tion.
cities. space.
lasers, powered ases or beans ol alull vali ticles to destroy Soviet missiles in flight. The technology of such systems has yet to be developed, and by some estimates would cost in the trillions of dollars.
Already, scientists have described inexpensive countermeasures that the USSR could take to render such systems ineffective.
these reasons, many analysts dismiss these space-based anti-ballistic missile schemes as completely unfeasiBut even if the more exotic weapons can never developed, the broad scope of the Star Wars programme paves the way for a major escalation of more conventional available ABM proAnd if the promise of protecting the population from a massive attack Is than pie-in-the-sky the prospect developing new weapons to defend US silos or cities against a retaliatory strike cauluctal limitations sysicill. either case, Star Wars fits more com fortably as a part of the US effort to Several scientists who were active participants in the ABM debates of the late 1960s have undertaken a comof space-based missile defence systems. Their analysis another Scientific this time from …Oc they and by physicists Hans Richard Garwin, Kurt GottTheir study points out that a successtul system would require several • Terminal-phase defence. Only when the warheads approach their target and the atmosphere would decoys in the 'threat cloud' burn up from the friction with air, exposing the flight. A last layer of defence against such warheads could only protect some missile silos against direct hits. It would no protection to population centres since incoming warheads could be designed to detonate upon intercepEven at high altitutde, such detonation would destroy people and For these reasons, any scheme to protect the population from nuclear attack hinges on a successful boost-phase defence. According to Bethe, such interception can be done only from The most plausible weapons discussion include ultraviolet X-ray lasers and particle-beam weapons.
An ultra-violet laser system, known as an eximer laser, would probably consist of a ground-based master laser, which would send its beam up to "fighting mirrors' in space. The mirrors would aim and concentrate the bean on booster rockets and after destroying them.