Why would the Space Elevator NOT work?

Question

I have heard some great discussion on the Space Elevator, but not yet heard all the good reasons why it won't work. Tell me what you think would cause this technology to fail, whether technical, social, political, or otherwise.
References:
A Space Elevator company: http://www.liftport.com/
NASA article on it: http://science.nasa.gov/headlines/y2000/ast07sep_1.htm

Answer 1

Talk about the largest terrorist target you can think of.
How would it be possible to protect something that big?
What if a plane hit it?
What if a meteor hit it?
And if it did malfunction and fall, how much damage would it do?
I'm betting a lot.
tc

Answer 2

The space elevator could work. However, there are so many things that have to work "just right" that it may be still some time away.

Things that could go bump?

We do not (yet) have materials that can support their own weight (in compression) to built it as a tower. The footing would be crushed out of shape.

So we must build it from space. If you want the entire elevator to remain vertical above a point on Earth, then the centre of gravity of the space elevator must be at the altitude of geostationary orbit. So, before the thing reaches a few hundred metres in length, the "manufacture" must be in geostationary orbit. We are not (yet) capable of manufacturing something so big in orbit.

As the elevator is built, there comes a point where it has to be placed in a vertical position (the first few km could be built along the orbital height, "parallel" to Earth's surface).

When that happens, the bottom part is going too slow to remain on its orbit (it wants to fall down), the top part is going too fast (it want to escape its orbit). The tension in the material will be enormous. We no not (yet) have a material that can handle so much tensile force.

Once in place, you'll want to sent stuff up the elevator. An object on the ground, on the equator, is going sideways at 1,670 km/h. At the geostationary orbit level (35,786 km), the object is still completing a complete circle around Earth's centre in 24 hours: 9,370 km/h.

So the objects lateral speed has to be increased from 1670 to 9370 km/h. Depending on how fast you want the object to get there, you have to accelerate it sideways at a proportional rate.

Let us say you want the object to reach geostationary orbit in 24 hours, then you have to increase its lateral speed by 320 km/h every hour. Acceleration of 89 m/s^2. If the object has a mass of one tonne (the vehicle plus the content), then the lateral force needed ( F = m a) is 89,000 N. I do not know (yet) how to make the vertical structure capable of supporting so much lateral stress. This means that we will need a reaction engine (a rocket) to provide the lateral trust so that the structure suffers no lateral force from the vehicle (on the way up AND on the way down). This reduces our payload.
This lateral push is the Coriolis "force" and is caused by anything that moves in a rotating frame of reference. So sending the fuel up in a pipe still causes the lateral push.

Also, try to find the money for such a project. Then have everyone agree on the perfect spot (on the equator) for the base station -- know of any good, stable countries on the equator? I thought so.

The project would probably take over a century. Stable governments anyone? You also need stable financial sources, stable contractors...

And then, there is the symbol and the target of opportunity, and...

Answer 3

The first problem is technical: we don't know how to build *anything* 22,000 miles long, and we don't know how to build anything strong enough to withstand the strain that a space elevator cable/ribbon would require.

The second hurdle is economic. It would cost a huge amount of money to build a space elevator, and how could the cost be justified? Consider that
(1) a climber would take many hours to several days to reach geosynchronous orbit (22,000 miles is a loooong way to climb!)
(2) there is a definite limit to the mass that a given cable/ribbon could support at one time, otherwise the elevator would fall;
(3) the only way to increase the mass limit is to increase the mass at the top end -- which means the cable/ribbon strength would also need to increase.

In other words, achieving orbit with the elevator would be both slower and probably more expensive than a rocket (albeit much more reliable).

Answer 4

I think this technology would be great, but we would still need to get over the technological challenges that it throws in our faces. I suppose that conventional elevator technologies would not work so we would need to come up with some sort of mag-lev system. Also, we would need a system to compensate for the pressure differences that would affect the passengers. Would the tube or structure be pressurized or would the passengers have to wear a space suit? Either one of those would add considerable weight to the lifting unit. Also, it is a big target that some wackos would love to hit. How would security for this thing work and who would handle it? Also, how would air space around it would have to be secure and it would have to be large. This would require regular patrols by some sort of military planes. This would cost money. Where would the funds come from? I am sure that there are many more, but right now I am eating breakfast and I can't think any more.

