OT: About Space Elevators - Page 3

geoschmo · #21 October 9th, 2002, 06:11 PM

The purpose of the ground link isn't to keep the ribbon taut. The ribbon doesn't have to be rigid, just basically stationary. You can't let it move around too much or you get problems with harmonic vibrations on the line. That would cause wild gyrations in certain spots that could damage the cable and/or cause the climbers problems. Anyone see the video of "Galloping Girdy", the bridge that tore itself apart in the wind. That wasn't because of a tremendous wind, it was just a slightly more windy than normal day, but the frequency of the vibrations in the bridge tore itself apart. That's the concern with the wind for the space elevator. That sort of thing can be actively dampened for the ribbon, but that requires manipulation at the ends. So they have to be attached to base stations. That is the danger of wind.

I don't know if they have any plans to reel up the cable in emergency situations like this, but there is no reason why you couldn't do it all the way from the high orbit. An intermediary station would be an unnceccesary complication. You don't have to take up the entire length of the ribbon, jsut reel up 15 miles or whatever to get the bottom end above the weather. The only quetions would be the reel having sufficent torque to take up the mass of the entire length of the cable. But the reel will have to be able to handle the mass of the entire length of the cable anyway or you would never be able to get it down to the ground in the first place. The only way to set the elevator up is to launch the spool in the conventional way and then reel it down from orbit.

Geoschmo

Suicide Junkie · #22 October 9th, 2002, 06:37 PM

Quote:

So I could buy myself a �50 ticket and scoot up a cable off the coast of Australia at 9am. Then I could zing around the Earth on a super-fast space cable car and scoot back down another cable in the North Sea in time for lunch the same day. (except that it would be midnight... yeesh, jet lag would be horrendous.)

You could also send packages from Tokyo at 8:00am, and they would arrive at the pacific coast of america by 5:00pm the previous day!

Urendi Maleldil · #23 October 9th, 2002, 06:43 PM

As long as they don't make you climb the cable in gym class.

geoschmo · #24 October 9th, 2002, 07:28 PM

If something like this gets built I can really see it become some sort of "Holy Grail" for those base jumping lunatics that climb tall buildings and parachute off of them.

Arkcon · #25 October 9th, 2002, 07:46 PM

Quote:

Originally posted by geoschmo:
If something like this gets built I can really see it become some sort of "Holy Grail" for those base jumping lunatics that climb tall buildings and parachute off of them.

Oh, you want to know about jumping from space do you. Well, try this OT link

sachmo · #26 October 9th, 2002, 08:26 PM

Ok, here is what space.com has to say about the space elevator...

http://www.space.com/businesstechnol..._020327-1.html

geoschmo · #27 October 9th, 2002, 09:43 PM

I was born on July 7th, 1969. Nine days later Apollo 11 was launched.

For the first time since I realised my poor eyesight was going to prevent my childhood dream of becoming an astronaut, I have a real hope of making it into space in my lifetime. Maybe by the time I retire, I can take a vacation on the moon, or at least stay a week in an orbital hotel.

This is really exciting stuff.

Geoschmo

Wardad · #28 October 9th, 2002, 10:23 PM

Quote:

Originally posted by Wardad:
Will it survive a colision with a fully laden 737?

I was just dramatizing a point about terrorism. As a high profile project, (actually another Wonder) the Space Elevator would attract some real nut balls.

geoschmo · #29 October 9th, 2002, 10:35 PM

Quote:

Originally posted by Wardad:

quote:
Originally posted by Wardad:
Will it survive a colision with a fully laden 737?

I was just dramatizing a point about terrorism. As a high profile project, (actually another Wonder) the Space Elevator would attract some real nut balls.

And it's a valid point. The website Baron linked too even talked abou tit some. They are hoping that this would open up space to everyone and so it wouldn't be something one of the disenfranchised would want to attack. That may be a little pie in the sky, but ya' know.

Actually as remote as it is likely to be placed, it would be fairly safe. It not like a hijacked airliner would be able to sneak up on it if the nearest flightpath is thousands of miles away. But on the other hand it wouldn't take a fully loaded airliner to bring it down.

Geoschmo

Suicide Junkie · #30 October 9th, 2002, 10:55 PM

Quote:

Actually as remote as it is likely to be placed, it would be fairly safe. It not like a hijacked airliner would be able to sneak up on it if the nearest flightpath is thousands of miles away. But on the other hand it wouldn't take a fully loaded airliner to bring it down.

Actually, if you plan ahead a little bit, it would take a lot more than that to bring it down.

If its out of the way, you have lots of time to take the plane down. They also have a very small, probably invisible from a distance, target to hit, so there is a fair chance they'll miss anyways.

Say a plane does come along and cut the ribbon. You will lose less than 30,000 feet of cable. Probably a LOT less, since they'd probably have to use the base station to locate the cable.
How do you repair the system? Just unwind some more cable from the counterweight station, and you're back in business...
Then put some more spare cable on the next elevator going up.