The Bush administration is requesting $10 million in funding in fiscal year 2008 (FY08) for a Space Test Bed as part of its effort to develop a space-based missile defense system (Program Element 0603895C). The program begins the process of putting weapons in space and would therefore have important long-term implications. Congress should not fund this program. 

What is it?
The Space Test Bed is a Missile Defense Agency (MDA) project in the Ballistic Missile Defense (BMD) System Space Program—the program to develop a space-based missile defense system. MDA's FY06 budget description for the Test Bed states "We plan to add a space-based defensive layer to complement" the U.S. missile defense system. Subsequent budget documents give less detail, and MDA currently describes it only as generating the technology and operational concepts necessary to make an informed decision about whether to field space-based missile defenses.

However it is described, the Test Bed would put in place the nascent infrastructure needed to develop and deploy such a system: the program is intended to develop a space-based kill vehicle; to develop the command, control, battle management and communications structures for space-based missile defense; and to launch a small number of interceptors and test them against ballistic missiles.

The FY08 request calls for planning, analysis, and development of the operational concepts for a space-based missile defense to start in FY08, with component demonstrations to begin in FY09 or FY10. The FY06 budget stated that at first the Test Bed would consist of five space-based interceptors, and the production phase for a small space layer would begin in FY16.

Space-Based Defenses: Enormously Expensive, Inherently Ineffective
A space-based boost-phase missile defense system is intended for intercepting attacking missiles while the missiles' engines are still burning. To reach attacking missiles very quickly, space-based interceptors (SBIs) must be stationed in low-altitude orbits. However, in these orbits SBIs move rapidly with respect to the ground and cannot stay over any one location. To keep at least one interceptor within reach of a given missile launch site at all times requires many SBIs in orbit. A 2003 American Physical Society study showed that many hundreds or thousands of SBIs would be required to provide limited global coverage against ballistic missiles and given the technology expected for the next decade, each SBI would weigh a ton or more. As a result, deploying such a system would be hugely expensive.

And yet even if such a system were built, it would not provide a reliable defense. Even with this large system, only one or two SBIs would be able to reach a given launching missile in time to destroy it.  The orbit of these SBIs would be low altitude and predictable, leaving them vulnerable to attack by inexpensive, short-range missiles. By eliminating only those few relevant interceptors, an attacker could create a hole in the defense. The defense could also be defeated by simultaneously launching multiple missiles from one location, overwhelming the system. In short, a defense based on deploying hundreds or thousands of space-based interceptors, at enormous cost, would be defeated by a handful of enemy missiles.

The Test Bed Preempts Congressional Decision-making
Under the guise of research and development, the Test Bed puts in place key parts of the infrastructure necessary to operate a comprehensive space-based missile defense. Though it may begin with a small number of interceptors, the system could be expanded readily. Yet Congress has never debated the wisdom of deploying space-based weapons, nor has it considered the total costs and capabilities for such weapons. Congress should be aware that by funding the Test Bed it may forfeit its ability and responsibility to decide formally whether to pursue a space-based missile defense system.

Anti-Satellite Capability
While the small number of Space Test Bed interceptors proposed in the near term could not provide any useful defense against ballistic missiles, those interceptors likely would have a significant ability to destroy satellites. Budget descriptions suggest that the system may be designed to provide missile defense during the midcourse, or unpowered, phase of the trajectory, in addition to defense during boost-phase. The sensors needed for a midcourse intercept of a warhead would also allow the interceptor to home on a satellite. And the large amount of thrust required to perform boost-phase missile defense from space would enable the interceptors to reach not just low-earth orbiting satellites, but satellites in geostationary orbits as well.

The Test Bed's anti-satellite capability is certain to be recognized, and perhaps responded to, by other nations. China recently tested a ground-based anti-satellite interceptor; the prospect of a space-based U.S. anti-satellite capability could encourage further testing and development by China. 

Additionally, the space debris produced by destroying satellites with interceptors would threaten other satellites that play a crucial role in civil, scientific, economic, and military endeavors.

Budget
For several years now, funding has been slated to begin in FY08. However, this year's request seeks considerably less money than in previous requests, especially for future years (see table). This reduction may indicate a decreased interest in the program, or recognition that other programs are a higher priority. Alternatively, it may indicate a decision to fund the effort primarily from the classified budget or to fund in other programs some elements that were previously included as part of the Test Bed.

For more information contact Dr. Laura Grego (617-301-8062), Dr. David Wright (617-301-8060), or Stephen Young (202-331-5429).

May 2007