Rocketing into space? Some think an elevator might be the way to go.

That's the future goal of this week's $2 million Space Elevator Games in the Mojave Desert.

In a major test of the concept, robotic machines powered by laser beams will try to climb a cable suspended from a helicopter hovering more than a half-mile (one kilometer) high.

Three teams have qualified to participate in the event on the dry lakebed near NASA's Dryden Flight Research Center at Edwards. Attempts were expected from early Wednesday through Thursday.

Funded by a space agency program to explore bold technology, the contest is a step toward bringing the idea of a space elevator out of the realm of science fiction and into reality.

Theorized in the 1960s and then popularized by Arthur C. Clarke's 1979 novel "The Fountains of Paradise," space elevators are envisioned as a way to gain access to space without the risk and expense of rockets.

Instead, electrically powered vehicles would run up and down a cable anchored to a ground structure and extending thousands of miles up to a mass in geosynchronous orbit _ the kind of orbit communications satellites are placed in to stay over a fixed spot on the Earth.

Electricity would be supplied through a concept known as "power beaming," ground-based lasers pointing up to photo voltaic cells on the bottom of the climbing vehicle _ something like an upside-down solar power system.

The space elevator competition has not produced a winner in its previous three years, but has become increasingly difficult.

The vehicles must climb a cable six-tenths of a mile into the sky and move at an average speed of 16.4 feet (five meters) per second.

The competition is sponsored by the nonprofit Spaceward Foundation with support from NASA's Centennial Challenges program.