Science: Tepee

Page one headlines trumpeted last week what may be a major breakthrough in the problem of detecting missile launchings and nuclear explosions anywhere in the world. The news: a radio-monitoring method—called Project Tepee—reported to be so sensitive that it can track Russian bomb tests and rocketry from stations within the U.S.

Tepee is the brainchild of young (33) Physicist William John Thaler (pronounced Thayler) of the Office of Naval Research. Thaler’s primary field is nuclear weapons effects. But two years ago, he had a sudden notion that certain characteristics of the behavior of radio waves might be the key to a simple and reliable long-range detection system. Since both the ionosphere and the surface of the earth will deflect radio signals, a transmitter can angle its beam upward and the broad waves will carom back and forth between ground and sky as they proceed to circle the earth. Each deflection sends back an echo to the home transmitter, and this “back-scattering” was the phenomenon that attracted Thaler.

Why wouldn’t the globe-girdling radio waves also bounce off the trail of ionized gases left by a high-altitude rocket or the cloud of ionized gases created by a nuclear explosion? Then, if there were even a slight difference in the returning echo patterns—and if receivers could be made sensitive enough to detect the difference —monitoring oscilloscopes could display telltale evidence of what the waves had encountered on their travels. Since these radio waves bounce around the earth, the new method would overcome the limitation of radar, whose line-of-sight waves travel in straight lines, thus cannot see beneath the horizon.

Personal Project. Thaler, then 31, did not wait for official encouragement, or even ask for it. Instead, he went ahead on his own. He borrowed radio equipment from a colleague, set it up and trained it in the direction of Nevada, where the AEC was about to fire a series of atom bombs. To his delight, the oscilloscope showed telltale wiggles. Two months later, he picked up the trail of the Russian rocket that launched Sputnik I. Enlisting the aid of other colleagues, he turned his attention to missile launchings at Cape Canaveral. There he ran into bureaucracy. None of the armed forces would give him notice of projected firings; Tepee’s men finally had to set up their own system of volunteer watchers on Cape Canaveral to warn them when a firing seemed imminent. Meanwhile, the FCC caviled about the frequencies he wanted to use. But such nonscientific problems came to an end in November, when Thaler tracked a Polaris so accurately that the top brass was immediately sold, gave him an appropriation of $400,000 to cover his expenses for 1958.

Soon Project Tepee was soaking up all the back-scatters it could handle. With experience. Thaler found he could distinguish and identify the special characteristics of everything from summer lightning to Polaris missiles, thermonuclear detonations and the aurora borealis. Last summer, in the line of his regular duty, Thaler directed the Navy’s Argus Project, in which atom bombs were exploded 300 miles above the South Atlantic (TIME, March 30). In Washington, some 7,000 miles away, a Project Tepee set picked up the shots. The same set had also successfully registered the Teak and Kettle high-altitude thermonuclear explosions over Johnston Island in the Pacific. As Tepee grew, its operators learned to track missiles with such discrimination that they could distinguish the successes from the failures.

Wrinkles Ahead. Navy enthusiasts point out that Tepee stations are low-powered and relatively cheap, talk of a system of six stations that would monitor any rocket the Russians set off or atomic bomb that they tested above ground. Thaler himself makes no such claims, recognizes that there are still plenty of wrinkles. “We know the theory and the equipment works.” said Thaler last week, “and our experiments have been successful from the beginning, but we will have to learn a lot more before we will be able to say we have a system. We have been trying to design a mousetrap without knowing the habits of the mouse.”

The mouse, in this case, is the ionosphere. Says Thaler: “We just don’t know enough about the propagation of radio waves through the ionosphere. It is not well understood.” Other scientists chipped in with equally cautious remarks. “It is not the greatest thing since beer,” said one; and an M.I.T. researcher pointed out that “obvious countermeasures [radio jamming] could be used against it.” But the Defense Department’s careful-going Research Director Herbert York concedes that “the ionospheric backscatter principle is a sound one.” Give him a year. Thaler predicted, and he hoped he could go to the Defense Department and say: “Here we have a system. Go ahead with the hardware.”

Tepee has nothing to do with Indians, merely stands for the initials of “Thaler’s Project.” The physicist more or less backed into long-range detection through his involvement in nuclear testing: now director of the field projects branch of the Office of Naval Research and chairman of the Navy’s special weapons effects planning group, he has watched almost every U.S. nuclear test explosion in the past ten years.

Born in Baltimore, William John Thaler majored in physics (but also won prizes in theology and philosophy) at Loyola College, took .his doctorate at Washington’s Catholic University of America, where he specialized in ultrasonics. A solid, 6-ft. 190-pounder and father of four. Thaler is a topnotch tennis player, has several times won the state doubles championship. Thaler took his sudden fame calmly. Reporters looking for him at his suburban home in Silver Spring, Md. found he had ducked out to buy his six-year-old son a small green turtle as a replacement for a pet chameleon that had died.

Thaler considers the ONR an ideal place for an idea man. “There are so many things going on there,” he explains, “and you can find out about them just by walking down the corridor. It stimulates your thinking along oddball lines and keeps you from getting in a rut.” The best example of that occurred two years ago, when he read a couple of published papers—one on the backscatter phenomenon, the other on ionized gases—and saw a method of connecting the two subjects that no one had seen before. The result was Project Tepee. “It’s so simple,” protests Thaler mildly. “I don’t know-why someone didn’t think of this before.”