Space Elevator vs Mars Direct - Anyone compare the costs?

deagleninja · 2004-09-20 08:18:55

It's just that I'm in a hurry (I'm 49 years old) and take great delight in reminding myself, as much as anyone else, that the rate of progress is accelerating.

I know how you feel. I turned 30 this year and there hasn't been one single human being to go beyond orbit since I've been alive. I was born two years after we left the moon and it seems I will be too old to possibly go to Mars.

SpaceNut · 2004-09-20 09:17:16

While not an elevator it is a novel approach to moving up. Could you picture oneself levitating to the ISS in little more than a space suit.

Phenomenon of levitation comes into everyday life

Modern scientists are developing anti-gravitational systems

http://english.pravda.ru/science/19/94/ … ation.html

SpaceNut · 2004-09-20 09:34:53

Another use for nanotubes.
Researchers invent antenna for light
Researchers said on Friday they have invented an antenna that captures visible light in much the same way that radio antennas capture radio waves
http://www.cnn.com/2004....ex.html

deagleninja · 2004-09-20 12:52:04

Reading Pravda again SpaceNut? You do know they are russia's equivolent to the national Enquierer.

SpaceNut · 2004-09-20 13:06:53

Still interesting reading even if a hoax...
Antigravity, Magnetic repulsion come to mind.
Makes you think of the possibilities either way.

SpaceNut · 2004-09-22 07:39:02

Space Elevator Now Subject Of Research By Cadets At USAF Academy

http://www.spacedaily.com/news/spacetravel-04zzb.html

Cadets at the United States Air Force Academy (USAFA) are doing research on the space elevator, one of the latest scientific concepts to emerge for sending cargo into space.

Shaun Barrett · 2004-09-22 22:47:42

More good news!
The Sept. 18 New Scientist magazine reports that Yuntian Zhu and colleagues at Los Alamos National Laboratory, NM, have devised a way to manufacture long nanotubes - much longer than the few micrometres achieved up until now.
Nanotubes require a catalyst to grow, such as a particle of iron. Previous methods were hampered by the growing nanotube bumping into surfaces but Zhu suspended an iron particle in a hot chamber containing alcohol vapour as the carbon source. The growing nanotube trailed behind the particle like the string of a kite and reached a length of 4 cm, a new record.
This new method of suspending the tube as it grows can theoretically produce longer CNTs still, according to Zhu.

This may be the breakthrough we've been waiting for. I can imagine a continuous production process, producing arbitrarily long pure carbon nanotubes. I can also visualise millions of iron particles simultaneously producing millions of tubes and an automated process to weave them together in some way.
Thus, we could have a space elevator cable of uninterrupted nanotubes all the way from the ground up to 100,000 km altitude, eliminating the need for any binding material. Such a cable would achieve the theoretical maximum tensile strength for carbon nanotubes.

John Creighton · 2004-09-24 08:56:46

the need for any binding material

You still want a binding material to keep to much load from being held by any single thread. Additionally if threads break the binding material will keep the whole thread from becoming useless.

Martian Republic · 2004-09-24 09:31:13

More good news!
The Sept. 18 New Scientist magazine reports that Yuntian Zhu and colleagues at Los Alamos National Laboratory, NM, have devised a way to manufacture long nanotubes - much longer than the few micrometres achieved up until now.
Nanotubes require a catalyst to grow, such as a particle of iron. Previous methods were hampered by the growing nanotube bumping into surfaces but Zhu suspended an iron particle in a hot chamber containing alcohol vapour as the carbon source. The growing nanotube trailed behind the particle like the string of a kite and reached a length of 4 cm, a new record.
This new method of suspending the tube as it grows can theoretically produce longer CNTs still, according to Zhu.
This may be the breakthrough we've been waiting for. I can imagine a continuous production process, producing arbitrarily long pure carbon nanotubes. I can also visualise millions of iron particles simultaneously producing millions of tubes and an automated process to weave them together in some way.
Thus, we could have a space elevator cable of uninterrupted nanotubes all the way from the ground up to 100,000 km altitude, eliminating the need for any binding material. Such a cable would achieve the theoretical maximum tensile strength for carbon nanotubes.

I doubt that they would be able to make a nanotube sixty two miles long, but even if they could, you would still have to glue those nanotubes together. Like how would you spoil 62 miles of nanotubes even if it were possible to produce them or get them all tangled up. But, even if they could only make those nanotubes ten or fifteen feet, that would be enough that we should be able to build our space elevator.

