Comments and alternatives, by Jim Cline, regarding the anchored tether Space Elevator project proposed by Bradley Edwards, developed under grant from NIAC between 2000-2002, and presented at ASCE's Space 2002 conference:

  1. Effect on the KESTS to GEO potential project: Although the original reason for creating the KESTS to GEO form of space elevator access to space from the ground, was to bypass the extraordinary strength to weight limitations of potential tether material when the earth tether space elevator concept was originally formed long ago, the nature of KESTS to GEO now go far beyond that of mere bypassing tether limitations. Nonetheless, since the tether technology now seems nearly ready for the "bending metal" stage, I recommend full steam ahead on Brad Edward's Space Elevator concept project. The tether concept was given a grant by NASA 2 years ago to proceed, while KESTS was not given a grant, so the tether is ready to go! Let's go for it ASAP!
  2. Brad Edward's tether project uses a newly-developed carbon nanotube matrix ribbon for the tether material. It is to be placed in GEO using 4 shuttle launches, enabling a start for the tether cable to be emplsced to the earth surface from GEO while the tether counterweight extends beyond GEO. Once this is emplaced and anchored to surface platform, crawlers will climb up the tether adding material to the tether, tacking it as it goes along. The resulting completed tether would have a taper in its crossectional area, 2.4 times as wide at GEO as it is at the surface platform's site. A new type of high efficiency laser on the ground will beam energy up to the crawlers to power them, and then to power payload carrying vehicles as they climb the tether to space during routine transportation. The new carbon nanotube matrix material that makes this possible has a density of 1300 kg/m3 and a working tensile strength of 100 GPa.
  3. Since I have been mulling over space elevator concepts for over 3 decades, some comments come to mind now, which possibly might enable the project to have new features beyond Edward's original proposal. Some of these thoughts have already been communicated to Brad Edwards by e-mail, but he is very busy, lacking the hired help he needs with his project. So the following is my effort to provide such thoughts.
  4. Continuing on the concept of adding cable taper only in the final stage of construction, using a linear or slightly inverted taper during construction:

Page updated 2002 04 17 by James E D Cline

Copyright © 2002 J E D Cline