(Business 2.0) -- Like a lot of entrepreneurs, Peter Diamandis and Granger Whitelaw have their heads in the sky -- 2,000 feet up, to be precise. That's the altitude of the new sport they're introducing in October: the Rocket Racing League.

Rocket-powered planes called X-Racers, designed especially for the RRL, will zip around a virtual track in the sky at speeds of more than 250 miles per hour, trailing golden plumes, their pilots chasing a purse worth as much as $2 million.

Will it fly? RRL pilots like ex-astronaut Rick Searfoss are set to battle for a $2 million purse.

More from Business 2.0 Live chat: your new online salesperson The hijack-proof truck Server farm goes solar Fastest Growing Tech Companies Current Issue Subscribe to Fortune

Diamandis and Whitelaw, however, are chasing a far larger prize. Their aim is nothing less than an aeronautical answer to Nascar, the fastest-growing league in professional sports and a veritable cash cow: Its 75 million fans spend an estimated $2.1 billion on merchandise annually.

Just as Nascar had its roots in drag racing on Daytona Beach, Diamandis and Whitelaw envision the RRL as maverick hot-rodding for the 21st century. If their broadcasting and sponsorship deals go as planned, the pair say, by 2010 they could be raking in revenue of $150 million a year.

That may seem outlandish, but these are no ordinary entrepreneurs. Diamandis, 45, created the X Prize, which offered a $10 million purse for the first private spaceflight (won by Burt Rutan's SpaceShipOne in 2004). He also co-founded Space Adventures, which books flights on Russian Soyuz rockets for rich tourists at $20 million a pop, and he runs Zero-G, a company that takes customers on parabolic flights to experience in-atmosphere weightlessness.

In short, Diamandis is driven by the desire to make space travel seem exciting again. "NASA isn't delivering that," he says. "We need the kinds of innovative breakthroughs that young companies can make."

Whitelaw, 39 and independently wealthy from high-tech and art business ventures, has run winning teams in the Indianapolis 500 and met Diamandis at an Indy event. After the race, over double steak burgers and cheese fries, they sketched out the plan for the RRL.

As in Nascar, the rocket planes would have a staggered start and then race around a track. But this track, five miles around, would exist only in the pilots' heads-up displays and on spectators' GPS devices.

Six years on, the league is finally ready for the first races at its headquarters in Las Cruces, N.M., partly funded by the state. The X-Racers, manufactured by Xcor Aerospace, cost about $1.1 million apiece. By the time the RRL begins official competition in 2007, 10 planes will have been built. The estimated annual cost of maintaining and fueling a rocket plane is $500,000 -- a paltry sum compared with the $12 million or so that a Nascar team can spend annually on a car.

"The nice thing about rocket planes is you're not blowing up engines and going through tires," says Tim Gormley, the RRL's COO. "And we can race anywhere there's an airfield." The plan is to ramp up to 10 events a year in 2008. Half a dozen pilots have already signed up for their shot at the $2 million prize.

But can the rocket men blast this new sport into the popular imagination? The RRL isn't going to start with the rabid following that Nascar enjoys. "The biggest challenge is, How can they attract fans?" says Eric Wright, vice president for research and development at Joyce Julius & Associates, a sports sponsorship analysis firm. "That will dictate the willingness of corporations to be sponsors."

Some major companies are intrigued, at least. A new sport like rocket racing "might offer us new and innovative ideas," says Susan McDermott, spokeswoman for Coca-Cola (Charts) sports marketing.

Diamandis and Whitelaw are cagey about their sponsorship and broadcast deals, which won't be revealed until the first exhibition race in October. But they have other revenue streams too.

The RRL plans to run each race itself, taking all the box office and concession sales. It will also webcast the races, with a 3-D track superimposed on the image. The high-powered William Morris Agency is negotiating RRL reality TV shows and Imax movies, and software company Simigon is working on a flight simulation. Most lucrative of all in the long run could be the intellectual property: The league is already taking out patents on rocket-engineering innovations.

Ultimately, though, the RRL will rise or fall on whether it can find a Dale Earnhardt-like hero with the right stuff.

"When you get away from all the marketing," says X-Racer pilot and former astronaut Rick Searfoss, "this is a serious business. You can die."

Which may be precisely the reason a generation reared on extreme sports will get hooked on the RRL.

More from Business 2.0:

• A car that could save the planet -- fast
• Blogging for big bucks
• The $100 million giveaway