On Thu, 07 Aug 2003 00:25:44 GMT, Joe Kultgen wrote:
Nope. We don't presently have the materials technology to build a
"Beanstalk". We don't have the technology for an escape speed catapult.
But we don't *need* one to make space a paying proposition! All we need
is to get the govt. completely out of the commercial launch business.

Actually, it looks like we do now have the materials technology to build
a beanstalk. Researchers have now made carbon nanotube structures
up to 5 feet long (limited only by their tabletop equipment) with the
requisite tensile strength. It is just straightforward engineering
development from there to the lengths needed for a beanstalk.

Getting government out of the launch business doesn't somehow
change the rocket equation. The mass ratio needed to reach orbit
ultimately determines the cost to orbit by rocket, and that's only
a function of the gravity well. The equation tells us best case cost
is still a couple of orders of magnitude too high for commercial
exploitation of space.

Gary