# Lifestyles & Discussion > Science & Technology >  Space Elevators Are Totally Possible (and Will Make Rockets Seem Dumb)

## jct74

> *Space Elevators Are Totally Possible (and Will Make Rockets Seem Dumb)*
> 
> Written by MEGHAN NEAL
> February 25, 2014 // 10:00 AM EST
> 
> It's the scourge of futurists everywhere: The space elevator can't seem to shake its image as something that's just ridiculous, laughed off as the stuff of sci-fi novels and overactive imaginations. But there are plenty of scientists who take the idea quite seriously, and theyre trying to buck that perception.
> 
> To that end, a diverse group of experts at the behest of the International Academy of Astronautics completed an impressively thorough study this month on whether building a space elevator is doable. Their resulting report, "Space Elevators: An Assessment of the Technological Feasibility and the Way Forward," found that, in a nutshell, such a contraption is both totally feasible and a really smart idea. And they laid out a 300-page roadmap detailing how to make it happen.
> 
> ...


read more:
http://motherboard.vice.com/blog/spa...kets-seem-dumb

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## CaseyJones

yep

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## jct74

is this how they will bring the asteroid gold to earth?

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## CaseyJones

I would think they would just drop it into the ocean with chutes, but asteroid mining will likely be how they get the material to build these

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## Origanalist

I hope I live to see this, what a huge advancement that would be. Space would suddenly become extremely accessible.

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## GunnyFreedom

> I hope I live to see this, what a huge advancement that would be. Space would suddenly become extremely accessible.


The development of carbon nanotube materials makes this a lot closer than it used to be.  I assume they are talking about running these to mini-stations just a smidge past geosynchronous orbit?  Add a few ergs of centripetal force to adjust the tension, and the amount of cargo can be lifted might be surprising, especially if the mini-station was relatively massive.  The popularization of space elevator out to geosynch would lead to all kinds of space hotels and space tourism and such; as well as make colonization of space via station and lunar colonies feasible.  That's when we'll start seeing manned expeditions to all over the doggone place inside the solar system, as the energy requirements would be cut to a mere fraction of a fraction of current.

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## Carson

Just doesn't add up to me.

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## Origanalist

> The development of carbon nanotube materials makes this a lot closer than it used to be.  I assume they are talking about running these to mini-stations just a smidge past geosynchronous orbit?  Add a few ergs of centripetal force to adjust the tension, and the amount of cargo can be lifted might be surprising, especially if the mini-station was relatively massive.  The popularization of space elevator out to geosynch would lead to all kinds of space hotels and space tourism and such; as well as make colonization of space via station and lunar colonies feasible.  That's when we'll start seeing manned expeditions to all over the doggone place inside the solar system, as the energy requirements would be cut to a mere fraction of a fraction of current.


It would be a pretty substantial turning point, but seeing a cable going straight up to the sky would take a little getting used to.

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## GunnyFreedom

> It would be a pretty substantial turning point, but seeing a cable going straight up to the sky would take a little getting used to.


Especially since the 'cable' will be about as big around as a small building.

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## Origanalist

> Especially since the 'cable' will be about as big around as a small building.


I might even put up with the TSA to see that.

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## Origanalist

> David Smitherman of NASA/Marshall's Advanced Projects Office has compiled plans for such an elevator that could turn science fiction into reality. His publication, Space Elevators: An Advanced Earth-Space Infrastructure for the New Millennium, is based on findings from a space infrastructure conference held at the Marshall Space Flight Center last year. The workshop included scientists and engineers from government and industry representing various fields such as structures, space tethers, materials, and Earth/space environments. 
> 
> "This is no longer science fiction," said Smitherman. "We came out of the workshop saying, 'We may very well be able to do this.'" 
> 
> subscription image. 
> Sign up for our EXPRESS SCIENCE NEWS delivery
> A space elevator is essentially a long cable extending from our planet's surface into space with its center of mass at geostationary Earth orbit (GEO), 35,786 km in altitude. Electromagnetic vehicles traveling along the cable could serve as a mass transportation system for moving people, payloads, and power between Earth and space.
> 
> Current plans call for a base tower approximately 50 km tall -- the cable would be tethered to the top. To keep the cable structure from tumbling to Earth, it would be attached to a large counterbalance mass beyond geostationary orbit, perhaps an asteroid moved into place for that purpose. 
> ...


http://science1.nasa.gov/science-new...00/ast07sep_1/

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## GunnyFreedom

The tether has always been the expected quantum leap in space tech.  once that goes live, everything in Earth/Moon subsystem opens up immediately.  Trips to asteroids, Mars, Venus become a lot less expensive.

