Directed Energy Missile Defense in Space April 1984 NTIS order #PB84-210111 Recommended Citation: Directed Energy Missile Defense in Space–A Background Paper (Washington, D. C.: U.S. Congress, Office of Technology Assessment, OTA-BP-ISC-26, April 1984). Library of Congress Catalog Card Number 84-601052 For sale by the Superintendent of Documents U.S. Government Printing Office, Washington, D.C. 20402 Preface This background paper was prepared by Dr. Ashton B. Carter under a contract with the Office of Technology Assessment. OTA commissions and publishes such background papers from time to time in order to bring OTA up to date on technologies that are the subject of frequent congressional inquiry. After Dr. Carter’s work was under way, Senators Larry Pressler and Paul Tsongas of the Senate Foreign Relations Committee requested that the resulting paper be made available to that Committee as soon as possible. OTA is issuing the paper in the belief that others in Congress and members of the public will find it of interest and importance. An OTA background paper differs from a full-fledged technology assessment. Background papers generally support an ongoing assessment of broader scope or ex- plore emerging technological issues to determine if they merit a fuller, more detailed assessment. On March 22, 1984, the Technology Assessment Board directed OTA to carry out a full-fledged assessment of “New Ballistic Missile Defense Technologies, ” for which this background paper will serve as one point of departure. This paper was prepared for OTA’s International Security and Commerce Program, under the direction of Lionel S. Johns (Assistant Director, Energy, Materials, and inter- national Security Division) and Peter Sharfman (Program Manager). Contents Section Page 1. Introduction . 3 2. Booster Characteristics. 7 3. Directed Energy Weapon Concepts for Boost Phase Intercept. 15 3.1 Space-Based Chemical Lasers: A First Example . 16 3.2 Ground-Based Lasers With Space-Based Mirrors . 22 3.3 Nuclear Bomb-Pumped X-Ray Lasers: Orbital and Pop- p Systems . 24 3.4 Space-Based Particle Beams . .. 28 3.5 Space-Based Kinetic Energy Weapons . 32 3.6 Microwave Generators.. 35 3.7 Other Concepts . 36 4. Other Essential Elements of a Boost-Phase Intercept System . 39 4,1 Target Sensing . 39 4.2 Aiming and Pointing. 40 4.3 Intercept Confirmation . 40 4,4 Command and Control . 41 4.5 Self-Defense . 41 4.6 Power Sources . 42 5. Countermeasures to Boost-Phase Intercept . 45 5.1 Anti-Satellite (ASAT) Attack, Including Directed-Energy Offense . 46 5.2 Fast-Burn Boosters . 48 5.3 Counter C3l Tactics. 48 5.4 Shielding . 49 5.5 Decoys . 50 5.6 Salvo Rate . 50 5.7 Offensive Buildup . 51 5.8 New Targeting Plans.... 51 5,9 Other Means of Delivering Nuclear Weapons . 52 6. A Word on ’’Old’’ BMD and “New” BMD. 55 7. A Hypothetical System Architecture . 59 7.1 System Description . 60 7.2 Assessment . 61 8. Defensive Goals I: The Perfect Defense . 65 8.1 Nuclear Attack on Society . 66 8.2 The Prospects for a Perfect Defense . 67 9. Defensive Goals ll: Less-Than-Perfect Defense . 73 9.1 Goals for Less-Than-Perfect Defense . 73 9.2 Side Effects of BMD Deployment . 77 10. Principal judgments and Observations . 81 Appendix A. Excerpt From President Reagan’s Television Speech, March 23, 1983 . 85 B. The ABM Treaty and Related Documents . 87 C. Other Applications of Directed Energy Weapons . 97 v Section 1 INTRODUCTION This Background Paper describes and assesses to achieve our ultimate goal of eliminating the current concepts for directed-energy ballistic threat posed by strategic nuclear missiles. ”2 Pur- missile defense in space. Its purpose is to pro- suant to the President’s speech, the Department vide Members of Congress, their staffs, and the of Defense established a Defensive Technologies public with a readable introduction to the so- Study Team under James C. Fletcher (of the Uni- called “Star Wars” technologies that some sug- versity of Pittsburgh) to prescribe a pIan for the gest might form the basis of a future nationwide R&D program. A parallel effort, called the Future defense against Soviet nuclear ballistic missiles. Security Strategy Study and headed by Fred S. Since these technologies are a relatively new Hoffman (of Research and Development Asso- focus for U.S. missile defense efforts, little infor- ciates), addressed the implications for nuclear mation about them has been readily available policy of renewed emphasis on BMD. This Pa- outside the expert community. per covers the same technologies and issues as these Defense Department studies. The ABM Directed-energy or “beam” weapons comprise 3 Treaty reached at SALT l severely restricts the chemical lasers, excimer and free electron lasers, development, testing, and deployment of BMD nuclear bomb-powered x-ray lasers, neutral and systems. Though this Background Paper treats the charged particle beams, kinetic energy