Our Quest for a Space Elevator Has Hit a Big Snag
The long-romanticized concept of a space elevator has popped up in science fiction for over a century and, for a while there, space elevators were thought to be a feasible option that could be achieved in the relatively near future. But unfortunately, the shining futuristic world in which we can take an elevator up to the stars might be a little further out of reach than we had hoped.
The material that encouraged these high hopes was the development of carbon nanotubes (CNTs), tubes made up of a layer of carbon atoms in hexagonal arrangements, which results in a material stronger than steel and lighter than air. But despite the exciting possible applications of this material, building a space elevator isn't one of them - at least not for the moment. The very atomic structure that makes CNTs so strong could also be their undoing when it comes to that particular pipe dream.
A team of nanotechnologists from Hong Kong Polytechnic University simulated what would happen when a single atom was out of place in CNTs, causing a kink in the tube. This had a profound impact on the tensile strength of the CNTs, causing the strength to go from 100 gigapascals (GPa), to 40 GPa. The more atoms that were misaligned, the worse the problem became as carbon bonds were easily snapped under these conditions, which can cause an entire tube to unzip and damage the CNT fibre.
The tensile strength of the cables required for a space elevator is estimated to be at least 50 GPa, but the chances of flaws increase with mass production of CNTs. If even a single atom is misplaced, the cable won't be strong enough to support a space elevator.
Producing a long enough network of CNTs to build an elevator won't be an option until the flaws in the process of synthesizing the material can be addressed. For the moment, if we want to hitch a ride into space, it looks like we're going to have to look elsewhere.
Via New Scientist