A space trip using an elevator may come true in 2050, as general contractor Obayashi Corp. is planning to construct a “space elevator” stretching 96,000 km above the ground.

While the concept of such an elevator has been described in science fiction novels, the construction has become possible after the 1991 discovery of carbon nanotube, a lightweight material more than 20 times stronger than steel, the company said.

Under the plan announced this week, the company will build an orbital station at an altitude of 36,000 km, a final destination for space travelers and housing experimental and development facilities utilizing the space environment.

A six-car elevator, expected to travel at a speed of 200 kph, will be capable of carrying 30 people and will take about seven and a half days to arrive at the orbital station.

According to the company, construction work will start around 2025. A rocket will be launched to transport two reeled cables using carbon nanotube and other materials to an altitude of about 300 km, where a space ship will be assembled.

The space ship will unreel the cables toward Earth, while continue soaring to the summit of 96,000 km, which is about one-quarter the distance from Earth to the moon, Obayashi said.

Then the cables will be reinforced from the ground using elevator cars, which will ascend to the summit. The reinforcement work will be conducted 510 times, the company said.

The elevator will be powered partly by electricity generated by solar power from space, the company said.

The company at present cannot calculate how much money would be needed to construct the space elevator and there would be some hurdles, such as where to build it, said Satomi Katsuyama, leader of the company’s space elevator project.

“But we’d like to realize the project, as it will greatly save on costs for space development in the future,” she said.