Immediate use would be against RPGs, short-range homegrown rockets and stones dispatched from a hostile area. Pretty simple in concept: the object is spotted and tracked by radar or whatever it is they use nowadays and then detonated in-flight with a ground-based, high power laser or particle beam. Basically a Phalanx Gun for the neighborhood instead it uses ammunition that doesn’t fall back to earth. The range on the gizmo as it exists now is “classified” but I’d figure it to be at least a couple miles–possibly much greater with a laser weapon?
What logistical problems are there with this setup? Combined with a “no fly zone”
doctrine the thing should be able to stop anything airborne, even those damned canada geese.
Daniel O. Graham was suggesting these back in 1980, with his “High Frontier” ideas (not to be confused with the O’Neill Space Colony thing). The idea has certainly been bandied about quite a bit.
Despite the results I’ve seen with MIRACL and other Big Whonking Lasers, I’m unimpressed. And if the optics aren’t all kept superclean, it’ll destroy itself.
Yeah, but you still have a detonated missle (shrapnel) falling back to earth. In one sense, it might have been better to let the missle hit and destroy it’s (perhaps military) intended target than to break it up in the air and let the pieces fall down on top of a (parhaps civilian) gathering of people.
Furthermore, I think you’re overestimating the power/efficiency of current laser technology. I think something like this would be pretty huge and would use an incredible amount of power.
Finally, tracking would be very difficult, though not impossible. Missles fly very fast don’t always have a line of sight to every given point. I’d say it’s generally more feasible to destroy missles with other missles if you have enough early warning.
p.s. Wasn’t this the basic idea of Reagan-era “Star Wars”, except putting the thing in space rather than on the ground?
Problems are more technical than logistical. Laser weapons require a heap o’ power to fire. For this kind of application, they usually get the power by mixing very reactive chemicals. That makes each shot very expensive. Lasers are also less effective in conditions of limited visibility — smoke, rain, fog, and so on.
Now there are some advantages to using lasers in this application (as opposed to shooting down ballistic missiles). The targets are nearer, so theoretically shouldn’t take as much energy to disable. The beams do propagate at the speed of light which certainly simplifies aiming. However, laser beams don’t remain tightly collimated over long distances – the beam spreads. So if you want to heat up a chunk of metal to detonating temperatures within a milli-microsecond or two, you need a lot of juice.
Basically, it’s easier and vastly cheaper to just throw a rock (ok, a chunk of steel or lead) at the incoming bogey.
Just thought of a (potentially GD) sidebar topic from this: If you had a laser that could reliably shoot down enemy missiles while they were still in their initial boost stage (ie: Going up to get altitude rather than cruising towards their targets), and you had a counter-missle system that could shoot down missiles during their final approach with somewhat less reliability, how heavily would you need to weigh the risk to the population of the launching country from the falling wreckage of their missiles against the risk of those missiles (presumably quite accurate) hitting their (presumably military or high-government) targets in your territory?
I mean, once the other guys launch their missiles at your guys, do the gloves basically come off? Assume for purposes of discussion that for whatever reason, the likliehood of intercepted missile debris falling on populated areas of the enemy are relatively high (maybe they have some coastal cities between their country and your country)
If anyone thinks I should just make a GD topic for this, I can do that and link back to here, but I’m just curious.
Back to the topic of atmosphere dispersal, one idea I’d heard was to use a weaker targeting laser to get a reading of how the air disperses the beam, and calibrate the actual weapons laser to compensate (thus making the atmosphere itself the last lens). Not sure how much an issue they would have with the lag (the time for the targeting laser to travel from launcher to target and back, and then the time to calibrate the launcher to compensate, while still trying to keep track of the fact that the missile is moving at great speed this whole time).
Yeah, I was quiet on the debris part of** Jayrot**'s response because I felt that was more of a GD point. I’d say that if you think you need to lob a rocket at someone, then you need to consider their natural desire to retaliate–and thus the debris from your own rocket is simply saving them a step, and only happens if you get aggressive.
Are there any missile launch sites in the US or USSR that are located near major population centers? It would make strategic sense to have them in remote areas, or mobile on railroads/submarines, so I doubt “falling debris” is really much of a concern to anyone.
For ballistic missiles (whether long range or short range) even a boost phase intercept is likely to occur well away from the launch site. With regard to damage from debris, while it is a real problem, in a warfare situation it’s certainly better to risk the (generally small) likelyhood of casualties on either side rather than the high probability of death and destruction from a direct hit. Back in the days of Nike-X/Sentinel (in which the nuclear-tipped Spartan and Sprint terminal phase intercepters were planned to defend cities and strategic assets near major population centers) it was just assumed that there would be some damage to the area being defended, but that this was preferable to a multi-megatonne class strike. Moscow is (or at least was) ringed with anti-missile interceptors, again nuclear armed. (Safeguard was eventually deployed at the Mickelson Missile Complex near Grand Forks, ND, and decommissioned mere months after achieving operational status.)
First of all, let’s separate the concept of divergence (the inherent angle of which a beam spreads) from diffraction in a medium and thermal blooming. Divergence (for a high frequency beam) isn’t a big problem at suborbital distances, and the atmosphere is pretty transparent to UV on up. The big problem, then, is thermal blooming, which is the result of even a small fraction of energy being absorbed by the atmosphere creating turbulent behavior, condensation of superheated steam, et cetera, which then diffracts the beam. It’s a problem that lacks a practical solution. (Despite the Tom Clancy-popularized idea of using adaptive optics to “tune” the laser to achieve optimal penetration, the fact is that thermal blooming is a chaotic and progressive behavior. It’s rather trying to make a boat go faster by piling on the horsepower; hull resistance increases with velocity and eventually you get no gain for additional power.)
The problem of power and throughput are real ones; not only do you have to be able to generate a lot of energy, but you have to do it very quickly. Many orbital laser proposals actually involved detonating a small nuclear weapon to power an x- or gamma ray laser. Obviously, this is neither acceptible nor strictly necessary for a ground based laser, particularly one for site defense in the megawatt range, but you can’t just use a generator and a set of batteries. The energy is generally created by a chemical reaction, often used to directly stimulate the lasing medium. As Finagle notes, this is both expensive and messy.
US land based ICBMs are generally located in remote farmland in Midwestern states like Missouri, Kansas, Nebraska, North Dakota, Idaho, et cetera. The same is predominantly true for the former USSR. This is not true, however, for sites in Eastern and Western Europe, where IRBMs were often based adjacent to population centers. (Not much choice in many cases.) Debris, in any case, may fall hundreds or thousands of miles downrange–hopefully in an ocean, but possibly on either the defender or the attacker. Again, the presumption is that it’s better than letting the weapon hit the target, which isn’t of much solice to you if an SR-73 motor lands on your house. But that’s why it’s called “collateral damage”.
Now that I think of it, Cecil wrote an article about the nuke-tipped counter-missiles. IIRC, there was come concern from Canada that the likely intercept area for missile batteries defending American cities along the nothern border would have our nukes blowing up over their cities.