It puts Strategic Defense Initiative (SDI) technologies in context by reporting the kinds of ballistic missile defense (BMD) system architectures that the SDI organization has considered for "phased deployment." It reviews the status of the various SDI technologies and system components. It analyzes the feasibility of producing dependable software of the complexity that advanced BMD systems would require. Finally, it summarizes what is now known-and unknown-about the probable survivability of such systems against concerted enemy attacks of various kinds. The study found that major uncertainties remain concerning the probable cost, effectiveness, and survivability of the kinds of BMD system (which rely on kinetic rather than directed-energy weapons) that might be deployable in the "phase-one' proposed for the mid to late 1990s. In addition, OTA believes several more years of SDI research would be needed to determine whether it is feasible to construct the kinds of directed-energy weapons contemplated as follow-ons to SDIO's "phase one" BMD system. The survivability of both short-term and longer-term BMD systems would depend heavily on the outcome of a continuing competition in weapons and countermeasures between the United States and the Soviet Union. Finally, developing dependable software for advanced BMD will be a formidable challenge because of the difficulty of testing that software realistically.
Woodrow Wilson School of Public and International Affairs, Princeton University, http://www.wws.princeton.edu/~ota