Physics of Folly
Ever since W. made missile defense a central feature of his campaign, boosters of all stripes have been salivating over the opportunity to get their various pet Star Wars projects funded. There are plans for putting missile defense in the ocean, in the air and in space. There are even researchers working on airplane-mounted lasers and killer satellites. Recently W. announced that he plans to expand Clintons already-contentious limited missile-defense research and deploy a comprehensive system over the objections of our allies.
The problem with all this is that none of it works. These systems use imprecise technology to track their targets, and most tests so far have failed. Last July, in the most recent trial run of the hit to kill vehicles currently being developed, the defensive rocket sailed wide of its target in an embarrassingly harmless arc high over the Pacific.
Ted Postol, a physicist and former Pentagon adviser who is now a professor of science, technology and national-security policy at MIT, is a leading critic of missile defense. Building a $60-billion-plus system, he argues, provides the worst of both worlds: no effective defense and less international stability. In a telephone interview from his MIT office, Postol explains why the so-called kill vehicles wont kill anything, why having them will make the world more dangerous, and why the whole scheme is as dumb now as when Ronald Reagan was seduced by the Star Wars fantasy.
L.A. WEEKLY: First, maybe you could describe a little bit about how the missile-defense system works.
TED POSTOL: Basically, it is a system of radars that try to track objects in space and an interceptor, which is a rocket booster with a device mounted on top called a kill vehicle. The kill vehicle weighs maybe 120 or 130 pounds, and it looks like a sort of telescope with small rocket motors on it. The kill vehicle gets launched towards the target of concern -- or targets, as youd expect in a real-world scenario.
Does it all happen quickly?
Yes. The rocket booster accelerates the kill vehicle to a very high speed -- between 7 and 8-and-a-half kilometers per second -- and the incoming warhead is itself traveling near that speed. So the crossing speed is quite high. This is why accuracy is important. But the system is not very accurate. The kill vehicle is launched a few minutes before the actual flyby, but it is launched to a point in space where the system has calculated that it will be near incoming targets. And only there does the kill vehicle open its eyes, so to speak, to look for the targets. And when the kill vehicle opens its eyes, its a very small field of view, perhaps 1 degree on a side. And then it has about 60 seconds to observe and home in on its target.
So the kill vehicle is not tracking the incoming missile the entire way. It goes to what it thinks is the vicinity, and then only has a brief moment to meet the target.
Right. It is a projected interception point calculated by the radar -- with some uncertainty, I might add.
I understand that the infrared sensors of the system are an issue too. The tracking system on the kill vehicle sees the incoming missiles as --
Points of light. Like little stars.
And the resolution of these sensors is not very good.
Thats part of the problem. Theres no dimensional information.
Is that a technological limitation that can be overcome? Will we be able to make more accurate sensors in a few years?
No, that limitation will not be overcome, and even if it were improved, it would not entirely solve the accuracy problem.
And, if I understand correctly, the reason increased resolution wouldnt solve the problem is that even a better image would still not allow the kill vehicle to distinguish between actual warheads and decoys.
Yes. For example, say theres a warhead flying through space, tumbling end over end as warheads do. And say theres also a decoy balloon shaped like a warhead, also tumbling end over end. There would be no observable difference that would allow the sensor -- even a better one -- to determine which was the warhead. This is the fundamental problem. This kind of system is designed to work in the vacuum of space, and in the vacuum of space, the two would behave exactly alike. In space, it is extraordinarily easy to deploy decoys.
What other kinds of decoys are there, and how do they affect the infrared signals?
You could take a decoy balloon, for example, and paint big stripes on it so that its signal scintillates like that of a tumbling warhead. Or tethering objects to a warhead would be a way to defeat the system for sure. Tethered flares, for example -- they would completely dominate the infrared signal. You wouldnt be able to see the warhead at all. Or you could throw flares out freely, and the system would have no way of telling one from the other.
And would that mean a total miss? How precise does the intercepting kill vehicle have to be?
It has to be precise within a fraction of a meter.
Thats a tall order.
Yes. Its ridiculous to believe that our potential adversaries would be able to build ICBMs and warheads but not be able to devise these kinds of countermeasures.
Youve said that the Pentagon went easy on its own tests of the systems. They didnt use these kinds of decoys.
