Star Wars' Hollow Promise

Ronald Reagan appeared to be standing on the threshold of a Buck Rogers future. In a Martin Marietta Corp. research plant outside Denver last week, the President stood before an 18-ft. partial mock-up of a chemical laser project that might one day be rocketed into space to zap Soviet nuclear missiles heading for the U.S. Reagan assured company engineers that the Strategic Defense Initiative, his space-based antimissile program, was "bounding forward" and that they were not working on a bargaining chip to be traded away in an arms deal.

But the project, called Zenith Star, has never produced a laser beam,...