Brilliant Pebbles

Although President George H.W. Bush announced a plan to "vigorously pursue" the Strategic Defense Initiative in 1989, change was on the way. Later that year, President Bush commissioned an independent review of strategic requirements for a "new world order." Also in 1989 the first full duration ground test flight of the Space-Based Kinetic Kill Vehicle (SBKKV) was conducted, as well as the first ground test of Space Based Interceptor with an integrated seeker.

The resulting Strategic Defense Architecture emphasized boost phase kill technologies and Brilliant Pebbles. In 1990, the SDIO decided to pursue an alternate system based on a weapons concept called Brilliant Pebbles, which would consist of many highly autonomous interceptors floating independently in orbit. Brilliant Pebbles stood in contrast to the Space-Based Kinetic Kill Vehicle concept of the original architecture, which would have been a large, garage-like satellite housing a number of interceptors. The housing for the interceptors would have been vulnerable to Soviet anti-satellite weapons and also was prohibitive due to its size and subsequent cost. The Brilliant Pebbles concept envisioned smaller, individual space-based interceptors in greater numbers, which would be mass-produced to achieve lower costs.

The decision to integrate Brilliant Pebbles into the architecture came in 1989, after Air Force Lieutenant General George L. Monahan, Jr., had become the second SDIO Director. In addition to replacing the SBI system, the new interceptors made it possible to eliminate one constellation of space-based sensors, further reducing the cost of SDS Phase I.

In 1990, the SDIO decided to pursue an alternate system based on a weapons concept called Brilliant Pebbles -- many highly autonomous interceptors floating independently in orbit. The solution to the vulnerability and cost problems with SBI was to make each small interceptor autonomous by using miniaturized sensors and computers to give it the capabilities needed to operate without the sensors and communications equipment of the SBKKV garage. Now, instead of confronting several hundred large, easy-to-find targets, Soviet ASATs would have to contend with several thousand small, hard-to-find interceptors orbiting the earth in a constellation covering appropriate regions of the world. Because these Brilliant Pebble interceptors were to be mass-produced, they were expected to be relatively inexpensive, thereby lowering the cost of SDS Phase I. Additional cost savings came from eliminating sensors that were no longer needed, given the increased sensor capabilities of Brilliant Pebbles.

SDI0 established two concurrent Brilliant Pebbles research and development programs to enable the President to make a decision not later than the summer of 1993 on deployment of strategic defenses. Both programs were part of the demonstration and validation phase, which precedes full-scale development.

One program, involving Livermore's design and test vehicles, consists of a series of flight and underground tests to demonstrate that Brilliant Pebbles technology can intercept ballistic missiles and survive in wartime conditions. The flight test portion of this program began in fiscal year 1990 and was scheduled to be completed in February 1993. Problems occurring before the first flight test resulted in a 10-month slippage of the test schedule. The test occurred on August 25, 1990. SD10 officials said that the first flight test did not achieve all its objectives due to a mechanical failure that occurred during rocket separation. This failure caused the date of the second and third tests to slip again - by the end of 1990 they were scheduled between November 1991 and May 1992. Livermore program officials stated that funding allocations in fiscal years 1989 and 1990 were too low to support the original test schedule.

The other program, involving system contractors, began in June 1990 and was scheduled to be completed in June 1993. During the first 8 months of the program, six competing system contractor teams prepared proposals to improve Livermore's Brilliant Pebbles design concept. SDI0 refers to this part of the program as "concept definition." During the remainder of the program, two of the six contractor teams were to develop and test their versions of Brilliant Pebbles. SD10 refers to this part of the program as "pre-full-scale development."

Development of Brilliant Pebbles was transferred from the BMDO to SMC in FY 1993. The last hover test, the only one in the third series, took place on 10 April 1992. It tested a vehicle that was partially miniaturized and much closer in weight to an operational interceptor. The hover accomplished almost all of its objectives despite an anomaly late in the test. The SBI pre-prototype interceptor became the pre-prototype for the SDIO's preferred space-based weapon system, Brilliant Pebbles.

Congress appropriated funding for the BPI for 1995, but future funding support from the Air Force and BMDO appeared uncertain. By that time, however, the program was being cut back, and it was terminated in 1994 as interest shifted away from defense against strategic missiles and toward defense against theater ballistic missiles launched by third-world countries. In August 1994, OSD approved a concept for a Boost Phase Interceptor (BPI) that would respond to the new threat. It endorsed a BPI technology demonstration led by the Air Force, and SMC was to manage the program and acquire the BPI missile. Congress appropriated funding for the BPI for 1995, but future funding support from the Air Force and BMDO appeared uncertain.