Exploring the High-Tech Frontier

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Meanwhile, the Pentagon plans to spend nearly as much of its 1986 S.D.I. budget request on sensors and battle-management systems ($1.6 billion) as on weapons development ($1.8 billion). Sensors are crucial to any system: they have to find the targets first and aim at them over thousands of miles of space. Keith Taggart, a researcher at the Los Alamos National Laboratory, likens the job to shooting out a specific window in New York City's World Trade Center by firing a rifle bullet from the top of the John Hancock Building in Chicago. The sensors also would have to flash back instantaneous assessments of what targets had been hit, so that a battle station would not waste vital seconds aiming a laser or particle beam at a missile or warhead already destroyed.

The computer requirements are straight out of science fiction. Computers would have to keep track of tens of thousands of objects (warheads, decoys, smart rocks) moving at high speeds, analyze instantly billions of bits of information from sensors and weapons platforms, determine which weapons to fire, when to fire them and at what targets. Not only could no human write such a program unassisted, no human could check it for errors. That would have to be done by computer too. James Fletcher, who headed the Administration's original S.D.I. study, estimates the program might have to be put through 50 million debugging runs before it would be battle-ready.

Other requirements, according to Fletcher: "The computers must be able to operate in a nuclear environment and must be hardened to survive radiation and shock. To keep crucial command, control and communications capabilities out of the fray, some of the computers would be placed in high orbit halfway to the moon." Humans would make the key strategic decisions in advance, determining under what conditions the missile defense would start firing, and devise a computer system that could translate those decisions into a program. In the end the defensive response would be out of human hands: it would be activated by computer before U.S. commanders even knew that a battle had begun. Fletcher insists that the "hardware requirements" are almost "within the state of the art" now, though 20 years or more might be needed to develop and deploy the battle program.

The real question is what the Soviets would be doing during that time. And the answer is all too obvious: taking countermeasures. Many are available, and they generally require less exotic technology than the defense they would be designed to defeat.

A simple though expensive method would be to multiply the size of the attacking force in the hope of overwhelming the defense. Some experts think the U.S.S.R. could double or even triple the number of warheads it could launch before the U.S could get a defense in place. A defense could be bypassed by bombers and cruise missiles, which, because they fly relatively low, could not be zapped from the heavens. After the Soviets shifted their main emphasis to ballistic missiles, the U.S. let its once extensive air- defense system deteriorate. Today it could not fight off a bomber attack, or even detect a cruise-missile assault. (It has trouble enough with drug- running airplanes.) A Star Wars system would have to be accompanied by a strengthening of air defenses that James Schlesinger estimates would add $50 billion a year to whatever might be spent on Star Wars.