No sooner did NASA’s deadline pass for companies to submit proposals for a new passenger space transit system than the agency changed the ground rules — a move that not only will challenge project bidders to accelerate development plans, but also opens the door for a partnership of eclectic space entrepreneurs to demonstrate if it has the moxie to fly people in space.

One member of the commercial space clan actually already has done so, designing, building and flying a sub-orbital spacecraft three times last year in a successful quest for a $10 million cash prize. To garner National Aeronautics and Space Administration support for its program, however, aircraft designer Burt Rutan, creator of the first privately built passenger spaceship, will have to aim higher.

Rutan’s firm, Scaled Composites of Mojave, Calif., is partnered with a diverse team of former X Prize contenders, business people, researchers, technical gurus and even a former astronaut to take a stab at designing part of a space transportation system to replace NASA’s space shuttles. Although the agency has a long list of new vehicles that never went farther than the drawing boards, this time around the stakes cannot be higher.

NASA plans to retire its shuttle fleet by 2010. The agency hopes to have the International Space Station completed by then, but even in the best-case scenario, NASA still will need to ferry crews and supplies to the outpost after the shuttles are decommissioned.

If a new vehicle fails to make if off the launch pad, the United States will be out of the human spaceflight business, at least as far as the government goes, dependent on the Russians, perhaps the Chinese, or other entities that build and fly operational space vehicles.

The space station is only the first stop for the new fleet, called the Crew Exploration Vehicle or CEV. The name is something of a misnomer, as NASA plans to incorporate several technologies into its next-generation space transit system.

“The idea is that we’ll have other vehicles to get us from space to the surface of the moon and Mars and back again. We’re not talking Buck Rogers here with one vehicle that can do it all,” NASA spokesman Michael Braukus said in an interview.

In addition to flying people from Earth to space, the CEV as currently envisioned also includes a travel system to the moon, a lander to touch down on the lunar surface and take off again, and future systems to take people to Mars.

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