Technology

U.S. arms for the battle of the beam

William Lowther November 5 1979
Technology

U.S. arms for the battle of the beam

William Lowther November 5 1979

U.S. arms for the battle of the beam

Technology

Scientists in the United States are now convinced that the Soviet Union has chosen high-energy lasers as the next arena for the superpower arms race. The Rand Corporation, an independent research organization, prepared a study which has just been released by the U.S. government. It indicates that the Kremlin is now giving laser development the same high-level political support that earlier went to the building of nuclear weapons and intercontinental ballistic missiles. Not surprisingly, the news has spurred the Pentagon on to an extensive, topsecret commitment of its own.

There have been leaks from military sources and congressional committees strongly indicating that, despite official denials, major breakthroughs have been made this year. The U.S. Air Force has developed an experimental laser “cannon” which, on a good day (performance is conditioned by the weather), can knock an aircraft out of the sky. Working separately, the U.S. Army has invented a high-energy laser beam which has, under test conditions, brought down such targets as remotecontrol helicopters and small, pilotless aircraft. But the news that excites the Pentagon the most comes from the U.S. Navy where scientists are perfecting a laser weapon that can stop missiles. To date it has been used to explode a small anti-tank missile in flight.

The U.S. programs are being co-ordinated by the secretary of defence whose own research department is working on lasers to destroy satellites in space. In any future Soviet-U.S. conflict, satellites would be used for communications, to guide nuclear missiles and to spy on the enemy. Former defence secretary James Schlesinger once told a Senate committee that “the side that controls the satellites will control the war.” Laser weapons could be the key to that control.

The most significant information to come out of the laser race so far was released recently by Dr. William J. Perry, undersecretary of defence for research and engineering. He told a Senate hearing that all available intelligence reports point to the U.S. being well ahead of the Soviets in laser research at this time. “But, the present Soviet laser program may be three to five times the scope of our own,” he added. “The U.S. operation is costing $200 million a year. That makes it the single largest science and technology program we are pursuing. In U.S. terms the current Soviet program would cost $1 billion.”

Pentagon programs have reached the point where money is now being sought in the fiscal 1980 budget to establish a highenergy laset test range at White Sands, New Mexico. The air force is transforming a KC-135 jet into a flying laser laboratory equipped with laser test devices which will be fired at ground and air targets at the White Sands range.

Enthusiasm over successes to date is tempered by the fact that they were achieved under perfect, or “laboratory,” conditions. The weapons might not work at all in a “battlefield” situation. A defence department official, showing the usual caution, stressed that the army and air force progress should not be overestimated because it was against

“relatively soft and slowmoving” targets. But the navy advances against missiles are a different matter. Said the official: “These tests have shown that we do understand how a high-energy laser weapon system could operate and the many elements of the complex application problem.”

In simplest terms, a laser (an acronym of light amplification by stimulated emission of radiation) is a device that pumps light into a highly concentrated beam that can be transmitted great distances with little loss of power. Enormous amounts of heat are generated and, in effect, a laser weapon would burn up or fry its target. For example, a one-second pulse from an industrial one-kilowatt laser can vaporize a steel ball bearing.

Long popularized as a death ray, the laser has numerous shortcomings as a super-weapon and a great deal of work is needed to perfect it. The major problem is that some lasers, as they are now produced, cannot penetrate clouds, fog or rain. They are also difficult to aim, partly because the operators never know if they are high, low or wide if they miss the target. In past tests the beam has been bounced off a swivelling mirror that tracks the target, but also distorts and bends the beam, causing inaccuracy. In space, however, where there are no clouds, fog or rain to block, bend or distort the beam, lasers really come into their own. Operated from spaceships they would be an almost unstoppable weapon against the vitally

important satellites.

William Lowther