Space elevator - closer to reality

Discussion in 'General Science & Technology' started by Watcher, Aug 26, 2003.

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  1. Watcher Just another old creaker Registered Senior Member

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    http://www.spacedaily.com/news/materials-03w.html

    Seems the space elevators of science fiction fame may not be so far off, after all.

    "The NASA Institute for Advanced Concepts (NIAC) commissioned Dr Bradley C Edwards to study all aspects of the construction and operation of a space elevator, and Phase I of the report was published in late 2002.

    The report very specifically addresses design and operations, which had until then escaped close scrutiny.

    Firstly, the elevator would not be a cable. It starts as a 1-micron thick piece of tape 91,000km long, tapering from 5cm wide at the Earth's surface to 11.5cm wide near the middle. This tape would be taken up by shuttle together with some booster rockets. It would then be 'flown-down' to the surface whilst the booster rockets provide the required counterbalance beyond geosynchronous orbit.

    Centripetal force throws the higher part of the tape away from the Earth, whilst the effect of gravity on the lower mass of the tape keeps it in tension. This first link is capable of supporting 1238kg before breaking."
     
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  3. cosmictraveler Be kind to yourself always. Valued Senior Member

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    This won't work, is very risky, and costs billions if even tried to build. The thinbg could fall down and it would crush anything under it. It would get in the way of aircraft. It would just collapse onto itself for nothing can hold that much weight for any length of time. Terrorists could blow it up. Where would it ne built, they won't want it to fall onto them. This project shouldn't even be discussed for everything about it screams it's IMPRACTICLE and USELESS.
     
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  5. youngbiologist Registered Senior Member

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    this stuff

    this stuff weighs less then paper, it won't kill anyone. Rockets, now they kill people. I believe brazil just lost 20 people as they were testing a rocket engine. Nanotubes are far stronger then anything else ever made, its definetly strong enough to build a space elevator out of. They plan on having the space elevator anchored to an ocean platform, which can then move around and avoid things like hurricanes. Also it will reduce the costs of going into space at least a 100 fold, instead of a 1000 dollars per pound we're talking about 10 dollars per pound. Spave elevators will undoubtedly open space for humanity, and not just astronauts. Cosmic, you are a stupid person.
     
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  7. Vortexx Skull & Bones Spokesman Registered Senior Member

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    Plans seem pretty feasible.

    We will probably figure how to make really long carbon wire/tape within 5 years and from that point human curiosity to explore will inevitably find a way to find the money to invest.

    The thing is it is, it is a financial risk cause it aint proven launch platform/technology, it would be nice if we have another space race like we had with usa/russia in the past, but this time usa/chine. You could bet the americans could suddenly find the resources/people and money to make this thing fly if they fear china might become the first to have a stairways to heaven...

    Or even better, some rich muslim oil state should have the spare pocketmoney to build something like this, surely the americans / cristians could not bare the thought of former goathearding muslims having the largest twin towers (Petronas) AND a spacetower, this would be the kind of competition we really need to make big things happen fast.
     
    Last edited: Aug 26, 2003
  8. cosmictraveler Be kind to yourself always. Valued Senior Member

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    How is it that paper can lift something that weighs over 5 tons? How is it going to actually lift anything without power and where's the power going to come from? A moveable barge won't move fast enough with that much weight on it to get out of the way of a hurricane.It isn't logical whatsoever and shouldn't be built or even thouight about. Whoever builds it is a damn fool and wacko for spending that kind of money on a worthless project like this.
     
  9. This does seems rather inexpedient and haphazard. One has to consider the likelihood of lightning, hurricanes, volcanic and/or surface conflagrations, other natural calamities, and the risks these pose to such flimsy fibers. Besides, wouldn't the heat absorbed by the cable in be immense? There could be stupendous levels of thermal expansion and consequent weakening to deal with.
    Imagine the tension of that material! Gravity and centripetal force and probably a dozen other extreme factors! So these Carbon Nanotubes are that durable?
     
  10. buffys Registered Loser Registered Senior Member

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    hey, neat article, thanks for posting it!

    ive always had the Aurthur Clarke/Kim Robinson vision of an elevator in my mind (therefore 150 years away at best - not to mention the devastation a failure could cause) so its interesting to read about this more plausible (for our century) and safer design.
    were your parents killed in an elevator crash or something? your getting pretty worked up considering its still a theory. you call it worthless? if you want to discuss worthless projects lets talk international space station - now that truly does nothing (the worst part is we knew that before we built it) yet we spent an ass load on it anyway. Unlike the space station an elevator actually has potential uses.

