THE Denver Post - Perspective
Magazine
Special to the Denver Post
April 6, 1986
By Dr. Howard A. Garcia
President Reagan's appeal for a spaceborne missile defense system has been widely debated primarily on the basis of its political ramifications. Adherents have posited that such a system will make nuclear war obsolete. Opponents argue that precisely the opposite would occur - that a new and inordinately complex extension of the arms race into space will lead to greater mutual distrust between the United States and the Soviet Union and, therefore, to a more exaggerated cycle of offensive weaponry.
Since this debate rests on the assumption that the space defense system will actually work, it cannot resolve the central issue of the system's real worth - its capacity for protecting American cities from Soviet attack. In-depth studies by independent groups of prominent Scientists have repeatedly demonstrated the basic unworkability of the general concept of star wars, given the most optimistic assumptions concerning the performance of its various components and the conditions under which it may be compelled to operate.
This two-part series focuses primarily on the physical description and the technical merits of star wars. Although the details of operation are subject to continual development, the ideas presented are the product of several years of conceptual design addressing the requirements of transporting large concentrations of energy over vast regions of space to hit small, resilient, high-velocity targets and do it in vanishingly small reaction times.
Considering the enormous problems posed by these irreducible physical barriers and the most promising technologies for surmounting these problems, members of the scientific community - both within and without the present administration - have criticized star wars on technical grounds for its clear inability to prevent the Soviets from inflicting mortal damage on the United States in the event of nuclear war.
Apologists will no doubt argue that in the past scientists have been unduly pessimistic about the prospects of new, emerging, radical technologies. Many brilliant and daring technological programs have succeeded where failure was predicted. Landing the first men on the moon required only about 10 years from concept to fruition.
On the other hand, it was confidently predicted that controlled fusion would
be lighting our homes within a few decades, but we are not much nearer to that
goal after 40 years and billions of dollars of applied effort. Some technical
problems, it turns out, simply defy solution, irrespective of cost.
The facts concerning the technical deficiencies of star wars are multifaceted,
convincing and well-documented: "The Reagan Strategic Defense
Initiative", Center for International Security and Arms Control, Stanford
University; "Space Based Missile Defense", Union of Concerned
Scientists, Cambridge, Massachusetts; "Directed Energy Missile
Defense", Office of Technology Assessment, U.S. Government Printing Office;
"Ballistic Missile Defense", Scientific American, just to name a few.
The average citizen simply does not comprehend the extraordinary constraints
placed on a space-based anti-ballistic missile system. These limitations have to
do largely with the ease by which the most advanced space-defense system may be
defeated by an aggressive and innovative opponent.
There is available to the enemy a virtually inexhaustible supply of potential
countermeasures and alternative offensive options. Such countermeasures are
simple in development and execution, and they are inexpensive. Consider what
formidable obstacles a space-based defense system must overcome against an
adroit and unexpected attack by an offensive force of perhaps 10,000 hardened
(damage-resistant) nuclear warheads, which is about the number the Soviets may
commit to an all-out strategic attack.
Considering today's technology, an ICBM is vulnerable primarily during its boost phase, which lasts less than five minutes. Immediately after the boost to intercontinental orbit velocities, 10 multiple warheads carried by each missile are deployed, one by one. Each ICBM thus proliferates into 10 independent lethal bombs, each directed to a different target. In order to save lives as Reagan has maintained, each bomb in this fleet must be unerringly destroyed.
However, the real problem is not quite that simple since the real warheads will be indistinguishable from hundreds of thousands of decoys that will permeate the localized space occupied by the warheads during their long midcourse flight. The resources - the available number of defensive satellites and their respective weapons - of any conceivable defending force may be easily exhausted without doing significant damage to such a swarm.
The defensive force must therefore try to destroy the emerging launch vehicles during the short boost phase. Because of the short reaction times, and the great distances separating the American defense satellites from the Soviet launch vehicles - 1,000 to 3,000 kilolometers - conventional weapons are totally inadequate. Only objects that travel at or near the velocity of light can reach the high-velocity targets in time to be effective, and the only ones fulfilling this requirement are light itself and high-energy atomic particles.
Consequently, laser light and particle-beam weapons have been the subjects of intensive star wars research. Laser light as a weapon is either generated on earth and reflected by orbiting mirrors in space or it is generated by the satellite, then focused and aimed by large mirrors attached to the satellite. Particle beams, on the other hand, are formed by accelerating charged particles - ions and electrons - but because charged particles are deflected by the earth's magnetic field, they must be reconstituted into neutral atoms before they leave the satellite's gun.
One of the cardinal elements of any successful attack is that of surprise. No warning would precede the initial attack unless the aggressor chose to eliminate the defender's early warning and communications satellites as well as the extremely fragile fighting mirrors in space. Consider the latter option further.
Destroying a relative handful of large, delicate and indefensible satellites on predictable orbits from close range and with prior intent is demonstrably achievable, as recent U.S. and Soviet experiments will attest. But destroying a fleet of approximately 1,400 launch vehicles under surprise conditions when the enemy commander knows the exact disposition of the defensive satellites and has planned carefully to exploit their inherent weakness, is quite another matter.
Nonetheless, assuming that the defensive force either does not sustain or manages to survive a pre-emptive attack, some means must be available to detect, lock on, and track each of the hundreds of lofted Soviet rockets. The system must then be capable of directing fire, be it laser or neutral particle beams, with exquisite and heretofore unachievable aiming accuracy over a range of thousands of miles.
The most effective countermeasure available to the aggressor to an attack by the defender during the boost phase is a highly energetic launch vehicle capable of attaining intercontinental velocities in about 60 seconds from lift off. This means that each defensive satellite must carry out a full program of target acquisition, tracking, weapon stabilization, firing and damage assessment 20 or more times in one minute or less from the moment of launch. The arbitrary assignment of 20 Soviet launch vehicles per defensive satellite assumes that about 70 defensive satellites are within range of the Soviet launch platforms at the time of the attack.
The case against star wars is really twofold. The first is that it won't work; the second is that if it is finally developed or even pursued in earnest, it surely will engender the most counterproductive, senseless waste of intellect, labor and treasure in human history.
It is an old and well-established rule of warfare, fully appreciated by President Dwight D. Eisenhower 30 years ago at the dawn of the nuclear age, that any defense can be overwhelmed by a sufficiently determined offense. The authors and signers of the 1972 ABM treaty recognized this fact and wisely chose to outlaw not only the deployment but the development of any ballistic-missile defense in space. Reagan's current proposition would violate both the intent and the letter of the treaty.
Some preliminary estimates place the cost of star wars at about $2 trillion, or about equivalent to the national debt. This extraordinary cost is certain to exact a heavy toll on the American economy. Moreover, the efficacy and the reliability of this system for which we may pay so dearly cannot be tested beforehand and will remain unknown until that fateful moment arrives.
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Next week in Perspective: Can directed-energy weapons in space destroy offensive
missiles?
Dr. Howard A. Garcia, a former aerospace engineer in orbital mechanics and spacecraft navigation systems, is a Boulder-based research physicist involved in space plasma physics and astrophysical problems.