They didnt do anything. First, their data showed clearly that the sensors wouldnt be able to distinguish tumbling warheads from tumbling decoys. So in the actual test series, they modified the tests to never deal with those kinds of a decoys. They removed that kind of threat from their test program in order to claim they can build a system thats workable.
Tell me about the test of the system last July, which failed altogether.
That test was an extraordinary set of failures. First, the only targets were a warhead and a large balloon. The balloon is almost 10 times brighter than the warhead. There was no discrimination necessary. They told the kill vehicle ahead of time, You are going to see two objects -- a large bright object and a less-bright one. Now, go after the less-bright one. Even if it had gone well, it would have proved nothing because it was the simplest possible situation you can imagine. But the test warhead and decoy didnt deploy properly; the kill vehicle didnt deploy properly. They screwed up the whole thing.
Clinton used this test as a reason for delaying the decision to employ the National Missile Defense program, citing the uncertain technology. But the current administration has signaled its interest in building the system --
Whether or not it works.
And weve been talking about what is called a midflight interception, right?
Right. This is not a boost-phase interception. This happens many hundreds of kilometers in altitude, where theres no atmosphere.
What about a system that tries to intercept the missiles at a different point in the trajectory?
A boost-phase interception or a re-entry interception, that is where the missile is exiting or re-entering the atmosphere, would make decoying much harder.
Let me ask you about that. Some, including Bushs advisers, propose boost-phase interception as a more workable alternative. How feasible is it?
Well, there are a lot of caveats here. I am not an advocate of a boost-phase system. But I will say that I have analyzed it more than anyone else. If the threat is North Korea, and theyre using a fairly primitive missile technology, you could build a system of radars and interceptors that would have a very good chance of getting those missiles.
But a good booster-phase system still wouldnt be able to answer a large-scale attack or even a limited attack from missiles launched inland, from China, for example, or even Iran for that matter.
Right. Well, let me say this. Suppose that I can build a defense system that is so capable and robust that no missile could get through -- 100 percent effective. Then, you might have a case for it. I say might because the likely response from our adversaries would be to try to develop weapons with different modes of delivery or to concentrate on short-range missiles [which are much harder to intercept because they are in the air less time] or to threaten our allies. So increased security for us, in this optimistic case, would come at the expense of arms control and the security of our allies. Now the other extreme, which is the situation we currently have, and will continue to have, is that defense, even under the most optimal conditions, is unlikely to work. But we will provoke the reaction anyway. This is the worst of both worlds: The defense has no capability, while also prompting our adversaries to step up the threat.
Is there any system that will ever work effectively, or is the whole idea a bust?
Right. There are new proposals all the time. The most recent idea is lasers mounted on airplanes.
Well, a laser on an airplane has some potential to shoot down an ICBM. Now theres an important caveat there as well. Its not yet demonstrated that lasers have the power or beam quality that would make it effective. And maybe they will. On the other hand, a laser can only destroy a rocket in powered flight, which means that it will target the booster, leaving the warhead or biological payload or whatever else is in there to fall to Earth before it gets here. That would mean a WMD [Weapons of Mass Destruction] payload falling somewhere else, like in Canada. And that might bother the Canadians.
So lasers or other systems, even if effective, wouldnt solve all the ancillary problems of missile defense: no protection against short-range missiles; no protection for allies; and the slippery slope of arms escalation and even militarizing space.
Right. The question always should be: What do you get in relation to the cost? And, with missile defense -- at least all forms of missile defense that will be available for the foreseeable future -- the answer is: not a lot. My own view is that it is important to analyze these things in a comprehensive way, as opposed to dismissing them out of hand. Because theres people out there selling noodles, as the Israelis would say. And the systems sometimes have some merit, but they get oversold -- way oversold in the case of whats on the table today. Missile defense has been completely politicized.
Its not only politicized, but it has become quite vitriolic.
Oh yeah. I had one guy threaten to attack me. A guy who works for Thad Cochran [Mississippis Republican senator, who is an ardent supporter of missile defense] wanted to have a fistfight with me. It was in London, and I was sure he was going to hit me, but a bunch of British officers fell on him just before he got to me.
Maybe you need a Congressional Staffer Defense System.
Right. Well, thats the mindset of some of these guys.
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