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Is this structurally possible?? re: space cable (1 Viewer)

todd s

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Would it be possible to create a wire that is attached to a point on the ground and the other end secured to a location locked in orbit directly above? The cable could be used to take small objects into space (ie-Space station)?
 

mylan

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Yes, i've read something about a "space elevator" used to carry supplies to the space station before in Popular Mechanics. It would be a huge undertaking and who knows how much that thing would cost?!!!
 

ChristopherDAC

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In principle, it is possible to construct a cable which would be connected at one end to a platform in geosynchronous equatorial orbit, and at the other end to a point at the Equator on Earth. The practical difficulties are immense. Among other things, the cable would require a material far stronger than steel (carbon nanotubes have been suggested) if it were not to weigh millions of tonnes, and if it wver broke the whiplash would be continental in scale.
 

MarkHastings

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Yeah, I would think that any failure in structure would be disastrous considering the shear weight and strength of the material used to keep it stable. Just think about all of the weather conditions it would have to hold up in.
 

Jason Seaver

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Not really - you've got to build it in an equatorial site anyway, which mostly leaves the choice of tropical or desert - go with desert. Then, only the bottom five miles or so are actually going to be exposed to "weather" (the rest will be exposed to thinner atmosphere and higher radiation), and if it breaks there, it might be devastating for the immediate area (again, desert - isolated), but the elevator and station will probably just wind up leaving orbit, since most designs I've read about have a second cable at the other end as a counterweight and to launch payloads to the moon and other parts of the solar system.

Sucks if you're on it, obviously, but there's a good chance to minimize the danger from nature. The terrorist who finds a way to plant a bomb 3/4 of the way up is another story.
 

Greg_R

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Yet another item that originated from Science Fiction. Check out Arthur C. Clarke's Fountains of Paradise.
 

RobertR

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Riding that elevator would be the ultimate challenge for someone with Acrophobia. :)
 

Yee-Ming

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One of Kim Stanley Robinson's Mars books had a similar space elevator but on Mars, which due to sabotage came crashing down, and he described that sequence.

IIRC, geosynchronous orbit is something like 36,000 km. And it would be the centre-of-gravity of the entire elevator structure that would have to be located at 36K km, so either the main platform or station would be there and there would be another 36K km long cable further as counterweight, or something shorter but stouter, or perhaps the terminal would be further out, its weight balancing the weight of the cable (which would now exceed 36K km in length). But that would require a continual balancing act as payloads arrived and left. I guess for that reason, the terminal station would have to be at 36K km, and an additional counterweight to balance the cable would be added. I recall reading something where such an elevator was built (probably an Arthur C. Clarke Short story, not Fountains of Paradise), and he suggested that the station would go up first, then the cable would be extended down, or from each end and mated in the middle.
 

BrianW

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It would work as long as, once the structure is in place, everything that goes up the elevator eventually comes back down the elevator. If you use the Space Elevator to launch satellites or space probes, or if you just send stuff up without bringing it back down (building, say, the Ultimate Skybox! :)), you'll eventually rob enough angular momentum from the structure that it would come crashing down.
 

Jay H

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Oh great, a super long 5+ mile elevator with the nerd at the bottom hitting the elevator button for a 1/2 hour just to see if it speeds up the elevator any faster... Great... :laugh:

Jay
 

cafink

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Yes, but we also have much more advanced technology then we did when skyscrapers were first built in the late 1800s and early 1900s. I'm no engineer or architect, but I can't imagine why we wouldn't be able to overcome these obstacles using today's technology or that of the near future, just as we did when constructing early skyscrapers using the technology of yesteryear.
 

drobbins

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I had read that article earlier today also. It is an interesting, but somehow just doesn't seem a good idea to me. Sooner or later something always goes wrong. What is the back up plan? A parachute for lower levers and a rocker powered pack for the higher levels? If they could master it though, it sounds like a cheaper way to get stuff in space.
 

Brad Porter

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It's seems like an interesting idea until you account for the low-Earth orbit satellites that have inclined orbits yet do not have propulsion systems to "dodge" the tether. Sure, the odds are large that they won't cross the equatorial plane at the site of the elevator for any given orbit, but with ~16 orbits per day times hundreds of satellites times 20+ years of orbital decay... well, I predict a collision in there somewhere.

Brad
 

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