NASA engineers work on alternative moon rocket

By day, the engineers work on NASA's new Ares moon rockets.

By night, some go undercover to work on a competing design. These dissenting scientists and their backers insist they have created an alternative rocket that would be safer, cheaper and easier to build than the two Ares spacecraft that will replace the space shuttle.

They call their project Jupiter, and like Ares, it's a brainchild of workers at the Marshall Space Flight Center and other NASA facilities.

The engineers involved are doing the work on their own time and mostly anonymously, with the help of retirees and other space enthusiasts.

A key Ares project manager dismisses their design as little more than a sketch on a napkin that won't work.

A spokesman for the competing effort, Ross Tierney, said concerned engineers at NASA and some contractors want a review of the Ares plans but can't speak out for fear of being demoted, transferred or fired.

The Jupiter design is being reviewed by a team of 57 volunteer engineers, from line engineers up to NASA middle managers, Tierney said.

Those numbers are dwarfed by NASA's Ares workforce, which has thousands of government workers and contractors. The head of the Ares office at Marshall said he can't rule out the possibility that some of his people are involved with the underground program.

"I don't know what people do on their own time," Steve Cook said in a recent interview with The Associated Press. But Cook said he is familiar with the Jupiter project, and he's not impressed. NASA informally reviewed plans for the rocket last fall and determined the idea to be a flawed scheme based on shaky numbers.

"It's not feasible. We said, 'It doesn't work' and moved on," Cook said.

Meanwhile, he said, work on the Ares I rocket is so far along that the first test flight is less than a year away. "We're down to the nuts and bolts ... on this rocket. This is not a napkin drawing," he said.

The debate reflects disagreement over the direction of U.S. spaceflight as NASA prepares to retire the shuttle in 2010. By 2015, the agency plans to begin orbital flights with Ares I and a companion heavy-lift cargo rocket, Ares V. Officials hope to return astronauts to the moon by 2020. - continued on cnews

I'm no rocket scientist, but it is clear that some real rocket scientists think their Jupiter design is better than the Ares design. Why exactly did NASA say Jupiter was a flawed design based on shaky numbers?