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## pcosmar

> a diverse group of experts


How does one become an expert at something that has never been done?

Oh,, and using Ballistic Missile delivery systems for getting into space is dumb.

Except it was never *about* getting into space. It was about showcasing Nuclear Delivery systems.

This was in space,,



well before this was.

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## pcosmar

> The tether has always been the expected quantum leap in space tech.  once that goes live, everything in Earth/Moon subsystem opens up immediately.  Trips to asteroids, Mars, Venus become a lot less expensive.


It is an interesting idea..but one that has many obstacles to overcome and is not anywhere near the realm of "doable". Not in the foreseeable future.

It does work nicely in Sci Fi.

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## eduardo89

Didn't realise that Vice was a science/technology magazine.

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## Origanalist

> It is an interesting idea..but one that has many obstacles to overcome and is not anywhere near the realm of "doable". Not in the foreseeable future.
> 
> It does work nicely in Sci Fi.


It is in the realm of the possible, and technology is advancing rather rapidly. I don't have any problems calling this foreseeable.

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## osan

> I might even put up with the TSA to see that.


Ho'.

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## eduardo89

I wonder what republicanguy thinks about space elevators.

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## Origanalist

republicanguy should be banned from space. Let's not infect the cosmos.

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## Origanalist

> Ho'.


I suppose. But the equator is a long haul on a boat...

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## eduardo89

> republicanguy should be banned from space. Let's not infect the cosmos.


You obviously hate humanity because you're stuck in this antiquated religious patriarchal worldview. Without religion you wouldn't be so oppressive and would realise that space is the future.

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## Origanalist

> You obviously hate humanity because you're stuck in this antiquated religious patriarchal worldview. Without religion you wouldn't be so oppressive and would realise that space is the future.


And guns, don't forget about us backwards, really nasty gun lovers.

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## eduardo89

> And guns, don't forget about us backwards, really nasty gun lovers.


Gun ownership is just another manifestation of backwards aggressive males subjugating women and rational thinkers (atheists, obviously).

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## osan

Now there's a job I'd like to have - operator.

Thirteen-thousandth floor.  Lady's lingerie, perfumes, dresses.  Going up.  Next stop, men's wear and sporting goods.  Please watch your step.

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## pcosmar

*Harmonic balance.*

Take a second to consider.

Even if you overcome the considerable obstacle of Tensile strength, v Gravity, and balanced the pull of the anchor to keep the thing stable. (some big "If's")

You would still have the issue of harmonic balance.
That is quite a bit of spinning mass.

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## Origanalist

> *Harmonic balance.*
> 
> Take a second to consider.
> 
> Even if you overcome the considerable obstacle of Tensile strength, v Gravity, and balanced the pull of the anchor to keep the thing stable. (some big "If's")
> 
> You would still have the issue of harmonic balance.
> That is quite a bit of spinning mass.


That's a great point. And there are a lot more things to consider, more than I can name for sure. I still believe it can be done.

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## Zippyjuan

> http://science1.nasa.gov/science-new...00/ast07sep_1/


START with a 30 mile tall tower? 



> Current plans call for a base tower *approximately 50 km tall* -- the cable would be tethered to the top.


That alone would be an incredible feat!

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## Origanalist

> START with a 30 mile tall tower? 
> 
> 
> That alone would be an incredible feat!


The whole thing would be. Nothing like this has been even seriously considered before. I don't know if it will ever happen or what the actual final product will look like if it does.

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## Zippyjuan

Not to mention the simple weight of a 23,000 mile cable going straight up into the air- even if it was nano carbon.

