A LONG CLIMB: An artist’s conception shows a climber pod ascending a space elevator’s tether to deploy a satellite.Image: ISEC
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SEATTLE—“I think building an elevator to space is maybe the best thing I could do in the world,” Michael Laine says.
His company, Liftport, has just raised over $62,000 on Kickstarter to build robot climbers on a skyward cable—an early step toward his eventual goal of putting a space elevator on the moon. A space elevator is just what it sounds like—a capsule that travels to and from space along a track or tether to provide reliable access to orbit.
Behind Laine is the cavernous Great Gallery at Seattle’s Museum of Flight, where dozens of aircraft are on display, chronicling the human adventure of flight. Meeting in a nearby conference room are about 40 space enthusiasts, in town for the annual Space Elevator Conference hosted by ISEC, the International Space Elevator Consortium. Some of them have sacrificed their careers, credit ratings or savings accounts—all in pursuit of a simple concept that has thus far proved impossible in practice.
None of the conference participants could be accused of thinking small, whether the discussion is about a 100,000-kilometer tether made of carbon nanotubes, space-based solar power, or man’s ultimate destiny to seed the galaxy.
Peter Swan, retired from over 40 years building space systems and now serving as ISEC’s vice president, calls a space elevator a way to “make the human condition better.” His altruism was shared by many of the conference attendees.
But it’s not all starry-eyed optimism. “I’m trying to tackle a project that a lot of people think is science fiction,” says Laine, who has gone into foreclosure seven times over nearly a decade to keep his company, and his dream, alive. “It’s appropriate to be skeptical, even at this stage.”
The idea of a space elevator has set the heart of many engineers aflutter. But all eventually run into the same obstacle—the so-called unobtainium problem, or the need for a material that does not exist.
A space elevator is a theoretical structure that reaches from the Earth’s surface into space, balanced by its own mass and the outward centrifugal force from the spinning Earth. The physics is sweet—complicated enough to be interesting, simple enough to seem doable, and the space elevator’s intrigue has grown exponentially since Arthur C. Clarke gave it a fictional treatment in his 1979 novel The Fountains of Paradise.
The problem is the construction material, which must be superstrong yet very light. Equations worked out decades ago by Russian engineer Yuri Artsutanov and, independently, by American space scientist Jerome Pearson, found that the ideal tether should be tapered, widest at the geosynchronous orbit altitude of 35,800 kilometers, and narrowest at Earth’s surface and at its far end. The tether should extend far past geosynchronous orbit, where a counterweight would help provide the needed tension.
The rub is that the tether must have sufficient tensile strength to hold up its own large mass. Any material works in principle, but even for stainless steel the tether would need to be 1043 times wider at geosynchronous orbit than at the ground.
The only known material that offers the required strength-to-density ratio is a carbon nanotube, a cylindrical chickenwire lattice of carbon atoms. The problem is that nanotubes exist in a form akin to a pile of soot, and no one knows how to fashion them into an extended rope, braid, cable or ribbon. In the view of elevator enthusiasts, carbon nanotubes, or CNTs are the last major “if only.”
BETTING ON A LONG SHOT
Bryan Laubscher has staked his career on carbon nanotubes and the space elevator. A former physicist at Los Alamos National Laboratory, he formed Odysseus Technologies in 2009, and has four other investors, including Ted Semon, president of ISEC. From his garage shop Laubscher works with CNTs with the goal of drawing them into a tether. While he has mostly learned what does not work, he filed for a patent on a so-called nanotube detangler in May, and a second patent for a CNT growth technology that he keeps under wraps.
“The space elevator breaks the rocket paradigm” because it does not carry its own fuel, Laubscher says. He believes chemical technology is near its limit, bound by theTsiolkovsky rocket equation to deliver only about 5 percent of its initial mass into Earth orbit. Those inefficiencies meant that it cost $64,000 for the space shuttle to put one kilogram into low-earth orbit (LEO); an elevator, Laubscher calculates, could do it with 17.2 kilowatt-hours of electricity—about two dollars’ worth.
He sees the space elevator as the future analogue of the Transcontinental Railway that opened the American West—once the infrastructure has been put in place at great effort and expense, transport becomes cheap, and new opportunities abound. “Once you’re at LEO,” Laubscher says, “you’re half the way to anywhere.” Still, he was clear that “the space elevator is far in the future.”
Peter Swan sees space-based solar power as the ultimate savior of a world starved for energy, and the space elevator as the only way to economically place the required infrastructure in space. The vision is of satellites in orbit, above clouds, weather and the atmosphere, collecting sunlight and beaming power to small surface dishes via microwaves. “Africa could skip the 20th century for telecom and power wires,” he says, and emergency power could be beamed anywhere to the surface.
“The space elevator would be a nonlinear event in history,” Swan says. He and colleagues are even designing organization charts for elevator operations at its presumed ocean-based floating anchor station (the community favors a low-lightning spot near the equator in the eastern Pacific ocean) and its on-shore marine base in San Diego.
But not everyone is as confident about the elevator’s fruition. Brad Edwards, who co-authored the 2003 book, The Space Elevator, that has since served as a template for all elevator discussions, dropped out of the field after years spent trying to make it a reality. “Technologically we could do this in the next 10 or 15 years,” he recently told the magazine Seattle Met. “But realistically it’s going to take much longer, and I had to ask myself whether I wanted to do this for the rest of my life.”
Arthur C. Clarke famously said the space elevator would be built 50 years after everyone stopped laughing. “I think we’ve quieted the people who are outright laughing,” says Laine, a former U.S. Marine and investment adviser who continues to put personal funds into his company. “We haven’t quieted the skeptics, and there should be people asking questions.”
Laine’s Liftport Group, formed in 2003 after he worked with Edwards on a NASA Innovative Advanced Studies (NIAC) grant to study the space elevator, once had 14 employees. Liftport unsuccessfully tried to produce carbon nanotubes and carried out some balloon and tether tests in an effort to sell weather data for revenue. The crash of the economy put them out of business for five years, but Laine sees the enthusiastic and unexpected response to his Kickstarter campaign—his goal was only $8,000—as a sign of optimism.
Like all the conference attendees, he is buoyed by the privatization of space, seen recently in SpaceX launches, Paul Allen’s Stratolaunch Systems, and the two test modules for expandable habitats that Bigelow Aerospace has placed in orbit. Laine is promoting an elevator from the lunar surface to a point in space between Earth and the moon, because the physics is kinder and at least five existing materials meet its requirements, including Zylon and Kevlar. A lunar tether would have the dimensions of dental floss, he says, and would be feasible with commercial, off-the-shelf technology—and perhaps $800 million.
One speaker at the conference said the elevator would be driven by those most prosaic of human motivations, greed and the opportunities to make money. Laine might once have agreed. “Eleven years ago when I started this, I was far more rational about it,” he says of his elevator quest. “But over time the making money part really dwindled, and it’s become a mission,” a way to change the global standard of living with ubiquitous energy and access to resources such as raw minerals from asteroids, helium-3 from the moon, or oxygen, water and other lunar materials for space- or Mars-based habitats.
“But,” he concedes, “I’m well past rational at this point.” That stubborn persistence may be just what it takes if an elevator is ever to ferry humans into outer space.