Alternative-energy elevators shoot for the stars

LAS CRUCES, N.M. — On a windy expanse of the Chihuahua Desert, the gangly 22-pound contraption began to climb up a thin carbon-fiber belt hung from a crane.

Directed toward the craft from the ground was an array of 135 mirrors to concentrate the blinding New Mexico sunlight to an intensity equal to 300 suns. The beam shined on the climber's high-efficiency solar cells. With a muffled whirring, it rose 35 feet.

Only 37,500 miles to go.

The solar-powered elevator car, dubbed the Jolly Roger, is one of a dozen prototypes from around the world for a device that could lift humans and cargo into geosynchronous orbit on a futuristic space elevator.

It's an admittedly bizarre idea, but NASA has taken it seriously enough to host a global competition this week, offering $150,000 to the team that can lift the most weight to the top of a 200-foot tether in the shortest time.

Instead of carrying heavy fuel, the machines must get their energy beamed onboard from sources such as sunlight, microwaves or lasers.

NASA is also backing a related contest to find a material strong enough to support an elevator whose top floor is marked "S" for space.

Aerospace giants such as Boeing and Lockheed Martin haven't taken the idea seriously, but NASA is seeking inspiration from the general public through its Centennial Challenge program.

The origin of the space elevator seems to date to 1960, when Russian Yuri Artsutanov proposed hanging a ribbon from space to transport material into orbit, said Roger Gilbertson, of the Spaceward Foundation, which is coordinating the elevator competition for NASA.

The idea really took off when science fiction writer Arthur C. Clarke used it as the basis for his 1979 novel, "The Fountains of Paradise."

Brian Turner, designer of the Jolly Roger, has sunk about $30,000 into his creation.

His design is a variation on the mythical Archimedes Death Ray, which the ancient Greek mathematician allegedly devised to set enemy ships ablaze by bombarding them with concentrated rays of sunlight.

The Jolly Roger generates 40,000 watts of power, and its solar cells get so hot they have to be cooled by water.

"It's a ridiculous distance that a space elevator has to go," Turner said. "But even if it's only a one-in-a-million chance, it's worth it."

The Punkworks team, a group of techie friends from Toronto, have built a device that converts microwaves beamed from a ground generator into electrical power.

Their climber, named Jack after "Jack and the Beanstalk," is made of hockey sticks, said team member Aman Dhanoa, 27. "Putting all these technologies together is the biggest challenge," he said.

So far, the team has spent $30,000. "But that's Canadian," said team member Erwin Lin, 30, laughing.

A father-son team from Auburn, Calif., have been working in a warehouse on the fairgrounds outside Las Cruces. Michael Fischer, a 51-year-old software engineer, and his son, Adam, 27, are building a climber based on the concept of a Sterling engine, which drives a piston by exploiting small temperature differences.

The concept is solid, Michael Fischer said. "I think I've got a chance," he said as he tightened a bolt on the coffee can, which they are using to contain the cooling fluid. Asked how testing went, he shook his head: "I never got to that part."