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## Origanalist

> Not to mention the simple weight of a 23,000 mile cable going straight up into the air- even if it was nano carbon.


It would be anchored in space.

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## fisharmor

So, how much tax money is it going to take?
How many people talking about this are not parasites?

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## Origanalist

> So, how much tax money is it going to take?
> How many people talking about this are not parasites?


Ya, that is a good point. I think so far it's only NASA.

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## Danke

Chip In to send Origanalist up?

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## Occam's Banana

> Chip In to send Origanalist up?


Only if he promises not to come back ...

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## eduardo89

> Only if he promises not to come back ...


If he's a Muslim he can't go, unless it's a return ticket.

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## pcosmar

> It would be anchored in space.


Anchored to what,, and counter balanced by what?

you are talking about considerable mass,, spinning at earths rotation. (centrifugal force)

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## pcosmar

> 4 And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth.
> 
> 5 And the Lord came down to see the city and the tower, which the children of men builded.
> 
> 6 And the Lord said, Behold, the people is one, and they have all one language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do.
> 
> 7 Go to, let us go down, and there confound their language, that they may not understand one another's speech.
> 
> 8 So the Lord scattered them abroad from thence upon the face of all the earth: and they left off to build the city.
> ...

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## eduardo89

> Anchored to what,, and counter balanced by what?
> 
> you are talking about considerable mass,, spinning at earths rotation. (centrifugal force)


Do you not read the articles posted before commenting?




> Current plans call for a base tower approximately 50 km tall -- the cable would be tethered to the top. To keep the cable structure from tumbling to Earth, it would be attached to a large counterbalance mass beyond geostationary orbit, perhaps an asteroid moved into place for that purpose.

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## pcosmar

> Do you not read the articles posted before commenting?


A huge mass,, tethered to the earth.. Spinning through space a hundreds of thousand MPH..

and you see no problems with centrifugal forces or harmonic balance?


Newtons Laws of motion apply here.
For every action there is an equal and opposite reaction.

And you do know that the gyroscopic forces are going to change as weights are moved up and down that cable.

Like I said,, It works well in Sci Fi.
.

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## GunnyFreedom

> Anchored to what,, and counter balanced by what?
> 
> you are talking about considerable mass,, spinning at earths rotation. (centrifugal force)


Anchored by centriPETAL force.  Place the center of mass about a meter above the actual geostationary orbit point, and the whole thing will actually lift and have to be anchored into the ground to keep it flying off. Reaction mass jets would take very little energy to stabilize synchronic to the ground. Only two concerns I have, 1) lifting mass would affect the center of mass, so the end station would have to be extremely massive, and 2) if there ever were some kind of disaster this thing would make an awful mess coming down.

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## GunnyFreedom

> 


We've been to the moon. Pretty sure nobody is trying to be like God simply by making it easier to reach median Earth orbit.

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## eduardo89

> We've been to the moon.


You sure about that?

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## pcosmar

> Anchored by centriPETAL force.  Place the center of mass about a meter above the actual geostationary orbit point, and the whole thing will actually lift and have to be anchored into the ground to keep it flying off. Reaction mass jets would take very little energy to stabilize synchronic to the ground. Only two concerns I have, 1) lifting mass would affect the center of mass, so the end station would have to be extremely massive, and 2) if there ever were some kind of disaster this thing would make an awful mess coming down.


And what of the harmonic balance?

Having a mass attached to earth,, and rotating with it.

What is going to counterbalance that? And yes,, weights moving up and down that are going to have effects.

And what power source is going to move those weights.. or is anti-gravity included in this plan?

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## pcosmar

> 2) if there ever were some kind of disaster this thing would make an awful mess coming down.


Torque induced precession.

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## GunnyFreedom

> A huge mass,, tethered to the earth.. Spinning through space a hundreds of thousand MPH..
> 
> and you see no problems with centrifugal forces or harmonic balance?
> 
> 
> Newtons Laws of motion apply here.
> For every action there is an equal and opposite reaction.
> 
> And you do know that the gyroscopic forces are going to change as weights are moved up and down that cable.
> ...


actually, I understand these forces intuitively. I'm not seeing anywhere near the scale of problems that you are. Sure, there will be some harmonic resonance in the cable, but that's easily damped. After all, with a fixed length you know ahead of time the frequency of the resonance. 

