inflatable space elevator
Artist impression of the inflatable space elevator Thoth Technology Inc

An inflatable space elevator, designed by a Canadian space company, has been given the go ahead after being granted a US patent for the technology. Thoth Technology Inc says it is planning to build a 20km-high (12.4 miles) freestanding space tower – 20 times higher than the world's tallest building, the Burj Khalifa skyscraper in Dubai.

Brendan Quine, the inventor of the space elevator, explained: "Astronauts would ascend to 20km by electrical elevator. From the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refuelling and reflight."

The tower would be made of reinforced inflatable sections, with flywheels that provide dynamic stability. According to the patent, the elevator tower is a "pneumatically pressurised structure formed from flexible sheet material", with a hollow core that cars could be run up.

The idea of space elevators has gained ground in recent years. Another concept proposed by Japan's Obayashi Corporation involves creating one that would be 96,000km in length – taking robotic cars a week to carry astronauts and cargo up. It hopes to have it in operation by 2050.

inflatable space elevator
The elevator's top platform could be used as a launchpad for spaceships Thoth Technology Inc

Thoth's space elevator is more modest, with its tower design leading to a platform from which crafts could more easily take off into space. It is thought the launch pad would result in a 30% reduction in fuel compared to a conventional rocket. The company also says it could be used for wind-energy generation, communication and tourism.

Caroline Roberts, Thoth's president and chief executive, said: "Landing on a barge at sea level is a great demonstration, but landing at 12 miles above sea level will make space flight more like taking a passenger jet." The company also says the space elevator could be used for wind-energy generation, communication and tourism.

A report on the space elevator by CNET notes, however, that there are several obstacles to overcome before the lift can be built: "The invention here is focused on the construction of the tower itself, but how to construct and maintain a strong, reliable elevator cable 12 miles long is the real challenge in the space elevator universe," it notes.