Physicists' war games led to brilliant space defense plan
By Ian Hoffman/Oakland Tribune/September 10, 2002

Brilliant Pebbles and its original braintrust of physicists -- the mercurial Edward Teller, lead co-inventor of the hydrogen bomb, and his creative proteges, defense theorists Lowell Wood and Greg Canavan -- are entwined in the public memory of the Reagan Strategic Defense Initiative.

In the early 1980s, Teller sold Reagan on the technical feasibility of making nuclear war obsolete, then assembled Wood and Cavanan month after month in 1986 for strategic thought exercises, based on John Nash game theory. Wood played attacking Soviet forces, the red team; Canavan played the American defenders, the blue team; Teller refereed.

Canavan stretched his imagination to envision all manner of defenses as Wood defeated them, one by one, laying America open to annihilation. The final battle came over breakfast on the north side of the Charles River, in Cambridge, Mass., Canavan recalled, "deep in the heart of enemy territory," the academic nexus of the anti-missile defense debate.

"Lowell was so confident then. He'd killed me like 40 or 50 times. He was reading his newspaper and not paying much attention when I laid it all out," Canavan said. "Teller said, 'That's it!' Lowell snapped upright. 'What? What? What?' And he started trying to construct a counterargument. But by then Teller was sold."

The basic premise was an automated multitude of inexpensive satellites at first known as "smart rocks" because they would each carry a powerful computer and their own sensors for seeing target missiles. Early space interceptor schemes were highly vulnerable to attack. But the team's satellites would be hardened against radiation, laser beams and shrapnel. They could maneuver to dodge anti-satellite missiles. They could kick off decoys and chaff to confuse attackers. As a last measure, they carried a tiny dart to fire in self defense.

"Nothing can get through all that. By the time he can get to you, he's expended a mass that's 100 times larger than you are, so you win," Canavan said.

Teller and Wood sold the idea in Washington and translated it into hardware, with Wood towing a sample pebble on a cart through the corridors of power. At the time, wags joked that after smart rocks and Brilliant Pebbles could only come "genius dust." Critics rolled their eyes and denounced the weaponization of the heavens. But of all SDI's beams and schemes, the pebbles came closest to the reality. Its major components were tested next to exploding nuclear bombs in the Nevada desert. They flew to the moon and mapped it in the Clementine mission.

In 1991, former Soviet weaponeers told Canavan that they labored hard but couldn't theorize a cost-effective assault against Brilliant Pebbles. "They said they realized at their level of technology they could not beat the Brilliant Pebble and it would bankrupt them to even try. So they didn't try."

Even after garnering a huge share of $40 billion spent on missile defense in the Reagan and first Bush administrations, no pebble has ever flown against a missile in space. Its backers haven't given up yet.