Reply To: What is the current state of the project?
KeithPickering wrote: The biggest technical challenge may not even be cable strength. It will be impact resistance/avoidance from gazillions of pieces of junk in Low Earth Orbit. A paint fleck at 17,000 mph can ruin your whole day. Shuttle damage is trivial by comparison, since the shuttle tends to travel in the same direction as other LEO objects, lessening the relative velocity. The cable for a space elevator isn’t moving at orbital speed until you’re up at 22,000 miles. Take a look at this diagram:
Now imagine having to move the cable bottom to avoid each and every one of those little dots, simultaneously. And those dots are all moving! Clearly it’s an impossible task. But if you don’t do it, your cable takes impacts. So how long can the cable survive under such bombardment? Not long, is the guess here. And the problem is only going to get worse as time goes on and more and more junk ends up in orbit.
I gots tha ansar!
Surround the cable with a braced hollow tube, about 0.5km internal space and .2km thickness of walls, of aerogel. It is insanely light and strong, and would be readily patchable with external extruder-spider thingies crawling up and down non-stop.
All fiksed!
(But I admit, it would definitely ruin the view for the cable passengers going up and down! Maybe laser light shows on the inner surface (or other effects from luminescent gizmos embedded in the gel? 😉 ) )