15 Oct '12 16:42>
http://phys.org/news/2012-10-techniques-carbon-nanotubes-stronger-composites.html
Originally posted by googlefudgeWow, they really thought that through!
Hmm with a youngs modulus of 293 GPa you have about 29% of the strength of a single CNT so you're not there yet.
But it's a step in the right direction.
Have a look at this for more details on space elevator feasibility...
http://www.spaceward.org/elevator-feasibility
Originally posted by twhiteheadIt makes more sense to use some kind of kinetic energy mechanism to transmit
A space elevator is such a good idea that it is well worth thinking through (and building as soon as is feasible).
Originally posted by Thequ1ckYes, I think you do. How much energy would you get from an asteroid and how would you go about harvesting it?
Then we could use the kinetic energy
of asteroids. I don't think I need to tell you how much that could be worth...
Originally posted by Metal BrainRemember that, unlike a steel lighting rod, carbon readily burns in air when it is heated.
Carbon isn't a bad conductor of electricity. Lightning would destroy it.
Originally posted by twhiteheadI dunno. Gotta be some kind of material that absorbs heat and emits light out there though.
Yes, I think you do. How much energy would you get from an asteroid and how would you go about harvesting it?
Are you talking about on a tether? If so, you need to get the asteroid to the same velocity as the tether first and that would probably take more energy than you eventually get out of it.
Originally posted by humyIf you follow the link you will find that yes, they not only thought about it, but factored replacement of the whole cable every few years into the equation.
Even the inevitable collisions with tiny bits of space dust would gradually damage the cable -have they even thought about that?
Originally posted by humyAircraft are not grounded or close to the ground. Lightning would still destroy it, especially from the ionosphere. Carbon is a dumb idea.
Remember that, unlike a steel lighting rod, carbon readily burns in air when it is heated.
But there are many ways to work around that such as covering the surface of the cable with a thin layer of non-combustible material.
Remember that may modern airliners have carbon and resin composite skins which are often struck by lighting with very little damage as a ...[text shortened]... of adequately protecting the cable and I don't see how that could happen for a very long time.
Originally posted by twhitehead
If you follow the link you will find that yes, they not only thought about it, but factored replacement of the whole cable every few years into the equation.
[b]There would also be the issue of how to stop terrorists from flying aircraft or missiles into the cable.
Would this be harder or easier than say flying a plane into the shuttle launch faci easily takes care of most of your protection issues - except possibly a large aircraft impact.[/b]
Would this be harder or easier than say flying a plane into the shuttle launch facilities?
Simply having multiple cables in a weave of some sort easily takes care of most of your protection issues
Originally posted by humyYou are probably right, but I think your argument is still flawed. If we follow your argument then we shouldn't have the space shuttle either because it is too expensive a target for terrorists. We should only have launch vehicles valued at under 1 million dollars each.
If you have figures for estimated costs that falsify this then I would like to see them.
However, most space elevator designs call for the use of multiple parallel cables separated from each other by struts, with sufficient margin of safety that severing just one or two strands still allows the surviving strands to hold the elevator's entire weight while repairs are performed.
Originally posted by twhiteheadI did not say we should not have a space elevator because of the terrorist threat.
You are probably right, but I think your argument is still flawed. If we follow your argument then we shouldn't have the space shuttle either because it is too expensive a target for terrorists. We should only have launch vehicles valued at under 1 million dollars each.
Remember that we have lost two shuttles including crew. (The loss of the crew was pos viving strands to hold the elevator's entire weight while repairs are performed. [/quote]
Originally posted by humyMy apologies then.
I did not say we should not have a space elevator because of the terrorist threat.
That was not my argument.