Here’s an update to my previous post about this.

HighLift Systems has a proposal for a small-scale space elevator. Instead of a large-diameter (5 to 20 meters) full-scale beanstalk, they propose a 10-20 cm wide ribbon which would be only fractions of a millimeter thick. This is based on a NASA Institute for Advanced Concepts study.

This design would drive costs down into the $10-billion range – much less than what AOL/TimeWarner lost last year – and allow payloads of a few tons.

The ribbon would be 100,000 km long and weigh about 750,000 tons. There’s a FAQ which answers many questions about safety. For instance, the ribbon would wrap 2.5 times around the Equator if it fell down… but such a thin ribbon would be mostly evaporated during re-entry. Dana Blankenhorn elaborates further on problems and opportunities. However, Carey Gage, among others, makes the point that such a structure is presently impossible to defend.