14 DAY TRIAL // Scientists at the Cambridge University may have discovered the key to the hypothetical space elevator – ultra-long and very resistant carbon nanotubes, which can now be grown to impressive lengths, due to innovations in their production methods. Up until this point, creating such long tubes was virtually impossible, because of the brittle structure of the material. Now, a new technique allows for such wires to be built at any length, thus satisfying most space elevator designs, which see a “climber” traveling up a very strong wire.
According to NASA estimates, the space agency would need approximately 144,000 miles of cable to set the foundation for the space elevator. And that's a pretty long wire, experts say, to be built in one piece. However, if it's not, there’s always the risk of a portion snapping off due to the incredible forces that will act on the structure.
The center of the lift will be in low Earth orbit, but the cable will also have to extend a long distance further than its final destination, a portion that will either house a massive counterweight, or simply more cable, running about the same length it takes for it to reach orbit from Earth. There will be massive forces acting on the structure – gravity will pull it towards the ground, and the force generated by Earth's rotation, the centrifuge force, will try to rip it off the ground and carry it in space.
The experts working on this ambitious design need to face these facts and design materials that wouldn't break under the strain, as well as a pretty large anchor for the entire structure.
"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. We are actually making elastic smoke, which we can then wind up into a fiber," says Cambridge materials science professor Alan Windle, who is a part of the team working on the new materials.
"The biggest problem has always been finding a material that is strong enough and lightweight enough to stretch tens of thousands of miles into space. This isn't going to happen probably for the next decade at least, but in theory this is now possible. The advances in materials for the tether are very exciting," adds John Winter from EuroSpaceward, the organizer of a space conference in Luxembourg, which drew representatives from most space agencies, including NASA and the European Space Agency.