A History of The Aerospace Corporation's Work in Missile Defense

Jon S. Bach

Throughout the long and occasionally contentious history of national missile defense, The Aerospace Corporation has provided consistent and crucial support to every major program and technology initiative.

The timeline of U.S. ballistic missile defense (BMD) extends back to World War II, but begins in earnest with the start of the Space Age. It moves through the Cold War and the era of President Ronald Reagan's Strategic Defense Initiative (SDI) up to today's Missile Defense Agency and the integrated Ballistic Missile Defense System. It progresses from an early emphasis on terminal-phase nuclear interceptors to the current focus on diverse multilayer missile-kill techniques.

Throughout the years, The Aerospace Corporation played an important role in the evolution of BMD concepts. When Aerospace was created in 1960, its initial contract was with the Air Force Ballistic Missiles Division, supporting the development of advanced ballistic missile technologies and missile defense programs. Aerospace was to be collocated with the appropriate Air Force organizations to provide the necessary support. Within months of the corporation's formation, the Air Force decided to move its Ballistic Missiles Division to Norton Air Force Base in San Bernardino, California, about 80 miles east of Aerospace headquarters in El Segundo. Aerospace followed, setting up a secondary corporate location known as San Bernardino Operations that would ultimately include more than 1000 employees supporting missile development and defense programs.

Although the San Bernardino location would be active only until 1972, when the Air Force returned its reentry vehicle program to El Segundo, Aerospace remained active in the area of ballistic missile defense and continues to support it today.

Artist's rendition of the San Bernardino offices, which housed Aerospace operations supporting ballistic missile defense and deterrence programs from 1963 through 1972.

Early BMD

The roots of ballistic missile defense reach back to the V-2 rocket developed for Nazi Germany by a team that included the famed engineer Wernher von Braun. The first modern long-range rocket to be used in warfare, the V-2 was clearly a powerful force capable of great harm; so, not long after World War II, the United States began to explore ways of intercepting and destroying such rockets.

In 1946, the U.S. Army Air Force began the Thumper and Wizard programs, which pursued a basic antiballistic missile (ABM) design. Wizard was to develop a missile that could intercept a ballistic missile traveling up to 4000 mph at altitudes ranging from 60,000 to 500,000 ft. During the 1950s, the United States also focused intensively on the development of families of offensive missiles (Atlas, Thor, etc.). Although these were for use in striking enemy targets, they later served as launch vehicles in the space program, too. Some BMD programs progressed very far through development, only to be canceled before deployment—usually because of cost or technical infeasibility. Others were canceled, only to reappear later under a new name.

For example, the Army's Nike programs were originally focused on air defense, but turned their attention to ballistic missiles. The Nike-Hercules could intercept some low-speed, short-range ballistic missiles, but not ICBMs (intercontinental ballistic missiles). The Army asked Bell Labs to develop a system based on Nike-Hercules that could shoot down ballistic warheads; this became Nike-Zeus. It made use of a nuclear warhead. Ultimately, the Nike-Zeus system was not deployed for several reasons, including limitations in radar and computer technologies.

A Nike-Zeus poised for firing at the White Sands Missile Range in New Mexico. Aerospace opened an office in White Sands in July 1962 to support ballistic missile development and defense programs.

Nike-X was a two-tiered defense program, composed of a Nike-Zeus missile, enhanced for greater power and range, supported by the faster shorter-range Sprint missile and much improved radars over Nike-Zeus. It was planned as a terminal-phase endoatmospheric system, one that could intercept and destroy reentry vehicles that had returned to the atmosphere. In 1960, Aerospace was given general systems engineering and technical direction (GSE/TD) responsibility for the Nike Targets program, established to support the Army's development of Nike-X through testing and evaluation. By June 1962, the first target vehicle was launched on an Atlas booster to test the Nike radars at Kwajalein Atoll in the South Pacific.