We are all already moving hundreds of thousands of miles per hour, so why don't all out homes collapse?

this tech would be governed by centripetal force, not centrifugal force. 

Newtons laws in fact are why this kind of engineering would actually work. Centripetal force pulls the mass away from the Earth supporting it's own weight from above rather than pushing it up from below. 

My primary concern would really be the transport of real mass up and down. As long as the substation was massive enough (someone mentioned using an asteroid) that becomes less of an issue, since mass imbalances are fractional, and the same metric ton is a smaller fraction of an aircraft carrier than a PT Boat. 

The other concern I can think of, is space junk impacting the tether.

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## pcosmar

> Torque induced precession.


Some people will need to look that up.

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## GunnyFreedom

> And what of the harmonic balance?
> 
> Having a mass attached to earth,, and rotating with it.
> 
> What is going to counterbalance that? And yes,, weights moving up and down that are going to have effects.
> 
> And what power source is going to move those weights.. or is anti-gravity included in this plan?


As long as center-mass is above the GS point, the mass will pull away from Earth rather than towards it. Keep the forces small enough to hold it in place by anchoring in bedrock and you are golden. Once it's in place, station-keeping reaction mass will be minimal, and we have plenty of experience with that. 

When moving serious mass up the cable, it would probably take reaction mass on the substation to keep proper GS orbit. Not as much as a rocket liftoff since you are only counting for discrepancies over time, but enough that it will still technically take rockets to lift enormous masses. 

As as to motive power, simple electricity and a wheel pulling at the cable will do. It's a pretty stunning piece of engineering, all told, but you are still making it way more complicated than it is. The physics of it are quite straightforward.

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## GunnyFreedom

> Torque induced precession.


Nothing we can possibly build in the next 500 years would have the sheer mass to destabilize the planetary axis and rotation. The Earth weighs some 6 sextillion metric tons. The amount of resting mass necessary to generate a gyroscopic instability would be in the hundreds of trillions of metric tons. But the time we gathered that much mass together we will have already destroyed the planet by Swiss-cheesing it.

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## pcosmar

> The physics of it are quite straightforward.


Actually the physics are quite massive.
 The gravitational forces on the cable itself, and the anchor
The anchor into tectonic plates,, and the continuous pull on these floating plates.
The orbiting mass,, that is now physically connected.

it would only take a small deviation to become truly catastrophic.(Torque induced precession)

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## Origanalist

> Only if he promises not to come back ...


By the time this gets built if it does, I would gladly accept those terms.

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## Origanalist

> Anchored by centriPETAL force.  Place the center of mass about a meter above the actual geostationary orbit point, and the whole thing will actually lift and have to be anchored into the ground to keep it flying off. Reaction mass jets would take very little energy to stabilize synchronic to the ground. Only two concerns I have, 1) lifting mass would affect the center of mass, so the end station would have to be extremely massive, and 2) if there ever were some kind of disaster this thing would make an awful mess coming down.


I wonder if it's possible to make it "fall up" in the event of a catastrophic failure? A disconnect mechanism at the bottom maybe. That would have the added benefit of not losing the base.

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## Occam's Banana

> By the time this gets built if it does, I would gladly accept those terms.


Come to think of it, I'll go too. They won't even need to stop the planet ...

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## GunnyFreedom

> I wonder if it's possible to make it "fall up" in the event of a catastrophic failure? A disconnect mechanism at the bottom maybe. That would have the added benefit of not losing the base.


That was my first thought too, actually.  ANYWHERE you disconnect it, everything "upwards" of that point will go up.  Which works well if the issue is in the middle or lower atmosphere; but what happens if the catastrophe is in low Earth orbit?  Everything from the break downwards is coming down to Earth.  Unless you can predict that a break is ABOUT to happen and disconnect LOWER to move those bits out of the way it could be a problem.

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## Original_Intent

I think this is pretty pie-in-the-sky, personally.

