Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!security!genrad!decvax!harpo!seismo!hao!hplabs!sri-unix!REM@MIT-MC From: REM%MIT-MC@sri-unix.UUCP Newsgroups: net.space Subject: Realistic space elevators Message-ID: <13289@sri-arpa.UUCP> Date: Wed, 9-Nov-83 02:19:00 EST Article-I.D.: sri-arpa.13289 Posted: Wed Nov 9 02:19:00 1983 Date-Received: Sun, 6-Nov-83 20:15:31 EST Lines: 23 From: Robert Elton Maas When actually finished, it won't topple under its own weight because it'll be hanging from its orbital point (hanging both up and down from there) rather than supported at the bottom. During construction, however, if it's built bottom-up, it'll have to support its own weight nitially. But more likely it'll be constructed in orbit and then deorbited at one end, so it'll never have to support its own weight by pushing from the bottom, even during construction. Note, it'd be widest at the middle, at the orbital point, and taper narrower both towards the ground and out to space. Alternately the very bottom part could be supported from the bottom, so it'd taper like the Eiffel Tower at the bottom, then reverse-taper up to the orbital point and back down above it as in the first paragraph. But the very bottom part would be infitesimal (a half mile?) compared to the rest (20,000 miles or more). Although there are some designs for having a tower supported from below, there's a problem in putting so much weight on a single point on Earth. I rather doubt the ground would hold. It would be embarassing to build such a tower only to have the whole island it's located on be sunk into the Earth by all that weight.