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A space elevator could make it much cheaper and faster to deliver goods to other planets, such as Mars.
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Japan-based Obayashi Corporation announced plans in 2012 to begin construction next year.
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Not only would it cost $100 billion, there are also enormous technological and organizational challenges.
Imagine a long cable connecting Earth to space that could put us into orbit at a fraction of the cost and hurl 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 estimate that a space elevator could get us there in three to four months or even 40 days.
The concept of space elevators is not new, but designing such a structure would not be an easy task, and many other problems besides technology stand in the way.
That is why the ambition to seriously build one is quite recent.
The Japan-based company Obayashi Corporation believes it has the expertise.
Japan wants to build a space elevator by 2050
Known for building the world’s tallest tower, the Tokyo Skytree, Obayashi Corporation announced in 2012 that it would reach even greater heights with its own space elevator.
In a report the same year, the company said it would begin construction on the $100 billion project by 2025 and could begin operations as early as 2050.
We checked in with Yoji Ishikawa, who authored the report and is part of the company’s future technology creation department, to see how the project is progressing leading up to 2025.
Although 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 doubt whether such a structure is even possible.
“It was quite a crazy idea,” says 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 into this and really want to make it happen,” Johnson said.
A cheaper route to space
Launching people and objects into space with rockets is extremely expensive. For example, NASA estimates that the 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 reach space, but the fuel is heavy, which increases the amount of fuel you need. “And so you see kind of a vicious cycle there,” Johnson said.
With a space elevator you don’t need rockets or fuel.
According to some designs, space elevators would carry cargo to orbit on electromagnetic vehicles called climbers. These climbers can be powered remotely, for example via solar energy or microwaves, so no fuel is required on board.
In his report for the Obayashi Corporation, Ishikawa wrote that this type of space elevator could help reduce the cost of moving goods into space to $57 per pound. Other estimates for space elevators in general put the price at $227 per pound.
Even SpaceX’s Falcon 9, which is one of the cheaper rockets to launch at about $1,227 per pound, is still about five times more expensive than the higher cost estimates for space elevators.
Besides the costs, there are other benefits.
There is no danger of a rocket exploding and the climbers can be zero-emission vehicles, Johnson said. At a relatively leisurely pace of 200 kilometers per hour, the Obayashi Corporation climbers would travel slower than rockets with less vibration, 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 humanity.
There is not enough steel on Earth to make a space elevator
Currently, one of the biggest obstacles to building a space elevator is the material from which the cable or tube must be made.
To withstand the enormous stress, the pipe would have to be very thick if it were made of typical materials, such as steel. But “if you try to build it out of steel, you need more steel than exists on Earth,” Johnson said.
Ishikawa’s report suggested that Obayashi Corporation could use carbon nanotubes. A nanotube is a rolled layer of graphite, the material used in pencils.
It is much lighter and less likely to break under stress compared to steel, so the space elevator could be much smaller, Johnson said. But there’s a catch.
Although nanotubes are very strong, they are also small: one billionth of a meter in diameter. And researchers haven’t made them very long. The longest is only about 2 feet.
To be properly balanced and still achieve a geosynchronous orbit – where objects remain in sync with the Earth’s rotation – the cable would have to be at least 35,000 kilometers long, Ishikawa’s report said.
“So we’re not there yet,” Johnson said of the nanotube length. “But that doesn’t mean it’s impossible.”
Instead, researchers may have to develop an entirely new material, Ishikawa said.
Other obstacles
Whatever the material turns out to be, there are other problems.
For example, the chain of a space elevator would be under such incredible tension that it could break, Johnson said. A lightning strike could vaporize it. There are also other weather conditions to consider, such as tornadoes, monsoons and hurricanes.
Locating the base on the equator would reduce the chance of hurricanes, but it should still be in the open ocean to make it harder for terrorists to target, Johnson said.
It would also take a lot of travel to make up for that huge construction price tag.
That’s just the beginning 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 money is very essential.”
There are many obstacles to overcome to begin construction in time for it to be operational by 2050, especially since Ishikawa estimated that construction would take 25 years. He noted that the 2050 estimate always came with caveats about the advancement of technology. “It’s not our goal or our promise,” he said, but the company is still targeting that date.
“I think these time estimates are optimistic,” Johnson said, “even assuming there would be a breakthrough tomorrow.”
Read the original article on Business Insider