Arthur Clarke is credited as the first sci-fi writer to describe a space elevator in Fountains of Paradise, which he published back in 1978, though the idea itself can be traced back to late 1800s Russia —or to Jack and the Beanstalk, take your pick. The idea makes sense, and would be far cheaper than hopping on a rocket, but the problem is really the cable, and finding a material strong enough to support the weight of people and cargo. But with the discovery of carbon nanotubes, we may have solved the problem that had been standing in the way of constructing a practical space elevator. At least, that’s what the Obayashi Corporation thinks. The Japanese company recently announced that they plan to construct a space elevator that will be ready for service by 2050.
Carbon nanotubes are tiny cylinders made from carbon atoms. They conduct electricity, heat, and light, and are roughly 200 times stronger than steel, as well as 5 times more elastic. They can also transfer electricity five times better than copper, and heat 1000 times better—and they weigh far less. They don’t corrode, they don’t expand or contract with temperature fluctuations like other metals. In short, carbon nanotubes are pretty darn magical, which is what Obayashi is banking on.
The company plans on extending its space elevator 96,000 kilometers (nearly 60,000 miles). The device itself will consist of robotic cars whose magnetic linear motors power them up and down the line. They estimate that people and cargo could reach the end of the line in a week. Now that they’ve got carbon nanotubes to work with, the challenge becomes making a cable long enough. Right now, the nanotubes the company is making are only 3 centimeters long, so they’re going to need quite a few. But the research and development manager at Obayashi predicts that the company will be able to make a cable that reaches space by 2030. They’re nothing if not optimistic.
A bunch of universities across Japan have been working on the various challenges and components of the space elevator, participating in conferences and competitions throughout the year for the development of robotic cars, as well as cables. The company also says that it will need international help to achieve its goal—one that would drastically reduce the cost of taking cargo into space to some $200 per kilogram, as opposed to $22,000 per kilogram. It could also reduce the cost of getting tourists into space.
I wonder what SpaceX, Boeing, and Virgin Galactic think of this plan.