One of Japan's biggest construction companies hopes to build a space elevator by 2050 using carbon nanotube technology.
Japanese engineering giant Obayashi believes the construction of such an elevator could soon become feasible as a result ongoing advances in carbon nanotechnology.
Obayashi, one of Japan’s big five civil engineering and construction firms, says the elevator it plans to build will extend 96,000 kilometres from the surface of the earth into space.
The elevator will slash the cost of sending human beings and associated cargo into space by dispensing with the need for hazardous rocket engines, which consume copious amounts of energy and fuel.
The terminal station for the elevator would be located at an altitude of 36,000 kilometres, and would be stabilised by means of an immense counterweight suspended 96,600 kilometres above the earth’s surface.
Robotic carriages powered by magnetic linear motors will convey up to 30 passengers at a time from the surface of the earth to the terminal station, travelling at speed of 200 kilometres an hour to complete the journey to the terminal station in seven and a half days for less than one per cent the cost of a rocket journey.
The space elevator could also boost energy generation by producing huge amounts of solar power for consumption back on earth. It could also be used to help dispose of the radioactive waste produced by nuclear reactors.
According to Obayashi research and development manager Yoji Ishikawa, advances in carbon technology will make the elevator possible by permitting the creation of super-strong cables nearly one hundred times stronger than those manufactured from steel.
While the maximum length of carbon nanotubes is still just three centimetres, Ishikawa is confident that they will have the technology to build a space elevator of the nanotubes mastered by as soon as 2030.
Ishikawa expects the project to be the result of international collaboration, in accordance with the results of a major study released in 2012 concluding that the construction of a space elevator was a feasible endeavour, but one best undertaken by a concert of nations.
While Obayashi is staking the fate of the project on advances in carbon nanotubes, Dani Eder of Boeing’s space systems division said via Reddit that even this technology will be unnecessary for the undertaking if a more modern space elevator design is adopted.
Instead of a single elevator extending all the way from the ground to the space elevator’s final destination point, a composite system could be built consisting of two sub-elevators – one in low orbit and other near geostationary orbit (GEO).
This would reduce the total cable length 60-fold – from 96,000 kilometres to 1,500 kilometres, reducing both cost as well as exposure to asteroids and orbiting debris.
Orbit mechanics would reduce total travelling time from seven days to seven hours, while the two-stage elevator using multiple cords would prove much safer overall by dispensing the single cable design, for which a single point of failure anywhere could lead to the collapse of the entire structure.