Contemplating the Eiffel Tower in 1895, Russian mathematician Konstantin Tsiolkovsky got an idea. He imagined a huge tower anchoring a cable that reached up to a way- station parked in a geostationary orbit. People and materials could ascend the cable into space without rocket propulsion. As recently as 15 years ago, the idea of such a “space elevator” was still pure fantasy. No known material was strong enough to extend 62,000 miles into the sky and support even its own weight.

All that changed in 1991 when Japanese scientists discovered carbon nanotubes, a molecular chain many times stronger than steel. As a result, the space elevator is now the stuff of NASA studies, academic research and business plans. In 1999 NASA gave a half million dollars to former Los Alamos physicist Bradley Edwards to develop a scenario for using the new carbon material in a space elevator. Edwards envisioned solar-powered robots ascending a three-foot-wide carbon-nanotube ribbon at 120 miles per hour, reducing the cost of getting materials to orbit from $10,000 per pound to just $100. All the technology, Edwards argued, was attainable within two decades. NASA was intrigued. “It could significantly increase our launch capacity,” says David Smitherman of NASA’s Advanced Projects Office.

There are still major challenges. No one has yet integrated carbon nanotubes into the necessary high-strength composite material. Lightning and hurricanes near the ground and debris in orbit also pose problems. Nevertheless, a nascent space-elevator industry is forming. A California foundation recently announced an annual X Prize-style contest to spur grass-roots development of elevator components. A Seattle company, LiftPort Group, has built “Squeak,” a prototype of the treaded robots that would climb the ribbon into space. And Edwards has started his own firm, Carbon Designs Inc., to continue research that would make up the elevator’s backbone. “I am still considered a dreamer,” he says. “But six years ago, there was nobody else working on it. Now there are hundreds of people.”

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