by Nick Kaloterakis: Nick Kaloterakis

It has a jet engine's roar but not the accompanying whine-just an ear-shattering thunder. And the airplane is far too small, like a Volkswagen with a semi's air horn. It blasts down the runway, climbs steeply, and then hurtles away from the crowd lining the fences at Las Cruces Airport in New Mexico, dwindling rapidly into a clear October sky. The roar fades, disappears. The plane, dubbed the EZ-Rocket, sails through a turn, wings back toward the spectators. Rick Searfoss, the Air Force-trained test pilot and former space-shuttle commander at the controls, glides in silence until he relights one of the two isopropyl-alcohol-powered rocket engines. He banks left, blasting through a high S-curve at 160 mph to come back around parallel to the runway, and swings the rocket's faint blue exhaust toward the cheering crowd. These people have come to the first annual commercial- spaceship expo, the 2005 X Prize Cup, to see the next generation of rocket vehicles, and they aren't disappointed. But no one's having as much fun as Searfoss. "Let me just tell you, it's a kick in the pants," he exults after landing.

Soon, if all goes well, 10 rocket-powered planes like these, only bigger and faster and belching 10-foot-long orange and yellow flames, will speed around a two-mile long, 5,000-foot-high racetrack, competing for a $2-million championship purse. That's the vision of space entrepreneur Peter Diamandis and former Indy Racing League team co-owner Granger Whitelaw, co-founders of the Rocket Racing League (RRL). The duo formed the League last year with the idea that automobiles tooling around a flat, oval racetrack are so last century. The RRL plans to debut the first of the bigger, badder rocket planes, called the X-Racers, at the 2006 X Prize Cup this October and to fly up to 10 of them in races around the country in 2007, leading to a championship race at the 2007 X Prize Cup.

Diamandis and Whitelaw hope to draw Nascar and IndyCar-size crowds and home viewers. They'll be watching on major network shows sponsored by top corporations. Of course, it all depends on raising millions in start-up capital, attracting team owners willing to pay just under a million bucks per X-Racer, building the airplanes, and, perhaps hardest of all, convincing sports fans to spend money on yet another event competing for their attention. A tall order by any estimation.

But Diamandis has built a career on making the impossible happen. His $10-million Ansari X Prize for the first private spaceship helped blast space travel out of the realm of big government programs and into the private sector. Now he wants to make spaceflight affordable to the average citizen. "I am one of those guys who grew up loving space and always feeling like it was just out of reach and being made impersonal," he says. "My mission in life is to make space a personal experience." For Diamandis, working toward that much loftier goal, the Rocket Racing League is just an intermediate step, one that will use a sporting event to propel rockets into the mainstream.