Answer 5

I can see possible problems that could cause this possible project to fail from either political, technical, or economic grounds--not that I'm negative toward the idea. But any potential technology faces problems.

The political tripwire is the need to place the ground point on the equator. There are several points this could be done--and with stable societies and governments. But--oddly enough, I see this problem as having to resolve what happens in orbit. There are--and willl be more--satellites in orbit--and every one must cross the equator twice each orbit. On any given day, the chance of a colllision with the elevator would be tiny--but with hundreds of satallites? Getting everyone on the same page as to a collisiion avoidance system could be a problem--we can't even agree that its a good idea to stopkilling each other.

The technical barrier is pretty straightforward--teory s fine, but can we actually produce materials strong enough--and in large quantities?

But--if anything prevents the building of a space elevator, I think it will be economics. But not the cost of the project--though it would cost hundreds of billions, it would pay off. But I suspect that by the time you completeted it, it would no longer be an economical option! That's totally counter-intuitive, but here's why:

There's no majic to the space elevator idea--and it will cost a lot to operate. In particular, although compared to any existing system, it would be cheap to operate, you will still have a high cost to lift a payload over 20,000 miles. But, by that time, we are very likely to have cost-effective launch vehicles, using any of a variety of technologies. and they can reach NEO (near-earth orbit)--quickly. This is a region of space which is also relatively radiation free--reducing the cost of building human-safe facilities-and the energy cost of coming down from syncronous orbit--where the space elevator "ends" (except for its ccounter weight--is about the same as the energy cost of going tolunar orbit (no kidding!).

So I think the economic problem that promotors of a space elevator might face is, suprisingly enough--not that it will cost a lot tobuild--but can they operate it at a cost competative with the kind of spacecraft we willl be able to build by then.

Answer 6

I think it won't work for several reasons:

Economic: Even though the science for it sounds perfectly reasonable , the cost for building such a thing is rather prohibitive. Because noone has ever done it before and because it is "untested" investors would be very leery of it.

Also, it is unclear if such a project would be economically beneficial. Yes, you could earn a pretty penny with satellites... but would you make enough to make an elevator profitable?


Political: With rockets, there are launch spots in several places around the world, i.e. countries can offer their own space program. With a space elevator, there is only one "launch site". Who controls the scheduling of it? I think the diplomacy angle would be a constant hindrance.


Social: I think that a significant number of people would be scared of it falling, angered that their tax dollars were being spent on it, or simply not care enough to save it from cost-cutting politicans. In short, the people aren't ready for it.

Answer 7

There are 3 issues that are required of the "satellite tv for pc" (man made or organic) to establish that this to artwork: a million) The satellite tv for pc must be geosynchronous (Mars-synchronous??). it is, it will be in an orbit such that it keeps to be at once over the comparable place on the planet in any respect cases. it fairly is so the the planet-end of the shaft could be linked to a minimum of one element on the planet. This element won't be able to pass! {if the planet-end of the shaft have been left floating, it may wobble and finally cave in. the two ends of the shaft must be solidly affixed to their admire planetary bodies.] 2) The orbit must be around, not "egg" formed. the shaft of the elevator is almost a fastened "radius" which won't be able to get replaced. ANY version in orbital top, whilst little as some inches, could pull the elevator shaft aside. 3) The satellite tv for pc's rotational era must be precisely equivalent to its orbital era, like the earth's moon. It ought to present day the comparable element of the satellite tv for pc to the planet atl ALL cases, so as that the shaft of the elevator could be hooked to a minimum of one spot on the satellite tv for pc. i don't be attentive to of ANY moon for ANY planet that does this. purely the Earth's Moon meets (3), above, yet would not meet (a million) or (2). the only answer to the orbiting end of a "area elevator" ought to, right this moment, be a guy made satellite tv for pc or area station. guy-made satellites might have "guidance jets" (the present ISS does) to maintain it appropriate aligned and on the properly suited orbital top.

Answer 8

The space elevator would not work.
The cable would wind up around the earth.
The outer end must orbit much slower than the earth end

Answer 9

its would work fine given it is built as a co-op and not by a single country (things like that have strange ways of pissing people off). The disignes work fine only problem might be th cost, that's a lot of materals to pay for

Answer 10

More like an economic issue. Scientists vie for funds everyday. This is a lesser known project and as such will have to compete for dollars for better known projects. This I believe will be it's undoing.