London, November 7 A laser-powered robotic climber has won 900,000 dollars NASA prize in a competition designed to spur technology for a future elevator to space.

Building a space elevator would require anchoring a cable on the ground near Earth's equator and deploying the other end thousands of kilometres into space.

The centrifugal force due to Earth's spin would keep the cable taut so that a robot could climb it and release payloads into orbit.

Though building a space elevator might require an initial investment of billions of dollars, proponents say once constructed, it would make for cheaper trips into space than is possible using rockets.

But, huge technological hurdles must first be overcome, including how to supply power to the robotic climber.

To that end, NASA offered 2 million dollars in prize money in a competition called the Power Beaming Challenge, in which robotic climbers, powered wirelessly from the ground, attempt to ascend a cable as fast as possible.

Now, according to a report in New Scientist, a robotic climber has made a prize-winning ascent worth 900,000 dollars, making it the first to win money in the competition, which has occurred annually since 2005.

Ted Semon, a volunteer with the Spaceward Foundation, a non-profit that organised the competition, , said that the feat shows space elevators are one step closer to getting off the ground.

"We've done a lot here to demonstrate that this technology is possible. This is just enormously exciting," he told New Scientist.

The winning climber was built by a team called LaserMotive, based in Seattle, Washington.

Like the other two vehicles in the competition, it used solar cells to absorb energy from a ground-based infrared laser.

On November 4, LaserMotive fired up its laser, powering the climber to ascend 900 metres up a cable suspended from a helicopter at Edwards Air Force Base in Mojave, California.

The climber reached the top in just over 4 minutes, for an average speed of 3.7 metres per second. The team's climber repeated the feat at a slightly higher speed of 3.9 metres per second on November 5.

On November 6, two other teams failed in their final attempted climbs. That means LaserMotive will receive the entire 900,000 dollars NASA set aside for climbers that could make the climb faster than 2 metres per second. (ANI)