At the time suggestions included microwave or laser power beamed up from the Earth's surface. Now, thanks to a group named LaserMotive, the dream is closer to becoming reality.
An AP article noted that a robot powered by a ground-based laser beam climbed a long cable dangling from a helicopter on Wednesday to
qualify for prize money in a $2 million competition to test the potential reality of the science fiction concept of space elevators.
The contest requires their machines to climb 2,953 feet (nearly 1 kilometer) up a cable slung beneath a helicopter hovering nearly a mile high.LaserMotive's system used a high-power laser array to shine ultra-intense infrared light onto high-efficiency solar cells, converting the light into electric power which then drives a motor, according to Slashdot. The second place prize level required the platform to travel up the tether faster than 2 m/s; their top speed was 4.13 m/s. For the top prize, the group needs to hit faster than 5 m/s.
LaserMotive's vehicle zipped up to the top in just over four minutes and immediately repeated the feat, qualifying for at least a $900,000 second-place prize.
The device, a square of photo voltaic panels about 2 feet by 2 feet and topped by a motor structure and thin triangle frame, had failed to respond to the laser three times before it was lowered, inspected and then hoisted back up by the helicopter for the successful tries.
Space elevators are envisioned as a way to reach space without the risk and expense of rockets.The idea is neat, but is it even practical? Surprisingly, doubting Thomases are running LaserMotive. The two principals, Jordin Kare and Thomas Nugent (no known relation to Ted), say their real goal is "to develop a business based on the idea of beaming power, not the futuristic idea of accessing space via an elevator climbing a cable. 'We both are pretty skeptical of its near-term prospects,' Kare said of an elevator."
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.