The plans for a “space elevator” have been approved by the US patent office, which granted Ontario-based Thoth Technology the rights to a “pneumatically pressurised structure for location on a planetary surface”.

The tower would be more than 20 times the height of the 830m-tall Burj Khalifa, current tallest building in the world located in Dubai.

Thoth Technology said the freestanding structure would provide a new way to access space that required 30 per cent less fuel than a ground-launched conventional rocket. It said the tower would provide secondary functions including wind-energy generation, communications and tourism.

Canadian space company Thoth Technology said the 20km tower would make flying to outer space like ‘taking a passenger jet’ (Thoth)“Astronauts would ascend to 20 km by electrical elevator,” said Dr Brendan Quine, its inventor. “From the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refueling and reflight.”

Though ascending 20km wouldn’t strictly take the lift’s passengers directly into outer space – considered to start around 100km up – it would be beyond the so-called 19km “Armstrong Limit”, the point where atmospheric pressure is so low that water within the human body starts to boil.