In the 1960s, the Ballistic Missile Boost Intercept (BAMBI) system was initiated through Project Defender, an ongoing BMD research effort conducted by the Department of Defense's Advanced Research Projects Agency. (Project Defender also gave rise to another program of particular importance to Aerospace: the Missile Defense Alarm System, or MIDAS, precursor to the Defense Support Program.) BAMBI was intended to destroy ICBMs in the boost phase. It would consist of low-orbiting satellites that would keep watch on Soviet launch sites and fire missiles against a launched ICBM upon detecting infrared emissions from its engines. In one concept, the BAMBI missiles were to deploy wire meshes to kinetically disable the ICBMs. Aerospace was tasked with GSE/TD. Sam Tennant, who later became Aerospace president, joined the corporation as manager of the BAMBI program in 1961. BAMBI was eventually dropped because of costs, reliability, and safety issues.

Sentinel, Safeguard, and the ABM Treaty

The Sentinel program, announced in 1963 by Secretary of Defense Robert McNamara, was a realigned version of the Nike-X program. It included the Spartan (formerly Nike-Zeus) missile for exoatmospheric intercepts, the Sprint missile for endoatmospheric intercepts, and radar and computer systems. Sentinel was to provide defense for the continental United States, protecting major cities from ICBM attacks.

In 1969, President Richard Nixon announced that instead of Sentinel, the United States would install Safeguard. It also made use of nuclear-tipped Spartan and Sprint missiles and employed the same radar technology, but it would be deployed at fewer sites and would be less costly to develop. Aerospace helped support Safeguard. The Army had asked the Air Force for reentry targets for use in developing the system. So, beginning in 1969, the corporation provided GSE/TD for the Safeguard Systems Test Target Program. This effort prepared ICBM reentry vehicle targets, which were successfully launched on Minuteman I and Titan II boosters from Vandenberg headed toward Army test sites on Kwajalein. The data obtained from the testing were used to evaluate ABM designs.

Reentry vehicle over Kwajalein in the South Pacific circa 1970. Aerospace supported programs that involved launching missiles toward Kwajalein to test the Nike-Zeus and Safeguard ABM radars and systems.

Unlike Sentinel, which was to protect major cities, Safeguard had the goal of protecting ICBM sites. This was the result of technical limitations, public opposition to locating nuclear missiles near population centers, and the terms of the 1972 ABM Treaty that emerged from the first Strategic Arms Limitation Talks (SALT) between the Soviet Union and the United States. The treaty, signed by Nixon and Soviet General Secretary Leonid Brezhnev, detailed what the nations were and were not permitted to do in the realm of missile defense. For example, it banned space-based, sea-based, and mobile land-based ABM systems. It also limited the superpowers to two missile defense sites each, with each site having a maximum of 100 interceptors. Under these terms, each country could have one site defending its capital and another defending a missile field.

A 1974 treaty modification limited each country to just a single ABM system, with up to 100 interceptors. The Soviet system used Galosh interceptors to protect Moscow, and decades later, that basic system is still active. The U.S. system was the short-lived Safeguard, intended to defend Minuteman ICBMs near Grand Forks, North Dakota. It was operational for only four months; then, in February 1976, Congress directed the Department of Defense to close the site. Technical problems with its radar systems were part of the decision, as were concerns over cost and effectiveness.

The Strategic Defense Initiative

On March 23, 1983, President Reagan introduced the SDI, a research program to develop technologies that would protect the United States from nuclear ballistic missile attacks. These BMD technologies would include both ground- and space-based systems.

In National Security Decision Directive 85, Reagan officially called for Americans to "decrease our reliance on the threat of retaliation by offensive nuclear weapons and to increase the contribution of defensive systems to our security and that of our allies." He announced SDI as a long-term R&D program for this purpose that would honor the country's ABM Treaty obligations. He even offered, in meetings with Mikhail Gorbachev in 1986, to share technology with the Soviets. With SDI's new focus on defense rather than deterrence, the priority was no longer the standoff based on MAD (mutually assured destruction) previously associated with the Cold War; rather, it became the creation of a "leakproof" system that could meet an aggressive large-scale threat to national safety (specifically, a Soviet ICBM barrage).

