Space and missile defense

Joint Force Quarterly, Winter, 2002 by Donald R. Baucom

By January 1992 it had become apparent to SDIO that the agency would not be allowed to demonstrate the effectiveness of the technologies developed under Brilliant Pebbles. Since NASA had earlier approached DOD about the possibility of using SDI-developed technologies in its own program, SDIO agreed to use BP components in a space probe known as Clementine. The mission called for the probe to orbit the moon for over two months and then depart the cislunar region for a rendezvous with the asteroid Geographos.

The probe was launched in early 1994 and completed the lunar portion of its mission. But while maneuvering for its flight to Geographos, a computer failure caused an extended burn of the altitude control system, depleting fuel and leaving the vehicle incapable of completing the second part of the mission. Nevertheless, Clementine served as a viable test in which 23 missile defense technologies performed successfully, including many derived directly from Brilliant Pebbles.

Clementine was the high water mark in space-based missile defenses. During the remaining years of the Clinton administration, space-based missile defense programs were largely limited to preparations for a far-term test of a high-power, space-based laser and the development of sensors that could cue ground-, sea-, and air-based missile defense systems.

George W. Bush assumed the presidency determined to deploy effective missile defenses in the shortest possible time. In support of this goal, the Secretary of Defense reorganized BMDO and renamed it the Missile Defense Agency (MDA) to prepare a set of options to reorient the missile defense program. These options were not to exclude ideas that conflicted with the ABM Treaty; they would be judged strictly on their technical merit. Furthermore, to end the bifurcation of missile defense into theater and national systems, a division that seemingly pitted U.S. interests against other nations, MDA would plan an integrated, layered defense to protect both America and its allies against ballistic missiles of all ranges.

The system that emerged from this restructuring divides the missile defense mission in three segments: boost, mid-course, and terminal--the major phases of ballistic missile flight. In theory, each segment could incorporate land-, sea-, air-, and space-based elements in the future. More over, all three segments will be integrated into a single ballistic missile defense system (BMDS) through both battle management and command and control systems.

To ensure the best technical and operational options in developing BMDS, Bush withdrew the United States from the ABM Treaty. Now, instead of designing a system to minimize violations of the treaty and then negotiating changes to preserve the agreement (the approach of the previous administration), MDA is drawing on the potential of all systems based on land, at sea, and in tire air and space.

Although withdrawal from the ABM Treaty ended the legal strictures on developing space-based missile defense systems, it did not assure that such systems would rebound to the position accorded to them in the SDI program. Indeed, the emphasis of the present administration on early deployment of the most effective defenses possible means that the immediate focus in the program must be on ground-based systems, mid-course and terminal, since work on these systems has been steadily sustained by four Presidents. Thus the first operational system based on work that flowed from the SDI program will be the Patriot Advanced Capability-3 terminal system, which is currently being operationalized. This will be followed by the ground-based midcourse system, which should provide a limited defensive capability in the form of an Alaskan test bed system, scheduled to be operational in late 2004 or early 2005.