Will Star Wars Ever Fly?

By BRUCE VAN VOORST

A space rocket that stalled helplessly on a White Sands, N. Mex., test stand last week seemed to symbolize the fears critics have long expressed about the Strategic Defense Initiative. What fizzled was not the payload -- a satellite designed to generate Buck Rogers-style neutral-particle beams in space -- but a thoroughly conventional solid-fuel Aries booster. Coming after an aborted mission in March using a Delta launcher, the unsuccessful mission crystallized suspicion that SDI is so riddled with potential failures that it will never get off the ground.

Last week's failure occurred as President Bush and his advisers huddled to formulate a new U.S. position for this week's resumption in Geneva of the Strategic Arms Reduction Talks with the Soviet Union. On one critical issue, the President ruled out any compromise. The U.S. is prepared to abide by the 1972 Antiballistic Missile Treaty for seven to ten years after a START agreement is ratified. The Soviets insist that even after that period, the U.S. should continue to refrain from deployment of SDI. Bush decided not to relax U.S. insistence on the ultimate right to install the system. He acted in part to avoid irritating his conservative supporters. But the Soviets say they will not agree to START without continuing constraints on SDI.

For all the fuss, SDI seems moribund. Despite appropriations of $17 billion over the past six years, there are no realistic prospects of deploying a Star Wars system for a decade. SDI has remained singularly unpopular in Congress, which has cut every White House request for SDI funding. This year Bush himself reduced the Reagan request from $5.6 billion to $4.6 billion, and Congress might slash even more.

Part of the problem is the consistent inability of SDI's designers to define its "architecture," the way it is supposed to work. Originally, there was much talk of space-age particle beams and laser weapons, until the practical difficulties of those technologies became apparent. In 1986 the fad was nuclear-generated X-ray lasers. Last year the SDI organization, fearful that Congress would further cut funding in the absence of a tangible program, pressured the Pentagon into endorsing "Phase I," a system of ground- and space-based sensors and interceptor rockets.

But then Lieut. General James Abrahamson, the outgoing SDI director, said he would be willing to scuttle some important elements of Phase I in favor of a new technology, "Brilliant Pebbles." Initially, SDI had called for hundreds of orbiting "garages," each carrying ten killer rockets that would crash into oncoming Soviet ICBMs. In the latest version, some 6,000 independent Pebbles, each 3 ft. long and weighing perhaps 100 lbs., would do the job. The new SDI director, Lieut. General George Monahan, has cautiously embraced the concept as "doable" but warns that it is still an experimental approach. SDI supporters have rallied behind Pebbles as a welcome boost for the faltering program.

When inspected closely, however, Pebbles appears less than brilliant. Much of the sensing technology remains unproved, and the difficulties of retaining human control of thousands of semiautonomous weapons hurtling through space are immense. Moreover, claims that the Pebbles would cost as little as $500,000 each are overly optimistic. Even if such difficulties can be overcome, it is unlikely that the American public would ever warm to the idea of cluttering the heavens with a swarm of rockets outnumbering existing satellites by a factor of six.

Not surprisingly, considering the huge sums that have been spent, SDI has achieved some technical breakthroughs. The new cryogenic sensors for tracking missiles are impressive. Last week's aborted neutral-particle-beam experiment will be an important scientific achievement when completed. But the biggest successes have been in miniaturization. Early models of the "inertial measurement unit" for steering rockets were as big as a bread box and cost $70,000 each. The latest versions are tennis-ball size and cost only $5,000 apiece.

SDI's overwhelming problem is the continuing confusion about its strategic objectives. Even its enthusiastic supporters have abandoned the Reaganesque notion of an "Astrodome" defense. Vice President Dan Quayle, the leading SDI proponent, now describes its near term value as "enhancing deterrence."

But enhancing deterrence is a far cry from replacing it. If SDI's function is only to increase the survivability of America's ICBMs and command centers by destroying less than 40% of the U.S.S.R.'s 9,000 warheads, then it must compete doctrinally and for funding with other systems that can do the same job. Deterrence might be more readily assured by building weapons better able to survive a nuclear attack, such as the Midgetman mobile missile or ) additional missile-carrying submarines. Particularly in times of declining defense budgets, SDI must demonstrate that it is superior to other systems and more advantageous than the protections offered by arms control. Given Soviet determination to block the deployment of SDI, Bush will have to arbitrate these issues in choosing between Star Wars and a fruitful outcome to the talks that resume in Geneva this week.