An uplifting experience

One of the great things we get for living through the years surrounding the end of last century and the beginning of this one is the ability to watch science fiction become science fact before our very eyes. We've seen communications and computing

One of the great things we get for living through the years surrounding the end of last century and the beginning of this one is the ability to watch science fiction become science fact before our very eyes. We've seen communications and computing devices hit mainstream that dwarf even Star Trek's tiny toys, and the blossoming of Cyberspace to a point that must mystify c-punk author William Gibson. And now, at long last Arthur C Clarke, SF writer and father of the telecommunications satellite, must be very pleased indeed, as his long scoffed space elevator has come one step closer to reality.

The idea of the space elevator actually predates Clarke, but he has been its biggest proponent. The idea is simple - you get a massive 'thread', place its center of gravity in geostationary orbit, and then anchor it either end and start running freight up and down its length. It sounds outlandish, but consider that the current cost to lift just one kilogram of cargo into orbit is something like $US22,000; the space elevator's projected one kilo lift cost is only $US1.50. Building one, even when we do get the technology right, is an outrageously expensive and complex proposition, but its cost savings could pay for it in time.

So while people used to laugh, NASA has nonetheless had top people looking into the concept, and it seems that they've found one possible material to build the thing out of. The cable needs to be narrow while also strong enough to withstand its own 47,000km length. Carbon nanotubes are the answer - created by laser vaporisation of graphite, and expensive process. Basically, we're talking very, very small hollow tubes of hexagonally arranged carbon atoms, though a new manufacturing process in development could drop that price considerably.

At the moment we've just got to work out a way to make the tube a little bigger - say in the realm of 4mm long. Cross that hurdle and you can start weaving them into other materials, or even make the thing out of one series of very long nanotubes. But however it's done, the fact is that there are more solutions being found every day.

If a space elevator is to be built, it will be arguably the biggest engineering feat the world has ever seen, and even then many people doubt the cost outweighs the benefit. Screw 'em, I say; I think cheaper space exploration is worth it.