October 18, 2006. Copyright 2006, Graphic News. All rights reserved

The space elevator -- shortcut to the stars or a bridge too far?
By Mark Rutter

LONDON, October 18, Graphic News:  When Arthur C. Clarke conceived the idea of a space elevator in his 1978 science fiction novel The Fountains of Paradise, few would have guessed that less than 30 years later it would spawn a competition to turn his idea into reality. On October 20-21, this yearÕs X-Prize Cup, the worldÕs biggest space exhibition, is to host the Space Elevator Games. Aimed at inspiring the development of technologies required to build an elevator capable of transporting machines into space, it is expected to attract over a dozen teams vying for the $400,000 prize money.
 
With recent advances in technology, some people now believe it is possible to build an elevator to provide a safer and more efficient alternative to rocket propulsion for sending equipment and humans into space. Several different kinds have been proposed -- named variously beanstalks, space bridges, space lifts or space ladders -- but the only type to receive serious attention from scientists is the tether. Consisting of a cable or ribbon anchored to the earth and stretching into space to an altitude of 35,800km (22,245 miles), it would be held in place by a satellite, in a geosynchronous orbit above the equator. The centrifugal force generated as the satellite revolves in sync with the EarthÕs rotation should enable the ribbon to counteract gravity and remain rigid, allowing vehicles clamped to it to climb into space.
 
By setting two competitions, the Space Elevator Games taking place at Las Cruces, New Mexico, is trying to encourage ideas for developing the tools for the initial stages of a bridge to the stars. Firstly, the Power Beam Challenge requires teams to build a machine powered by a remote beam of light and capable of climbing up a crane-suspended vertical ribbon. The winner of the competition will be the climber carrying the largest load to a height of 50 metres (164 feet) in the shortest period of time. The Tether Challenge is intended as a way of developing a suitable material for the ribbon. Teams will compete directly against one another to find out which has the strongest tether. In order to claim the $200,000 prize, the winning tether has to be at least 50 percent stronger than the current standard. The material would need to be lightweight, strong enough to endure enormous stresses, and relatively inexpensive to enable it to be manufactured in large quantities. Carbon nanotube composites offer the best hope of todayÕs materials, but despite having the necessary theoretical strength the practical results have yet to live up to that potential.
 
Irrespective of the outcome of these Games, interest in and funding for the technology required for a space elevator is set to continue. As well as organising the 2006 Games, Spaceward Foundation, in partnership with NASA, has just announced the Elevator:2010 project -- a scheme offering up to $4,000,000 in competition prizes over the next five years. However, it is likely to be many more years before push-button access to space makes the transition from the pages of science fiction to reality.
/ENDS