Imagine a long tether linking Earth to space that could launch us to orbit at a fraction of the cost and slingshot us to other worlds at record speed.
That’s the basic idea behind a space elevator.
Instead of taking six to eight months to reach Mars, scientists have estimated a space elevator could get us there in three to four months or even as quickly as 40 days.
The concept of space elevators isn’t new, but engineering such a structure would be no easy feat, and many other issues besides technology stand in the way.
That’s why the ambition to seriously build one is fairly recent.
The Japan-based company Obayashi Corporation thinks it has the expertise.
Japan aims to build a space elevator by 2050
Known for constructing the world’s tallest tower, the Tokyo Skytree, Obayashi Corporation announced in 2012 that it would reach even loftier heights with its own space elevator.
In a report that same year, the company said it would begin construction on the $100-billion project by 2025 and could start operations as early as 2050.
We checked in with Yoji Ishikawa, who wrote the report and is part of the company’s future technology creation department, to see how the project is progressing ahead of 2025.
While Ishikawa said the company likely won’t start construction next year, it is currently “engaged in research and development, rough design, partnership building, and promotion,” he told Business Insider.
Some have doubted such a structure is even possible.
“It’s been sort of a kooky idea,” said Christian Johnson, who published a report on space elevators last year in the peer-reviewed Journal of Science Policy & Governance.
“That said, there are some people who are real scientists who are really on board with this and really want to make it happen,” Johnson said.
A cheaper route to space
Launching humans and objects into space on rockets is extremely expensive. For example, NASA has estimated its four Artemis moon missions will cost $4.1 billion per launch.
The reason is something called the rocket equation. It takes a lot of fuel to get to space, but the fuel is heavy, which increases the amount of fuel you need. “And so you see the kind of vicious cycle there,” Johnson said.
With a space elevator, you don’t need rockets or fuel.
According to some designs, space elevators would shuttle cargo to orbit on electromagnetic vehicles called climbers. These climbers could be remotely powered — like through solar power or microwaves — eliminating the need for on-board fuel.
In his report for the Obayashi Corporation, Ishikawa wrote that this type of space elevator could help drop the cost of moving goods to space to $57 per pound. Other estimates for space elevators in general have put the price at $227 per pound.
Even SpaceX’s Falcon 9, which, at around $1,227 per pound, is one of the cheaper rockets to launch, is still about five times as expensive as the higher cost estimates for space elevators.
There are other benefits besides cost, too.
There’s no danger of a rocket exploding, and the climbers could be zero-emission vehicles, Johnson said. At a relatively leisurely pace of 124 miles per hour, the Obayashi Corporation’s climbers would travel slower than rockets with fewer vibrations, which is good for sensitive equipment.
Ishikawa said the Obayashi Corporation sees a space elevator as a new kind of public works project that would benefit all of humankind.
There’s not enough steel on Earth to make a space elevator
Right now, one of the biggest obstacles to building a space elevator is what to make the tether or tube from.
To withstand the tremendous tension it would be under, the tube would have to be very thick if it were made out of typical materials, like steel. However, “if you try to build it out of steel, you would need more steel than exists on Earth,” Johnson said.
Ishikawa’s report suggested Obayashi Corporation might use carbon nanotubes. A nanotube is a rolled-up layer of graphite, the material that’s used in pencils.
It’s much lighter and is less likely to break under tension compared to steel, so the space elevator could be much smaller, Johnson said. But there’s a catch.
While nanotubes are very strong, they’re also tiny, a billionth of a meter in diameter. And researchers haven’t made them very lengthy. The longest is only about 2 feet.
To be properly balanced while still reaching geosynchronous orbit — where objects stay in sync with Earth’s rotation — the tether would need to be at least 22,000 miles long, per Ishikawa’s report.
“So we’re not there,” Johnson said of the nanotube length. “But that doesn’t mean it’s impossible.”
Instead, researchers might need to develop an entirely new material, Ishikawa said.
Other obstacles
Whatever the material turns out to be, there are still other problems.
For instance, a space elevator’s tether would be under such incredible tension that it would be prone to snapping, Johnson said. A lightning strike could vaporize it. There’s also other weather to consider like tornadoes, monsoons, and hurricanes.
Locating the tether base at the equator would lessen the likelihood of hurricanes, but it would still need to be in the open ocean to make it more difficult for terrorists to target, Johnson said.
It would also take a lot of trips to make up for that giant price tag for construction.
