The construction of a space elevator would be a huge advancement in space exploration and satellite maintenance and deployment. The biggest hurtle to building one is probably funding, but given the advantages of having one it probably would be an international venture, the engineering aspect of it probably would not be a problem for us. I believe we will likely begin construction on one with in the next 50 to 100 years.

Feel free to past your thoughts.

It would be a huge project alright and, until the human race is ready to move into space in a really big way, not practical.

I know the theory is that ‘if they build it, they will come’ but I doubt that any country or group of countries would be willing to pony up the trillions that would be needed on such a gamble.

At some point there will be enough space activity to justify it but not at the moment. Probably not in 50 years either. Unfortunate because it would be a magnificent project and I would love to be still around to see it. :)

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

I think money is not the only problem: We still haven't found out how to build a cable that is strong enough to carry its own weight over a height of hundreds of kilometres. There are some materials (don't remember what it was now) that are theoretically strong enough. But then it turned out that if they try to actually make a longer cable from that, strength suffers by a factor of 2 or something.

The 1st hurdle that comes to my mind about this is positioning, + thus how e.g air traffic would avoid it. I trust it would not be able to move at the ground level. Looking at a worst-case scenario, how would a disaster be dealt with if e.g a plane did hit it?!

The answer to the question is when will we ever fund a space mission 100% Apollo may have been the only one where requests for money for R&D were approved rather routinely. There isn't a nation on the earth that is committed to basic R&D any more. Until the answer is several nothing will be built.

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The 1st hurdle that comes to my mind about this is positioning, + thus how e.g air traffic would avoid it. I trust it would not be able to move at the ground level. Looking at a worst-case scenario, how would a disaster be dealt with if e.g a plane did hit it?!

And what about thunderstorms, jetstreams, lightnings, icing conditions (that increases the weight of the structure), moisture, birds (nests/excrements) and plants that might find it a nice place with lovely views!!!???

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And what about thunderstorms, jetstreams, lightnings, icing conditions (that increases the weight of the structure), moisture, birds (nests/excrements) and plants that might find it a nice place with lovely views!!!???

More interesting is when it short-circuits the entire ionosphere down to ground.

That should make for the greatest earthly lightning strike ever!

It should also obliterate a lot of radio for a while also!!

Keep searchin',
Martin

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what ML1 says could in fact be a problem, but I think that "normal" lightning strikes won't be a big problem. Either we build the cable from a non-conductive material. In that case the electric resistance of air would be lower and lightning would still take the normal route. Or we build it from a conductive material. In that case the atmosphere around the cable would be constantly discharging creating a weak and constant electric current instead of a low number of powerful strikes.

Good that's that problem solved. When can we start?

It will have to be more reliable than the elevators at some stations on the London UndergrounD, which when they break down, you have to use the staircase ! This would take raaaather a long time...

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There are only a few selected countries where the space elevator could be built - and all of them have political problems of one sort or another. The space elevator needs to be built on the equator to keep the position of the upper station in a geosynchronous orbit that does not swing very far.

Not imagine the ride :)

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There are only a few selected countries where the space elevator could be built - and all of them have political problems of one sort or another. The space elevator needs to be built on the equator to keep the position of the upper station in a geosynchronous orbit that does not swing very far.

Not imagine the ride :)

If an international effort, might be better to build it at sea. Mid Atlantic or Pacific oceans, anchored to the sea floor.

After figuring out how to build a 40 000 km long elevator, anchoring it through a few km's of salt water shouldn't be much of a challenge.

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

though you'd have to find someplace equatorially that has very little weather. Thats hard to do over water. I'd think placing the elevator on stable land would be more appropriate.
I think its just so much easier keeping idoits away from your elevator by using a fence than the alternative on a body of water

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In a rich man's house there is no place to spit but his face.
Diogenes Of Sinope

imagine you have to travel in that elevator for hours and all you get is that crappy elevator sound they use to play in elevators... guess I'd jump off the thing after 1000 meters... ;)

though you'd have to find someplace equatorially that has very little weather. Thats hard to do over water. I'd think placing the elevator on stable land would be more appropriate.
I think its just so much easier keeping idoits away from your elevator by using a fence than the alternative on a body of water

Motion or other effects caused by weather or ocean currents, etc., shouldn’t be too difficult to engineer for.

Remember, the a few kilometres of water and fifty kilometres of atmospheric weather is only about one tenth of one percent of the elevator’s length. That other 99.9% represents one heck of a lot of motion dampening mass. Inertia sucks when it knocks you down on a moving bus but it is a definite advantage in this sort of situation.

Now earthquakes is something else entirely. .

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

imagine you have to travel in that elevator for hours and all you get is that crappy elevator sound they use to play in elevators... guess I'd jump off the thing after 1000 meters... ;)

Trips shouldn't take too long.

Assuming some sort of linear accelerator motor is used that can maintain constant acceleration of, say, 1g (9.8 m/s/s) then one way trip would only take a little more than an hour. (2000 seconds of initial acceleration gets you up to 20 000m/s, and takes you nearly half way. Another 2000 seconds of deceleration brings you to the top.)

Better hope that there is no deceleration issues because you’ll be traveling well past escape velocity at the midway point. If the brakes don’t work then you go shooting off the far end at 20 km/second and you won’t be coming back. :~~

And that first 1000 meters will only take about 15 seconds, so you have a very low boredom threshold. ;p

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

Trips shouldn't take too long.

Assuming some sort of linear accelerator motor is used that can maintain constant acceleration of, say, 1g (9.8 m/s/s) then one way trip would only take a little more than an hour. (2000 seconds of initial acceleration gets you up to 20 000m/s, and takes you nearly half way. Another 2000 seconds of deceleration brings you to the top.)