This was a tall order, and the solution was correspondingly elaborate. Complex, multilayered, and driven by the newest technology, the SDI plan was called "Star Wars" in reference to the popular science-fiction film. (The name originated with SDI's detractors but was adopted by supporters, as well.)

SDI contained programs for developing laser and neutral-particle-beam weapons as well as space-based sensors and interceptors. Ambitious designs included laser battle stations and satellites carrying nuclear-pumped x-ray lasers. SDI's overall goal was to produce a good defense at an appropriate cost, using sensors and weapons targeting all phases of flight. The early years saw a focus on directed-energy weapons, including lasers and particle beams, for boost-phase kill. Later, that focus would shift to kinetic-energy weapons (interceptors) for both boost- and midcourse-phase kill. Although SDI was never fully realized, it was of tremendous historical importance. The R&D work had far-reaching effects.



Conceptual drawings of several space-based chemical laser and directed-energy weapons, among the many proposals that Aerospace studied under SDI.

Philosophically, the program's movement from deterrence to defense was a big change. Reagan stated, "If the Soviet Union will join with us in our effort to achieve major arms reduction we will have succeeded in stabilizing the nuclear balance… Wouldn't it be better to save lives than to avenge them?" That often-quoted question resonated powerfully with many Americans.

In April 1984, the Department of Defense chartered the Strategic Defense Initiative Organization (SDIO), to be headed by Air Force Lt. Gen. James A. Abrahamson. SDIO brought missile defense programs together from a number of government agencies with a clear goal—to develop non-nuclear missile defenses. Until then, most ABM systems were primarily managed by the Army. SDIO has evolved through the years; in 1993, it was renamed the Ballistic Missile Defense Organization (BMDO) to reflect a shift in emphasis from global protection to theater defense. It subsequently became the Missile Defense Agency (MDA), as it is known today.

Aerospace's involvement in SDI was substantial. The corporation supported a number of programs managed by the Air Force's Space Systems Division and had a role in the development of SDI architecture and analysis, and in research areas of sensor, spacecraft, interceptor, and directed-energy weapon technology. Aerospace played a prominent role on SDIO's Phase One Engineering Team (POET), focused on developing a Phase One Strategic Defense System to enhance deterrence. Aerospace worked with the technologies of neutral-particle beams, kinetic-energy weapons, infrared focal planes, cryocoolers, and electric power. In the area of phenomenology, Aerospace scientists participated in projects such as the Delta 180–183 series of experiments, the Infrared Background Signature Survey, and the Midcourse Space Experiment and led phenomenology working groups for SBI and Brilliant Pebbles (see below). The company supported the creation and evaluation of SDI architectures whose acquisition, tracking, and pointing requirements had been identified, and technology programs for the pointing, tracking, and structural dynamics of large space-based optics.

SDI Components

The multilayer Phase One Strategic Defense System had three major space-based elements: the Boost Surveillance and Tracking System (BSTS), the Space Surveillance and Tracking System (SSTS), and the Space-Based Interceptor (SBI). Aerospace supported demonstration and validation efforts for these and other technologies.

The Boost Surveillance and Tracking System was intended to detect missile launches and track missile trajectories, especially in boost phase. It was removed from the SDI architecture and transferred from SDIO to the Air Force in the early 1990s because of simplifications made possible by the Brilliant Pebbles system. So, it did not enter full-scale development. Aerospace provided support for BSTS, and in 1990, participated in the completion of the demonstration and validation program, the final design review, ground demonstrations, and simulations to verify sensor and data-processing performance. Although BSTS was removed from SDI, BSTS-generated technology and design data were included in a new Air Force program for an advanced missile warning system outside of SDI.

Two concepts for the Boost Surveillance and Tracking System (BSTS) in 1987. Aerospace supported research, concept development, and validation for this and other space-based SDI elements.

