Stairway to heaven: building a real elevator to space using paper-thin, carbon nanotubes.

Back about 15 years ago, scientists conducted laboratory experiments aimed at simulating the conditions under which carbon nucleates in the atmosphere of a cool carbon-rich red giant star. The specific goal of this Fullerene Research was to explore the possibility that long carbon chain molecules could form when carbon vapour nucleates in the presence of hydrogen and nitrogen. Then, in 1991 and purely by accident, these scientists discovered what may end up being the most significant spin-off of Fullerene research.

They created tiny carbon tubes referred to as nanotubes or C60 "buckyballs" that can assemble themselves into microscopic scaffolds. These hollow carbon-based nanotubes consist of graphitic layers seamlessly wrapped to cylinders that are 100 times stronger than steel--yet so tiny that 50,000 of them would fit into a human hair. They would have immeasurable applications in the future to build molecular structures of a specific size from the atom up, and they can take on different chemical properties. The discovery of this new form of carbon was a tantalizing surprise to scientists. Just imagine the possibilities of a molecule that has the strength of a diamond but is six times lighter than steel.

The scientists used principles of biology to create long chains of carbon atoms that form structures spontaneously when mixed in water. The first structures they created were simple rosettes of six groups of molecules. Rings form because the inside and outside react differently to water. The inside surface of the ring is trying to avoid water, but the outside surface of the ring is attracting water. The rings then form tubes. Electrical charges on the outside of the tubes form a belt that holds them together. This system of tubes could be used to build new materials, nano-sized electronic devices, and even machines that could enter the human body and deliver drugs.

Scientists envision an even more significant application of this technology. They're looking into the possibilities of building a fixed link into outer space. That's right--an elevator made up of a metre-wide, paperthin ribbon of nanotubes stretching from the earth's surface straight up 35,800 kilometres and linked to a space station that was in a synchronous orbit with earth. Up to now, the biggest hurdle to building a space elevator was in finding a material strong enough and light enough to construct it. As amazing as it sounds, a carbon-nanotube ribbon would be durable enough to carry as much as 5 tons of payload for every trip. About 22 tons of carbon-nanotube cable would be lifted up into orbit, then reeled down from an anchor (space station) like a fishing line to a location on the equator where it would be tethered. Robotic climbers would then slide up the ribbon, strengthening it with more carbon nanotubes material as they ascended.