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Space elevator climbs closer to being reality


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POSTED: Friday, November 20, 2009

”;If we are to achieve results never before accomplished, we must expect to employ methods never before attempted.”;

Sir Francis Bacon (1561-1626)

Earlier this month a laser-powered robotic climber won $900,000 in a NASA's Centennial Challenges competition to develop a space elevator that would require anchoring a cable to the ground near Earth's equator and attaching the other end to a large mass thousands of miles above the surface.

Visionary author and inventor Arthur C. Clarke popularized the space elevator in his 1979 novel, “;The Fountains of Paradise,”; set in the 22nd century. He once quipped that the space elevator would succeed “;50 years after everyone has stopped laughing.”;

Many have already stopped laughing, and some believe that the elevator could be built and be in operation by the middle of this century.

Cost estimates for the initial program range from $10 billion to $20 billion, in the range of Honolulu's controversial rail system. Spread across the entire U.S. population, it amounts to less than $50 per capita. When compared with an estimated $185 billion over the life of the Space Shuttle program, it seems like quite a bargain.

The two primary challenges are beaming power to an electric motor in the elevator as it ascends a lightweight tether made from carbon nanotubes or a material yet to be developed. These are no more difficult than the obstacles that confronted the development of rocket-powered space travel, and the technologies needed for a space elevator project could lead to spinoffs in the same way that rocket science led to personal computers and cell phones.

Travel to Earth orbital altitudes on the space elevator would be like a 10-hour train trip, with no extreme g-forces, no on-board fuel and none of the danger of explosions associated with rocket launches.

A fully operational system of elevators could send people and goods into space cheaper, easier, safer and cleaner than with chemical rockets.

Because space elevators could be built to any scale, there would be no practical limitations on payload size. Using a 2 1/2 -inch tether instead of a quarter-inch tether would allow the elevator to lift 100 times the weight, and could conceivably lift 40 shipping containers or the equivalent of three complete International Space Stations per day.

Consider the cost and efficiency of a ferry versus a bridge here on Earth and then consider that the rocket ferries we use for space cargo today are just as cost-inefficient by comparison with the space elevator. The elevator system could cut the cost of putting a pound of cargo into space to $10 from $10,000 compared with about $1 to fly a pound on a jetliner.

Among other things it is easy to imagine restaurants and hotels for space tourists, wind turbines attached to tethers generating power 24 hours a day, as well as a cheaper, easier and more environmentally friendly way to launch rockets to the moon and beyond.

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Richard Brill is a professor of science at Honolulu Community College. E-mail questions and comments to .(JavaScript must be enabled to view this email address).