A space elevator is being planned by Obayashi Corporation, a Japanese-based construction company. Their intent is to complete the device by the year 2050 with a capacity to carry 100-ton climbers.
(Space Elevator Planned By Obayashi Corp video)
The space elevator will be composed of a 96,000-km (60,000 mi) carbon nanotube cable, a 400-m (1,300 ft) diameter floating Earth Port and a 12,500-ton counterweight.
The counterweight, which will be attached to the end of the cable in space, will help in stabilizing the cable by keeping the center of mass well above geostationary orbit level. Other facilities will include Martian/Lunar Gravity Centers, Low Earth Orbit Gate, a Geostationary Earth Orbit Station, a Mars Gate and a Solar System Exploration Gate. The video below shows the concept as proposed by Obayashi Corporation.
Although the original insight for space elevators came to Russian scientist Konstantin Tsiolkovsky in 1895, sf writers have been encouraging scientists and builders to construct a space elevator for generations.
"If the laws of celestial mechanics make it possible for an object to stay fixed in the sky, might it not be possible to lower a cable down to the surface – and so to establish an elevator system linking Earth to space?"
(Read more about Arthur C. Clarke's visualization of space elevators from his 1978 novel The Fountains of Paradise)