Today, let's fly without an airplane. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

As WW-II wound down, we were all ready to take to the air. Before the war, we'd read in Popular Mechanics about airplanes with retractable wings that turned into automobiles. Helicopters had been around since 1939. Soon we would have one in every garage.

Writer Barry DiGregorio tells about another device tickling our fancy in the late '40s. It was the rocket belt, a ring of downward-facing jets you could strap on and use to fly away. The rocket belt first appeared in Amazing Stories magazine in 1928 -- in a sci-fi story about a WW-I air ace named Buck Rogers. Buck Rogers suffered an accident and woke up in the 25th century. He and his 25th-century rocket belt have been the stuff of comic books and movies ever since.

But who could wait for the 25th century? As early as 1933, a German inventor got on roller skates, strapped a home-made rocket to his back, and lit the fuse. He was lucky. It only knocked him off his feet and sent him tumbling forward.

In 1949 one of Werner von Braun's team developed a jet vest for the Army. With it, a soldier could jump over a low obstacle. But here the real problem with Buck Rogers's rocket belt surfaced.

The cost in rocket fuel for generating thrust to get off the ground without wings is huge. The cost of staying in the air is prohibitive. Still, the idea of flying without an airplane is such heady wine. In 1957 the Army got seriously interested. By 1961 they'd staged a 13-second flight that carried a man 113 feet. By 1962 a test pilot flew over 800 feet and stayed up for 21 seconds.

Then the technology took a not-too-surprising turn. The government funded Bell to build a 170-pound contraption powered, not by rockets, but by a small jet engine. In this version, a person could stay up for 20 minutes. But now the line between Buck Rogers's rocket belt and a small airplane was seriously blurred.

A century ago, railroads offered the first commercial engine-powered travel. But trains immediately passed out of individual control and left us longing to make rapid travel a personal thing. That's what the bicycle gave us -- then the automobile. But the airplane never really did.

We never did have a helicopter out in the garage. But that hasn't stopped us from wanting one. Buck Rogers's rocket belt is a primal dream -- an elementary craving that will not go away.

For now, rocket belts lurk in the fringes -- the stuff of fairground entertainments and James Bond movies. Meanwhile, the American Flying Belt Company, here in Houston, continues working on lighter and more feasible versions. So don't count it out. Behind it lies something far too elemental. As Dickens once wrote:

O running stream of sparkling joy
To be a soaring human boy!

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

DiGregorio, B.E., The Rocket Belt. American Heritage of Invention and Technology, Spring 1996, pp. 46-50.