Reply #5: I Thought There Were More Immediate Challenges

[On the Road]

than creating light-powered machines to climb the tether. Maybe all these things are proceeding at the same time -- it just seemed to be putting the cart before the horse.

First, you need to develop mass quantities of a material strong enough to withstand the tremendous stresses that the tether will be under. The only material that may be strong enough to do that is buckeytubes, which now are able to be made only in small quantities and at great cost. Unless the tether is a single piece, the different parts have to be joined in a way that maintains the strength. Those are the biggest hurdles.

After that the material has to be transported into space. Since the tether will be flexible, it can't be built from the ground up. Don't know how many trips on the space shuttle that will mean.

Once those obstacles are overcome, the light-powered (or laser-powered) climbers will probably be available.