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Posted: August 25, 2007

Nanotechnology key to space elevator

(Nanowerk News) Tie a rock to the end of a piece of ribbon, then spin it over your head. It will be pulled taut as the rock circles about. Now, imagine a ribbon 62,000 miles long, anchored near the equator with a weight on the other end. The centrifugal force of the earth's rotation will make it behave the same way. You'll end up with not only the world's biggest nunchuck, but also a kind of elevator to outer space.
A space elevator is one of those ideas from 1950s-style futurism that are so whacky they might just work.
Today's Wall Street Journal runs an article titled "Is the Final Frontier Just One Ride Away On a Space Elevator?" (subscription required) about NASA's Elevator 2010 Annual Space Elevator competition
The 2007 competition takes place in October in Salt Lake City with entries to demonstrate serious power beaming and Carbon Nanotube tether technologies. The prize money is now $500,000 per each of the two competitions.
The WSJ writes that, to the extent that a space elevator is feasible at all, this due to advances in the science of nanotechnology, especially carbon nanotubes.
The long spine of the proposed elevator would be 30 inches wide but only as thick as a sheet of paper. Nanotechnology engineers have alreday created threads 15 percent as strong as those needed for an elevator, and continue to make steady progress. Existing nanotube threads are already triple the strength of the Kevlar strands used in bulletproof vests.
The main theorist of the space elevator is Brad Edwards, a former Los Alamos National Lab physicist who spent three years under a NASA contract figuring out if a working elevator could be built. Yes, he concluded, and here's how:
A rocket would take two spools, each the size of a living room with 31,000 miles of ribbon wrapped around it, to an orbit of 22,000 miles. Both would be unrolled, one being allowed to waft back to earth, the other pulled up and away from earth by a spacecraft and then anchored with a weight at the end. Then they'd be joined in the middle.
The bottom portion would be secured onto an oil rig-like platform located along the equator, 1,500 miles west of Mexico, a location chosen for its uneventful weather.
The ribbon would weigh 800 tons, or about 26 pounds a mile. Were it to break, the top segment would float away into space while the bottom would fall to earth. Nothing you'd want to be on hand to see, of course, "but nothing that would threaten the planet," said Edwards.
Edwards estimates a real elevator would cost $12 billion and could pay for its operations by capturing 25 percent of the commercial satellite-launching.
Source: Wall Street Journal
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