In response to a congressional request, GAO reviewed the Strategic Defense Initiative Organization's (SDIO) research on the Space Surveillance and Tracking System (SSTS) to determine its cost, schedule, and performance status.

GAO found that: (1) SDIO spent $65 million over 3 years for three contractors to analyze technology, propose preliminary system concepts and requirements, define data needs, and develop preliminary plans; (2) SDIO uncertainity over the SSTS role and its requirements in the overall system delayed completion of the contract phase; (3) although SDIO and the Air Force awarded contracts to begin development, considerable uncertainty remained concerning sensor needs; and (4) funding constraints in fiscal years 1986 and 1987 also contributed to the delays.