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Laser Shoots Down Artillery Shell In Flight
An anonymous reader writes "The Mobile Tactical High Energy Laser is a joint project between the US Army and the Israeli Defense Ministry, with much of the work being done by TRW. Tuesday they had a spectacular success when they shot an artillery shell out of the air."
Lasers to knock out 'metal things' have been around for decades as well. The difficult part has been tracking very high speed objects from a distance.
There was a big Navy project to put a laser on a ship. I have no idea if that was ever put into operation.
There was the 'Star Wars' Alpha program that was run during the Regean military buildup. And King George the Second appears to be trying to breath life back into the project.
What makes this news item 'interesting' is that the DoD seldom comments on successes like this unless program funding is at stake or some politico needs to be impressed.
Regards.
The BBC has more.
Phil, just me
"Cattle Prods solve most of life's little problems."
A cloud of shell parts has a very different aerodynamic profile. The remnants of the shell might still be initially traveling in the same direction, but the fragments will not maintain that course. You only have to change the trajectory of the shell enough to make it fall short of its target.
Outside of a dog, a book is a man's best friend. Inside a dog, its too dark to read.
Proximity fuses detonate their shells at an optimum height; the terminal velocity of an artillery fragment isn't very high, it's the fact that it's being driven into you by a bursting charge that's the dangerous part.
If the shell detonates below this height, the resultant spread of the fragments will be limited. If it detonates above this height, then the fragments will both be spread over a wider area and lose more energy to air resistance.
In either case, you're better off than if the shell detonates at the proper altitude.
Take a look at this thread from a recent article on laser weapons.
The angel in the oatmeal.
If you are an Opfor arty commander and you find out your shell gets knocked out of the sky by one of these, you have about 2 minutes to call in fire before some MLRS counter-battery fire knocks your ass into next week.
With UAVs, counter-battery radar and mobile systems like Paladin and MLRS, it's suicide for Opfor with Soviet doctrine and Soviet arty to fire on US/NATO/IDF positions.
If you are lucky Opfor with South African guns, you can stand off from normal 105/155 NATO guns, but you are still in MLRS range.
As it begins it's decent, itmay speed up with gravity, or slow down even more, depending on the air-resistence.
It's still going to closely approximate an ideal paraboloid, except at the terminal stage of flight where it's going to travel more vertically than ideal equations predict. In addition, the shell travels way up high, easily visible to radar, where most missiles people on the surface worry about tend to lose themselves in ground clutter, SR/IR/ICBMs aside.
Second, a shell goes much faster than a rocket.
No, not really, especially during the terminal stage when the shell's maximum speed is limited by terminal velocity; a shell gets one big push at the start of its flight, and is purely passive afterwards (well, excepting rocket-assist and basebleed, but still). A rocket continues to accelerate as long as the motor burns, and can reach speeds far in excess of artillery shells, which can routinely be seen with the naked eye as they hurtle downrange. The trouble here is that "rocket" spans such a wide range; a rocket can be a nice slow fat subsonic target like a Silkworm, or a Mach 2.5+ evasive-action-capable SS-N-22. HARM missiles have a top speed of 2300kph, ferinstance, a good bit faster than terminal velocity of most things that only travel ballistically.
But in either case, shooting down a shell in flight is really nothing new. The Brits had Sea Dart back in the Falklands, and that was capable of shooting down 4.7" artillery shells. Shooting down the shell is *not* new, or exciting or innovative. Doing it with a laser is.
It took a little poking around, but I found an explanation of how this thing works... looks like deuterium gets them a longer wavelength that travels through the atmosphere better.
Whatever the reasons are, I wouldn't want to be anywhere near that thing while it's fueled. Raw flourine is incredibly nasty stuff, and the hydrogen flouride exhaust is really awful, too... it dissolves in water to form hydrofluoric acid, which is reactive enough to eat glass (you have to keep it in teflon bottles). I hope they're not discharging it into the atmosphere!
--Larry
Never attribute to malice that which is adequately explained by incompetence
Israel gets this technology because it, unlike Syria, Jordan, Egypt or Saudi Arabia, has an industrial capacitiy and a healthy research and development environment.
The United States part in THEL is 20% of the R&D budget, same as the US part in the Popeye long-range missile. The US funded Arrow to the tune of 80% because Israel wasn't an ABM signatory and could work on some things the US was treaty-bound not to work on.
Israel has made some serious technological advances in Agriculture, Desal, Military Avionics, Artillery, Small Arms, Computer Science without US assistance.
