End of their tether

Teams from industry and universities joined amateur enthusiasts last weekend to compete in NASA’s 2005 Beam Power and Tether challenges — two contests to build a climbing robot and high-strength tether for possible application in the construction of a space elevator.

Engineers believe that in a couple of decades it will be possible to build a fixed line from Earth to space to carry an elevator. The line would consist of a high-strength tether made from carbon nanotubes. Elevator cars would travel up and down the tether, powered by highintensity, Earth-based lasers aimed at photovoltaic cells on the cars’ undersides.

To speed up research into technologies needed for such a project, NASA offered £28,000 prizes to innovators who could reach two key milestones. The competition, sponsored by the non-profit Spaceward Foundation, took place at the NASA Ames Research Centre in Mountain View, California.

The Beam Power Challenge, designed to create a solution for powering the space elevator, required teams to build a robotic climber that could scale a 61m cable, powered by photoelectric cells capable of converting light from a 10,000W industrial searchlight into electricity.