Space elevator could soon become a reality (sort of)

Travelling into space is a gruelling, costly, and environmentally-unfriendly process which is also inherently dangerous as it involves strapping your passengers or other payload on top of what is essentially an enormous firework, lighting the fuse and hoping for the best.

But that could soon change, thanks to a Canadian aerospace company Thoth Technology that hopes to build the world’s first space elevator.

The idea of a space elevator is not a new one, as it was first time theorised by Russian scientist Konstantin Tsiolkovsky in 1895, when this pioneer of theoretical rocketry and astronautics inspired by the Eiffel Tower in Paris, imagined a similar tower that reached all the way into space and was built from the ground up to the altitude of 35,786 kilometres, the height of geostationary orbit.

Thoth Technology’s space tower would be freestanding and pneumatically pressurised and when completed would reach an impressive 20 km above the ground.
The space tower, coupled with self-landing rocket technologies developed by others, will herald a new era of space transportation.

As building a solid structure that would be many kilometres tall from the ground up proved to be unworkable (there is no material in existence with enough compressive strength to support its own weight at such a height), another Russian scientist, Yuri N. Artsutanov, improved on Tsiolkovsky’s idea by suggesting using a geostationary satellite as the base from which a cable would be lowered all the way down to the surface of Earth, while the counterweight would be extended from the opposite side of the satellite, keeping the cable constantly over the same spot on the surface of the Earth. Artsutanov introduced his idea to the general public in the article ‘V Kosmos na Elektrovoze’ (Into space on an electric locomotive) published in the Sunday supplement of Komsomolskaya Pravda in 1960, where he discussed the concept of the space elevator as a convenient, safe and economic way to access orbit and facilitate space exploration. Artsutanov also correctly pointed out that the thickness of the cable would have to be tapered so that the stress in it would be constant. This gives a thinner cable at ground level that becomes progressively more and more thick and is thickest at the level of geostationary orbit. Unfortunately, Artsutanov’s article was not translated into English at the time, so that his idea became largely forgotten until much later.

More recently, the idea of a space elevator was touted by science fiction writers A.C. Clarke, who mentioned it in his Hugo Award-winning 1979 novel The Fountains of Paradise and Kim Stanley Robinson who envisaged a Mars-bound space elevator (Mars would be especially well suited for a space elevator because of its low gravity and much lower areostationary orbit at only about 17,000 km) in his also Hugo Award-winning Mars trilogy (Red Mars (1993), Green Mars (1994), Blue Mars (1996)). However, until now, the concept remained firmly in the realm of science fiction, as the technical challenges involved in the construction of such a structure are enormous. Space elevator cable must carry not only its own weight , but also the additional weight of climbers (i.e. the vehicles carrying passengers and/or cargo that would climb up a stationary cable). Therefore, the cable will have to be made of a material with a very large tensile strength/density ratio. To put it in lay terms, a material with extremely high strength and at the same time exceptional lightness is required.

The platform at the top of the tower could serve as a spaceport for launching single-stage-to-orbit spaceplanes, as well as for a wide range of other uses, such as wind-energy generation, communications and tourism.

This proved to be almost an impossible challenge given that even the super-strong metals, such as steel or titanium have breaking lengths of only 20–30 km. Modern fibre materials such as Kevlar, fibreglass and carbon/graphite fibre fare a little better, but even they start to break at lengths of 100–400 km. Nano-engineered materials such as carbon nanotubes are expected to have much better breaking lengths of some 5000–6000 km, so are at the present considered to be the best candidates for the construction of the space elevator.

Following the recent advances in nano-engineering, Google X's rapid evaluation research and development team began investigating the feasibility of a space elevator, eventually abandoning the idea in 2014, finding that no one had yet managed to manufacture a perfectly formed carbon nanotube strand longer than a metre.

Landing at 12 miles above sea level will make space flight look more like taking a passenger jet.

While the idea of a fully-fledged space elevator, extending all the way up to outer space lives on, at least at the moment, only in the stories of science fiction writers, Canadian aerospace company Thoth Technology came up with the next best thing – a space elevator extending 20 km above the ground. While this is still some way from the official boundary of space (defined as an altitude of 100 kilometres above the sea level,), and a mere fraction of the desired 35,786 kilometres of the geostationary orbit, it is certainly an ambitious start.

Back in July 2015, Thoth Technology has been granted the United States patent for a space elevator. Announced in the USPTO’s official gazette, the freestanding space tower would be pneumatically pressurised and actively-guided over its base. Reaching 20 km above the planet, it would stand more than 24 times the height of the current tallest structure on Earth Burj Khalifa in Dubai and could be used for wind-energy generation, communications and tourism. Moreover, the technology offers also an exciting new way to access space using completely reusable hardware and saving more than 30% of the fuel of a conventional rocket.

“Astronauts would ascend to 20 km 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 re-flight” said Dr. Brendan Quine, the inventor of the tower.

Caroline Roberts, Thoth president and CEO, who believes the space tower, coupled with self-landing rocket technologies being developed by others, will herald a new era of space transportation, 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.”