Remeber that Israel developed nuclear weapons in a partnership with South Africa, not the United States.
And do not forget that in the late 40s and early 50s the USSR, France, Czech and United Kingdom supported Israel while the United States supported Iran and Jordan.
It wasn't until the 1973 war that the United States threw it's support behind Israel, a point at which most of the Israeli industry was already developing.
As for World Peace, all it does is keep the status quo, which is not always a good thing.
Nuclear devices cannot be detonated by random shots. They require very precise triggers. The most you'd get would be radioactive shrapnel from the destroyed bomb.
"The question of whether a computer can think is no more interesting than that of whether a submarine can swim" -EWD
As an ex army cannoneer, I'd like to know more about the artillery shell that was destroyed by the laser.
...
... we used radar at night to track where our shells were landing.
Here's what I can tell you
I worked on the m198 Howitzer, which can fire a 100 pound 155mm HE (high explosive) shell at a muzzle velocity of around 750m/s. With other combinations of propellants and rounds, the velocity could easily reach 1 kilometer per second or greater. Not too shabby for a 100+ pound piece of steel going down range into a target the size of a 5 gallon bucket.
The inherent problem with an artillery shell is that its trajectory is highly predictable... its all about math. So, for the purposes of a high powered laser, as long as it can perform some really nifty calculations in a split second, and point itself right into the path of a traveling artillery shell, then the shell will actually fly into the laser if everything goes according to plan.
Artillery shells can also be detected with radar
So, whats next... assuming that the laser works by calculating the trajectory of the shell, and positions itself ahead of the shell, would the next advancement in artillery be shells that wobble to avoid running into a high powered laser?
Besides these basic artillery shells, there are also laser guided and rocket assisted shells, whos trajectories may be a bit harder to calculate.
Here are just some of the factors that go into calculating the trajectory of an artillery shell...
1. The exact weight of the shell.
2. The type, amount, and temperature of the propellent.
3. Resistence of travel (air friction) based on weather conditions and altitude.
4. Curvature of the earth and gravity.
So there you have it folks... this laser is an amazing piece of technology.
Skiers and Riders -- http://www.snowjournal.com
ofcourse they knew exactly which flightpath the shell was going to follow and where it was going to be at what time beforehand. So taking it down wasn't really that hard.
They probably shot some shells before and got the flightpath recorded into a computer. Then they shot the "test" shell during compareable weatherconditions and perhaps they even did some minor adjustments, it doesn't really matter, they knew the trajectory beforehand, so when they shot the "test" shell the laser knew exactly at which point to fire at which coordinates.
This isn't how things go in the real world, so I wonder how much of an defense contractor technology bragging hype this is and whose interests are behind this (it's not difficult to make a guess here).
This wasn't rigged. Everyone was told ahead of time that the target missle had a GPS receiver on the warhead as well as a C-band beacon.
The purpose of the test was not in acquisition and tracking, but in the kill vehicle technology (plot a path to a moving point, get within infrared range, correct course, and detonate). Sounds simple, but it gets a bit trickey a closing speeds of ~10km/s.
The x-band satellites just weren't operational over the pacific when these tests were being done. So, when Colo springs control asked Hawaii where the missle was, it responded with information from the GPS receiver but provided artifically 'degraded' data stream. This was underlined and not hidden in the test plan (released before the test). It was done as a 'simulation' of x-band (national missle defense system) data.
Honestly, peoples hostility to this program in current time has me baffled.
The reson pundits of ABM tech would underscore every little failure, or break out conspiracies and wave around "rigged" results, was that we should not be researching ABM technology. Russia's on board now, you can stop pissing your pants worrying were going to invoke a nuclear war by having this technology.
If you hate being lied to, you should take the time to better research what people (including myself) and news sources in general tell you.
-malakai
-Malakai
A Dragon Lives in my Garage
ARGHHHHHH. This question gets asked every time a new "laser shoots something that flies out of the air" story appears on slashdot. (Strangely enough these stories are quite regular.)
The answer I've seen most often is that even the best mirrors don't reflect 100% light, and any laser light that gets "through" will quickly degrade the mirror from the inside out, allowing even more light through.
But for even more info... try a slashdot search for laser stories, and then search the comments for the word "mirror."
"And like that
The DoD has had laser guided munitions for decades. Since Vietnam, in fact.
This isn't about LGMs, it's about fully-functional tactical laser weaponry. Right now, its the MTHEL system. Next, it will be hand-held laser weapons for the individual soldiers. The technology exists for laser weapons (basically just high-powered laser pointers), the problem is with a power supply.
