But what has engineers and scientists excited is the single walled kind - carbon nanotubes that are cigar-shaped molecules with atoms connected in a kind of hexagonal chicken wire, with the seams sealed along the vertical axis and in their rounded ends. Such a carbon nanotube, which is now the standard reference when using the term, is wholly self-contained, so it has no reactive edges from which it might unravel. It's also flexible, with great tensile strength. The number most often quoted is, 100-times stronger than steel, at about one-sixth the weight.

Theoretically, one could create nanotubes that extend from the Earth into space - there's no physical limit to their length. They are currently made using four basic approaches, with two fastest out of the gate: pulsed laser vaporization and electric arc discharge. In the former technique, pulsed lasers strike a catalyst of graphite and metal - cobalt and nickel - which are vaporized into a tube filled with pressurized argon in an oven heated to 1473 degrees Kelvin. In those extreme conditions the nanotubes self-assemble from the carbon vapor and then condense on the flow tube's walls. In the latter, faster, method developed at the University of Montpellier in France, the carbon is also vaporized. But instead, this time catalysts of nickel and yttrium are vaporized from an anode when it's hit with 100 amps of electricity at 35 volts. The nanotubes self assemble in a stainless steel chamber filled with low-pressure helium gas, cooled by water. A newer third method simply decomposes carbon-containing molecules on nanometer-sized particles of metal catalysts.

Smalley's team recently began producing nanotubes from, essentially, car exhaust. High-pressure carbon monoxide (HiPco) is reacted with iron pentacarbonyl, which is also under high pressure, and heated. The iron clusters phase into a gas and the carbon atoms grow into nanotubes around those clusters. A NASA research paper described this method promising because it's rapid and relatively clean, meaning that there's less carbon soot and catalyst to remove to purify samples. Smalley said he could even imagine making huge sheets of carbon that have rounded corners and seamlessly connected sides, a flattened Fullerine just two atoms thick, almost like a giant pita bread. "I'm not sure what you could do with it, but it sure would be cool stuff," Smalley said, but then added that it might be layered and adhered in a superstrong composite.

"In regards to the space elevator using carbon nanotubes - I myself do not personally see the benefit of using single walled or multiwalled carbon nanotubes when composite materials made from graphitic fibers can perform similarly, and much more cheaply.  The bulk use of carbon nanotubes is still a very long way off, and a tremendous amount of development effort will be required for this vision to ever be realized. I think this application for CNTs is a little crazy, but hey, a lot of crazy ideas have eventually found their niche.  It just may take a very long time," argues Dr. Alan M. Cassell, Senior Research Scientist of the Eloret Corporation at NASA Ames Research Center.

As Smalley remarked, "until strong, continuous tubes are in the hands of engineers, it's all idle speculation."