WASHINGTON — The first phase of a "Star Wars" missile defense system cannot be deployed before the turn of the century and will cost more than $170 billion, figures that contrast sharply with more optimistic Reagan Administration estimates, a new congressional study has concluded.
Even if the system worked as planned, it would intercept no more than 16% of incoming Soviet missiles and would be capable of defending only a limited number of missile silos and military installations, leaving American cities wholly unprotected, the report from three Democratic senators contends.
The space-based missile defense system "is embarked on a schedule it cannot achieve, with assumptions of funding that will not be forthcoming," the report warns. "When coupled with significant underestimates of Soviet responses, this is a prescription for financial and military disaster."
The Pentagon, in a written response to the study, said it contains "more misleading assertions than facts."
The Pentagon's strategic defense office disputed the report's contention that "Star Wars" would stop only 16% of Soviet missiles but said that the actual figure is classified. It also said that the first part of the program will cost no more than $150 billion and will be ready for deployment "at the earliest possible moment." It was not more specific about the program's timetable.
The Pentagon office, which is responsible for the "Star Wars" program, also said that both military and civilian targets would be protected by the space shield.
The Senate report, drafted by aides to Democratic Sens. J. Bennett Johnston of Louisiana, Dale Bumpers of Arkansas and William Proxmire of Wisconsin, is the latest of several studies raising doubts about the viability of the missile defense program.
A study released last month by the Pentagon's Defense Science Board urged that the program, formally known as the Strategic Defense Initiative (SDI), be broken into smaller, more realistic stages, beginning with a limited, ground-based system of rocket interceptors.
The report said that "technical, budgetary, political and arms control uncertainties" surrounding "Star Wars" are likely to slow or halt development of a broad defensive system.
In another study, House Democrats found that SDI is unlikely ever to meet President Reagan's goal of making nuclear weapons obsolete and warned that the Soviets could develop cheap and effective responses to any American "Star Wars" program.
And last week, Congress' Office of Technology Assessment, after a two-year SDI study, found that the defensive system is likely to suffer "catastrophic failure" the first--and presumably only--time it is used because of flaws in computer software. The Office of Technology Assessment report also concluded that the Soviets could easily counter the missile shield with anti-satellite weapons, leading to a destructive arms race in space.
The latest report says that the Pentagon's planned Phase 1 of the SDI program, employing a limited number of sensors and missile interceptors in space, will cost at least $170 billion, in contrast to the Administration's estimate of $75 billion to $150 billion.
A more comprehensive Phase 2 program would cost $541 billion, bringing the total cost of the first two pieces of the missile defense system to nearly three-quarters of a trillion dollars, the study estimates.
The entire plan is jeopardized by a lack of launch vehicles for boosting the millions of pounds of "Star Wars" hardware into space, the report says. The Pentagon currently is designing an "advanced launch system" heavy-lift rocket needed to put "Star Wars" components in space, but even the most optimistic planners do not expect the rocket to be ready until the late 1990s.
"We find the SDI program in trouble, built on shifting sands, with rationales and justifications changing frequently," the report says. "The once-clear vision of its purpose has been clouded, even distorted, by new missions and roles. Constantly shifting priorities and unrealistic budget planning have put contractors and national laboratories on a roller coaster of on-again, off-again funding."
The Pentagon SDI office agreed with the last finding, blaming lawmakers for cutting the program's funding every year. "Clearly, given the budget cuts we have received from Congress, it is difficult to administer a smooth research program," it said.
The congressional study was prepared by Senate staff members James T. Bruce III, senior counsel to the Senate Committee on Energy and Natural Resources; Bruce W. MacDonald, a former State Department strategic weapons specialist now working for Bumpers; and Ronald L. Tammen, Proxmire's chief of staff and a former CIA analyst specializing in Soviet and Chinese missile and space programs.