From Star Wars to Smart Rocks

By BRUCE VAN VOORST

Even by the tongue-twisting standards of the Star Wars lexicon, the newcomer is something of a mouthful: space-based kinetic kill vehicles, or SBKKVs for short. Some scientists refer to them as "smart rocks," since they are basically just projectiles designed to smack into enemy missiles. But they also have the potential of smacking into and perhaps even destroying the 1972 Anti-Ballistic Missile treaty. It is the alleged "stunning success" of smart-rock experiments, rather than any progress on the laser and particle- beam zappers usually associated with Star Wars, that has prompted Defense Secretary Caspar Weinberger to argue that "we are closer to being able to recommend deployment decisions."

The problem is that the ABM treaty, as currently applied, prohibits testing or deploying antimissile systems in space. Weinberger has been leading the fight within the Administration for a "broader" interpretation of the treaty, which emphasizes an appendage that may allow the development of systems based on "physical principles" that were unknown when the treaty was written. The State Department agreed that this interpretation is "legally correct," but Secretary of State George Shultz has so far been able to prevent the Administration from abandoning the more restrictive reading that has been in force for 15 years.

Reagan last week agreed to hold off making any changes in applying the treaty until he has consulted with Congress and NATO allies, a process that could take months. Meanwhile, the debate raises scientific questions that may turn out to be more important than nuances of treaty interpretations. Among the most critical: How feasible is the type of system that Weinberger says will soon be ready for testing and deployment?

According to advocates of an SDI speedup, it might be possible in the mid- 1990s to orbit a space-based system of hundreds of satellites, called "garages," each capable of launching a dozen or so smart rocks that could strike Soviet missiles as they are launched. The system would also include ground-based smart rocks capable of striking warheads as they re-enter the atmosphere. Gerold Yonas, until recently the chief SDI scientist, says "even a modest deployment of this sort would run over $100 billion." By contrast, a full-fledged Star Wars system involving lasers and other futuristic technology could cost $1 trillion or more and would not be ready until early in the next century.

Supporters of what has come to be called "phased deployment" -- meaning putting in place a simple system of smart rocks as a prelude to a more advanced system -- base their optimism on the success of last year's Delta 180 demonstration; in this experiment, a space vehicle launched on a Delta rocket tracked and targeted another rocket and then maneuvered to collide with a satellite. The demonstration, however, was somewhat rigged: the rocket orbits were preprogrammed, and a reflector on the target rocket magnified its image 1,000 times. Nevertheless, Air Force Lieut. General James Abrahamson, SDI's director, argues that the $150 million demonstration proved it is feasible for a smart rock to locate a missile shrouded in its own exhaust plume and track other objects in space. Although he says Delta 180 fell within the strict ABM guidelines, SDI supporters argue that the broad interpretation is necessary to conduct the next such test, known as Delta 181.

Opponents of changing the treaty interpretation argue that even the broad reading would not permit the testing of smart rocks in space, because they do not represent new or exotic physical principles. With the exception of a long- wavelength infrared sensor, the SBKKVs involve no technical breakthroughs, says John Pike of the Federation of American Scientists, and the land-based interceptors are merely upgraded, nonnuclear versions of the ABM systems developed during the 1960s. Says Democratic Senator J. Bennett Johnston of Louisiana: "The Delta 180 test demonstrated obsolete technology that is ineffective and vastly expensive."

The proposed system of smart rocks is a far cry from the original, exotic technologies. One plan was to use laser weapons in space, but the generators have proved too heavy to put into orbit. Researchers are now considering a more complicated plan to use ground-based lasers and bounce the beams off mirrors in space. Attempts to develop neutral particle beams or electromagnetic "rail guns" have likewise proved difficult.

Even the smart-rock technology faces daunting obstacles. According to the most optimistic projections, such a system would require putting more than 6 million lbs. into orbit, the equivalent of 125 space-shuttle loads. Nor have scientists come up with a workable way to discriminate between thousands of incoming warheads and ten times as many decoys. Perhaps the major unresolved issue is survivability. "Satellites in orbit are sitting ducks," says one expert, "far easier to hit than ICBMs in ballistic trajectories."

In setting up the SDI project, President Reagan signed a directive requiring that the system be "cost effective at the margin." Translation: adding new defenses must be cheaper than it would cost the Soviets to deploy missiles to counter them. Critics charge that hastily embarking on a smart- rocks system is a way to evade this requirement. "Phased deployment is an effort to obfuscate the 'cost-effective' argument," says Spurgeon Keeny, president of the Arms Control Association. "Supporters will concede that Phase 1 isn't cost effective but will argue that the ultimate, undefined SDI system would be." With so little genuine technological advancement, why the sudden push for phased deployment? One factor is clearly the pleas from SDI supporters in Congress for some evidence of progress to justify the program's budget, which this year calls for a 60% increase, to $5.2 billion. Weinberger and others add that early deployment would encourage the Soviets to be more cooperative in arms control. But the primary driving force seems to be the sense among SDI supporters that if the program, ready or not, is not locked into place during this Administration, it may never be.