Zapping Back

A panel shoots down Star Wars

A year after President Ronald Reagan unveiled his proposal for stationing a U.S. missile defense system in space, the basic feasibility of the idea continues to generate superheated controversy. It has been soundly endorsed by two Pentagon scientific commissions, which contend that advances in laser and other directed-energy technology make zapping enemy missiles from space a viable defense strategy. Last week the results of an inquiry into the notion were announced by a nine-man study group of the Union of Concerned Scientists, an organization based in Cambridge, Mass., that supports a nuclear freeze and has been critical of the nuclear-power industry. The group’s unsurprising verdict: the Star Wars space defense system envisioned by Reagan is technologically “unattainable.”

Achieving the degree of effectiveness that would provide a shield for the entire U.S. population, the panel said, depends on the ability to intercept Soviet missiles just after they have been launched, when their heat-emitting rocket engines provide a distinctive radar clue. No such “signature” is available during later stages of deployment, and detection is further complicated after the booster phase, when the rocket fires multiple reentry vehicles, including some decoys. Even if only 5% of Soviet missiles penetrated the space shield, the group argued, as many as 60 million Americans would die.

The Soviets already have several means of foiling attempts at booster-stage interception. For example, the U.C.S. panel said, the Soviets could increase the power of their weapons’ rocket boosters, cutting their burn time from a present average of 5 min. to as little as 40 sec. “We know very well how to defeat these defensive systems,” says Henry Kendall, an M.I.T. physics professor and U.C.S. chairman. “We don’t know how to build them.” Further work on the project, the U.C.S. scientists contend, will destabilize the strategic balance, which depends on both sides being equally vulnerable to attack. In addition, it would almost certainly force the U.S. to abrogate the twelve-year-old antiballistic missile treaty with the Soviets, dealing a blow to nuclear-arms-control efforts in general.

Supporters of the space defense system were unfazed by the union’s scathing report. Retired Army Lieut. General Daniel Graham called it the product of “those Charles River boys who say it can’t be done.” The Administration is continuing to press for an initial funding of $1.8 billion in next year’s defense budget, currently before Congress. Over the next five years, it wants the U.S. to spend a total of $26 billion on the project.