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Author Topic: Does the technology exist to build a space elevator?  (Read 1985 times)

Offline Airthumbs

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With new discoveries of materials such as Graphine are we any closer to being able to build a space elevator?


 

Offline CliffordK

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Does the technology exist to build a space elevator?
« Reply #1 on: 02/01/2011 22:48:54 »
Everything I've seen indicates that a space elevator would be a monumental undertaking. 

A geosynchronous or geostationary orbit is at an altitude of about 35,786 km (22,236 mi). 

The weight of a 35K Km cable exceeds the tensile strength steel, and I believe all known materials.

The tallest skyscraper ever made is about 1/2 km tall, dwarfed by Mt. Everest at 8.8 km, but still falling 35,777 km short.

I don't think single layer graphene will help.  There is a lot of hope for carbon nanotubes, but so far they have been plagued by being very short, and nanotube yarn composites have lacked strength due to the short fiber lengths. 

One of the most unique substances is silica aerogel (nanofoam)

http://en.wikipedia.org/wiki/Aerogel

With the record lowest density being 1 mg/cm3

Air has a density of about 1.2 mg/cm3

So, this is a solid that will literally float in air.  It would make a most unique construction material, although I doubt it has has the tensile strength of carbon nanotubes. 

But, perhaps there would be a way to combine evacuated silicagel (or helium filled silica gel) & carbon nanotubes to create something that has high compressive strength, tensile strength, and is lighter than air.  Would it be too much to ask for a substance that wasn't hygroscopic?  Maybe eventually one will be able to construct an evacuated carbon nanotube cable, or helium filled carbon nanotube cable.

What would be the wind forces on a 100 mile tall foam building?
« Last Edit: 02/01/2011 22:51:30 by CliffordK »
 

Offline Airthumbs

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Does the technology exist to build a space elevator?
« Reply #2 on: 03/01/2011 01:53:20 »
Thanks for your response CliffordK,

I see that Japan has already had a conference to decide on a time scale to build this.  There are going to be some technical difficulties hey!!  I also understand that at present our technology does not provide the materials strong enough either!

Still it looks like people are beginning to take this idea seriously as we get closer to developing a material strong enough to make that 22,000 mile long cable!

BTW, the worlds tallest building is closer to 1km then 1/2, standing at 828mt!  Still a little bit short of the target though! :) I would not like to calculate the stress factors on a building 100 miles tall but I imagine it would have to be pretty big. 

 

Offline CliffordK

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Does the technology exist to build a space elevator?
« Reply #3 on: 03/01/2011 05:53:33 »
I think that NASA in the USA is also seriously pursuing a space elevator.  And there have been competitions such as solar/laser powered crawler competitions.  However, there are some huge technical issues to contend with too.  There may be "control" issues and duplicated efforts.  But, I would imagine that once some of the technical issues are overcome such as a light enough "cable" with enough tensile strength, that there will actually be progress on an international scale.

Another technical issue is the "counterweight".  Which may mean either importing a moon from Jupiter, or an asteroid from the Asteroid belt, or mining the moon. 

A lunar space elevator has also been considered, with a geosynchronous orbit of 56,000 on the Earth side, or 67,000 km on the "dark" side.  While the distances are nearly twice as long, I believe that the technical issues may actually be less due to the lower gravity.

In many senses, the decisions about the creation of a space elevator will impact all of humanity.  What would happen if a 36,000 km cable breaks loose?  Are we willing to mine a several cubic mile chunk out of the moon?  Or, try to move a large asteroid into Earth's orbit?  What if we miss? 
 

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Does the technology exist to build a space elevator?
« Reply #3 on: 03/01/2011 05:53:33 »

 

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