According to this CNN story:
It seems that the shell was destroyed, “at a point well short of its intended destination”.
What are the odds that this happened in the picture perfect way described in the story? Remember that the military claimed sucesses with their ABM defenses. Of course it was later shown that the ABM tests didn’t work properly, even when they cheated.
The article didn’t claim that all was picture perfect, only that the system worked under optimal conditions:
The THEL system did well against katyusha missiles in 2000.
-TRW THEL site
TRW press releases
If TRW is 'faking it, and I see no reason to think so, they’ve certainly left themselves very little in the way of a survivable exit strategy.
IANA Rocket Scientist, but it seems to me that locking onto a missile as in Squink’s link would be much easier than locking onto an artillery projectile in ballistic flight. Reasoning: the rocket ras the hot flame coming out of its back end, enabling a lock-on to its light or heat source using something like a Sidewinder seeker; slaving that to a laser would mean a laser could then shoot at the target. I would also think that the rocket is going slower than an artillery shell, but I couldn’t say for sure.
I think an artillery projectile would be pretty damn hot too.
Artillery shells move faster than short-range free-flight ballistic missiles. They’re also much more robust, having to withstand the massive jolt they get when fired. A conventional artillery shell is mostly solid metal, with a surprisingly small bursting charge. They also tend to be smaller than a free-flight missile of similar capacity. Any Directed Energy System that can aquire, track, engage, and cause to prematurely detonate an artillery shell, is a seriously impressive system.
To start, it has sufficient energy to likely do serious damage to aircraft, too. Short-range missiles barrages can be seriously degraded by a relative handful of such systems. Ballistic reentry vehicles for SRBMs and above may even be vulnerable.
The success in tracking and engaging an artillery shell, even if only in a testing environment, changes many of the most common assumptions about ballistic defense. These systems will only become more and more capable as time passes. Star Wars isn’t so far-fetched anymore.
With the ABM system, one test takes a significant of effort to set up. In this system, it seems like you could do tests all day and night until you finally hit the thing and put out your press release.
I remain highly skeptical after all their missile interception jokes.
Sub orbital re-entry vehicles travel rather faster than artillery shells, though, and for the most part, a real missile defense that doesn’t include that expectation is a pointless boondoggle. Not to even mention that higher reentry speeds are readily achievable with only modest development. It could be one of those cases where a million dollar weapon improvement can overcome a billion dollar defensive system.
It doesn’t seem to me to be a really pressing security issue, compared to some other areas, such as rapid deployment NBC attack response systems to protect civilian targets. Everyone else is belt tightening, and the defense industry needs to do it too.
“You can’t always get what you want.” ~ M. Jagger/K. Richards ~
The British and Canadian Armies in Italy and NW Europe had quite a few radar batteries formed for location of German artillery by tracking the shell in flight (and working backwards to its point of origin). The FA No 3 Mk I set was used for this; however, it was mainly used against high-angle mortars and nebelwerfers.
Whether it would have been effective against high velocity, flatter-trajectory shots from, for example, an 88mm is something I don’t know.
The US Army has the “Firefinder” radar system, in service since the mid-1980s: http://www.fas.org/man/dod-101/sys/land/an-tpq-36.htm
The site notes that as the system ages, “it is increasingly difficult to obtain many of the components. The system’s reliability is also degrading.”
All of the current batch of ABM tests involve a physical interceptor trying to stop a very fast moving re-entry vehicle. They do move much faster than a conventional artillery shell. You’re comparing apples to army boots when you try to draw conclusions about a laser test from tests on a totally different technology.
Tracking artillery shells in flight is, as has been noted, a mature science. Some of the first mechanical and electronic computers were basically fire-control systems for doing just that.
It is very doubtful that this weapon could ever be used as a ABM weapon for a couple of reasons. The laser must deliver a lot of power to a small area in order to destroy the target. Tracking and hitting artillery shells, as <b>Trucido</b> stated, is a mature science. The problem with destroying ICBMs is one of range. The radius of a laser (gaussian) beam increases linearly with distance (and thus the power / area decreases with the square of the distance). This fact cuts down the range of any laser weapon dramatically.
The second problem is that the atmosphere will scatter the light in the beam, further decreasing the power. The best bet would be to pick a wavelength of light that is not scattered by the atmosphere, probably somewhere in the ultraviolet range (anybody out there know the absorptioin characteristics of the atmosphere?). Here you get into another problem though, the power required to make a laser scales approximately inversly to the wavelength to the 5th power. This could make a long range laser weapon prohibitive.
I do however think this would be a good theatre weapon (Isreal and Scud missles.). Would also be a good thing to have on aircraft carriers and battleships to knock down those pesky anti-ship missles.
This is true at sufficient distance from the laser, but “sufficient distance” is on the order of D[sup]2[/sup]/ lambda where D is the diameter of the source, and lambda is the wavelength. Within that range, the spread can be much smaller. As an example, a circular Gaussian beam with initial characteristic radius of 10 cm, and a wavelength of 5500 Angstroms, will take almost 100 km to double it’s beam diameter.
This wasn’t a test of acquisition and tracking, the target missile had a GPS receiver on the warhead and a C-band beacon. They were just testing out of if they could destroy a missile if they eventually figured out the whole tracking part. IMO, Star Wars is still pretty far-fetched. Not like that will stop the government from dumping billions into it while education and healthcare go down the crapper.
cainxinth, the artillery shell test mentioned in the OP wasn’t part of the NMD test program. It was for the army’s theatre defense system. AFAIK they haven’t yet released details on whether the laser’s tracking system had help in finding the shell.
This gets to the heart of the question I was asking. Was the test sucessful in a meaningful way? Was it able to track the shell and then destroy it or was the system pointed in one place that had artillary fired infront of it? Given the ABM tests results, I am more inclined to think that the latter is true, or at least more true.
Even if the system is just a prototype and it was able to track and destroy the target, what would keep the US and Israel from starting to deploy it next week?
Nit: Being unguided, the Katyushas are rockets, not missiles.
Hitting artillery shells is certainly not a mature science.
That’s a totally different kind of tracking. That was to see if the shells were hitting the intended targets, and if not, making modifications so they would.
This is true at sufficient distance from the laser, but “sufficient distance” is on the order of D2/ lambda where D is the diameter of the source, and lambda is the wavelength. Within that range, the spread can be much smaller. As an example, a circular Gaussian beam with initial characteristic radius of 10 cm, and a wavelength of 5500 Angstroms, will take almost 100 km to double it’s beam diameter.[/quote]
zenbeam:
Your numbers didn’t sound right, so I crunched them myself. The numbers can come out to different results, depending upon how youi define beam size, but it’s on the order of 100 km. On the other hand, 10 cm at the beam waist is a pretty damned big beam…