Sending people into space with a space elevator

By 2050, astronauts are expected to reach the International Space Station in just two and a half hours.

Spectacular idea

One of Japan’s leading construction companies, Obayashi Corporation, recently announced it has begun testing carbon nanotubes, which could theoretically help build a giant elevator that could reach into outer space.

This “space elevator” would propel humans out of the Earth’s atmosphere at record speeds. Based on some scientists’ estimates, the idea could reduce the travel time to Mars from 6-8 months to just 40 days. But is such an ambitious project really possible? Obayashi Corporation says “Yes.”

What would this space elevator look like? According to concept images and plans drawn up by the Obayashi Corporation, it would look like a giant tube, connecting Earth to a geostationary satellite outside the planet’s atmosphere. The carbon nanotube would be nearly 60,000 miles long, using a wheeled elevator called a “climber” to transport materials and people.

Obayashi Corporation said the construction of the space elevator will be carried out by transporting materials via rockets at various stages during the construction of the spacecraft in Low Earth Orbit (LEO).

The spacecraft will then use electric motors to move upward as it orbits the Earth until it reaches Geostationary Earth Orbit (GEO), at which point it will begin to orbit at a speed similar to the Earth’s rotational speed.

At a distance of about 35 thousand kilometers from Earth, the spacecraft will begin deploying the carbon nanotube with a thruster attached to its tip, and then move further away from Earth again.

Eight months later, Obayashi Corporation estimates, the carbon nanotube will reach the Earth’s surface and the spacecraft will reach its final altitude of 96,000 kilometers, where it will act as a counterweight for the tube. From there, a climber will climb the tube, reinforcing it with cables before connecting it to the counterweight at the top.

Obayashi Corporation estimates that after being reinforced about 500 times, the tube will be able to support a 100-ton wheeled elevator, which will be used to transport materials to complete the GEO station.

Below, scientists plan to build Earth Harbor, a gateway to space in two parts, one on land at the equator and one at sea. Each part would be connected by an underwater tunnel.

From Earthport, climbers will travel up the carbon nanotube at speeds of around 150 kilometres per hour, reaching the altitude of the International Space Station in about two and a half hours. The entire journey will theoretically be powered by solar energy, with the GEO station acting as a giant solar panel.

Each launch, the corporation said, would likely cost several thousand dollars, which compared to the current cost of sending a spacecraft into space, is quite cheap.

The idea of ​​a space elevator.

Is it possible?

Yoji Ishikawa, a member of Obayashi’s future technology innovation division, said that although elevator construction is unlikely to begin in 2025 as originally estimated in 2012, Obayashi Corporation is still “engaged in research and development”, hoping to complete it by 2050.

Of course, not everyone shares Obayashi’s optimism when it comes to the project. Scientist Christian Johnson, who has written a paper on space elevators by 2023, says it’s a quirky idea but one that would certainly have some benefits.

First, there would be no risk of the missile exploding, and the speed at which the material is transported would cause less vibration, which would be good for sensitive equipment. Transporting the material would also be significantly cheaper than most missile-based systems.

There are some hurdles, though, such as not having enough steel on Earth to build such a massive structure, especially if it’s strong enough to withstand the strain. This may be why the Obayashi Corporation is researching carbon nanotubes, which are essentially rolled-up layers of graphite.

Carbon nanotubes are certainly strong, but at just a billionth of a meter in diameter, they are incredibly small, while a tether for a space elevator would need to be 35,000 kilometers long, a whopping 35,000 kilometers.

There are also a host of other issues, including potential threats to people, to the elevators, weather-related events that could damage the elevators, and the huge cost of construction — estimated at around $100 billion.

While the idea of ​​a space elevator has captured the imagination, it still has a long way to go before it becomes a reality. The Obayashi Corporation project is a bold step into the future of space travel, but its success will depend on solving many technical and financial problems.