Bull's-Eye in Space

" Ta bad night in the Kremlin," Edward Wilkinson announced as he hoisted a glass of champagne in mid-Pacific, 4,800 miles from California. Wilkinson, director of U.S. Army effort known as "Homing Overlay Experiment," had good reason to hope for some insomnia in Moscow: his project scored its first success last week. A special interceptor rocket fired from Meek Island in the Kwajalein archipelago had struck the dummy warhead of a Minuteman I intercontinental ballistic missile (ICBM) that had been launched from Vandenberg Air Force Base in California some 30 earlier. Military analyst described the collision, which pulverized both projectiles more than 100 miles above the earth's surface, as a major technological advance that would support President Reagan's controversial idea of developing strategic defenses against enemy missiles.

The novel gadgetry that made Homing Overlay successful is a sophisticated guidance system in the interceptor's warhead. It is able, thanks to a remarkable infrared sensor, to fix in space a target as small as a human being 1,000 miles away.

As the missiles raced toward each other at a combined speed of 18,000 m.p.h., the interceptor's warhead expanded into an umbrella-shaped array of aluminum "ribs," 15 feet in diameter. As it turned out, the sensor aboard the killer rocket was so accurate that the ribs were unnecessary: the missiles themselves collided. The feat has been compared to one bullet hitting another, but, said Wilkinson, the two missiles were moving "about twice as fast as bullets."

Army spokesmen emphasized that Homing Overlay was merely an experiment, the fourth in a $300 million series that has been under way for six years. The three previous tests failed for various mechanical reasons. According to the spokesmen, the point of the experiment is to prove that incoming missiles can be destroyed well before they reach their targets without resorting to defensive nuclear explosions. Some scientists believe that radioactive fallout from such interceptions would be minimal, since the target warheads would be demolished without exploding. The Army insisted that Homing Overlay was "completely and absolutely compliant" with the 1972 anti-ballistic missile (ABM) treaty between the U.S. and the U.S.S.R. that banned the deployment of defensive missile systems while allowing experiments to proceed. (The Soviets were permit ted to keep the ABM system they had already built to defend Moscow.) So far, the Soviets have had no official reaction to the Homing Overlay test, even though an electronic spy ship stationed off Kwajalein monitored the entire experiment.