    As far as it being dangerous, im sure dangers are involved (as with anything) but compared to having to ride a controlled explosion to escape the planet's gravity (as is the case in every method used to date) it seems hard to argue an elevator would be more dangerous.
    I think the article mentioned that excess energy may be a problem and methods of dispersal are being looked at, I assume they won't start construction until these issues are addressed. After all this is just the start, there is still a long way to go.
     
    Last edited: Aug 27, 2003
  11. youngbiologist Registered Senior Member

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    arg

    arg, thank god I'm moving to that biology forum...tired of this junk. First off the only heat the elevator is exposed to is that from the sun, nothing major. The heat you probably are thinking about is that created when an object enters the atmosphere, and that is created by the friction with the air. Since the space elevator is *NOT* moving through the air at 10,000 milers per hour, it will NOT burn up in the atmosphere. And yes, nanotubes are freakin strong. The space elevator will essentially be one enormous molecule. Contruction would cost roughly 20 to 30 billion dollars, and be a solid money maker once constructed. An elevator would climb the shaft, using power sent to it by a laser.
     
  12. eburacum45 Valued Senior Member

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    A space elevator would need to taper, as all the weight of the lower parts will be carried by the upper parts. Any breaks would be likely to occur in the thin lower levels; the thicker upper levels would then fall upwards, strange as this may seem.

    There are many different configurations involving shorter tethers and lifting mechanisms; lofstrom loops, skyhooks, rotating tethers, space fountains and dynamic orbital rings.

    Of these the skyhook and rotating tethers are relatively easy to achieve, and involve a rendevous between fast moving atmospheric craft and a moving tether suspended from a satellite.
    Before beanstalks become possible I would expect something along these lines to be tried in earnest, as the cost of lifting mass to orbit is so great.
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  13. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Did you guys ever read Battle Angel Alita?

    The weight on the bottom is supposed to be counterbalanced from the other end (the one in orbit). That means, first of all, that the stresses would tend to be in the middle.

    Second, this thing doesn't need to be attached to the ground. It could instead be counterbalanced at 10km off the ground, or some such distance, and easily be above the range of ground fires, hurricanes, volcanoes and so on. The most major problem that occurs to me is stabilizing the thing in geosynchronous orbit, which would take vast amounts of power for something so large.

    Anyway, remember that something OUTSIDE of geosynchronous orbit moving at geosynchronous speeds will tend to fall AWAY from the Earth, and anything INSIDE it will tend to fall TOWARDS the Earth, hence the counterbalancing effect. We need only be sure that it weighs about the same on both sides.

    Simple

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  14. eburacum45 Valued Senior Member

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    The weight on the bottom is supposed to be counterbalanced from the other end (the one in orbit). That means, first of all, that the stresses would tend to be in the middle.

    That is true, but in most design studies the end that points away from the centre of gravity terminates in an asteroid or other heavy counterweight, and is much shorter;
    the end that reaches earth does not need a wieght on it, as it is heavy enough as it is.
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    Last edited: Sep 13, 2003
  15. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

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    As an engineer, I'll repeat my position on the space elevator: impossible, impractical and waste of money to even try with today's technology*. Doesn't even make good sci-fi. You're far better off keeping your eye on fusion tech for that magic space launch system.

    While it's good that they're looking into it, the practicality of this is so far off that I wouldn't be surprised a bit to learn that this is a trojan project to see what interesting technologies fall out of it. I think that everyone here will have long since passed out of living memory before any meaningful moves are made toward a space elevator, and maybe a generation after that when it becomes practical.

    * And the projected technology of the next half century, so don't get your hopes up.
     
  16. eburacum45 Valued Senior Member

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  17. eburacum45 Valued Senior Member

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  18. eburacum45 Valued Senior Member

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  19. cosmictraveler Be kind to yourself always. Valued Senior Member

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    What a bunch of bullshit!
     
  20. eburacum45 Valued Senior Member

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  21. Truenemo1889 Registered Senior Member

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    something better..........

    Lets build space station Babylon 5, Deep Space 9 or the Death Star in Orbit ..........it might make more sense

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  22. ElectricFetus Sanity going, going, gone Valued Senior Member

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  23. Anomalous Banned Banned

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    Why not use the tree from Jack and the bean stalk
     
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