Lasers to knock out 'metal things' have been around for decades as well. The difficult part has been tracking very high speed objects from a distance.
Where have these been? I haven't seen a one of them.
There was a big Navy project to put a laser on a ship. I have no idea if that was ever put into operation.
Nope...it was cancelled.
There was the 'Star Wars' Alpha program that was run during the Regean military buildup. And King George the Second appears to be trying to breath life back into the project.
The 'Star Wars' project was for a space-based laser missile-defense system.....this system is both ground based, and not meant for just ballistic missiles, as the 'Star Wars' project was.
What makes this news item 'interesting' is that the DoD seldom comments on successes like this unless program funding is at stake or some politico needs to be impressed.
Unless, of course, the release of the information causes the use of a weapon to fall. In this case, it would be targeted more at cruise missiles and other short- to medium-range weaponry rather than ICBMs.
--CypherDragon
Personally I could give 2 shits about Israel. Until the US annexes Israel I think the US should stay out. They are more than capable of taking care of themselves and dealing with anything that they have (or have not) brought upon them.
No, the problem was that more than 90% of those Patriot missles didn't hit their target! It was pure spin control that made them seem effective...and the spin was so good that even now so many people think the Patriot missile systems worked. Even after so many documentaries/newsreports/etc. saying they didn't. Problem is of course that those reports weren't made until the very late 90's. Of course, you're final point still does stand.
-- Waht? Tehr's a preveiw buottn?
There was some confusion as to what value there was in shooting a hole in an artillery shell.
If you hit a rocket with a laser, your best shot would disable its guidance and control systems. This would quite possibly shut down its engine, but would certainly prevent it from hitting you at all. Secondary targets on a misile include control surfaces, engine, and fuel, all of which have the potential to destroy the misile before it reaches you.
Now if you are applying these countermeasures on a misile that is already very near you, another factor comes into play... what kind of a hit it is. If you're on an aircraft carrier and someone shoots an antiship misile at you from reasonably close range, and it's of a Russian design, it's going to fly up at 45deg, and then sharp down at 45 degrees at you, very fast. If you manage to detonate the propellant or disable the rocket, there's still a good chance it will hit you and deliver its full damage. (a "hard" hit) If you get luckier and detonate its payload, or destroy the control and detonation systems, you are still going to get hit, but this is a "soft" hit. The misile body, rocket motor, and all the other bits (in one piece or many) will still do appreciable damage, but at least it's not likely to sink the boat.
Shells are different. Major shells are going to have armor piercing or high explosive payloads, and C4 just doesn't blow up if you vaporize it with a laser... it burns. So you are not all that likely to detonate it. Shells are fired with great precision, and if all factors are known, they will land with that same precision. Your best hit on a shell is to damage it physically, and change its aerodynamic characteristics. Take a shell and scar the nose with a pocket knife, and it's totalled... you won't hit anything with it, it's not going to fly straight anymore. The laser just has to damage the casing. It's worth noting that if you punch a hole in it fast enough and start burning up the C4 inside, you might just plain burst the shell by simple gas expansion. In any event, it's effectively dealt with. It may still land and blow up, but it's not going to hit what it was aimed at.
Even changing the orientation of the misile/shell is very useful in countermeasures. Most of these have "shaped charges", where the explosive payload is directed in a very carefully engineered way to do maximum damage. When hitting a tank with an antitank round, having the "business end" hit the tank is the difference between destroying the tank (piercing the armor and sending chaff all around the cabin to kill the crew) or doing negligible damage by exploding harmlessly outside the tank. Misiles are essentially the same... a misile that would normally destroy a target may not even detonate if it's tumbling when it hits and contacts sideways, and if the target is even lightly armored, damage will be minimal rather than fatal.
I expect lasers to prove very effective as a projectile countermeasure.
I did have one curiosity about the shell test they did... does anyone know how long they "beamed" the shell before it was effectively dealt with? That's one thing that must be considered... if you have to hold the beam on the target for a considerable length of time, it may be much more difficult to get in a fatal shot. Misiles tend not to roll, so if you are shooting at it from the side, (i.e.you're not the target) you still can hit one spot continuously. Shells on the other hand, are usually designed to spin as they fly downrange, and so targetting the side is actually targetting a band around the shell.
I work for the Department of Redundancy Department.
Before long we will have the ability to render even sophisticated armies totally obsolete. I think this is a good thing.
Hmmmmm, now this may be slightly off-topic but....
