Going to space is expensive.
NASA's space shuttle programme ran at a cost of $1.5bn (£957m) per launch, while Space X's latest Falcon 9 rocket costs a neat $57m (36m).
Which is why space companies the world over are keen to crack the 'space elevator': a platform structure reaching a high above the planet, acting as a lift from the surface of the Earth to the skies, thus negating costly rocket launches. NASA even set up a competition to entice engineers into having a crack at it - but now Canadian group Thoth Technology has been granted its own patent for a new "space tower".
The ThothX Tower is described as a "freestanding space tower", standing 20km above the surface of the Earth, with a pneumatically pressurized tube allowing astronauts to take a short cut to a high(ish) altitude platform. From here, they would be able to take a "space plane" into orbit, hugely reducing the costs associated with current rocket systems.
The Thoth news release also details how the tower would be used for "wind-energy generation, communications and tourism, replacing some of the functions of current satellites (the communications bit, not the tourism bit, obviously).
Thoth's CEO Caroline Roberts believes that when self-landing rockets (like Space X's Falcon 9) become a normal aspect of space travel, a tower such as the Thoth X will make perfect sense.
“Landing on a barge at sea level is a great demonstration," said Roberts, "but landing at 12 miles above sea level will make space flight more like taking a passenger jet."
There are still some serious question marks hovering over several of the technologies mentioned in the patent, from the 'stabilisation devices' to the 'flexible sheet material' - but this concept could well be a sign of things to come.
If it ever gets off the ground.