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Strategic Defense Initiative

The Strategic Defense Initiative concept envisioned a three-tiered defensive system - creating the ability to intercept a target missile in the boost, midcourse and terminal phases of its flight.

By 1984, with over 25-years of experience in ballistic missile defense, the Army and more specifically this command, then known as the U.S. Army Strategic Defense Command (USASDC), was given the lead in most of the SDI programs. In the boost phase, the system incorporated a Boost Surveillance and Tracking System, the Space Based Laser and the Ground Based Laser. The Army shared responsibility for the SBL with the Air Force, while it was assigned sole control over the GBL.

In the midcourse phase, the SDI system architecture envisioned a Space-Based Surveillance and Tracking System, a Space Based Interceptor (SBI), a Neutral Particle Beam, and the Exoatmospheric Reentry-vehicle Interceptor Subsystem (ERIS). The Air Force oversaw the development of the SSTS and the SBI and shared responsibility with USASDC for the NPB. The Army directed the development of the ERIS. The final layer of defense, the terminal phase, employed the Airborne Optical Adjunct, the Ground Based Radar, the Ground Based Surveillance and Tracking System (GSTS) and the High Endoatmospheric Defense Interceptor (HEDI). The USASDC was the lead on all of these programs. Finally, development of a Battle Management/Command, Control and Communications system was shared by all three primary elements: the Air Force, the Army and SDI Organization.

When President Reagan announced the establishment of SD1 in 1983, he said that its goal was to eliminate the threat posed by Soviet nuclear ballistic missiles. Through its studies, research, and technology development activities, SD10 concluded that this goal can best be achieved through a phased deployment program. Each phase would be required to meet specific military and policy objectives and provide the basis for deploying subsequent phases.

In 1987 SDI0 established an initial architecture, called Phase I, for the Strategic Defense System, which would enhance deterrence of a massive Soviet attack. On September 17, 1987, the Secretary of Defense approved for demonstration and validation six Phase I elements. The approved six elements of Phase I are

  • Boost Surveillance and Tracking System (BSTS)
  • Space-Based Interceptors (SBI)
  • Space-Based Surveillance and Tracking System (SSTS)
  • Ground-based Surveillance and Tracking System (GSTS)
  • Exoatmospheric Reentry Vehicle Interceptor System (ERIS)
  • Battle Management/Command, Control, and Communication (BM/C3)
Since June 1987 SDI0 made a number of changes in the Phase I system architecture. By March 1989, for example, a ground-based radar was being considered as an option to help detect, identify, and track reentry vehicles in midcourse. SD10 revised its estimate of the quantities of sensors and weapons needed for Phase I.

In 1989 the President directed the Department of Defense to provide suffcient information so that he could make an informed decision within 4 years on deployment of strategic defenses. He specified that particular emphasis should be given to Brilliant Pebbles, a space-based weapon system concept developed at Lawrence Livermore National Laboratory. In the summer of 1989, the Strategic Defense Initiative Organization (SDIO) initiated studies to identify the best spacebased weapon concept, and in February 1990 it announced that Brilliant Pebbles was replacing the Space-Based Interceptor, one of several elements in the Phase I Strategic Defense System, which has been in development since 1987.

The space-based element of the concept includes two major pieces of hardware: an interceptor to destroy ballistic missiles and a lifejacket that houses the interceptor in space until it is launched at a target. Each interceptor is housed in a garage until launched. The garage for the Space-Based Interceptor was called a carrier vehicle, and each would have housed 10 interceptors. The garage for Brilliant Pebbles is called a lifejacket, and each will house one interceptor.

SDIO's cost estimate for a Phase I Strategic Defense System decreased from $69.1 billion to $55.3 billion due to substituting Brilliant Pebbles for the Space-Based Interceptor. The estimated cost of Brilliant Pebbles is less than the Space-Based Interceptor primarily because the lifejacket that will house Brilliant Pebbles interceptors in space is less costly than what would have housed the Space-Based Interceptors and most of the money for risk (cost increases) was eliminated. SDI0 projected that a Brilliant Pebbles interceptor can be produced for less than half that of a Space-Based Interceptor.

Because Brilliant Pebbles does not need information from the Space Surveillance and Tracking System, SD10 decreased the number of satellites. Additional Ground-Based Surveillance and Tracking Systems were added to Phase I to make up for the change in role of the Space Surveillance and Tracking System. Launch costs decreased primarily because the launch weight of the Brilliant Pebbles system is about 50 percent less than that of the Space-Based Interceptor system. The performance reserve for buying additional quantities of system elements was eliminated.

In 1990 SD10 significantly revised the Phase I architecture when it replaced the Space-Based Interceptor with Brilliant Pebbles and dropped the Boost Surveillance and Tracking System. As the programs continued to progress through the decade, they were increasingly redefined by budget concerns. With the advent of the 1990s, budget cuts in the SDI program resulted in the termination in some of these technology programs. The Ground Based Laser Project Office closed in January 1991, six months after the dedication of the ground based free electron laser facility. Both directed energy programs, however, continued in a research status.

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." The resulting Strategic Defense Architecture emphasized boost phase kill technologies and the Brilliant Pebbles.

The new world order was soon upon us. 1991 saw both the advent of the "age of Star Wars" and the demise of the Soviet Union. Coined by a reporter from The Los Angeles Times, the Age of Star Wars recognized the first use of missile defense technologies to intercept a target missile during combat. At the end of that year with the dissolution of the Soviet Union, the Cold War came to an end. The new environment brought a reassessment, but not a termination of the Ballistic Missile Defense program and an increased emphasis upon the Theater Missile Defense program.

In 1991 SDI0 dropped the Phase I architecture and replaced it with GPALS, which is focused on a global protection against accidental or unauthorized Soviet attacks and third-world threats. In his 1991 State of the Union Address, President Bush announced a new direction for the Strategic Defense Initiative. The new system known as the Global Protection Against Limited Strikes or GPALS would provide a defense against "purposeful strikes by various Third World powers developing ballistic missiles, or accidental or unauthorized launches from the U.S.S.R."

Between fiscal years 1985 and 1991, SD10 received $20.9 billion for research and development in five technology areas. About $6.3 billion was for sensors, $4.9 billion for directed energy weapons (DEW), $4.8 billion for kinetic energy weapons (KEW), $2.7 billion for systems analysis and battle management (SA & BM), and $2.2 billion for survivability, lethality, and other key technologies (SLKT). The Department of Energy received $1.6 billion for research on space-based nuclear power sources for SD1 weapons, X-ray laser research, and other SD1 research.

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Page last modified: 21-07-2011 00:48:34 ZULU