Here's what makes me doubt your comment. We are getting very close on some of this cool-high tech stuff. But there's one weapon system in particular that gives me pause. HERF. High-Energy Radio Frequency. The military refers to it as High Power Microwaves. Imagine a steerable localized EMP. This is what HPM is. Have some electronics that aren't protected by a Faraday Cage that depend on transistors or microprocessors and these weapons will fry the systems.
That's all nice and good, if it's the good guys that possess the technology, but what if the bad guys get ahold of it. The United States Military has become the HERF Gunner's dream target. Can you imagine a HERF weapon system combined with a phased array radar? Hell the systems could be one-in-the-same with enough design. Now Saddam's AAA just watches for Aircraft coming by and zaps their computers. An F-117 won't fly without it's computer. Even if the planes manage to get their JDAM's off before they turn in jumbo sized lawn darts you just zap the guidance package on the bomb and your $100k precision guided munition just became a dumb bomb again.
I mean really HERF/HPM is something to worry about. What's to stop AlQuida from aquireing the technology and camping out on the approach lanes to JFK or National? I mean if the Airlines complain about walk-mans and laptops interfering with aproach and landing signals how are they going to do when the bad guys start zapping airliners with directional EMP?
What if it is just turtles all the way down?
-> cooling ... sounds impossible ? it is. But it must be possible to withstand that kind of power for a second (and a supersonic missile could travel a mile in that second at mach 5).
... i know it sounds impossible to reflect light perfectly, but consider that the laser beem is monochromatic light. So what about a small expencive and perfect mirror at the top of the rocket that is kept clean by a small shield that evaporates upon contact with the laser)
... ever noticed some things get totally transparent under monochromatic light. Infrared shines perfectly through dark lenses without any burdon. It must be possible to find materials that the laser will simply not hit, as the photons would find nothing to interact with.
-> misdirection. If I read the article correctly, the laser needs several seconds to lock on. Let's say it takes two. If your rocket gets hit (you ought to be able to detect that and react to it) you immediately release the hull plate it contacted (an explosive between hull and rocket ought to do it, and provide a cooling border by rapidly expanding the distance between hit point and rocket), and will throw of the rocket's course (hopefully) off sufficiently to get out of harm's way. The target beam will continue on it's merry way and hit something else.
-> mirrors
-> refraction. Reflection is hard to do perfectly. BUT do you remember the way a prism reflects light ? You can combine a mirror and a refraction system all in one simple package. I have little doubt you could cover the whole rocket, so you should be able to take care of the beam at most angles (only those direcly on the refracion surface would pose a problem, and you can probably make those angles virtually impossible to hit)
-> transparency
-> people bring up that even slight imperfection in the material would become a serious heat source in laser light. That would not hurt much if the gas were to be transparent (and a substance that only evaporates at 5000 will not stay gaseous for very long unless under constant illumination), these people fail to take into account that the aerodynamics would remove those imperfecions in less than a millisecond at mach 5.
-> misdirection : detect the targeting beam (this weapon needs to use an active targeting beam), and start modifying your course randomly. Using wings at mach 5 you should be able to change course multiple times every millisecond), this would have the added advantage that the naked eye would simply not notice the rocket, nor would a normal camera. Given you can do it fast enough, it MAY be possible to fool a radar (ie, make sure you are in a totally different location each measurement interval, and the radar won't see you)
-> a plasma cloud would reflect light at any frequency, which would prevent the laser from impacting as long as you can keep the cloud from evaporating. More importantly it could block the targeting beam and deny the laser needed information (if it is totally black for the targeting beam the laser will not receive any light back and will be forced to conclude there is no attacking rocket at all)
-> the previous attack has a very low-tech version. Detect the targeting beam's frequency, and paint your rockets with the correct paint.
because the us gave them everything they have
To provide some numbers in the shell vs. rocket speed contest: Artillery shell (from another post) muzzle velocity is ~750meters/second. This is ~ mach 2.2 (at sea level). For comparison, a .308 bullet has a muzzle velocity of ~ 820m/s (mach 2.4).
Many of the #'s listed for missile speeds may be at altitude, but I did find one listing that seems to be near sea level: mgm52c = lance = american battlefield support missile, speed = mach 3.
Also, some missile speeds are listed as ~ mach 5, which is 1500 m/s even at 10,000 meters.
So, it seems that missiles are considerably faster than artillery shells. Actually an sr-71's speed is given as 1100m/s (2500 miles/hour) at altitude, which is faster than an artillery shell.
