St. John Barned-Smith April 24, 2019 Updated: April 24, 2019 10:57 a.m.
Scientists and space enthusiasts hope that future astronauts will be able to travel beyond earth’s orbit by means of a “space elevator.”
The concept is relatively simple: Ditch the rockets. Build a tether anchored to a space station beyond Earth’s gravitational orbit. Astronauts or materials could then travel along the tether — which would be kept taut by the rotation of the earth — in cars powered by solar energy or magnetic motors.
Once there, the astronauts could move about more easily and supplies could be distributed.
Proponents say space elevators would bring the costs of space travel plunging downward, making space exploration more affordable. It would also make getting out of orbit safer, since it wouldn’t require controlled explosions to get to space.
That could prove especially useful with humanity’s expanding reliance on space resources for tools like GPS, communications or weather alerts, said David Alexander, director of the Rice Space Institute at Rice University
“Having a reliable, safe, low-cost access to space only improves these capabilities,” he said. “Additionally, in the future we may be relying on having a much larger human presence living and working in space. A space elevator may be one way to help achieve these future aspirations.”
If the concept behind space elevators is simple, making it a reality is far more complicated. Current plans call for an almost 60,000-mile-long tether — a length nearly 300 times farther than the distance to the current International Space Station.
It would be one of the most expensive public works project in human history.
“The sheer scale of the project is so immense that it barely can be afforded by any nation — or all nations,” said Boris Yakobson, a Rice University materials scientist who produced some of the first calculations showing carbon nanotubes might theoretically be able to support a space elevator.
“To illustrate it,” he said, “just the amount of carbon for a two-to-three meter diameter space elevator would take all the coal annually produced in the United States.”
Scientists say current technology doesn’t exist to build an elevator that could withstand the gravitational force or other stresses that would be placed on it, or other damage from high-energy cosmic rays, electric transmissions, and collisions with space debris.
But Yakobson and others say a material called graphene, composed of carbon nanotubes that are extraordinarily light and strong cylinders and just an atom thick, could theoretically provide the building blocks needed to build a space elevator.
The idea for a space elevator first surfaced in the late 1800s, after a Russian scientist visiting Paris saw the Eiffel Tower. Over the next century, scientists suggested other proposals, but the idea has remained little more than a science fiction dream.
Still, that hasn’t stopped enthusiasts, scientists, and construction developers from pushing ahead with trying to make space elevators a reality one day.
One New Jersey-based company in 2006 lifted a tether attached to an observation and communication platform a mile into the air while robotic lifters climbed up and down the tether.
An International Space Elevator Consortium launched in 2008, holding conferences in Europe and Japan. Then in 2012, a Japanese company announced plans to build a space elevator by 2050. The company, Obayashi, said it will use carbon nanotubes as the basic building block for the tether, and plans to transport 30 people at a time in elevator cars that could travel more than 120 miles per hour.
The International Academy of Astronautics in 2013 published results of a four-year study which posited that a space elevator could reduce the cost of lifting a kilogram of cargo space to around $500.
Even Google took a look: In 2014, Google X’s Rapid Evaluation R&D confirmed it had started a space elevator project but shelved the effort after learning about the difficulty in manufacturing carbon nanotubes longer than a meter.
In late 2018, Japanese scientists from Shizuoka University sent a miniature version of a space elevator to the International Space Station for testing.
The test would mark the world’s first experiment of elevator movement in space, a company spokesman said, and involves running a small box, slightly larger than a matchbox, along a 10-meter cable suspended between two miniature satellites.
For now, a working space elevator remains a long shot. Of course, half a century ago, most people scoffed at the idea of landing a man on the moon.
“If you don’t ask the big questions, you don’t make progress,” Alexander said.