I love sci-fi, and I love science. Some things that immediately come to mind:

If you are even going to do this, at least start atop Everest. You have the first few miles done for you. To even get to the starting point on Everest you have to build a seven mile high "base" and you are going to then be encountering Everest-like conditions anyway.

Passing thru the jet stream - so your structure will have to withstand winds exceeding 100 mph. And if the winds vary, on a structure of this size, you will need to be worried about harmonics (above and beyond precession).

As far as the idea of everything "falling up" you would need to build so that the majority of the bulk was BEYOND geo-synchronous orbit. I guess once you have reached geo-sychronicity it gets easy (?)

Gunny, you are backwards on your thinking. The higher up the break, the easier for the wreckage to "fall upwards", the lower the break, the more is going to be pulled down in collapse. That's pretty basic physics, essentially any break ABOVE the point of geo synchronous orbit will fall away from earth, anything lower falls down. An easy thought experiment is imagine climbing a mile up and dropping a ball - it will plummet to earth. 50 miles up it will still fall, but  a lot more slowly. Above the point of geo sychronicity (I want to say ~100 miles?) releasing the ball and the centrifugal force will fling the ball away from earth.

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## Brian4Liberty

> *Harmonic balance.*
> 
> Take a second to consider.
> 
> Even if you overcome the considerable obstacle of Tensile strength, v Gravity, and balanced the pull of the anchor to keep the thing stable. (some big "If's")
> 
> You would still have the issue of harmonic balance.
> That is quite a bit of spinning mass.





> Anchored to what,, and counter balanced by what?
> 
> you are talking about considerable mass,, spinning at earths rotation. (centrifugal force)


Been a while since college physics. Not sure what effects might occur. As much as people worry about global warming, if this did mess at all with the Earth, no telling what could happen.




> To keep the cable structure from tumbling to Earth, it would be attached to a large counterbalance mass beyond geostationary orbit, perhaps an asteroid moved into place for that purpose.


Hmm. How big of an asteroid?

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## GunnyFreedom

> I think this is pretty pie-in-the-sky, personally.
> 
> I love sci-fi, and I love science. Some things that immediately come to mind:
> 
> If you are even going to do this, at least start atop Everest. You have the first few miles done for you. To even get to the starting point on Everest you have to build a seven mile high "base" and you are going to then be encountering Everest-like conditions anyway.
> 
> Passing thru the jet stream - so your structure will have to withstand winds exceeding 100 mph. And if the winds vary, on a structure of this size, you will need to be worried about harmonics (above and beyond precession).
> 
> As far as the idea of everything "falling up" you would need to build so that the majority of the bulk was BEYOND geo-synchronous orbit. I guess once you have reached geo-sychronicity it gets easy (?)
> ...


No, actually I am not.  The mass of the structure is the mass all the way down and any mass being supported by the end-station.  the "center of mass" for the entire assembly is placed just higher than Geo Stationary, so that even if it breaks just above the ground the entire assembly starts making for higher orbit.

You are correct that the higher the break the FASTER it will lift, as that would put the center of mass even higher on the orbital track developing even more centripetal force and pushing it out faster; but a higher break will also leave everything under the break to fall uncontrolled back to the Earth.

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## AFPVet

Count me out... I wouldn't want to be stuck during a "service call"

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## GunnyFreedom

Whereas I very very much want to the be IT guy for this thing.

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## Original_Intent

Ah, I see, center of mass for the whole enchilada is above geo-synch. That being the case, you are right - but wow. Something that big there would be interesting "tidal forces" on the object depending on the relative positions of the sun and moon.

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## Zippyjuan

Theoretically possible to build- perhaps.  Realistic? No. There are far less costly ways to get something or somebody into space. (how many trillion just to build the 30 mile tall "base" building for this rope to space)? Would suck if the thing got stuck on you part of the way to your destination too.  Might be a while before they get a service technician up to you.

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## Henry Rogue

Gargantuanus Brokenus Windowus.

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## Henry Rogue

Instead of "a bridge to nowhere", we can have a rope to nowhere.

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## timosman

bump - http://www.ronpaulforums.com/showthr...ave-the-planet

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