Lasers play a key role in missile-defense program

In July, the Bush administration unveiled its blueprint for developing defenses against enemy ballistic missiles, and laser technology may well play a major role in whatever system is deployed.

In broad brush, the missile-defense system would resemble systems championed by previous Republican administrations. It would include a variety of weapons that would seek to destroy ballistic missiles at a variety of points—while the missile's rocket engines were burning, while the warheads were coasting through space, and in the final moments of flight as the warheads plunged downward through the atmosphere.

Laser technology appears most likely to surface in the first phase, known as the "boost phase," which lasts for several minutes while the missile's rockets are thrusting. Laser-equipped aircraft and satellites are both candidates for this part of the missile-defense system, said Lt. Gen. Ronald T. Kadish, head of the Pentagon's Ballistic Missile Defense Organization.

A ballistic missile's rocket fires for only 180 to 300 seconds, Kadish said. "That's not a lot of time to intercept a boosting rocket." It's a very limited time to get an interceptor rocket to the boosting enemy missile—but a laser beam travels much more quickly, he noted. "The speed of light cuts down that distance rather tremendously, so that's why we like laser energy for that type of a system."

ABL poised for flight in 2004

Kadish expressed optimism about the Airborne Laser (ABL), a laser-equipped Boeing 747 that is being designed and built by a team of contractors headed by TRW Space and Electronics (Redondo Beach, CA), Boeing Co. (Seattle, WA), and Lockheed Martin (Palo Alto, CA).

"We've been working on this for a number of years, and then the Air Force has brought this along, maturing that technology very well," he said. In 2003 or 2004, the Air Force should be able to test the ABL against a ballistic missile in flight, "which would be very exciting if we were able to make that technology work," he said. "All of this is high-risk in terms of this type of technology, but we are building our confidence every day in our ability to do this."

Paul D. Wolfowitz, the deputy secretary of defense, told the Senate Armed Services Committee that the threat posed by enemy missiles is great. "If you go back to the Gulf War, we overestimated virtually every Iraqi capability except this one. Ballistic missiles were the only area in which Saddam Hussein was much more capable than we thought he would be . . . Today, we know if there were a war in Korea this year that the ballistic missile threat from North Korea would be one of the most serious threats we would face," Wolfowitz said. "When you do an analysis of what would make the greatest difference for theater missile defense on the Korean peninsula, I believe the analysis concludes the most important effective advance would be airborne lasers."

Kadish told lawmakers that the agency plans to have the ABL ready for use in a crisis in 2004, and for a fleet of ABL aircraft to be fully operational by 2008. Although the ABL originally was touted for its ability to destroy short-range and medium-range missiles, the Pentagon wants the laser aircraft to intercept long-range ballistic missiles as well, according to Kadish.

Future laser-based developments

Kadish also said the Pentagon will begin "intense concept studies" for using missiles to conduct the boost-phase interceptions instead of the laser aircraft, "should we run into problems there."

Further down the road, Kadish said, is the prospect of an orbiting laser weapon. The Ballistic Missile Defense Organization is continuing with plans for a space test of a laser, known as the Integrated Flight Experiment, in 2012.

Kadish said the Pentagon is planning how it would test the ways the various elements of the missile-defense system would work together. "I could see an airborne laser, for instance, in a multiple-shot target-shot engagement being told to take out the first missile that's launched, and then the midcourse system take out the second missile launched."

He explained that such a layered approach would help address limitations in the airborne laser. "Even though there might be some safe havens that it can't reach, it has a pretty good capability for the ones it can reach, and you supplement it with a midcourse system," he said. "Then you have the situation where you've greatly complicated the adversary's problem because he doesn't know whether or not that airborne laser is going to take this thing out . . . If he does the calculations and wants to take the chance, and he's right, we still have another system to go after it."

Not everyone is convinced that a layered defense means that laser weapons are necessary, however. Philip Coyle, who was the Pentagon's director of weapons testing in the Clinton administration, told the same committee, "I understand the logic behind a layered defense. It does give you three bites at the apple." But, Coyle said, sea-based missiles appear to be a better prospect for boost-phase interceptions of missiles. "The technology for boost-phase defenses from ships is much further ahead than the airborne laser or the space-based laser, in my view. he said. "And the airborne laser has a very long way to go in development."