Despite biggies like Google X have shelved the science fiction space elevator project, Japan’s Obayashi Corporation is planning to build the coveted future gateway to space for mankind by 2050 with a capacity to carry at least 100 travelers.
A space elevator is conceived as a cable fixed to the equator and reaching into space with a counterweight at the upper end that keeps the center of mass well above geostationary orbit level. This produces enough upward centrifugal force from Earth’s rotation to fully counter the downward gravity, keeping the cable upright. Climbers can carry cargo up and down the cable.
Buyoant with the successful completion of the world’s tallest free-standing tower, TOKYO SKYTREE, Obayashi Corp. said it is designing a space elevator which climbs from the Earth Port as a departure port for people to Geostationary Earth Orbit Station at a height of 36,000 km.
The space elevator will be composed of a 96,000-km carbon nanotube cable, a 400-m diameter floating Earth Port and a 12,500-ton counter-weight. It will have Martian/Lunar Gravity Centers, a Low Earth Orbit Gate, a Geostationary Earth Orbit Station, a Mars Gate and a Solar System Exploration Gate, said the company.
The construction involves deploying the cable and constructing the facilities, taking into consideration the cable dynamics such as cable properties, counter-weight, facilities and climbers. Cable properties include tension, displacement and elongation of the cable due to ascending climbers, masses of counter-weight and cable, wind, and fixed loads of facilities.
The company said based on a computer simulation of the equations of motion, it has designed the system and finalized the construction process for the proposed space elevator.
Technically construction will be feasible with an assumed cable tensile strength of 150 GPa, which may take about 20 years to construct the cable, it said. The wind impact or Coriolis force on cable displacement are small, and it is essential to fix one end of the cable to the earth’s surface, always applying pre-tension at the ground end, according to the blueprint of the Space Elevator project of Obayashi Corp.
A 20-ton cable will be deployed initially, and it will be reinforced 510 times by climbers up to 7,000 tons, ascending in succession over roughly 18 years. The facilities are then transported and constructed within one year, said the sketch.
However, the company said, “The current technology levels are not yet sufficient to realize the concept, but our plan is realistic, and is a stepping stone toward the construction of the space elevator.”
Space Elevator has been a dream project of astronomers and engineers for over two decades now and it had its mention first in 1895 when Russian scientist Konstantin Tsiolkovsky, inspired by the Eiffel Tower in Paris, proposed a similar tower that reached all the way into space to the altitude of 35,790 kilometers, the height of geostationary orbit.
Science fiction write Arthur C. Clarke broadened the concept to all with his 1978 novel, Fountains of Paradise. He visualized engineers construct a space elevator on top of a mountain peak in the mythical island of Taprobane (close to Sri Lanka, where Clarke lived).
Several contests and competitions have been held in the last 10 years with little result. In 2014, Google X’s Rapid Evaluation R&D team began the design of a Space Elevator, eventually abandoning it after it was found that no one had yet manufactured a perfectly formed carbon nanotube strand longer than a meter. It remains to be seen how far Obayashi’s claims can see the future of Space Elevator unfold.