The Fading Dream Of The Space Elevator

Well it seems like the space elevatour we all hoped to be built in the near future has hit an apparent major techical problem. Apparently connecting many carbon nanotubes will result in to much stress on the cable's atmoic structure and cause it to lose a lot of its strength.

In something of a "downer" for space elevator fans, Pugno has calculated that inevitable defects will greatly reduce the strength of any manufactured nanotubes. Laboratory tests have demonstrated that flawless individual nanotubes can withstand about 100 gigapascals of tension; however, if a nanotube is missing just one carbon atom, it can reduce its strength by as much as thirty percent. Bulk materials made of many connected nanotubes are even weaker, averaging less than 1 gigapascal in strength.

In order to function, a space elevator ribbon would need to withstand at least 62 gigapascals of tension. It therefore appears that the defects described above would eliminate carbon nanotubes as a usable material for a space elevator cable. Pugno will publish his paper in the July edition of Journal of Physics: Condensed Matter. Nanotube enthusiasts counter that ribbons made of close-packed long nanotubes would demonstrate cooperative friction forces that could make up for weaknesses in individual nanotubes.

I hope this technical hurdle can be overcome but its a major blow for a company such as liftport who are pushing the elevator idea.

Link: www.space.com...


[edit on 2-6-2006 by rufi0o]

I still can't believe that anyone actually believed that this would be possible in the first place. I don't need any fancy physics tests or ASTM test results to indicate to me that this was a bad idea. This fails on so many levels that simple logic tells you that such an effort could never get funded. Sorry to all of those who held out hope - this is just my opinion.

I've got to agree with Kozmo here. As much as I can't wait for space travel to become accessible to the common man, this idea just seemed way too far fetched. Can't blame them for trying though.

CK

Originally posted by kozmo
I still can't believe that anyone actually believed that this would be possible in the first place. I don't need any fancy physics tests or ASTM test results to indicate to me that this was a bad idea - this is just my opinion.

And a common opinion it has been thru out history. You can follow it back for almost as far back as you can trace mankind itself. A timeline could go like this:

“I still can't believe that anyone actually believed that this would be possible in the first place. Trying to put a man on the moon.”

“I still can't believe that anyone actually believed that this would be possible in the first place. For man to think he can fly faster than the speed of sound.”

“I still can't believe that anyone actually believed that this would be possible in the first place. Man thinking he could fly.”

“I still can't believe that anyone actually believed that this would be possible in the first place. Man thinking the Earth was round.”

And on and on and on as far back as you can trace our history. Now how does that old saying go? “Those who say it can’t be done shouldn’t get in the way of those that are doing it.”



wupy

This is being touted as a new discovery? I've known of the purity and structural geometry problems for a few years now. It's a Major Hurdle yes. I doubt it's insurmountable though. If we can figure out how to make Nanotube strands at any length, it would be a huge leap forward and would most certainly be used on any Space Tether.

Tis merely a hurdle...

Yeah, they'll figure something out. The biggest problem will be with creating the first few strands and support structures at the very beginning. Once the first link between the earth and the top is established and stabilized, then other materials can be used to broaden and strengthen the tower. Layer by layer, lamination by lamination.

Somebody will figure something out. We humans are clever like that.

Yea if the history life had been full of people like some of the above posters. We would all still be huddled around some water vent in the bottom of the ocean lving with the bacteria.

Originally posted by Xeven
Yea if the history life had been full of people like some of the above posters. We would all still be huddled around some water vent in the bottom of the ocean lving with the bacteria.

LOL, fantastic.

I'm not ruling this out just yet.