22 September 2008

Been A While...

since we've had a good space elevator discussion. Now Japan has has turned its attention to building a space elevator, although the linked article is somewhat unclear on who "Japan" is.

5 comments:

aog said...

Aaaaaaaugh!

"The biggest obstacle lies in the cables. To extend the elevator to a stationary satellite from the Earth's surface would require twice that length of cable to reach a counterweight, ensuring that the cable maintains its tension. [emphasis added]"

No! That is completely false. You only need a bit more than the distance to GEO, if you have enough mass hang off the end. Just like a teeter-totter, there's a distance / mass trade off where the bigger your counter weight, the less extra length of cable you need.

Duck said...

Weren't they supposed to leapfrog us with the "next generation" computer? Or was it High Definition TV? Somehow I remember that in the late 80s they were poised to bury us by virtue of their centrally coordinated industrial policy.

What's to prevent one of these space elevator ribbons from being severed by a terrorist flying an airplane?

Don't ever teke technology direction from a science fiction writer. They are all closet statists, plus to them technology is how they get orgasms.

aog said...

Collisions with airplanes is a real concern. Terrorists don't tend to show up as concerns as there's little they can do that couldn't also happen as an accident (e.g., plane collisions). A plane can take out only a very small part of the ribbon (less than 10 km.), the rest being pulled up, not down.

Duck said...

Yes, but once the ribbon is broken it isn't easy or cheap to reconnect it, I reckon.

It will all come down to economics, and what economic incentives develop to exploit space on a large scale. I don't see large scale settlement of space anytime soon. The population bomb refuses to develop, and where it does it will be in countries where space settlement is not a feasible alternative. By 2070 or so we'll have a surplus of housing in the middle and upper class regions of the globe.

aog said...

It doesn't seem like it would be any harder than setting it up in the first place. I strongly doubt any reconnect attempt would be made. You'd just pretend you were back at the original deployment point where the cable as far above the ground as the lost section. If you're doing extrusion from orbit, you just lengthen again and you're set. It's the collision of the lost segment on the ground that's going to cause problems.