Imagine a long tether linking Earth to space, launching us to orbit at a fraction of the cost and slingshotting 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 isn’t new, but engineering such a structure is a monumental challenge, and many issues beyond technology stand in the way.
Japan’s Ambitious Plan
The Japan-based Obayashi Corporation, known for constructing the world’s tallest tower, the Tokyo Skytree, announced in 2012 its goal to build a space elevator. The company projected that construction on the $100-billion project would begin by 2025, with operations starting as early as 2050. Yoji Ishikawa, part of the company’s future technology creation department, stated that while construction likely won’t start next year, they are engaged in research and development, rough design, partnership building, and promotion.
Cost of Space Travel
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 the rocket equation: it takes a lot of fuel to get to space, but the fuel is heavy, which increases the amount of fuel needed. This creates a vicious cycle of weight and cost.
A space elevator could break this cycle. Designs suggest it would shuttle cargo to orbit on electromagnetic vehicles called climbers, powered remotely through solar power or microwaves, eliminating the need for onboard fuel. Estimates suggest a space elevator could reduce the cost of moving goods to space to as little as $57 per pound, significantly cheaper than even SpaceX’s Falcon 9, which costs about $1,227 per pound.
Technological Hurdles
One of the biggest obstacles to building a space elevator is the material for the tether. To withstand the tremendous tension, the tether would have to be very thick if made from typical materials like steel. “If you try to build it out of steel, you would need more steel than exists on Earth,” Johnson said. Instead, Obayashi Corporation suggested using carbon nanotubes, which are incredibly strong and much lighter than steel. However, the longest carbon nanotubes produced so far are only about 2 feet long, far short of the 22,000 miles needed for a space elevator tether.
Researchers might need to develop an entirely new material. Even if a suitable material is found, other issues remain. The tether would be under such tension that it would be prone to snapping. Weather events like lightning strikes, tornadoes, monsoons, and hurricanes pose significant threats. Locating the base at the equator and in the open ocean could mitigate some risks, but it introduces new logistical challenges.
Collaboration and Future Prospects
The challenges of building a space elevator cannot be solved by one company alone. Ishikawa emphasized the need for partnerships across different industries and significant funding to move forward. He noted that the 2050 target for operation always came with caveats about technological progress. While Obayashi Corporation aims for that date, it’s not a firm promise.
Dream of a space elevator faces numerous technological, logistical, and financial challenges, ongoing research and development keep the possibility alive. If successful, a space elevator could revolutionize space travel, drastically reducing costs and enabling more frequent and efficient missions to other planets. The path to realizing this dream is complex and uncertain, but the potential benefits make it a pursuit worth exploring.