A Cheap Ride to Orbit?

     Once considered far fetched, the idea of running an 'elevator' from Earth to geosynchronous orbit is getting new attention as materials that can take the required high stresses are developed; there are even companies being formed to try and build one. The idea is not a new one. I know that Arthur C. Clarke (the inventor of the geosynchronous comsat) was fascinated by the idea, and Tsiolkovsky studied it in the late 1800's. The basic idea is to start at geostationary orbit (obviously a non-geostationary orbit wouldn't do for an elevator!) and run cables 'down' and 'up', simultaneously, in such a way that the center of mass stays at the radius of geosynchronous orbit. To avoid having to send the 'up' cable a significant fraction of the way to the Moon a large counterweight, say a small asteroid, is attached to the 'up' end.
    Unfortunately a cable made of most currently known materials (e.g. steel) would snap long before reaching the surface, under the tension that would develop due to its own weight. Even if the cross section of the cable is variable with altitude (a constant cross section cable turns out not to be the best choice), almost no known material would be able to reach anywhere near Earth's surface.
    However, the recent discovery and rapid progress in the study of Carbon 60 (commonly known as "Bucky balls") and subsequent discoveries have led to "carbon nanotubes" which turn out to be enormously strong (one of the people I learned alot of Physics from at UVM has done a lot of work on nanotubes). Now we need to figure out how to make alot of it . . .
    If this thing ever looks like becoming a reality, invest in equatorial, mountain-top real estate since that's where it would have to be built!

Click here for a NASA summary of this subject.