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#51 2004-11-23 01:06:52

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Capillary action in a carbon nanotube???

build a ring of inflatable balloon pillars

The demonstration of a large number of people standing on a piece of plywood, supported by balloons is impressive. Pressure is distributed between the balloons,
and a highly stressed outside retainer ring is not needed.

Space age column, possible, to geosynchronous ?

For the space elevator, the maximun stress is at geosynchronous.
For the space column, it is at the base.
Dividing into optimized stress sections might be the way to go.

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#52 2004-11-23 09:02:56

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Capillary action in a carbon nanotube???

Not really. It isn't very practical to make a tower more then 10km high, give or take, no matter what its made of. Geostationary orbit is a long, LONG way, and a tower won't take much pull off the cable. Spend your money on stronger cable instead.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#53 2004-11-23 15:06:12

Trebuchet
Banned
From: Florida
Registered: 2004-04-26
Posts: 419

Re: Capillary action in a carbon nanotube???

Evacuated balloon tunnel into LEO... well, its one of the more original technical ideas I've heard around here.

The problem with it is that when you get to LEO, you wouldn't have any horizontal velocity, and thats the killer, you need to be going Mach 25 to reach a stable orbit.

Yes, I know that. However, what is actually necessary to achieve orbit is to throw the spacecraft at the earth and miss, so to speak. What I was envisioning is to use the railgun system in place of the first stage of a TSTO system; the accelerated mass would be a pod consisting of payload and an upper stage which provides enough sideways momentum to push the craft into an elliptical orbit about the earth.

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#54 2004-11-23 15:13:29

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Capillary action in a carbon nanotube???

First off an eliptical orbit isn't much good, and second it would still require a pretty darn big 2nd stage.

You are going to have to either include alot of fuel in the stage or reach much higher then LEO in order to even enter an eliptical orbit. There is no trick or magic with an eliptical orbit, it isn't special.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#55 2004-11-23 15:30:51

Trebuchet
Banned
From: Florida
Registered: 2004-04-26
Posts: 419

Re: Capillary action in a carbon nanotube???

You are going to have to either include alot of fuel in the stage or reach much higher then LEO in order to even enter an eliptical orbit. There is no trick or magic with an eliptical orbit, it isn't special.

I know that the upper stage will require a nontrivial amount of fuel. The idea is to replace the first stage of the rocket, not the entire rocket or everything but a tiny corrective bus-like stage. It's more like a very long cannon that accelerates a rocket at non-lethal-to-humans speeds. The air evacuation part is merely to reduce air resistance, and it might not be worth it in terms of energy saved, to be honest.

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#56 2004-11-25 13:49:11

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Capillary action in a carbon nanotube???

I've just thought of a different, equally crazy idea for getting stuff into orbit cheaply. Instead of building an incredibly long tether, build a ring of inflatable balloon pillars instead, reinforced with aluminum rings every so often, to a height of 150 miles or so. Pressurize the balloons with helium and reinforce them with Kevlar or something and wrap the structure with plastics to make the whole structure airtight. You could evacuate the air from inside the tube, since it's sticking out into LEO, and run a linear magnetic accelerator up the center to accelerate payloads.

I was looking to calculate the pressures, and resulting http://hyperphysics.phy-astr.gsu.edu/hb … ml]tension.

Looks like have to do numerical http://www.zadar.net/space-elevator/#Ca … ntegration.

How high could a carbon nanotube reinforced pipe reach pumping air or water ?

If you pumped air into the water, as in a fishtank filter, what effect would that have ?

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