Space elevator could be built by 2050

Posted by Emma Woollacott

Japanese construction company Obayashi says it's working on plans for a space elevator that could take people to orbit by 2050.

The company's told the Daily Yomiuri that it's a serious venture, but that it would need to work with other organizations round the world.

As anyone that's read Arthur C Clarke's Fountains of Paradise will know, the space elevator, or orbital tower, is a way of lifting a payload to geostationary orbit that could be very low cost. 

A tower, or cable, reaches from the equator to a point beyond geostationary orbit which holds a counterweight, keeping the tower's terminal station in position. As one car goes up, another descends, recovering a lot of the energy used.

Obayashi's tower, it says, would reach a quarter of the way to the moon, with a station at the 36,000km mark. While the tensile strength required would be incredible, it's believed that carbon nanotubes could handle the job.

Obayashi's considering using magnetic linear motors as the means of propulsion, and the journey to the station would take at least a week. The station would house laboratories, tourists, and even a solar power generator that could supply energy back to Earth.

"At this moment, we cannot estimate the cost for the project," an Obayashi official told Yomiuri. "However, we'll try to make steady progress so that it won't end just up as simply a dream."

Quite apart from the challenge of producing carbon nanotubes in enough quantity, there are, obviously, many other problems to overcome. At the speeds expected, radiation during transit through the Van Allen belt could be dangerous. There's also the risk that a structure that large would be hit by space debris.