Obayashi

Japanese construction company Obayashi wants to build an elevator to space and transport passengers to a station about a tenth the distance to the moon.

The elevator would use super-strong carbon nanotubes in its cables and could be ready as early as 2050, according to Tokyo-based Obayashi.

The cables would stretch some 60,000 miles, about a quarter the distance to the moon, and would be attached to Earth at a spaceport anchored to the ocean floor. The other end would dangle a counterweight in space.

The elevator would zip along at 125 mph, possibly powered by magnetic linear motors, but would take about a week to get to the station. It would carry up to 30 people.

Up above, the space station would have living quarters and lab facilities. Solar panels connected to the station would generate electricity that would be transmitted to the ground.

NASA has also investigated space elevators, awarding $900,000 in 2009 to LaserMotive for developing a laser-powered robotic climber. Aside from the tremendous technological hurdles involved, while space elevators could significantly reduce space-related costs compared with rocket launches, the infrastructure could cost billions to build.

"At this moment, we cannot estimate the cost for the project," the Yomiuri Shimbun newspaper quoted an Obayashi official as saying.

"However, we'll try to make steady progress so that it won't end just up as simply a dream."