Carbon Nanomaterials For A Space Elevator

[scie]

By increasing number of people, the people's work area will have to move from the earth to the space in the near future. Now they go to the space using the space ship. But it cannot carry a lot of people in one flight. Furthermore there are some problems of the cost and air pollution by burning the fuel of space ship. Therefore it is necessary to propose an easier method for going to the space. There is a space elevator as one of new methods to efficiently go to the space. I would like to report about a problem whether a space elevator can be made using macro structures made of carbon nanotubes was discussed by ideal models of carbon nanotube yarn and sheet and experimental data reported by other groups. I'm looking for some collaborative partners.

 

You can see my report from here or an attachment file.

 

I'm glad if give me your opinions. I would like to realize my dream.

manuscript.pdf

Edited March 29, 2012 by ence

[CraigD]

Welcome to hypography, ence! :) I like your avatar graphic, the smiling hexagon, which I assume represents the CNT yarn you describe in your paper.

 

Please feel free to start a topic in the introductions forum to tell us something about yourself.

 

There is a space elevator as one of new methods to efficiently go to the space.

We’ve had several enthusiastic discussions about space elevators in the forums, such as

• (started 2005 Sep 28) LiftPort Successfully Tests Its Space Elevator Technology
  
• (started 2006 Mar 02) Another Space Elevator Concept
  
• (started 2007 Jan 27) Space Elevator. . .
  

Though I recommend reading at least these threads, and even others found via a search of our site for “space elevator”, I’m especially interested in what you think of this post and some following ones of mine, where I used a simple program to calculate the mass of a space elevator given various material tensile strengths and densities.

 

You can see my report from here or an attachment file.

That’s an impressive-looking paper. :thumbs_up Are you an academic or industry professional material engineer, ence?

 

The main take-away I get from it is from figure 2, from which I gather that there exist now carbon nanotube yarns with tensile strengths of 5, or possibly as great as 15 GPa (10⁹ N/m^2). In my 2006 calculations, I considered single enormous CNTs with a strength of 65 GPa, and a density of 2600 kg/m³, finding a mass of such a space elevator cable was about 2 x 10⁶ kg, well within present day rocket launching capabilities.

 

Assuming the same density and a strength of 5 GPa, I find a total mass of about 1.74 x 10¹⁷ kg, a prohibitively high mass exceeding the total mass of carbon available on Earth. Assuming a strength of 10 GPa, I find the mass reduced by a factor of 500,000, to about 3.4 x 10¹¹ kg, a mass within a factor of 10 of the largest manmade structures. For strengths of 17 and 20 GPa, I find masses of 1.3 x 10⁹ and 3.7 x 10⁸ kg, comparable to that of very large ocean-going ships.

 

I'm looking for some collaborative partners.

 

I'm glad if give me your opinions. I would like to realize my dream.

Like most of the members here at hypography, I’m not a professional engineer or scientist, but an enthusiastic amateur, so of limited value in a collaborative effort toward a major space engineering project. However, I hope I and my friends here can be supportive, and offer some help, in your work.

 

It looks to me as if it might be reasonably possible to make a space elevator using the present-day CNT yarns and sheets summarized in your paper.

 

Some questions:

• Am I correct in assuming that CNT yarns and sheets have a density of about 2600 kg/m³?
  
• Do you believe there is any hope for fabricating very-long single molecule CNTs in the near future? Or will the best CNT engineering materials continue to be “woven” yarns and sheets?
  

[scie]

Welcome to hypography, ence! :) I like your avatar graphic, the smiling hexagon, which I assume represents the CNT yarn you describe in your paper.

 

Please feel free to start a topic in the introductions forum to tell us something about yourself.

 

 

We’ve had several enthusiastic discussions about space elevators in the forums, such as

• (started 2005 Sep 28) LiftPort Successfully Tests Its Space Elevator Technology
  
• (started 2006 Mar 02) Another Space Elevator Concept
  
• (started 2007 Jan 27) Space Elevator. . .
  

Though I recommend reading at least these threads, and even others found via a search of our site for “space elevator”, I’m especially interested in what you think of this post and some following ones of mine, where I used a simple program to calculate the mass of a space elevator given various material tensile strengths and densities.

 

 

That’s an impressive-looking paper. :thumbs_up Are you an academic or industry professional material engineer, ence?

 

The main take-away I get from it is from figure 2, from which I gather that there exist now carbon nanotube yarns with tensile strengths of 5, or possibly as great as 15 GPa (10⁹ N/m^2). In my 2006 calculations, I considered single enormous CNTs with a strength of 65 GPa, and a density of 2600 kg/m³, finding a mass of such a space elevator cable was about 2 x 10⁶ kg, well within present day rocket launching capabilities.

 

Assuming the same density and a strength of 5 GPa, I find a total mass of about 1.74 x 10¹⁷ kg, a prohibitively high mass exceeding the total mass of carbon available on Earth. Assuming a strength of 10 GPa, I find the mass reduced by a factor of 500,000, to about 3.4 x 10¹¹ kg, a mass within a factor of 10 of the largest manmade structures. For strengths of 17 and 20 GPa, I find masses of 1.3 x 10⁹ and 3.7 x 10⁸ kg, comparable to that of very large ocean-going ships.

 

 

Like most of the members here at hypography, I’m not a professional engineer or scientist, but an enthusiastic amateur, so of limited value in a collaborative effort toward a major space engineering project. However, I hope I and my friends here can be supportive, and offer some help, in your work.

 

It looks to me as if it might be reasonably possible to make a space elevator using the present-day CNT yarns and sheets summarized in your paper.

 

Some questions:

• Am I correct in assuming that CNT yarns and sheets have a density of about 2600 kg/m³?
  
• Do you believe there is any hope for fabricating very-long single molecule CNTs in the near future? Or will the best CNT engineering materials continue to be “woven” yarns and sheets?
  

 

Thank you for your reply and discussions. I'll check the introductions forum.

 

And thank you for the information of threads. I'll read them and study by them.

 

Although I cannot say whether I'm a scientist, I can say that my hobby is to think about various phenomenon. Although a space elevator is one of my thinkings, I would like to achieve it in my life.

In my report, I use existing data from other reports. I show an ultimate strength of CNT yarn using my model and the data.

 

 

>Am I correct in assuming that CNT yarns and sheets have a density of about 2600 kg/m3?

 

Thank you for your above discussion and questions. About the density of CNT, they say that CNT has some densities. For example, a single CNT and multiwalled CNT is difference. Those are as follows.

 

Single-walled cnt 1300 - 1400 kg/m^3

Multi-walled cnt 2000 - 2600 kg/m^3

Amorphous carbon 2000 - 3000 kg/m^3

 

Furthermore, CNT has an amorphous carbon on the surfaces when CNTs are grown by CVD and others. So the density is different from them. However estimating the average density is very important as a building block of CNT. I affirm your consideration.

 

>Do you believe there is any hope for fabricating very-long single molecule CNTs in the near future? Or will the best CNT engineering materials continue to be “woven” yarns and sheets?

 

I think the both. Because I have already known how to make such a very-long CNT and weave CNTs. My report is one of my considerations. I always provide those technologies when I can cooperate. So I would like to achieve the space elevator.