On a windy expanse of the Chihuahua Desert in New Mexico, the gangly 9.8 kilogram 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 10.7 meters.

Only 59,544 kilometers 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 aboard a futuristic space elevator.

It's an admittedly bizarre idea, but NASA has taken it seriously enough to host a global competition offering US$150,000 (HK$1.17 million) to the team that can lift the most weight to the top of a 61m 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. That energy is then converted to electricity to drive the crafts' motors.

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 trace back 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 took off when science fiction legend Arthur C Clarke used it as the basis for his 1979 novel, The Fountains of Paradise. Clarke described an umbilical built out of "a continuous pseudo-one-dimensional diamond crystal" a few microns thick that stretched from the fictional equatorial island of Taprobane to a satellite in geosynchronous orbit.

The space elevator quickly ascended into the pantheon of far-out sci-fi ideas, right up there with warp speed and teleportation.

But it was only in the late 1990s that scientists began taking the idea seriously, after some scientists said that carbon nanotubes might be strong enough to serve as the space elevator tether. The idea has stoked the field. The first space elevator contest took place in 2001. The winner made his device out of Lego. It traveled 3.05m, Gilbertson said.

NASA sponsored its first elevator games last year. Now there are as many ideas on display as there are teams.

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

Turner's 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.