In a five-story building 12 miles north of Washington, US Army scientists simulated the explosion of a nuclear warhead in outer space.
It was the latest in a series of experiments to test the feasibility of space warfare. Tuesday's test at the Aurora simulator in Adelphi, Md., subjected delicate space equipment, of the sort that might be used in orbital weapons, to an intense barrage of gamma and X-rays, Denis Whittaker, an Army physicist, said.
The barrage, like that emitted from a nuclear blast, produces an extremely powerful electric field known as electromagnetic pulse (EMP), which can play havoc with electronic devices in space or on the ground. The job of the 15 scientists working at Aurora is to test ways of protecting such devices against EMP.
Some critics of the US space laser program claim such weapons, however shielded, are simply too delicate. The critics are less than optimistic about prospects for protecting space weapons against EMP.
Pentagon weapons designers are under pressure to come up with space weapons quickly. According to some Pentagon officials, the Soviet Union has already conducted successful tests of its killer satellites.
US strategists are increasingly concerned about a Soviet atomic blast in space aimed at orbiting satellites and laser weapons. Since the EMP threat is so great, some researchers are working on ways of detecting such attacks in advance and equipping satellites with rockets to boost them out of the danger area.
Other officials say it would be foolish for the Kremlin to ignite a nuclear bomb in space because it could also destroy Moscow's own satellites. But it would be possible for the Kremlin to set the explosion when its own satellites were shielded by the earth, according to some Pentagon experts.