Nanotech's promise is out of this world. Just ask Brad Edwards, who's planning to build a carbon-nanotube elevator that goes 62,000 miles straight up.
Of all the revolutionary technologies just ahead, nanotechnology seems the most outlandish. Machines the size of molecules made from materials stronger than titanium, self-assembling computers smaller than bread crumbs: We've heard the hype about such microscopic marvels for a decade, but it's still kinda hard to believe.
The nuts and bolts are familiar. Nanotubes, bonded-carbon cylinders mere billionths of a meter wide, are highly resistant to tension, heat, and decay. Woven into fibers, nanotubes could create a fabric potentially hundreds of times sturdier than steel, and a fifth the weight - the strongest material ever found on Earth.
Or off. Listen to what Brad Edwards suggests doing with the things. The founder of Seattle-based Highlift Systems, Edwards proposes a carbon-nanotube space elevator: a ribbon 62,000 miles long, 3 feet wide, and thinner than the paper your thumb is pressed against right now. The elevator would stretch high into the heavens, allowing easy transport from Earth, launching spacecraft, new industries, even tourists - at a fraction of today's costs. And he says he can be well under way in a decade, ushering in a new era of space exploitation.
For all its revolutionary potential, the space elevator is an old idea. In 1895, Russian scientist Konstantin Tsiolkovsky looked at the elevators ascending the Eiffel Tower and dreamed of a "celestial castle" tied to Earth. In 1979, Arthur C. Clarke's novel Fountains of Paradise concerned a supercarbon elevator that produces great change and not a little chaos.
Twelve years later, in a research lab in Japan, science surpassed the science fiction. Experimenting with soccer ball-patterned carbon cages called fullerenes, Sumio Iijima noticed a sooty-looking byproduct. Looking at the residue under an electron microscope, Iijima found that the fullerenes had transformed into tubular graphite structures with a remarkably strong lattice of walls. A flurry of research showed that these carbon nanotubes, as they came to be called, were able to conduct both heat and electricity. From Los Alamos National Lab, a young Brad Edwards kept close watch with more than idle curiosity. He was heading up an ill-fated plan to explore Europa, one of Jupiter's moons, and impossibly high transport costs had just grounded the project. "I started thinking that if I was ever going to get up in space," Edwards says, "I'd have to do it myself." With the nanotubes, he reasoned, he just might make it.
Edwards had already won a virtuoso's reputation at Los Alamos for thinking differently. Many told Edwards that his idea for an optical refrigerator - which keeps machines from overheating by using lasers to cool a specialized form of glass - defied the laws of thermodynamics. The concept had been around since the 1920s, but previous lasers only melted the glass. Edwards' team developed a precisely tuned beam that, paradoxically, absorbed the heat it produced and more. After two years of work, they created a prototype, beating other researchers, including a Nobel physicist, to the punch.
In 2000, Edwards left Los Alamos for Eureka Scientific, a research group for NASA grant proposals. Two years later, he set up Highlift in downtown Seattle. On a recent day in his small office there, Edwards holds up a black strip 2 feet long. It's a prototype of the ribbon, hundreds of hairlike fibers strung together to distribute tension. The strip represents what could be Highlift's first commercial product, a nanotube composite four times stronger than steel. When it hits the market, it could be used to, for example, make superstrong tennis rackets, create cars and planes that are at once lighter and sturdier, and add decades of durability to infrastructure projects like bridges or freeways. Within two to three years, Highlift should have a material strong enough for the space elevator ribbon.
The elevator itself will be built upon something resembling an offshore oil platform (way offshore: Highlift is looking at a site in the eastern Pacific, 1,000 miles from the Galépagos Islands). Construction would start with expendable rockets (such as the Delta 4 or Atlas 5) shooting into low Earth orbit. There, the rockets will link up, creating an 80-ton spacecraft that will ascend to 22,000 miles and lock into geosynchronous orbit.
From there, the craft will unreel the ribbon 40,000 more miles into space, and lower a weighted ribbon to the ocean platform (centripetal force will do most of the work getting it up; gravity will help get it down). Edwards estimates that the ribbon will land within 100 miles of the platform; a GPS locator and beacon on the ribbon's end will help a ship retrieve it and attach it to the platform.
With a counterweight attached at the far end, the strand will stay taut through sustained centripetal force. Now comes the heavy lifting: 7-ton climbers, each the size of a semitrailer, will ascend the ribbon at 120 miles an hour, carrying payloads weighing as much as 13 tons. The climbers will be powered by earthbound free-electron lasers, which is the same tech behind Stanford's linear accelerator. The lasers are aimed at photocells on the climbers' undersides, the photocells power the climbers' motors, and the elevator goes up. Edwards reckons it will feel like taking an elevator in a tall building. In a few hours, you'll reach outer space. In two weeks, you'll reach the ribbon's end - one quarter of the way to the moon.
The economies of scale behind the space elevator could make a trip into space as mundane as a trip to Maui. Launching a pound of cargo by rocket or space shuttle runs about $40,000. Edwards figures the space elevator can do it for $200, a figure that could drop to $10. Go weigh yourself and multiply.
In short, Edward's lift could do for the new century what railroads did for the 1800s: slash the cost of a ticket to the new frontier. Outer space is suddenly a lot closer than we think.
Every time the 39-year-old Edwards presents his project, scientists pelt him with the same questions. He answers each with the equanimity of a parent explaining why the sky is blue. What if an airplane crashes into the thing? (Doubtful, given a base 400 miles from the nearest air route.) What about a terrorist attack? (There will likely be military protection.) Lightning? (Few storms strike in the area.) A meteorite? (Like a spacecraft, the material will just need to be strong enough to take it.)
Edwards' patient explanations are paying off. He's received $570,000 from NASA's Institute of Advanced Concepts program, which funds experimental projects, and hopes for more from Darpa and the Air Force. Highlift expects private investors to put up much of the $40 million for its composite. Later, the company will pass the hat again, for $7 billion, to build the elevator itself.
The space elevator remains a dream. But like many things nanotech, it's a dream that could happen - and indeed change the way we live. "If you start putting people, factories, cities into orbit cheaply, it would have a profound effect on every aspect of human life," says Harley Thronson, technology director in NASA's Office of Space Science. "Humans would occupy a three-dimensional world, rather than the two-dimensional world of Earth's surface." The gateway to that dimension may be as small as a ring of carbon molecules.
10 YEARS OF NANOTECHNOLOGY
1995
White House science adviser Jack Gibbons calls nanotechnology "a powerful economic engine" and urges further research.
1996
Richard Smalley, Robert Curl, and Harold Kroto share a Nobel for finding supercarbon fullerenes, aka buckyballs.
1997
Nadrian Seeman at NYU develops the first DNA-based nanomechanical device.
1999
Cees Dekker of the Delft University of Technology designs the first carbon-nanotube transistor.
2000
US launches the National Nanotechnology Initiative, investing $270 million to fund nanoscale science.
Carlo Montemagno and other scientists at Cornell create the first nanomachine, a motor connected to a propeller.
2001
IBM and other outfits make molecular-logic circuits entirely from nanotubes, a major step toward carbon chips.
2002
NASA Ames Research Center builds a latticed nanostructure from modified microbial proteins.
