At around 7:00 am (1400 GMT), the stubby SpaceShipOne will take off from California's Mojave desert on the belly of a specially-adapted jet to complete its prize bid with its second flight into space within two weeks.

If all goes well, the craft will blast off from its carrier jet just over an hour later, breach the 328,000-foot (62-mile 100-kilometer) barrier, and return to a runway landing around 8:30 am -- thus winning the Ansari X Prize purse ahead of any of two dozen competitors.

Some 30 members of the SpaceShipOne team spent Sunday night relaxing at the pyramid-shaped home of the rocket's designer, aviation pioneer Burt Rutan, in the Mojave Desert.

"We're just waiting for the sun to go down and come back up again," a keyed-up Rutan, 61, told CNN television.

"Probably our biggest concern is getting enough sleep," he said.

"Our test team down here... has to be at a briefing at 4:30 and we gotta go fly and win 10 million bucks," he said to cheers from colleagues.

Organisers who proposed the competition hope it will spawn an age of space travel rivalling the dawn of commercial air transport in the late 1920s.

"What we finally have here, after 40 years of waiting, is the beginning of the personal space flight revolution," said Peter Diamandis, president of the X Prize foundation.

SpaceShipOne in June became the world's first ever manned space vessel not funded by a government, shifting the paradigm of celestial exploration and marking the start of a new space race.

Wednesday, test pilot Mike Melvill took it on its second successful -- if hair-raising -- foray out of the earth's atmosphere that simultaneously bedazzled and horrified onlookers.

After a heart-stopping corkscrew ride into the sky, SpaceShipOne burst out of the earth's atmosphere and reached an altitude of 37,500 feet, or 103 kilometers (64 miles), qualifying for the last phase of the competition.

Melvill then glided the craft back to earth for a text-book landing, before proclaiming a "near perfect" flight, despite his unintentional "victory roll" that saw SpaceShipOne spin up to two dozen times during its ascent.

Travelling at speeds of up to 3,500 kilometers (2,100 miles) an hour, SpaceShipOne's seemingly uncontrollable rolls spooked television viewers across the world.

Rutan said the spins were not likely to be repeated Monday.

"Obviously we have some stability issues. We believe that we have solved them and I don't believe you'll see the rolls tomorrow. But if we do, we don't believe they're dangerous.

"They only happen at the highest mach numbers and they only happen at a special condition which we intend to avoid on the flight tomorrow."

DESKTOPS SpaceShipOne's Says Hello To Luna OPINION SPACE New Entrants Versus Incumbents: Triumph of Truth and Technology Risk In Private Rocket Flights Worthwhile StuntShipOne: The GeeBee Of Outer Space?

Rutan selected the October 4 date to coincide with the 47th anniversary of the 1957 launch of the Soviet Union's first satellite, Sputnik I, which sparked the original space race between Moscow and Washington.

The Ansari X Prize, funded by private donors, was established in 1996 and modelled on the Orteig prize that aviator Charles Lindbergh won when he became the first solo pilot to cross the Atlantic in 1927.

His feat spurred a proliferation of airlines and allowed ordinary people to fly for the first time in history.

To win the X Prize, the same reusable manned spacecraft must make two journeys into space within two weeks, rising to at least 100 kilometersmiles) each time while carrying the equivalent weight of two passengers.

On Wednesday's initial journey, the rocket plane's ballast weight was made up by a range of memorabilia proffered by team members, including a teddy bear and the ashes of Rutan's late mother.

SpaceShipOne was Rutan's brainchild and was funded by Microsoft computer billionaire Paul Allen, who joined with Rutan's company Scaled Composites to form the Mojave Aerospace Ventures team behind SpaceShipOn.

But whether or not the craft succeeds in Monday's second attempt to snag the X Prize, organisers said the competition's true goal had already been achieved and that the first buds of commercial space travel were already burgeoning.

Last week Rutan and British tycoon Richard Branson announced a 14-million-pound (25-million-dollar) tie-up between Virgin Atlantic Airways and Mojave Aerospace Ventures to set up Virgin Galactic, the first company to offer the public trips into space using SpaceShipOne's technology.

All rights reserved. © 2004 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.