The Space Surveillance and Tracking System was supposed to provide space-based acquisition, tracking, and discrimination of incoming ballistic targets. The original concept proved to be too unwieldy, and in 1990, Aerospace personnel served on a team led by the Air Force tasked to define a distributed version of SSTS. This came to be known as Brilliant Eyes, conceived as a large constellation of small spacecraft that would perform midcourse ICBM detection and tracking as well as discrimination of warheads from decoys and debris. Aerospace was active in concept development, and throughout the early 1990s, made many contributions to this program. The Brilliant Eyes system became a critical part of SDIO's Global Protection Against Limited Strikes (GPALS) program. In the late 1990s, Brilliant Eyes became the low Earth orbit component of the Air Force's Space-Based Infrared System (SBIRS) program. In its latest incarnation, it is known as the Space Tracking and Surveillance System, part of the space element of the Ballistic Missile Defense System.

The Space-Based Interceptor program was originally intended to house kinetic interceptors within large satellites; they would detect Soviet ICBM launches and destroy the missiles in their boost phase. The size and cost of the satellites and interceptors proved to be a major drawback. In 1989, the prevailing SBI concept was replaced with Brilliant Pebbles, a space-based ABM system consisting of thousands of small satellites with kinetic warheads. Brilliant Pebbles was intended to detect and destroy missiles without any external guidance; it was designed to work in conjunction with Brilliant Eyes. The program was canceled in 1994, but more recently has been reevaluated.

Aerospace supported a number of hover experiments and miniature kill vehicle assessments in support of SBI. The Aerospace 1990 annual report noted that the greatest Brilliant Pebbles technology development of the year was "an on-target hover flight at an Air Force Astronautics Laboratory test facility, which demonstrated the prototype of a miniaturized homing interceptor." In 1991, Aerospace was involved in a hover test of the Lightweight Exo-Atmospheric Projectile (LEAP), a fully integrated kinetic kill vehicle with an electro-optical sensor, inertial measurement unit, flight-data processor, and divert propulsion. During the test, the propulsion system lifted the unit off a cradle and through an onboard preprogrammed flight profile, making it the first interceptor to perform divert maneuvers during a hover test.

Conceptual drawing of Brilliant Pebbles spacecraft in 1992. Brilliant Pebbles was envisioned as a constellation of tiny satellites for negating ballistic missiles in flight.

Aerospace was also involved in investigating other missile-kill technologies. Notable efforts drew upon the corporation's longstanding expertise in high-power chemical lasers. For example, in 1982, Aerospace supported Talon Gold, a space-based laser technology experiment intended to demonstrate target acquisition, tracking, and pointing. Aerospace activities included general systems engineering and integration (GSE&I) in the areas of sensor development, experiment planning, and mission integration. Later, Aerospace supported the Starlab program, intended to demonstrate the extreme pointing accuracies needed to make directed-energy weapons such as high-power lasers and neutral-particle beams a reality in space. Aerospace was particularly involved with design analyses, simulations, and brassboard tests of the control system as well as efforts to accelerate software development. Even after the demise of SDI, lasers remained an item of interest for ballistic missile defense, and Aerospace supported the Air Force in preparing BMDO's Space-Based Laser Integrated Flight Experiment, particularly in regard to the Beam-Control Risk-Reduction Testbed.

Beyond the Cold War

Major geopolitical changes were taking place as the 1980s came to a close, including the dismantling of the Berlin Wall. The Soviet Union was unraveling, and its ultimate demise would occur in December 1991. The collapse of that superpower had critical implications; for all practical purposes, the Cold War was over.

Aerospace supported a number of hover tests at Edwards Air Force Base in the late '80s and early '90s.

With the start of the 1990s, SDI received increased support from Congress. George H. W. Bush, succeeding Reagan as President, made Brilliant Pebbles and GPALS primary elements of the SDI system. SDI, however, was upstaged by other concerns. During President Bill Clinton's administration, Secretary of Defense Les Aspin renamed the Strategic Defense Initiative Organization as the Ballistic Missile Defense Organization, and thereby signaled the end of SDI.

