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U.S.: Experts Review Technology Behind The Missile Defense System

  • Askold Krushelnycky

The National Missile Defense system, known widely by the initials NMD, being considered by the new U.S. administration is a $60 billion project with the potential to grow. The system proposes to bring together existing and developing technology to intercept and destroy missiles launched by rogue nations against the U.S. and its allies. In this second of a two-part series, RFE/RL correspondent Askold Krushelnycky looks at the feasibility of creating such a massive integrated system and whether NMD will ever be able to do the job it is designed for.

Prague, 21 February 2001 (RFE/RL) -- As the new U.S. administration spends the next several months reviewing its commitment to the proposed National Missile Defense system, a crucial question remains: Can NMD even be built?

NMD is supposed to defend the U.S. and its allies against limited attacks from hostile "rogue nations" like Iran or North Korea, both of whom are widely believed to have acquired nuclear capabilities. It proposes to coordinate early-launch detection and tracking of hostile missiles with a system of intercepting missiles that will destroy any incoming warheads by force of collision.

The system calls for a sophisticated interactive network of surface- and space-based sensors. The intercept missile, which comprises a booster rocket and the so-called Exo-atmospheric Kill Vehicle (EKV) -- designed to target and collide with incoming hostile missiles -- is perhaps the project's single most ambitious element.

After separating from its booster rocket, the EKV must rely on its own propulsion, guidance, and communication systems while still receiving updated information from the NMD command center on Earth.

The EKV has been given three test runs since 1999. Only one was successful. Now many U.S. scientists are saying the technical challenges involved in creating a national missile defense are insurmountable. They say the project risks becoming a hugely expensive failure.

A team of physicists and engineers issued a report on NMD several months ago for the Security Studies Program at the Massachusetts Institute of Technology and for the Union of Concerned Scientists, which monitors scientific developments.

The report argues that one of the system's primary challenges is determining how to reliably strike a moving object with another moving object. One of the report's authors, physicist David Wright, describes the difficulty of using one missile to hit another as comparable to trying to stop a bullet by firing another bullet at it.

"That's a difficult thing to do, although I think myself and other scientists would say with enough time and money and tests you can probably do that with some level of reliability. The real issue that we've found is what happens if the attacker decides to do things to make our life much more difficult, so that you can't figure out which object coming at you is actually the warhead?"

Wright says NMD's chief flaw is its vulnerability to countermeasures as simple as enemy missiles that release decoys that may be difficult for NMD sensors to distinguish from real warheads:

"One of the things that we have looked at is the possibility of the attacker using simple decoys so that instead of seeing a single warhead coming at the defense, you might see 30 or 40 objects -- all of which look roughly similar but a little bit different -- and the job then is to figure out in the short amount of time available which of those objects really has the warhead in it."

Wright adds that in the case of chemical or biological weapons, the warhead could divide into a number of small bombs which could overwhelm the NMD system with too many targets. He says present-day science is simply not equal to the task of creating a NMD system that can quickly respond to every available countermeasure:

"People sometimes point to landing a person on the moon and say that was a very difficult technical problem which we solved at the time and we could solve much more easily today given the advance in technology. But again it's a situation where the moon wasn't actively trying to fight back. The moon wasn't actively trying to keep us from landing there and that would have been a vastly more difficult problem."

The U.S. Defense Department spokesman for NMD, Lieutenant Colonel Rick Lehner, says project researchers were fully aware of the problems posed by countermeasures.

"Right now, we're engaged in a very sophisticated development effort to ensure that any developed National Missile Defense system can effectively deal with the type of countermeasures that we expect from the potential threat nations. And we plan to continually test and evaluate our ability to defeat these measures and incorporate its technology into any operational or NMD system."

Lehner says many important advances have already been made to overcome countermeasures, but that details cannot be revealed:

"The countermeasures program we have in place is very active, it's very sophisticated, it's very highly classified, and for this reason it's very difficult to offer a response to the allegations made by these eminent scientists."

But Wright remains unconvinced. He says: "The Pentagon is saying that with time they'll be able to tell which is the warhead and which aren't and we're saying it looks to us like the physical information available to the sensors may not be available for that."

The team that prepared the skeptical report on NMD believes that the test program for the system is itself flawed because researchers are concentrating on solving how to hit a target before fully addressing how to overcome enemy decoys. They say both problems should be addressed simultaneously.

Wright says the tests have also been unrealistic in that NMD faces far fewer decoys than an actual enemy would use. He says no final deployment decision should be made by the U.S. government without testing the system on realistic targets.

"The problem is those deployment decisions will only come based on those very simple tests. And so we would say the deployment decision is getting way ahead of the testing program to show you whether you've got a system that could do anything. And based on our research we think that when they get down the road and really try to do honest testing against real countermeasures they'll find that this system does not have much capability."

Wright and his fellow scientists say they are not opposed altogether to the feasibility of a missile defense system. They say a different type of missile-intercept system might offer more promise.

One such system is being developed by the U.S. Air Force. It uses powerful lasers in planes to shoot down missiles soon after they are launched.