countermeasures and reactive threats, and demonstrate resolve to sustain a measured steady effort by the U.S.

The technology effort, even in its early phases, complicates and confuses Soviet plans to modernize strategic nuclear forces, the report said. "It drives them to try and develop possible countermeasures, increase emphasis on their air-breathing forces and conduct research and development on new families of weapons delivery systems. It drives the USSR away from preferred approaches of updating and proliferating existing strategic forces.'

The program being recommended to the President is designed to increase the Soviets' role in cooperating with a stable strategic environment. It also is designed to "alter the Star Wars fantasy, establish the credibility and then the reality of defensive technologies."

The successful demonstration of the technology required to develop and deploy a defense system will build credibility and confidence, the report said. But the pressure to demonstrate the technology could push for rapid deployment of "marginal or brittle systems based on available technology," and this should be avoided, the report cautioned.

It proposes rapid development of technology that can deal with postulated Soviet countermeasures. This development approach also would provide a hedge against similar Soviet defensive technologies.

The interagency proposal to the President stresses that North Atlantic Treaaty Organization countries and Japan should be convinced that even research and development for ballistic missile defense will enhance the potential for arms control or reductions, decrease the nuclear threat overall, increase crisis stability and improve long-term relations with the Soviet Union. "It does not alter the commitment by the U.S. to its allies' defense," the report said.

The Soviet Union has over the last decade conducted substantial research and development in this technology area, "and vigorous defensive activity is necessary to counter ballistic missile defense work by the USSR," the report added. The key to effective defense is low leakage with an indepth layered defensive system.

The boost-phase intercept is essential to the system because it destroys the missile before it can deploy multiple warheads. This minimizes the attractiveness to the Soviets of high-throw-weight missiles with large numbers of reentry vehicles.

Even a very effective boost-phase intercept capability would be augmented with post boost, midcourse and terminal interceptor defenses. "All of the concepts use some space-based assets and survivability of these is a critical issue requiring combinations of technology and tactics available or becoming available. X-ray lasers, chemical, excimer and free electron lasers, particle beams and kinetic energy hit-tokill devices all have high potential for boost-phase intercepts," the report said.

APPENDIX 5

AVIATION WEEK AND SPACE TECHNOLOGY ARTICLE OF FEBRUARY 23, 1983 ENTITLED "ADVANCE MADE ON HIGH-ENERGY LASER" BY CLARENCE A. ROBINSON, JR.

WASHINGTON.-High-energy laser technological breakthrough scored by the Lawrence Livermore Laboratory has the potential to blunt a Soviet nuclear weapons attack on the U.S., according to Defense Dept. and congressional officials.

In a recent test at the Nevada underground nuclear test site, the laboratory demonstrated-in a vacuum chamber simulating space-a very small, compact laser device pumped by X-rays from a small nuclear detonation.

The laser operates in the X-ray wave-length at 0.0014 microns and produces and pulsed beam of very high intensity-several hundred terawatts (trillion of watts). The beam pulse is "in the order of nano-seconds, one of the shortest pulses measured by Livermore," one U.S. official said.

Operating under the code name Dauphin, most recent test of the device took place within the past few months. The project had been added to the budget of the Energy Dept. and cost approximately $10 million.

The government is only now beginning to address maximizing military impact of the X-ray laser. "It's not clear yet just how to best use it, but not much thought has been given to that aspect," one Defense Dept. official said. It is clear the project can have a big impact and offers a number of options, he said, including:

Use of rings of X-ray lasers positioned in space to defend against a massive salvo attack on the U.S. by the Soviet Union firing intercontinental and submarinelaunched ballistic missiles in a short time—about a 30-min. period. Each ring would have approximately 50 lasing rods arranged around a very low yield nuclear warhead functioning as the pumping source.

Positioning a given number of X-ray laser rings in reentry vehicles on boosters to be fired into orbit during a time of crisis or in response to an alert from an early warning spacecraft that an attack is under way by the USSR. The X-ray laser battle station with its pumping source and lasing rods mated to a dual-mode ultravioletinfrared telescope for target acquisition and tracking is very compact and could fit in a reentry vehicle.

Operating both X-ray pumped laser battle stations in low earth orbit in conjunction with a series of continuous wave chemical, high-energy laser battle stations, with other X-ray lasers in reserve on boosters housed in silos for use when needed. The X-ray lasers based on the successful Dauphin test, when mounted in a laser battle station, are so small that a single payload bay on the space shuttle could carry to orbit a number sufficient to stop a Soviet nuclear weapons attack on the U.S., Pentagon officials confirmed.

The lasing material in a series of laser rods is an atomically dense substance in solid form. The rods are arrayed around the nuclear device. Each rod in an operational system is estimated to range from 3 ft. to 8 ft. in length with a very small diameter, according to congressional members and staffers.

Livermore officials last week briefed members of Congress on the device, and Defense Dept. officials earlier had been provided information on the new laser system. It is not clear yet whether the program will remain under Livermore direction with Energy Dept. funding or whether it will be pulled under the Defense Advanced Research Projects Agency (DARPA) directed energy office. DARPA already has expressed interest in funding the project and moving it under its aegis.

"Developing this X-ray laser simultaneously with the 5-megawatt, 4-meter-dia. high-energy laser battle station (AW&T Feb. 16, p. 16) makes a lot of sense. They both likely will have to be integrated in an overall battle management system, and both will probably use the same pointing and tracking and onboard computational capability," a Pentagon official said.

"But because of the extremely small, low-yield nuclear device for pumping and the special physics involved, it might make more sense for Energy Dept. to remain involved along with DARPA," he said.

The most recent test in Nevada was carried out as a physics experiment by the laboratory, and it followed another earlier test of the X-ray laser. The first test was not successful because of a failure in the diagnostic instrumentation, not the laser concept, according to a Pentagon official.