weapons, strategic roles of missile defenses, including many and microwave weapons. In addition to describ- of their arms control implications, it does not treat ing these devices, this Background Paper assesses the vital international political implications of a he prospects for fashioning from such weapons major U.S. move to BMD. robust and reliable wartime defense system esistant to Soviet countermeasures. The assess- Focused on directed-energy intercept of mis- ment distinguishes the prospects for perfect or siles in their boost phase, i.e., on “Star Wars” ear-perfect protection of U.S. cities and popula- proper, this paper does not analyze midcourse on from the prospects that technology will and reentry BMD systems or non-BMD applica- chieve a modest, less-than-perfect level of per- tions of directed-energy weapons.4 “Star Wars” formance that will nonetheless be seen by some efforts generally further concentrate on intercept xperts as having strategic value. Though the of intercontinental ballistic missiles (ICBMs) rather focus is technical, the Paper also discusses, but than the related but somewhat different problems oes not assess in detail, the strategic and arms of intercept of submarine Iaunched ballistic mis- ontrol implications of a major U.S. move to de- siles (SLBMs) or intermediate-range ballistic velop and deploy ballistic missile defense (BMD).1 missiles (IRBMs). This Paper is therefore not a substitute for a more complete treatment of the This Background Paper grows indirectly out of entire subject of BMD.5 Moreover, BMD itself is resident Reagan’s celebrated television speech only part of the larger subject of strategic defense, f March 23, 1983, in which he called for a “long- comprising defense against bombers and cruise erm research and development program to begin missiles, civil defense, passive defense of military targets, anti-submarine warfare (ASW), and pre- ‘ BM D IS the most common of four rough Iy equivalent acronyms emptive counterforce attack in addition to BMD. verl ng defense against nuclear ba II istic m issl Ies. Such defenses ~re formerly ca I led a ntl-ba I I i st ic m issi [e (ABM) systems, but this slgnatlon fell out of favor after the debate over and eventual de- se of the Sentinel and Safeguard ABM systems in the late 1960’s 2The relevant portions of President Reagan’s speech are d early 1970’s. BMD largely replaced ABM as the term of choice, reproduced in Appendix A. t recently the more self-explanatory Defense Against Ballistic 3The ABM Treaty and related documents are reproduced in Ap- sslles (DABM) has gained popularity. Within the Executive pendix B, ~nch, BMD efforts pursuant to President Reagan’s so-called ‘‘Star 4Appendix C describes briefly, but does not assess, other pro- ~rs” speech are referred to as the Strategic Defense Initiative (SD I). posed military applications of directed-energy weapons. )rmally the term strategic defense comprehends other methods 5For a more complete treatment, see f%//;sf;c Missile ~efe~set Ilmltlng damage from nuclear attack besides BMD. ed. Ashton B. Carter and David N. Schwartz (Brooklngs, 1984). 3 4 It is unusual for the President to express himself reason is that at this early stage of conceptualize on, and for the Congress and public consequently tion there is simply no point in (and little basis to concern themselves with, long-term research for) discussion at the detailed level where classi- and development. “Star Wars” is thus a some- fied particulars make a difference. The properties what unusual subject for a technology assessment of actual weapon systems in engineering devel intended for a public policy audience. It is in the opment, by contrast, are normally and under nature of this subject that unknown or unspeci- standably classified. fied factors outweigh what is known or can be The author and OTA wish to thank officials o presented in concrete detail. Many of the tech- the Army’s Ballistic Missile Defense Systems Corn nologies discussed in this Paper, and most cer- mand (BMDSCOM), the Lawrence Livermore Na tainly all of the schemes for fashioning a defense tional Laboratory, the Los Alamos Nationa system from these technologies, are today only Laboratory, the Defense Advanced Research Proj paper concepts. In the debate over the Safeguard ects Agency (DARPA), the Sandia National Labo ABM system a decade ago, or over basing modes ratory, the Air Force Weapons Laboratory (AFWL) for the MX missile in recent years, one could ana- the Office of the Secretary of Defense (OSD), and lyze in detail the technical properties of well- the Central Intelligence Agency (CIA) for thei defined systems in engineering development. So hospitality and cooperation. Many individual vague and tentative are today’s concepts for “Star aided the research for this Background Paper Wars” BMD that a comparable level of analysis though none shares the author’s sole respons is impossible.