ABM activity took place in the 1990–1991 Gulf War. The first tactical ABM system to be deployed was the Patriot anti-aircraft missile system, which was used in attempts to intercept Iraqi Scud missiles. Patriot's radar and control systems had problems, though, in discriminating the warhead-bearing missile body from other objects during reentry.

Clinton signed the National Missile Defense (NMD) Act of 1999, a sparsely worded law that stipulated deploying "as soon as is technologically possible an effective National Missile Defense system." However, in a September 2000 speech at Georgetown University, Clinton announced that he would not deploy such a system, but would instead defer the decision to the next administration. He cited as issues technological readiness, concerns of U.S. allies, and the opposition of Russia and China. "I simply cannot conclude with the information I have today," he stated, "that we have enough confidence in the technology, and the operational effectiveness of the entire NMD system, to move forward to deployment."

On May 1, 2001, President George W. Bush delivered a speech at the National Defense University in which he stated explicitly, "We must move beyond the constraints" of the ABM Treaty. He explained why the treaty was outdated, with reminders that the Cold War was over and that Russia and America, while aware of their differences, were no longer adversaries. "Today's most urgent threat stems not from the thousands of ballistic missiles in the Soviet hands," he said, "but from a small number of missiles in the hands of … states for whom blackmail and terror are a way of life." As Reagan and others before him had done, Bush propounded the need to move beyond the model of MAD and deterrence into a position more aligned with the realities of the post–Cold War world.

Ron Lash of the Brilliant Eyes baseline design team with a model of the Brilliant Eyes satellite in 1992. Aerospace supported development of the infrared surveillance satellite under the auspices of SDIO. Brilliant Eyes later evolved into SBIRS-Low and ultimately became the Space Tracking and Surveillance System (STSS).

In December 2001, Bush announced the U.S. intention to withdraw from the treaty, and in June 2002, the withdrawal became official. The United States was no longer limited to a single site of interceptors. In January of 2002, Secretary of Defense Donald Rumsfeld renamed BMDO as the Missile Defense Agency. It began developing missile defense systems that the ABM treaty would have prohibited. The move was a source of controversy, both within the United States and among its allies.

Conclusions

Besides simply relaying facts about events and Aerospace's role in them, this look at U.S. ballistic missile defense has provided an opportunity to observe patterns and trends over time. It has revealed a number of contrasts between the present state of affairs and "the way it was" at earlier dates.

Technology has grown vastly more sophisticated since the early days. Early ABM systems dealt only with the terminal phase of missile flight, whereas multilayered systems that have been introduced since then attempt to intercept missiles in all phases—boost, deployment, midcourse, and terminal. In earlier years, ground-based defenses played the primary role; today, not all systems are ground-based—space-based systems have been considered, though never deployed. Another shift has been the transition from nuclear warheads to hit-to-kill technology. A cyclical pattern of concept formulation, design development, scope reduction, and cancellation (and resurrection) is also evident throughout the history of U.S. BMD efforts. For example, the parallels between BAMBI and Brilliant Pebbles are easy enough to trace.

When the Space Age began in the late 1950s, the Cold War was on, with the United States and the Soviet Union as the only players. With the Soviet Union's dissolution in 1991, that situation changed, and so did BMD. More nations became nuclear-savvy or behaved erratically, and were perceived in the West as potential threats. Policies and practices have varied. The philosophical tenets underlying the idea of deterrence in MAD gave way to an orientation to defense as put forth in the announcement of SDI. There have been shifts in geographical emphasis, from global to regional, from national missile defense to theater missile defense and back again.

BMD has changed during this period, no question. It will continue to evolve as major powers and their relationships change. As in the past, the form missile defense takes will be not only a function of what the most current technology enables, but also a reflection of the leadership and societies whose ways of life are at stake.

Acknowledgment

The author thanks Jim Pearson, John Watson, and Harry Eden for their assistance with this article.