Larry,
.

John Creighton · 2004-09-24 09:44:16

It remembered that they can be woven together. But even if woven there still must be some advantages of a flexible glue.

Shaun Barrett · 2004-09-25 19:41:31

Well, I don't claim to be a materials science expert by any means but it's only common sense that the longer we can make the nanotubes, the closer we can get to the theoretical maximum tensile strength.
Martian Republic estimates that nanotubes 3 - 5 metres long should be sufficient to make adequately strong cable (or ribbon) for the space elevator. I personally haven't a clue how long they need to be but I'm quite confident that we'll be able to produce the nanotubes in the lengths needed.

News like this, which seems to be coming thick and fast these days out of labs all over the world, makes me think the obstacles to the actual construction of a space elevator will quickly be overcome.
Rather than a time frame of decades, I'm inclined to think we'll be in a position to look seriously at starting work on this thing even sooner than Brad Edwards visualises!

The whole concept of a series of elevators spaced out around Earth's equator, like the spindliest imaginable spokes of a wagon wheel, and carrying hundreds of tonnes of material and passengers up and down each day, is breathtaking to imagine.
It will surely become the 21st century equivalent of the Great Pyramids - a wonder of the modern technological world.
I'm so looking forward to it I can hardly contain my enthusiasm!
:band: :up:

Euler · 2004-09-25 21:10:47

Well, I don't claim to be a materials science expert by any means but it's only common sense that the longer we can make the nanotubes, the closer we can get to the theoretical maximum tensile strength.

No, it does not necessarily follow that longer nanotubes=stronger nanotubes. You could make an argument that with longer tubes you should be able to make a nanotube cable that is closer to the tensile strength of the individual tubes, but if the tubes themselves do not have the required tensile strength(and right now they do not), you will not be able to make a space elevator.

Shaun Barrett · 2004-09-26 00:36:14

Hi Euler.
I didn't actually mean to imply longer = stronger, as such. If we were restricted to very short nanotubes, we would need to use a significant amount of matrix of some sort in which to embed them. My understanding is that this must necessarily reduce the tensile strength of the cable.
The maximum theoretical strength of pure, perfect, unbroken carbon nanotubes is, fortunately, significantly greater than that required to construct a space elevator in Earth orbit. This allows us a little elbow room for things like falling short of theoretical maximums (always the case in the real world) and building in a safety factor so that the cable isn't operating too close to its breaking strain.

I'm sorry I didn't explain myself clearly - must be more careful in future.

The main point I was hoping to draw attention to is the fact that swift progress is being made. I have little doubt that longer purer nanotubes will soon be mass produced and that the minimum requirements for the space elevator will be met and probably surpassed.
I confess I am completely unencumbered by formal qualifications in materials science, and therefore blissfully free to allow my imagination full rein! But looking at the big picture, as far as advancements in technology are concerned, I don't think I'm being unduly optimistic.

SpaceNut · 2004-10-12 08:34:25

Space elevator dream for early success may or may not be for it to carry heavy lift cargo but with delevery of crews to a space platform first. Low and behold another contest.

Spaceward members are starting more modestly this year. They're recruiting college teams, companies -- anyone, actually -- to design an elevator car that can climb a 200-foot ribbon suspended from a crane.
The top three teams, based on speed and payload, will divide an $80,000 purse. There is a second contest for material design. See www.elevator 2010.org.

Space visionaries aiming high
ELEVATOR WOULD CARRY SUPPLIES INTO ORBIT
http://www.mercurynews.com/mld/mercuryn … 548.htm?1c

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#51 2004-09-20 08:18:55

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#52 2004-09-20 09:17:16

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#53 2004-09-20 09:34:53

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#54 2004-09-20 12:52:04

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#55 2004-09-20 13:06:53

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#56 2004-09-22 07:39:02

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#57 2004-09-22 22:47:42

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#58 2004-09-24 08:56:46

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#59 2004-09-24 09:31:13

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#60 2004-09-24 09:44:16

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#61 2004-09-25 19:41:31

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#62 2004-09-25 21:10:47

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#63 2004-09-26 00:36:14

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

#64 2004-10-12 08:34:25

Re: Space Elevator vs Mars Direct - Anyone compare the costs?

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