you have to see the laser beam bolt thingie go from ship to the other at that low speed. This also opens up the possibility of dodging laser beams. Now, it could be that these are not really laser beams but particle beams (http://en.wikipedia.org/wiki/Physics_and_Star_Wars).
I like the way they did it in Eve Online with the mining animations. The "bolt" animation should be plasma weapons, and "pew pew" seems a bit too cute and cuddly for that.
Here the link I am referring to before I get 4 down votes. This "joke" actually is referring to something special. A 1980s movie about technology, military and academia.
The key though is the $10 a shot versus $100,000 a missile. That is what will change the equation permanently. If the price of operation of a PATRIOT type missile battery (or Israel's IRON DOME) goes from $1M/day in combat to $100/day, you will see them deployed a lot more frequently.