Wary as any test pilot taking up an experimental craft, the man in the fireproof blue suit kissed his wife before sliding into the cockpit. One by one he started the eight rotary engines, then pushed a small red throttle with his left hand and a joystick with his right. With that, engines whining, the flying saucer rose 40 feet into the air.

The moment may not have been as dramatic as, say, man's landing on the moon, but the flight definitely was one giant leap for Paul Moller. Last month, after 30 years of tinkering with flying vehicles, he took his "volantor" (from the Latin volare—to fly) on a 150-second spin in Davis, Calif. Although he was tethered to the jib of a crane as a precaution against sudden letdowns, Moller, 52, was able to hover on the downdraft from his engines.

In its way, the saucer's launch was as hard earned as the Wright Brothers' historic flight in 1903. A Canadian-born engineer who became a U.S. citizen in 1979, Moller built his first flying saucer, the XM-2, back in 1964, and flew a version of it in 1967, but the craft never got more than three feet off the ground. "We had to wait for the technology to catch up with us," he says. He eventually modified a snowmobile's rotary engine to produce one that cranks out 150 horsepower.

The way is thus clear, Moller says, for development of the Moller 400, a four-seat version of the saucer. Within a year, the inventor insists, it will be zipping through the sky at 322 mph. "No rudders, no gas pedals," he says. "Just point the joystick to where you want to go." Moller predicts he will start mass-producing the craft within five to 10 years.

Dr. John Zuk, chief of civil technology at NASA's Ames Research Center, isn't so sure. He points out that the volantor will have to undergo extensive safety testing by the Federal Aviation Administration. Plus, before widespread commercial use, the government would have to create a staggeringly complex system to designate flight paths that would keep speeding saucers from colliding in midair. Still, says Zuk, "given the state of commuting in this country, I'd say there's no place for Moller to go but up."

Moller, who grew up on a farm in British Columbia, came early to inventing. When he was only 12, Paul built a four-seat Ferris wheel. After high school he decided on a four-year aircraft mechanics course instead of college. Later he enrolled in some grad courses in aeronautical engineering at McGill University and so wowed professors that they let him pursue a doctorate without having a B.A. In 1968 he landed an assistant professorship at the University of California, Davis—and started work on his dream.

Through the years, Moller—who lives with his wife, Rosa Maria, an economist, and their three kids on a 90-acre almond ranch in nearby Dixon—has shown himself to be unfazed by the saucer's fits-and-starts progress, perhaps because his other endeavors have been so successful. In 1974 he and several partners bought 38 acres of land for $100,000 and developed them into Davis Research Park. In 1983, desperate to keep his saucer dream aloft, he sold his share for $4 million. Last year he also sold a highly successful motorcycle muffler business, a spin-off from the volantor project, for $2.7 million. All told, his belief in flying saucers has cost him and his 40-odd investors $25 million.

But that's only money. Moller says he remains inspired because of a single incident that occurred 45 years ago. On that bright spring afternoon, 6-year-old Paul found two hummingbirds trapped in an abandoned house. "One of these days," he says, recalling how the birds zipped off and disappeared when he opened the door to release them, "I'll be able to untether my M400 and fly home to Dixon."

—William Plummer, J.E. Ferrell in Davis