A laser-powered machine has zipped hundreds of metres up a cable dangling from a helicopter in a competition to develop space elevator technology.

LaserMotive of Seattle qualified for at least $US900,000 ($A986,842) in the $US2 million ($A2.19 million) NASA-backed Space Elevator Games, which began on Wednesday at the Dryden Flight Research Centre on Edwards Air Force Base.

LaserMotive's vehicle climbed nearly one kilometre in just over four minutes and then repeated the feat.

The Kansas City, Missouri, Space Pirates went first. Their vehicle was too slow to qualify for a prize but apparently was only about 50 metres short of the top when it had to stop.

Theoretically, space elevators are a way to reach space without using rockets. They would use a cable stretched between the Earth's surface and a platform in geosynchronous orbit.