Last month at a conference in Luxembourg, Cambridge University scientists announced a way of making long thin carbon nanotubes link together to form a material that might suffice to built a space elevator, perhaps a decade from now after the process has been successfully scaled up. From PhysOrg.com “Long, Stretchy Carbon Nanotubes Could Make Space Elevators Possible“:
Scientists from Cambridge University have developed a light, flexible, and strong type of carbon nanotube material that may bring space elevators closer to reality. Motivated by a $4 million prize from NASA, the scientists found a way to combine multiple separate nanotubes together to form long strands. Until now, carbon nanotubes have been too brittle to be formed into such long pieces.
And a space elevator — if it ever becomes reality — will be quite long. NASA needs about 144,000 miles of nanotube to build one. In theory, a cable would extend 22,000 miles above the Earth to a station, which is the distance at which satellites remain in geostationary orbit. Due to the competing forces of the Earth’s gravity and outward centrifugal pull, the elevator station would remain at that distance like a satellite. Then the cable would extend another 40,000 miles into space to a weighted structure for stability. An elevator car would be attached to the nanotube cable and powered into space along the track.…
Currently, the Cambridge team can make about 1 gram of the new carbon material per day, which can stretch to 18 miles in length. Alan Windle, professor of materials science at Cambridge, says that industrial-level production would be required to manufacture NASA’s request for 144,000 miles of nanotube. Nevertheless, the web-like nanotube material is promising.
“The key thing is that the process essentially makes carbon into smoke, but because the smoke particles are long thin nanotubes, they entangle and hold hands,” Windle said. “We are actually making elastic smoke, which we can then wind up into a fiber.”
—Jim