That’s only scratching the surface of the challenges. And they can’t all be solved by one company, Ishikawa said. “We need partnerships,” he said. “We need different industries.”
“Of course,” Ishikawa said, “raising funds is very essential.”
That’s a lot of obstacles to overcome to start construction in time for operation by 2050, especially since Ishikawa estimated it would take 25 years to build. He noted that the 2050 estimate always came with caveats about the technology progressing. “It’s not our goal or promise,” he said, but the company is still aiming for that date.
“I think that those time estimates are optimistic,” Johnson said, “even assuming there was a breakthrough tomorrow.”
Japanese Firm Plans Space Elevator That Could Get Us To Mars In Record Time
Obayashi Corporation first announced its plan for a space elevator in 2012. The company said it would start construction on $100-billion project in 2025 and operations could begin by 2050.
A space elevator is an innovative concept aimed at revolutionising access to space. This theoretical structure would consist of a cable or tether anchored to the Earth’s surface, extending into space, possibly to a counterweight or a satellite in geostationary orbit. The idea, first proposed by Russian scientist Konstantin Tsiolkovsky in 1895, envisions using the cable to transport materials and spacecraft directly into orbit without traditional rocket propulsion. So far, the technology has limited us from creating a functional space elevator.
But a Japanese firm Obayashi Corporation thinks it can do that. In an interview with Business Insider, Yoji Ishikawa, who is a part of the company’s future technology creation department, said the company is currently “engaged in research and development, rough design, partnership building, and promotion”.
Instead of taking six to eight months to reach Mars, scientists have estimated a space elevator could get us there in three to four months or even as quickly as 40 days.
Obayashi Corporation first announced its plan for a space elevator in 2012. The company said it would start construction on $100-billion project in 2025 and operations could begin by 2050.
But according to Ishikawa, the construction won’t start next year.
Some experts, meanwhile, doubt if such a structure is even possible.
“It’s been sort of a kooky idea. That said, there are some people who are real scientists who are really on board with this and really want to make it happen,” said Christian Johnson, who published a report on space elevators last year in the peer-reviewed Journal of Science Policy & Governance.
The primary advantage of a space elevator is its potential to significantly reduce the cost and environmental impact of sending payloads into space. Unlike rockets, which require large amounts of fuel and produce significant emissions, a space elevator could use electric motors to move cargo and passengers along the tether, offering a more sustainable and economical alternative.
However, the engineering challenges are immense. The material for the tether must possess extraordinary strength-to-weight ratio, far exceeding that of any current material. Additionally, considerations such as stability, weather impacts, and space debris pose significant hurdles.
Despite these challenges, the concept of a space elevator continues to inspire scientists and engineers, representing a bold vision for future space exploration and transportation.
In NDTV
Full Research Study “The space elevator construction concept”
Abstract
We describe a newly-designed, whole-space elevator system, including its construction process, and we examine its feasibility. The space elevator is planned to be built by the year 2050 with a capacity to carry 100- Ton climbers. It is composed of a 96 000-km carbon nanotube cable, a 400-m diameter floating Earth Port and a 12 500- Ton counterweight. Other facilities include Martian/Lunar Gravity Centers, an LEO (Low Earth Orbit) Gate, a GEO (Geostationary Earth Orbit) Station, a Mars Gate and a Solar System Exploration Gate. The construction process consists of deploying the cable and constructing the facilities. It is necessary to analyze the cable dynamics in order to estimate the characteristics of the cable, counter-weight, facilities and climbers, and in order to determine the construction procedures. Parameters for the cable dynamics include tension, displacement and elongation of the cable due to ascending climbers, masses of counter-weight and cable, wind, and fixed loads of facilities. With the help of a computer simulation of the equations of motion, we designed the system and determined the construction process. Based on the results, we conclude the following: construction will be technically feasible with an assumed cable tensile strength of 150 GPa, it will take roughly 20 years to construct the cable, the impacts of wind 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 plan, a 20- Ton cable is deployed initially, and is 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. For our model, we estimate that the construction cost will be approximately 100 billion USD, and the transportation operation cost approximately 50 to 100 USD/kg. The large initial construction cost, according to our estimate, will be paid off simply by using the space elevator to construct and operate a single, conventional space solar power system, with an output of 5 GW and a mass of 50 000 tons. This would mean that all other space transportation would benefit from the significantly lower operational cost of the space elevator, which would be roughly one-hundredth of that of conventional launches. 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 Today 