era preoccupied with the fact that engaging attacking missiles early in their boost phase may require that many, if not most, of the system elements be deployed in space, thus opening up a new which they have characterized as "the militarization of space". In so doing the media have focused on space technologies often confusing the issue of antisatellites with strategic defense. Listed in order of their importance the really knotty problems for any strategic ballistic missile defense system are: System Complexity 1. 2. A system capable of dealing with 3,000 to 6,000 launchers and 10,000 to 25,000 RVs will be incredibly complex. it will be required to deal with an evolving attack which involves a great many uncertainties. No system has ever been engineered with this level of complexity or uncertainty A likely Soviet countermeasure will be the use of decoys, radar chaff and other techniques for rendering the real targets undetectable or untrackable. Techniques and technologies to provide unequivocal discrimination of targets in the exoatmosphere do not exist and must be invented. 3. Kill assessment. Some weapons, though disabling a target re-entry vehicle or MIRV bus, do not leave an unequivocal signature of their killing effect. Technologies and concepts for kill assessment must be found in order to avoid exhaustive re-engagement of already disabled targets. 4. 5. Survivability or resistance to attack. Both tactics and doctrine will be key to survival of space, air and ground based assets of any future systems. Technologies which harden and protect system elements against both nuclear and conventional weapons attacks will be needed. Cost of Space Deployment. - Large scale deployment of system elements in space may be Thousands or perhaps tens of thousands of tons required. lifted to low earth orbit may be required. Currently, the space shuttle is the primary means for space lift in the U.S.. It is limited to 30 metric tons per trip to Low Earth Orbit and volume limited to about 380 cubic meters. The cost for lifting one pound is about $4,000. The cost to lift mass into low earth orbit must be reduced to less than $100 per pound to make space based elements of a strategic defense system affordable. Technology to accomplish this cost reduction is key to the potential space elements of a strategic defense system. Note that lasers, particle beam weapons, rail guns, smart rocks and other exotic weapons are not the key issue. It is my view that effective weapons, which, after all, perform only one of the vital functions of a strategic defense system, will be developed in due course. However, there are many other knottier problems to be solved, which have much greater technical risk associated with them, before system feasibility will be proven. Substantial funding to attack these problems is currently allocated within the Strategic Defense Initiative research program. However, these funds should be protected from resource raids for large scale field demonstration or moves toward early deployment. SYSTEM COST cannot be Questions are inevitably raised about how much a possible future system might cost. This question, of course, answered because no one knows either the structure of a system which would meet the goals or many of the essential elements of cost by which an estimate might be made. In response to a query at a Senate Foreign Relations Committee hearing in 1983, Dr. Richard D. DeLauer, former Undersecretary of Defense for Research and Engineering, answered this question by pointing out that one might expect a future ballistic missile defense system to cost as much as the development and deployment of U.S. strategic offensive forces. To estimate that number, the record shows that, since World War II, the U.S. has allocated about $7.7 trillion (1985 equivalent dollars) to Defense appropriations. Last year 16% of the Defense budget was allocated to the "Strategic Forces" account. If that ratio applied throughout the past 40 years, then $1.2 trillion has been allocated for strategic offensive forces. Some interesting current numbers to keep in mind are: U.S. National Debt U.S. Federal Budget $4 Trillion U.S. Defense Budget Some day, perhaps ten years hence if the strategic defense research program is fully successful, the public may be faced with the question of how much is strategic defense worth. Only then, certainly not now, will engineers be able to estimate within reasonable error bounds (say 20%) what the cost of a reliable strategic defense system would be. SUMMARY AND OBSERVATIONS ABOUT THE FUTURE So far I have made the following points: We have not yet determined the feasibility infeasibility of a reliable, comprehensive strategic defense system and it will be ten years before the issue is settled. The long term goal of a comprehensive strategic defense against ballistic missiles is conceivable though very, very challenging. Advanced technology is our only hope of achieving it. The public should insist on the most for its money in the ongoing research program. It is premature to discuss any specific system design although system functions and functional elements are fair game for discussion to guide research, a future Many advanced technologies may contribute to strategic defense system, probably the least of which are the weapons technologies. No one can estimate the cost of a future strategic defense system at this time, but it is likely to require 15% to 20% of the Defense budget for 15 to 20 years to build. Given that these points represent a balanced picture of the past and the present status of strategic defense research, what will likely come of all this? What is likely to be achievable in the future? CITY DEFENSE AGAINST MODEST THREATS In 1972 the corresponding strategic defense initiative of the 1960's decade had produced radar, computer, interceptor and nuclear warhead technology suitable to design, build and deploy the Safeguard System. The concept was based on two-level intercept of reentry vehicles first in late midcourse and second during atmospheric entry. At that time the system concept was deemed suitable to defend the top 30 U.S. cities against a total attack level of, perhaps, several hundred re-entry vehicles. Many radars and several thousand interceptors would have been deployed throughout the U.S. to accomplish this purpose. Nuclear weapons with yields in the tens of kilotons and several megatons range were required to be detonated over the U.S. and Canada for the system to be effective. Most responsible ABM system engineers of that era believed that large scale deployment of such a system could have limited the damage from an uncoordinated Soviet attack, at the design level, to that of a few bursts on a few cities. A more coordinated attack could have resulted in more detonations, but these would have again been concentrated on a few cities. The main issue faced by the system was whether its protection would scale as the Soviet ICBM force expanded? Would the system be cost effective on a marginal basis? The answer was Particularly because the Soviet Union was rapidly moving its heavy missile forces to multiple, independently-targeted, reentry vehicles (MIRVS). no. Although the system was not designed to provide ICBM silo protection, a political decision was made to negotiate an ABM treaty and deploy a limited system to protect Minuteman. A few years later the deployed system was dismantled and defense was abandoned. Safeguard technology could be revived in modern form. Performance of all system elements would far outstrip those originally incorporated into Safeguard. If Soviet forces could be negotiated back to several hundred RVs with a verifiable treaty, then a modern version of Safeguard could be deployed and would be completely effective as a city defense. PROTECTING U.S. STRATEGIC FORCES Despite political rhetoric from the administration denying any interest in defending missiles, U.S. landbased ICBMS are under increasing threat due to accuracy improvements growing out of the Soviet strategic forces modernization program. If the Soviets were to achieve a corresponding technical breakthrough in anti-submarine warfare, which suddenly placed U.S. strategic submarines at risk, the temptation to launch a first strike attack on all U.S. strategic nuclear forces could become overwhelming. Terminal defense technology developed over the past 15 years plus progress in new endoatmospheric sensors and interceptor techniques, now underway in the SDI research program, could form the basis for an excellent defense system for MX and Minuteman. Rebasing of MX and Minuteman in hardened silos or using deception techniques would further enhance the increased deterrence derived from terminal defense of U.S. landbased forces. |