The Engineer Q&A: Space elevators

The concept of a space elevator has been around for over a century, originating in 1895 with a Russian scientist, Konstantin Tsiolkovsky. The idea is that, rather than using the stored explosive energy of rocket fuel to lift objects into orbit, a structure would be built with its lower end on the ground and its upper end high above the planet — preferably in orbit itself. The orbital payload could then be lifted up the structure and released at the top; potentially reducing the cost of space launches by a huge factor. It’s always been seen as extremey fanciful, but recently a Canadian company called Thoth Technology patented a design for a 12.4-mile high inflatable structure topped with a runway for spaceplane-type craft to take off and land. While not the full orbital elevator concept as envisioned by Tsiolkovsky, it would still cut launch costs by about a third, Thoth claims.