Not dumb at all. First, most larger naval vessels have enough room for a large system, more so than a ground-portable defense system. And second, while naval combat is no longer line of sight, defending a multibillion dollar carrier against a less-than-a-million-dollar missile is a major challenge, and most naval vessels now carry the Phalanx close-in system which is basically a last-ditch attempt to take out an inbound missile _right_ before it hits the ship by firing very rapid projectiles at it -- think of it as shrapnel/chaff on megasteroids.
:)
Of course, Trafalgar would have been a lot different if Nelson had had a laser defense system on the Victory that could intercept bullets...
Anyone who has served on board ship in the US Navy since 1980 knows just how good our targeting systems can be. Ever heard of the acronym CIWS? It stands for Close In Weapons System. It was designed to take out inbound projectiles such as cruise missiles between 10 km and 1 km from the ship. It is still actively deployed on many US ships.
The system consists of a tracking radar system with enough computing power to track up to 150 threats at once. It prioritizes the targeting system based upon inbound speed, size of the object, IFF status, and distance from the ship. Once this sucker is enabled, you'd better hope your planes have their IFF turned on, or they'll be shot down quicker than you can blink.
The system did all this using a Vulcan cannon, which is a gatling gun design throwing depleted uranium rounds downrange. The system was designed to fire and correct inflight to hose down a target until it dropped out of the sky. The system's biggest weakness was the fact that it went through rounds so fast (up to 6,000 rpm theoretical, 2,000 rpm typical) that the magazines had to be HUGE. I once saw a picture of the USS New Jersey after its refit. The 4 magazines on board held enough rounds to fire for a grand total of 15 minutes without stopping. The smaller ships that had the system frequently were limited to less than 2 minutes. A decent laser system's power plant occupying the same space would solve this problem.
This system was successfully demonstrated almost 25 years ago. Its first active deployment was in 1980 or 1981. And you "experts" are trying to tell me that the targeting technology hasn't improved enough since to take down an artillery shell? Oh, please. Go do some very basic research on what's in use TODAY before hollering about weapons tests for stuff that might be deployed tomorrow.
The only question in my mind is the size of the power plant necessary to drive a powerful enough laser to be useful. Can it be mounted on anything smaller than a ship? Anyone know?
Artillery shells follow a parabolic path. Elementary calculus shows that the maximal range of a shell is achieved by firing it at an angle of 45 degrees from horizontal (or marginally higher when air friction is taken into account.)
The maximal height of a shell fired at 45 degrees is about half its maximal range. So for a shell fired a mile high, its maximal range is about two miles.
For distances that are a small fraction of the circumference of the earth, the curvature of the earth measures about 8 inches in a mile. A laser at ground level twenty miles from the front lines could intersect an artillery shell flying a hundred feet off the ground, not to mention one flying a mile high, assuming the terrain is flat.
Since the maximal range of such a shell is only two miles, this means that a ground-based laser could theoretically shoot down shells from a distance that is orders of magnitude greater than the range of the gun.
No mirrors needed.
-ccm
Too much Law; not enough Order.
"Calculating an object like a mortar's trajectory is trivial"
Calculating a trajectory from known information is trivial. Calculating a trajectory based on radar coordinates when the object is already in motion is time consuming. You need at least two range vectors to get a rough idea and three or more to get somewhat accurate. These vectors currently come from radar which means the radar has to be conveniently pointing in the direction the shell is coming from to get the best time response. From there the system has to get the vectors, do the math, spin up the laser and reorient it, and fire it all in the relative short time that an artillery shell is in flight which is between 4 to 15 seconds give or take. Systems in the 80's were not that responsive regardless of how little actual computation is involved.
I've dirtied my hands writing poetry, for the sake of seduction; that is, for the sake of a useful cause. --Dostoevsky
Interesting summary of Soviet and the Nato battle plan. I would add that there was a condition to both plans being implemented, air superiority.
Which wasn't a given considering the size and quality of the opposing forces. These air forces couldn't have been knocked out preemptively or *first* (current US doctrine seems to apply a domino strategy, first air defence, then infrastructure, then battlefield components - highly effective I have to say).
Without air superiority, the battlefield aircraft would have had a quite *difficult* time.
Further, until air superiority was gained, it would have been the German grunt (albeit in a Leopard or two) who would have been trying to stop the Red Army, he would have been vulnerable to artillery. And the Mi-24s. And the T-72s. And the Specnacz running around behind Nato lines.
As far as going to war with the EU, hmm, that's a lot of (nuclear armed) territory to conquer and occupy. Unlike Isreal which you can drive through and across in an afternoon.