A total of eight physics experiments have been planned under the Dauphin project, but because of the success of the most recent test, that number may be reduced.

Unlike chemical lasers, which destroy their targets with coherent beams of thermal energy, the X-ray laser produces shock or impulse kill of the target. "It is so powerful that the beam evaporates the target surface with radiation creating spallation," one Defense Dept. official said. “It is roughly akin to directing the energy in the nuclear pumping device in the laser beam."

The laser concept provides a formidable problem for the USSR or any other hostile nation. The use of ablative materials to harden against the thermal energy of a chemical laser will not provide a countermeasure against the X-ray lasers on a battle station.

The nuclear pumping source can only be detonated after each lasing rod is separately aligned on a target by the pointing and tracking systems. Once each is in position to place the beam on the target, the pumping takes place, destroying the battle station, but not until after the beams are fired at the targets.

Some Pentagon officials calculate that it would take between 20-30 X-ray battle stations to handle a ballistic missile attack on the U.S. over a 30-min. period, destroying boosters in the boost phase.

Because the nuclear pumping device on each battle station can only be fired once, there is a synergism in having chemical high-energy laser battle stations to engage a limited number of ballistic missiles over an extended period. Such an attack is referred to as a flexible option attack.

"The weakness with chemical laser systems is that theoretically they can be overwhelmed by a massive ballistic missile attack because of the dwell times required for the beams, or because it will take a large number [of the chemical systems] to handle hardened targets using ablative technology," one Defense Dept. official said. "This new device could handle the large-scale ICBM or SLBM attacks, freeing chemical lasers to engage some ICBMs, satellites or to perform air defense missions," he said.

The X-ray laser system has the potential of tipping the battle in favor of the defense for the first time in the history of nuclear warfare, one Pentagon official said. "It's one of those kind of things that if it works out you win the war; if not it hasn't cost you very much to add it to your strategic systems," he said.

Livermore has been developing concepts for using nuclear explosive generators to pump lasers for several years. An earlier concept was based on the use of krypton fluoride to lase in the untraviolet wavelength in an excimer laser (AW&ST July 28, 1980, p. 34).

In the next few underground tests, pointing and tracking may be simulated. The pointing and tracking system for ultimate deployment in space would be the one being developed by DARPA for initial use with chemical lasers under the Talon Gold program.

Another attraction to the X-ray laser system is that no optics are required for the lasing rods, eliminating a very costly, complex subsystem the U.S. is just beginning to develop in diameters large enough for chemical laser application in space.

In a study funded by DARPA, Boeing Aerospace is looking at a number of battle scenarios as part of its initial integration effort for a 5-megawatt, 4-meter-dia. laser battle station. Those studies can be applied to chemical lasers in general such as a 10-megawatt, 10-meter-dia. system, but also can be used to incorporate the X-ray laser system, one Defense Dept. official said. The study examines countermeasures, counter-countermeasures and the leverage gained by using space-based lasers in certain conflicts.

Laser battle stations in space gain the most leverage for the U.S. in thwarting a strategic weapons counter military attack on the U.S.- -an attack designed to destroy not only U.S. strategic systems but general-purpose forces as well.

Such attacks would be targeted against ICBMs, SLBMs, particularly submarine bases, logistical centers and key tactical bases. An example is that, if the submarine base at Bangor, Wash., were attacked, a nuclear warhead would be targeted against Anaheim, Calif. Shipboard inertial navigation systems for ballistic missile submarines are manufactured there. Replacement submarines could not go out to sea without the inertial system.

"The concept would be an echelon strategic weapons attack designed not only to destroy but to atrophy the force," one U.S. official said.

"An attack would be based on limiting collateral damage so that the population could be coerced. An example is that there are four target areas which, if destroyed, could deny 97% of the Army's ammunition capability," he said.

Laser or beam weapons really come into their own under this type of scenario, according to Pentagon officials. "Even though a Soviet ICBM/SLBM salvo attack can help mitigate beam weapons, lasers can subtract from the attack, and such an

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attack must be closely coordinated and tailored. To insure this when lasers are used, the USSR would have to multiply the size of the attack."

Pentagon officials emphasize that beam weapons are not substitutes for military power. Laser weapons are "force multipliers, additives or levers."

Laser battle stations in space will be a finite resource and the tendency will be to hold them ready for use against a direct USSR attack on the U.S. It is less likely that they would be used against a USSR-backed client state where surrogates are employed. The likelihood of laser use grows if there is direct Soviet intervention in a client state hostility, one Pentagon official said.

"There is, therefore, a strong argument to get a laser system in space quickly before the dynamics of the balance of power change in a dramatic way.”

APPENDIX 6

AVIATION WEEK AND SPACE TECHNOLOGY ARTICLE OF JUNE 13, 1983, ENTITLED "LASER TEST"

Successful underground test of the Lawrence Livermore Laboratory's Excalibur Xray laser pumped by a small, low-yield nuclear device in April at the Nevada underground site under the code name Cabra preceded a meeting last week by President Reagan with Sen. Malcolm Wallop (R-Wyo.). The senator is a proponent of developing space-based, directed-energy weapons-lasers and particle-beam technology-to defend against Soviet nuclear weapons attack. The Reagan-Wallop meeting centered on technology and a possible early feasibility demonstration of a space-based laser. Wallop is offering an amendment that would add $280 million in Fiscal 1984 to $127 million being sought by the Pentagon for this technology. He asked Reagan for Administration support of the amendment and recommended that Reagan name a special assistant to manage a national effort for ballistic missile defense. The senator suggested retired USAF generals Bernard A. Schriever and Samuel C. Phillips and former senator/astronaut Harrison Schmitt.