By my recollection, geosynchronous satellites are at ~22,000 miles / ~35 km up. In this orbit, obviously, centrifugal acceleration exactly counterbalances gravity. (Else the thing would rise or sink to a different orbit).
Objects in higher orbits travel more slowly (they are further away, and therefore fight against less gravity). As I understand it, the space elevator will be geosynchronous, with an elevation far beyond the "force-balanced" geosynchronous orbit point 35 K up.
Any geosynchronous object more than 35K up (i.e., the top of the elevator) will be travelling far faster than necessary to maintain its orbit; in fact, it will be fighting like hell to escape to a higher orbit (trading its kinetic energy for gravitational potential energy).
The problem is similar to that of many carnival rides -- keeping tethered to the center.
I don't think current nanotube manufacturing processes are sufficient to handle these forces. I could be wrong -- I haven't found good public descriptions on nanotube manufacturing.
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By my recollection, geosynchronous satellites are at ~22,000 miles / ~35 km up. In this orbit, obviously, centrifugal acceleration exactly counterbalances gravity. (Else the thing would rise or sink to a different orbit). Objects in higher orbits travel more slowly (they are further away, and therefore fight against less gravity). As I understand it, the space elevator will be geosynchronous, with an elevation far beyond the "force-balanced" geosynchronous orbit point 35 K up. Any geosynchronous object more than 35K up (i.e., the top of the elevator) will be travelling far faster than necessary to maintain its orbit; in fact, it will be fighting like hell to escape to a higher orbit (trading its kinetic energy for gravitational potential energy). The problem is similar to that of many carnival rides -- keeping tethered to the center. I don't think current nanotube manufacturing processes are sufficient to handle these forces. I could be wrong -- I haven't found good public descriptions on nanotube manufacturing.