A mere 30 years after Arthur C. Clarke first mooted the idea of running super-thin, lightweight cables into space and tethering them to a satellite in his book The Fountains of Paradise, Japanese scientists reckon they’re ready to bring all the parts together and make it happen.

For a relatively low in space travel terms bill of £5bn, the boffins think they’re close to solving the carbon nanotube technology issue that could make the existence of 22,000 mile-long cables possible. That amount of rope or even Ethernet cable…