Better hope that there is no deceleration issues because you’ll be traveling well past escape velocity at the midway point. If the brakes don’t work then you go shooting off the far end at 20 km/second and you won’t be coming back. :~~

If you can reach escape velocity, let go of the cable as you don't need it any more!

The speed on the cable will be much slower than that and there won't be constant acceleration.

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Trips shouldn't take too long.

Assuming some sort of linear accelerator motor is used that can maintain constant acceleration of, say, 1g (9.8 m/s/s) then one way trip would only take a little more than an hour. (2000 seconds of initial acceleration gets you up to 20 000m/s, and takes you nearly half way. Another 2000 seconds of deceleration brings you to the top.)

Better hope that there is no deceleration issues because you’ll be traveling well past escape velocity at the midway point. If the brakes don’t work then you go shooting off the far end at 20 km/second and you won’t be coming back. :~~

If you can reach escape velocity, let go of the cable as you don't need it any more!

The speed on the cable will be much slower than that and there won't be constant acceleration.

Well, since we are talking pie-in-the-sky technology here, why not go for constant acceleration. Assuming some sort of electric (magnetic) motor, like a mono-rail albeit vertical, and once you get high enough so that air resistance is no longer a factor, constant acceleration is the way to go.

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

Trips shouldn't take too long.

Assuming some sort of linear accelerator motor is used that can maintain constant acceleration of, say, 1g (9.8 m/s/s) then one way trip would only take a little more than an hour. (2000 seconds of initial acceleration gets you up to 20 000m/s, and takes you nearly half way. Another 2000 seconds of deceleration brings you to the top.)

Better hope that there is no deceleration issues because you’ll be traveling well past escape velocity at the midway point. If the brakes don’t work then you go shooting off the far end at 20 km/second and you won’t be coming back. :~~

If you can reach escape velocity, let go of the cable as you don't need it any more!

The speed on the cable will be much slower than that and there won't be constant acceleration.

Well, since we are talking pie-in-the-sky technology here, why not go for constant acceleration. Assuming some sort of electric (magnetic) motor, like a mono-rail albeit vertical, and once you get high enough so that air resistance is no longer a factor, constant acceleration is the way to go.

I assume you mean something like a rail gun. To keep the projectile (elevator car) near the rails you are going to need something sliding or rolling along a guide. The issue becomes that contact point and friction. As you should know, if spin a wheel fast enough and it flies apart. So there is a speed limit. As to friction as you go faster the heating will melt the parts. Neither of these is good.

Then there is the wave motion that will be on the cable. There will always be something that starts it, be it a breeze at ground level, the jet stream, the fact that the earth is lopsided so it doesn't spin at a constant rate, tides from the sun and moon, an earthquake, never mind another elevator car on the cable. If your straight line speed is fast enough when the wave reaches you, your car will pull on the cable sideways hard enough to break it. Not good.

My guess is a practical speed limit would be less than a modern fighter jet. Your trip is going to be a couple of days, but that is on par with a rocket and for a lot less energy.

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Trips shouldn't take too long.

Assuming some sort of linear accelerator motor is used that can maintain constant acceleration of, say, 1g (9.8 m/s/s) then one way trip would only take a little more than an hour. (2000 seconds of initial acceleration gets you up to 20 000m/s, and takes you nearly half way. Another 2000 seconds of deceleration brings you to the top.)

Better hope that there is no deceleration issues because you’ll be traveling well past escape velocity at the midway point. If the brakes don’t work then you go shooting off the far end at 20 km/second and you won’t be coming back. :~~

If you can reach escape velocity, let go of the cable as you don't need it any more!

The speed on the cable will be much slower than that and there won't be constant acceleration.

Well, since we are talking pie-in-the-sky technology here, why not go for constant acceleration. Assuming some sort of electric (magnetic) motor, like a mono-rail albeit vertical, and once you get high enough so that air resistance is no longer a factor, constant acceleration is the way to go.

I assume you mean something like a rail gun. To keep the projectile (elevator car) near the rails you are going to need something sliding or rolling along a guide. The issue becomes that contact point and friction. As you should know, if spin a wheel fast enough and it flies apart. So there is a speed limit. As to friction as you go faster the heating will melt the parts. Neither of these is good.

Then there is the wave motion that will be on the cable. There will always be something that starts it, be it a breeze at ground level, the jet stream, the fact that the earth is lopsided so it doesn't spin at a constant rate, tides from the sun and moon, an earthquake, never mind another elevator car on the cable. If your straight line speed is fast enough when the wave reaches you, your car will pull on the cable sideways hard enough to break it. Not good.

My guess is a practical speed limit would be less than a modern fighter jet. Your trip is going to be a couple of days, but that is on par with a rocket and for a lot less energy.

Actually I was thinking magnetic motor, like in a monorail except vertical. No physcal contact between elevator and the support structure, supported and accelerated by electromagnets, so no friction.

RE: wave motion: do you mean harmonics? Like the bridge that came apart back in the '50's?

That was a harmonic problem that was easily corrected once the physics was better understood. And, again, I remind you that low level atmospheric issues will be largely overcome by the sheer mass of the 99.9% of the structure that is above the atmosphere. Since we live in, and are utterly controled by, our atmosphere, it can be hard to grasp just how insignificant it really when compared to the mind-numbing scale of a 40 000 km long cable.

The jet stream will no more be a factor than an ant is pushing on the tire of a car.

As for the other issues (lopsided earth, etc) I haven't really thought those through yet. But, as I noted in an earlier post, earthquakes could well be the big issue. even a small one could be catastrophic given the mass (inertia) difference between the planet and a cable hanging from space.

Of course, I am stoned on NeoCitran and a 102 degree temperature at the moment, so what do I know. lol.

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein