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Future of Space Elevator Looks Shaky

kdawson posted more than 5 years ago | from the a.-c.-clarke-quaking-in-his-grave dept.

Space 486

lurking_giant writes "In a report on NewScientist.com, researchers working on development of a space elevator (an idea we have discussed numerous times) have determined that the concept is not stable. Coriolis force on the moving climbers would cause side loading that would make stability extremely difficult, while solar wind would cause shifting loads on the geostationary midpoint. All of this would likely make it necessary to add thrusters, which would consume fuel and negate the benefits of the concept. Alternatively, careful choreography of multiple loads might ease the instability, again with unknown but negative economic impacts."

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Told you so (5, Funny)

Junior J. Junior III (192702) | more than 5 years ago | (#26049381)

I told everyone it wouldn't work. But would they laugh at me? No!

I believe I speak for all (0)

Anonymous Coward | more than 5 years ago | (#26049435)

realists when I say:

DUH!!!

Thank you

Re:Told you so (4, Interesting)

pitchpipe (708843) | more than 5 years ago | (#26049785)

Seems Charles Stross has it about right, from his book "Saturns Children" [amazon.com] p. 113:

Most of the inner planets have no space elevator at all; Venus and Mercury because their days are unfeasibly long, Earth because its gravity well and debris belts challenge the limits of engineering.

Re:Told you so (3, Interesting)

Anonymous Coward | more than 5 years ago | (#26050007)

Very amusing indeed.

Especially since Kim Stanley Robinson wrote his "Red Mars" series & specifically addressed these issues. He correctly identified the problems, and came up with very realistic solutions.

Yes, the orbital section had to have thrusters to combat what is mentioned in the article.

He also determined that the 'elevator' portion would require significant advances in materials, and require a futuristic substance that could withstand the sheer loads & twisting due to wind, atmosphere, etc.

He even took it to the point of examining what happens when the terrorists from Earth blow up the link cable that connected the orbital portion, resulting in the elevator 'crashing' down to Mars. He even correctly showed how it would actually wrap around the planet (as opposed to falling straight) and when the final piece impacted it caused a huge crater from the sheer kinetic energy. (like a whip-lash).

Good stuff. Maybe these 'scientists' should bother to read once in a while, they might save themselves quite a bit of time. Of course, that would mean budget reductions, so they probably wouldn't have bothered anyhow.

What about the glass elevator? (2, Funny)

JCSoRocks (1142053) | more than 5 years ago | (#26049385)

Willy Wonka had it right. We should just be doing that instead.

Space cannon (1, Funny)

Anonymous Coward | more than 5 years ago | (#26049403)

How about a space "cannon" like in Final Fantasy 8 then?

Alterantives (5, Funny)

Anonymous Coward | more than 5 years ago | (#26049407)

If an elevator won't work what about a space escalator?

Re:Alterantives (4, Funny)

JCSoRocks (1142053) | more than 5 years ago | (#26049607)

Why take the escalator when I can take the stairs? *steps down behind couch*

Re:Alterantives (2, Funny)

jbeaupre (752124) | more than 5 years ago | (#26049649)

With my luck, I'd get halfway up the space escalator and drop my luggage. It would thump its way down to with me running after it. It was embarrassing enough at the Aukland airport having everyone watch me put on a show, but to have it happen in front of half a continent, argh!

Re:Alterantives (1, Funny)

Anonymous Coward | more than 5 years ago | (#26049697)

No, but I think you can buy a stairway to heaven...

Re:Alterantives (5, Funny)

gardyloo (512791) | more than 5 years ago | (#26049747)

But when you get there the shops are all closed. Bollocks to that.

Re:Alterantives (1)

Golias (176380) | more than 5 years ago | (#26049909)

Yeah, but you can get what you came for with just a word anyway.

Re:Alterantives (0, Redundant)

jgtg32a (1173373) | more than 5 years ago | (#26049925)

However, With a word you can get what you came for.

Re:Alterantives (0)

Anonymous Coward | more than 5 years ago | (#26049793)

...and she's bi..ii..ying the stairway..to..HEH-VUUNNNNNNNN.....

Re:Alterantives (1)

pitchpipe (708843) | more than 5 years ago | (#26049841)

But how in the hell are they going to make it comply with the ADA? 8^)

Serious Alterantives (5, Informative)

MozeeToby (1163751) | more than 5 years ago | (#26049859)

In all seriousness, the space elevator gets a lot of press because it's the concept that is easiest for the average person to understand, that doesn't mean it is the only option (or even the best option) to efficiently get stuff into orbit without rockets. I always thought the launch loop made more sense (http://en.wikipedia.org/wiki/Launch_loop/ [wikipedia.org] ).

The idea is that the moving parts are what keeps the structure stable, rather than tension or compression. In theory it could be built with today's materials and technologies and could be cabable of launching more into orbit in its first month than has been launched to date with conventional rocket launches.

Then of course, there are the non-traditional rockets such as laser propulsion, where a laser is shined up from the ground to superheat the air in the rockets cone, which, in turn, produces thrust. And of course, my personal favorite, there's always Project Orion. Not the wimpy one NASA is using to get to the moon, I'm talking about the original Project Orion. As in, using thermonuclear bombs to launch a city sized spaceship into orbit.

Re:Serious Alterantives (2, Informative)

liquidpele (663430) | more than 5 years ago | (#26049951)

For future reference, Wikipedia does not like the slash at the end of links.

Perhaps a zepplin? (1)

LrdDimwit (1133419) | more than 5 years ago | (#26049929)

What about a stairway to heaven? It seems to me there are two paths we can go by; in the long run, there's still time to change the road you're on.

Stairway to Heaven (1)

flyingfsck (986395) | more than 5 years ago | (#26049987)

Just ask a rock band to solve the problem.

Don't forget the ninjas (3, Insightful)

brian0918 (638904) | more than 5 years ago | (#26049419)

There's also the problem that any ninja can come along and cut the cord, and suddenly you have a $500M paperweight wrapping around the earth tearing a path of destruction.

Re:Don't forget the ninjas (1)

theaveng (1243528) | more than 5 years ago | (#26049773)

Ahhh.... I see you've read the Red Mars trilogy where exactly that happened (albeit on Mars not the Earth.)

I always thought the space elevator seemed impractical. First there's a LOT of material needed to create the cable. Than there's the problem of "lowering" that massive cable to the ground. And of course it's vulnerability to shifting; half the time we can't even keep our satellites in the sky - how could we guarantee a cable would stay there?

Like "warp speed" it's a neat scifi idea, but not going to happen within our lifetime. Possibly never.

Re:Don't forget the ninjas (2, Insightful)

SanityInAnarchy (655584) | more than 5 years ago | (#26049871)

First, GP:

There's also the problem that any ninja can come along and cut the cord

I think it'll survive a katana if it can survive the other stresses being placed on it.

Now...

Than there's the problem of "lowering" that massive cable to the ground.

Actually, I think the idea is that cars would run up and down the cable -- even as simple as, the cable stays put, and the cars use motorized wheels.

And of course it's vulnerability to shifting; half the time we can't even keep our satellites in the sky - how could we guarantee a cable would stay there?

Well, the base would be mobile too -- in the ocean. But I see your point.

Like "warp speed" it's a neat scifi idea, but not going to happen within our lifetime.

No, unlike "warp speed", it's actually not make-believe, and very likely not impossible. It just might turn out to be impractical, or not worth it.

That is: We know roughly how we would build it, and how it would work, if it worked. No one has any idea how a "warp drive" would work -- there's only various levels of technobabble thrown at it, like dilithium crystals (Star Trek), or contained black holes (Event Horizon).

Re:Don't forget the ninjas (1)

Devout_IPUite (1284636) | more than 5 years ago | (#26049897)

My grandmother said the moon landing would never happen too..

Scary stuff (5, Interesting)

glaswegian (803339) | more than 5 years ago | (#26049425)

The engineering required for this elevator is mind boggling. After witnessing the amount of time and effort that went into a small suspension bridge spanning the river Thames in London (The Millenium Bridge [wikipedia.org] ), the mere idea of this elevator scares the shit out of me.

Re:Scary stuff (1)

MrMista_B (891430) | more than 5 years ago | (#26049531)

Why does it scare you? Because it isn't easy? Just because it's difficult, doesn't mean you should be scared.

Re:Scary stuff (5, Funny)

IceCreamGuy (904648) | more than 5 years ago | (#26049547)

you will be... you... will... be...

Re:Scary stuff (0)

Anonymous Coward | more than 5 years ago | (#26049573)

Well I know I'd be worried about what would happen if the cable broke. Why doesn't anyone consider that?

100,000 km worth of cable crashing back down onto the earth would be a bad thing!

Re:Scary stuff (2, Informative)

FiveLights (1012605) | more than 5 years ago | (#26049617)

If memory serves, the cable has a very low mass per linear foot. Supposedly it would be more like a giant piece of paper floating down onto the earth.

Re:Scary stuff (1)

theaveng (1243528) | more than 5 years ago | (#26049813)

Take a ball of paper and throw it at 100,000 miles an hour. Tell me that's not going to cause some damage.

Re:Scary stuff (5, Insightful)

glaswegian (803339) | more than 5 years ago | (#26049609)

I'm not saying it shouldn't be done. I guess my point is that the Millenium Bridge is so simple by comparison, yet it needed ~2 years of repairs after opening because of a wobble. People could have been thrown into the Thames, but no big deal, I guess. The space elevator, however, seems so much more prone to failure and with much bigger consequences.

Re:Scary stuff (0)

sir_eccles (1235902) | more than 5 years ago | (#26049943)

To be fair, the Millennium Bridge was badly designed from the outset and they didn't do their homework on resonance effects before building it.

You think the engineering is mind boggling? (4, Funny)

zmollusc (763634) | more than 5 years ago | (#26049715)

Your mind will be hyperboggled by the amount of paperwork, business trips and expense account lunches the project will generate. The engineering will look like chump change.

Re:Scary stuff (1)

Grishnakh (216268) | more than 5 years ago | (#26049721)

The engineering that was required for the Apollo missions was mind-boggling too, especially when you consider they were using computers back then less powerful than a typical scientific calculator, and didn't have much of our advanced materials science. Regardless, they managed to send people to the Moon many times, without any loss of life, and only one incident (13) which didn't result in any casualties.

You forgot Apollo 1 (2, Informative)

name_already_taken (540581) | more than 5 years ago | (#26049837)

From Wikipedia:

The first failure resulted in the deaths of three astronauts, Gus Grissom, Ed White and Roger Chaffee, in the Apollo 1 launchpad fire.

Re:You forgot Apollo 1 (1)

Grishnakh (216268) | more than 5 years ago | (#26049933)

Ok, so I missed Apollo 1, but that wasn't even a real in-progress mission; they were just doing tests on the launchpad, and weren't ready for an actual launch. After that tragedy, they not only avoided any future incidents during testing, they launched the rockets, traveled to the Moon, and (with the exception of Apollo 13 which skipped the Moon landing) landed there, took off again, and came back home safely.

Re:You forgot Apollo 1 (5, Funny)

Rayban (13436) | more than 5 years ago | (#26049973)

Apollo 1 doesn't count, as NASA declared a mulligan.

Re:Scary stuff (4, Informative)

MeanMF (631837) | more than 5 years ago | (#26049849)

The families of Ed White, Gus Grissom, and Roger Chaffee will no doubt be thrilled to learn that their loved ones are still alive!

Re:Scary stuff (1)

Mr. Slippery (47854) | more than 5 years ago | (#26049869)

Regardless, they managed to send people to the Moon many times, without any loss of life

Would that it were so. [wikipedia.org]

Re:Scary stuff (1)

theaveng (1243528) | more than 5 years ago | (#26049879)

There was loss of life (on the ground). And the Russians sent several cosmonauts into deep space (they missed the moon).

Re:Scary stuff (0)

Anonymous Coward | more than 5 years ago | (#26049979)

The article says that "The bridge opened on an exceptionally fine day...". The article sounded respectable up to that point, but now I know some well-meaning bumbler has probably crapped all over it in other places as well.

Rockets to the rescue? (2, Interesting)

Cyberax (705495) | more than 5 years ago | (#26049439)

Why not compensate for Coriolis force by using rockets?

Coriolis force is tiny, so we won't need a lot of reaction mass.

Probably, it can be used together with multiple loads choreography for greater effect.

Re:Rockets to the rescue? (1)

gEvil (beta) (945888) | more than 5 years ago | (#26049549)

Why not compensate for Coriolis force by using rockets?

I see you made it through two sentences in the summary. How about trying to read the third? "All of this would likely make it necessary to add thrusters, which would consume fuel and negate the benefits of the concept."

Re:Rockets to the rescue? (0)

Anonymous Coward | more than 5 years ago | (#26049633)

And the fourth:
"Alternatively, careful choreography of multiple loads might ease the instability, again with unknown but negative economic impacts."

Re:Rockets to the rescue? (1)

Cyberax (705495) | more than 5 years ago | (#26049723)

There's a difference - Coriolis-negating thrusters need not to have high power. We can use small effective ion engines with high ISP. They can't be used for launching rockets from the Earth.

It might be possible to save more general capacity by using small thrusters. I'm trying to calculate it right now.

Re:Rockets to the rescue? (2, Funny)

Rayban (13436) | more than 5 years ago | (#26049993)

Easy fix:

Build the elevator in the Florida everglades and use mosquito carcasses as reaction mass.

I call bullshit! (2, Informative)

girlintraining (1395911) | more than 5 years ago | (#26049459)

The coriolis effect is not a real force. It's an illusionary effect that happens when you have a moving point of reference. As to solar winds and stuff; can you be a little less vague. Let's say for a 10 meter thick cord, white color, how much force would be imparted on the cable over its length? Is the concept currently economical? No, and that's hardly news. Is it unstable and unworkable? Well... if you're pinning your conclusions something that doesn't actually exist to answer that, I think you might have a problem.

Re:I call bullshit! (5, Funny)

Yetihehe (971185) | more than 5 years ago | (#26049569)

The coriolis effect is not a real force. It's an illusionary effect that happens when you have a moving point of reference.

Obligatory xkcd reference: http://xkcd.org/123/ [xkcd.org]

Re:I call bullshit! (4, Informative)

khendron (225184) | more than 5 years ago | (#26049645)

You are right, but you are wrong. The Coriolis effect is very real, but it is not force in the strict sense.

The gist of the point in the article is that as a payload is moved up the elevator, it must be accelerated to the side, since the upper portions of the elevator are moving circumferentially faster than the lower portions. The force required to accelerate the payload must come from the elevator itself, causing small displacement of the elevator. The use of the term "Coriolis effect" is not strictly wrong, though it is somewhat sloppy.

Re:I call bullshit! (1)

Grishnakh (216268) | more than 5 years ago | (#26049805)

It doesn't really matter if it's a "real" force or not, the effect exists.

If you're sitting at your desk, and someone asks if you're moving, what's your answer, yes or no? If you say no, they'll agree with you, but you'll be wrong, because in reality you're moving as the Earth's surface spins in orbit, and you're moving even more since the Earth is orbiting the Sun, and then there's movement from the solar system moving through the galaxy. But if you bring this up in conversation, people will just think you're annoying, because those motions aren't relevant to the conversation, which deals with a small frame of reference, namely the patch of ground you're sitting on at the moment.

So of course the Coriolis effect is not a "real" force, just like centrifugal force, but that doesn't mean you can neglect its effect on you.

I call bullshit! (1)

2short (466733) | more than 5 years ago | (#26049867)

"The coriolis effect is not a real force."

You are correct only in a narrow technical sense that you clearly do not actually understand. The difference between that and being wrong is a bit philosophical for me.

The coriolis effect is not a "force" in the clasical Newtonian definition. The coriolis effect is a real effect, that will cause real problems for anyone trying to build a real space elevator.

Bah (2, Funny)

Verteiron (224042) | more than 5 years ago | (#26049485)

No one said it would be easy.

Re:Bah (3, Insightful)

Cadallin (863437) | more than 5 years ago | (#26049803)

Damn Straight! This kind of instability is something that has been found and defeated many times before, particularly in Aerospace.

The Rocketdyne F-1 engines on the first stage of the Saturn V had a similar problem early in development. They had a nasty tendency to ring like a bell until they disintegrated (being very loose with this description for the sake of illustration). And they fixed it. The end design was incredibly stable and self damping. With little more than pluck, slide rules, and raw engineering talent. Hell, the entire computer facilities available to NASA at the time (late '50's to early '60's) were less than are available on any engineers desk today.

Solving supersonic flight was another issue of instability. The planes had a tendency to shake themselves apart. We solved that one with essentially no computer help at all (late 1940's).

I have confidence that this problem is solvable. It may not be easy, and may take some genius, but it is solvable.

Fixed thrusters rockets (2, Interesting)

KlaymenDK (713149) | more than 5 years ago | (#26049487)

Nobody said this would be easy (quite the opposite), and nobody is claiming we're even close to being "there" yet. But is the space elevator dead? No. Just still working out the kinks. Look, have you any idea of the number of launches required to prepare, by tiny increments, for the eventual (and still debated, snicker) moon landing? We'll get there, eventually.

Even with thrusters, it's bound to be a better long-term solution than rockets. Especially using ion drives, you could hard-wire the fuel supply from down below, so to speak, and so not need to haul that mass, too.

Re:Fixed thrusters rockets (5, Informative)

MadCow42 (243108) | more than 5 years ago | (#26049585)

Ion drives need physical fuel as well as power... they just are a lot more efficient than traditional chemical-reaction drives. This is because they accelereate the fuel to near-lightspeed, maximizing the reactionary force per kg of fuel. (force is a combination of the mass expelled and the speed of which it is expelled... the faster the exhaust, the higher energy per kg of exhaust).

So, you'd still have to haul up fuel, just not as much as with chemical rockets.

MadCow.

Re:Fixed thrusters rockets (0)

Anonymous Coward | more than 5 years ago | (#26049701)

Ion drives need physical fuel as well as power...

So, you'd still have to haul up fuel, just not as much as with chemical rockets.

MadCow.

Yeah, I know.

My point was more that, unlike with rockets, you could deliver the fuel in steady stream (elevated by solar-driven pumps, near-asphyxiated climbing space donkeys, or whatever). Which I suppose, in the long run, *has* to be better than strapping a rocket to a rocket to bring the fuel for the rocket for the fuel for the rocket! ;-)

Re:Fixed thrusters rockets (1)

QuantumRiff (120817) | more than 5 years ago | (#26049821)

My understanding is that Ion drives also need a ton of time, as their acceleration is like a giant curve. It would not be suitable for countering things in anywhere near real time.

IE, a probe might take a month to get to the moon, but only 2 months to get to mars, etc.. (I know, my numbers are way, way off)

Re:Fixed thrusters rockets (1)

khallow (566160) | more than 5 years ago | (#26049913)

Ion drives are limited by a combination of available power and specific impulse (thrust to propellant mass efficiency, if you will). If you want very efficient thrust and have extremely limited resource for power, you're stuck with the current very small accelerations. However, it is possible that these thrusters may have access to enough power to do credible real time adjustments and still maintain the specific impulse/high efficiency. Or the thrusters may go with somewhat lower (but still much better than chemical rockets) specific impulse.

Re:Fixed thrusters rockets (1)

Cyberax (705495) | more than 5 years ago | (#26049941)

No. You're thinking about the distance vs. time curve.

That's because ion drives create a very small force, which gives only a very small acceleration.

But Coriolis force itself is not large, so ion drives might have just enough thrust.

Re:Fixed thrusters rockets (0)

Anonymous Coward | more than 5 years ago | (#26049985)

Technically you'd have to haul up the propellant, where as the "fuel" would be the electric power used to accelerate the propellant. Posting as AC for being overly picky.

Re:Fixed thrusters > rockets (0)

Anonymous Coward | more than 5 years ago | (#26049593)

Great. That heading was supposed to have been "Fixed thrusters > rockets". Hm.

It took how many scientists to figure this out? (0)

Anonymous Coward | more than 5 years ago | (#26049507)

In addition to coreolis effects and solar wind, simple atmospheric turbulence would pose significant problems with such a massive structure.

Examine the problems associated with the construction of skyscrapers. A cable ascending out of our atmosphere would have tremendous torsion stress.

Not to mention the absurd logistical costs involved in trying to get the cable taught in the first place. Before the orbital tether is entered into geosynchronous orbit, it would be subject to gravitational compressive forces as well. Attempting to unspool form orbit would energize the holy shit out of the cable, as it was drug through the atmosphere.

An orbital elevator is a novel idea, but it is best left in the realm of science fiction.

A solution to coriolis force (1, Insightful)

Anonymous Coward | more than 5 years ago | (#26049535)

Place the elevator on the North Pole.
If that doesn't work, we can always use the South Pole.

Re:A solution to coriolis force (3, Informative)

hidden (135234) | more than 5 years ago | (#26049591)

if the top of the elevator isn't in geo-synchronous orbit, the elevator has to be a free-standing structure. You can only put stuff in geo-synch on the equator...

Good luck with that!

Re:A solution to coriolis force (1)

mbone (558574) | more than 5 years ago | (#26049725)

Not necessarily. You could place a big enough solar sail at the far end of the elevator arm to put the whole thing in tension, which would make it stable. That may be the only way to have a space elevator for Venus.

Re:A solution to coriolis force (1)

Sulihin (612608) | more than 5 years ago | (#26049751)

http://en.wikipedia.org/wiki/Space_elevator [wikipedia.org] might be a good starting point for you to join the discussion.

Re:A solution to coriolis force (1)

Sulihin (612608) | more than 5 years ago | (#26049809)

Curse those hidden parent posts cuasing lack of context. Disregard.

Re:A solution to coriolis force (0)

Anonymous Coward | more than 5 years ago | (#26049855)

It looks like the article agrees with GP. Space elevators would be at the equator.

ACC already covered this... (3, Informative)

Anonymous Coward | more than 5 years ago | (#26049553)

...,kind of, sort of, in Fountains of Paradise.

In that novel he proposed timing the departures of loads for a space elevator on Mars. Not to damp oscillations, in this case, but to cause them. By timing the oscillations correctly, the elevator would oscillate out of the way of the moon Phobos, which orbits lower than the Martian geosynchronous orbit.

Shaky? (3, Funny)

Gr8Apes (679165) | more than 5 years ago | (#26049557)

Yep, anything 24K+ miles long and thin as a wire and zipping through the upper reaches of the atmosphere would probably be "shaky"....

Just jump. (5, Funny)

skgrey (1412883) | more than 5 years ago | (#26049565)

If all goes to hell, just jump in the elevator right before it hits the ground. Problem solved.

Re:Just jump. (1)

mazarin5 (309432) | more than 5 years ago | (#26049743)

If all goes to hell, just jump in the elevator right before it hits the ground. Problem solved.

Don't be ridiculous. It's obvious that you would want to jump out of the elevator at the last second.

Re:Just jump. (1)

dzfoo (772245) | more than 5 years ago | (#26049961)

No, he meant jump up from within the elevator.

Whoosh!

          -dZ.

there goes another dumb jet pack idea (5, Interesting)

magsk (1316183) | more than 5 years ago | (#26049575)

When it came down to it the space elevator though nice, is a dumb idea. Like the jet pack. Think if the resources needed to defend it from terrorists, or maintenance costs. Seemed also like a put all your eggs in one basket as well I mean we would be much better off to just improve our propulsion ability. Personally i like a rocket powered mag-lev launch vehicle, that would travel down a rail that ends up pointing to the sky.

Re:there goes another dumb jet pack idea (3, Informative)

TheMeuge (645043) | more than 5 years ago | (#26049733)

At 2G the entire way, that rail would have to be 1600km long, and would have to rise >20km into the atmosphere to prevent annihilation by friction.

Even at 4G, the track would have to be 400km long.

Frankly, I am not sure that this project would be any more realistic.

Re:there goes another dumb jet pack idea (2, Insightful)

moderatorrater (1095745) | more than 5 years ago | (#26049823)

Just the opposite, actually. The jet pack is closer to what we're doing with space right now, which is strapping huge rockets on a much smaller payload. The space elevator would allow us to use whatever energy source we want to use to get the payload into space (still a significant amount of energy). In addition, it would provide a possible electrical line for electricity to go from space to the earth.

Arguing about protecting it from terrorists is, in a word, retarded. There's no reason that it will be any harder to defend than Cape Canaveral; in fact, it'll probably be easier if it's in the middle of the ocean.

Finally, once we've got one space elevator in place, putting more up will be much easier because of the refined design and the greater ability to send things to space.

Re:there goes another dumb jet pack idea (1)

SanityInAnarchy (655584) | more than 5 years ago | (#26050003)

Like the jet pack.

The jet pack that someone has actually built?

Think if the resources needed to defend it from terrorists

Terrorists are an exaggerated threat in any case, but let's think. How is this harder than, say, defending a plane from terrorists? Or defending a building from terrorists who have planes?

or maintenance costs.

Would it cost more to maintain than the shuttle? Do you actually know how much it would cost, or are you just wanting to feel more-skeptical-than-thou?

So, can we get back to the antigravity reseach now (0)

AeiwiMaster (20560) | more than 5 years ago | (#26049625)

A good place to start is to read the book
They All Told the Truth: The Antigravity Papers
by Richard P. Crandall

http://www.amazon.com/They-All-Told-Truth-Antigravity/dp/1553957237 [amazon.com]

Notice that the typesetting on this book is very bad, so if that is all you look at you will be very disappointed.

But this book will teach you how to build a anti-gravity generator and will provide you with
the theoretical foundation for understanding anti gravity.

But to understand the theory you should know about
general relativity and quaternionic electromagnetism.
http://www.scribd.com/doc/4445/quaternionic-electrodynamics [scribd.com]

Re:So, can we get back to the antigravity reseach (1)

ColdWetDog (752185) | more than 5 years ago | (#26049853)

I, myself, subscribe to Gene Ray's [timecube.com] view of the world. Works for me.

Having read the article... (5, Informative)

ceoyoyo (59147) | more than 5 years ago | (#26049635)

Their big objection seems to be not that the forces on the elevator are unmanageable but that oscillation could lead to payloads being released into orbits that are "10 km" too high or too low, or that the oscillation could put the elevator in the path of a satellite. Correcting that would require thrusters.

For the first, surely you could simply time your release with the oscillation, to get into the orbit you want. Even if you couldn't, the space elevator would be good for putting things in geosynchronous or interplanetary transfer orbits. The cost of a bit of propellant to correct a +- 10 km error is pretty minor compared to getting into one of those orbits in the first place.

For the second, thrusters to purposely oscillate the cable to allow it to dodge out of harms way are a pretty standard part of any space elevator proposal. That is, the ability to move the cable a little is a desired, even necessary part of its design.

Re:Having read the article... (0)

Anonymous Coward | more than 5 years ago | (#26049719)

However, there is still the issue of harmonic resonation of the cable caused from atmospheric turbulence lower down.

The taught cable would be a bit like a violin string. It WOULD resonate from being struck. Being continually struck by unending air currents could lead to harmonics induced structural failure, much like "Galloping Gurdy."

A tether can only be secured at one end, and thus, harmonic dampening is not possible.

Re:Having read the article... (2, Interesting)

Cormacus (976625) | more than 5 years ago | (#26049771)

I agree with your assessment of their stated problem, but I'd like to know where they got that idea in the first place. Launching directly from the space elevator has never (in my understanding) been part of the concept. Instead, cargo (+ people) is offloaded at a station and is moved into a shuttle. The shuttle detaches from the station and then applies a thrust vector to move away.

The point of a space elevator is not to launch items directly into space, but to create a more efficient, higher through-put method of getting people and equipment out of the Earth's gravity well.

No fly zone (2, Interesting)

Adrian Lopez (2615) | more than 5 years ago | (#26049653)

I wonder how large a no-fly zone would be required for a space elevator? After all, just imagine the damage it might cause if the thing were to collapse and land over a populated area.

Re:No fly zone (1)

tripmine (1160123) | more than 5 years ago | (#26049757)

Halo 3 style [wikia.com]

Re:No fly zone (2, Insightful)

moderatorrater (1095745) | more than 5 years ago | (#26049881)

just imagine the damage it might cause if the thing were to collapse and land over a populated area.

Depends on how you build it. If you're using carbon nano-tubes, then not much at all. Basically, much of it would go into space, a lot would get burned up on the way down, and the rest would be light enough that it's be more like a bunch of paper floating to the ground instead of a giant steel structure falling down. If it's heavy enough to cause damage, it's probably not going to be a good material to make the elevator out of in the first place.

No Big Deal (1)

Plekto (1018050) | more than 5 years ago | (#26049683)

All they have to do is redesign the car/platform/etc a little bit to compensate.

And a small rocket would be a very small rocket, actually. we're talking hardly any more powerful than a few model rocket engines to counteract these forces.(think small thrusters or a tiny jet engine)

It's doable. Just not as easily as we once thought.

Not impressed (0)

mbone (558574) | more than 5 years ago | (#26049691)

By the farking article.

There may be some real stuff behind this, but it sure doesn't read like it. You might go into orbit, 40,000 km from the Earth, off by a few dozen km ! And that might take fuel to fix !

I would guess that whoever wrote that doesn't know much about geostationary satellite station keeping. And, of course, if you have an elevator, fuel will be cheap to lift too.

It is clear that a space elevator arm will be a dynamic structure. And the schedulers of traffic will have to take the conservation of angular momentum (the way to look at the Coriolis force in a non-rotating reference frame) into account. But just because the arm moves around doesn't mean it can't function.

Re:Not impressed (1)

maxume (22995) | more than 5 years ago | (#26049953)

I would think that the stuff in the article would be trivial compared to the tensile strength necessary for the cable to be able to hold itself up. After that, I would be worried about the atmosphere pushing on it (again, it doesn't seem like this would be a big deal if the cable were strong enough to support itself).

The internet makes playing "telephone" boring (5, Informative)

roystgnr (4015) | more than 5 years ago | (#26049711)

The "Space Elevators are unstable! The concept is doomed!" Slashdot summary would have been much more thrilling if there wasn't a link to the "Space Elevators are tricky! There might still need to be tiny final orbital adjustments!" New Scientist article, and even that would have been more exciting than the "Space Elevator dynamics is modeled by these stable but undamped equations! Sending multiple payloads up in the right phase causes the minor Coriolis-induced wobbles to cancel out!" Acta Astronautica article.

You people with your damn hyperlinks are ruining journalism. It's getting so a guy can't even wait breathlessly for the News At 11 anymore to find out what common household product might be Killing Our Children.

Re:The internet makes playing "telephone" boring (2, Funny)

Chris Burke (6130) | more than 5 years ago | (#26049795)

You people with your damn hyperlinks are ruining journalism. It's getting so a guy can't even wait breathlessly for the News At 11 anymore to find out what common household product might be Killing Our Children.

I know what you mean. Turns out it was steak knives. Anti-climactic for sure.

Elevator won't work? (2, Funny)

Anonymous Coward | more than 5 years ago | (#26049737)

OK... what if we built this large wooden ladder...

These seem like the least of the problems (2, Informative)

jandrese (485) | more than 5 years ago | (#26049755)

Of all of the technical and political roadblocks to building a space elevator, both of these seem quite minor in comparison. This is kind of like saying "I was going to bench press this Hummer H2, but since you added a fuzzy steering wheel cover it's going to be completely impossible now."

Of course (3, Funny)

Strange Ranger (454494) | more than 5 years ago | (#26049761)

This idea has it's ups and downs.

Apply thrust as you move up... (0)

Anonymous Coward | more than 5 years ago | (#26049839)

... if you apply horizontal thrust as you move upwards, you can exactly compensate for the coriolis force. Since you know the vehicle weight, and the distance you move upwards, you know exactly how much thrust to apply.

Why not... (0)

Anonymous Coward | more than 5 years ago | (#26049891)

Just go up from the pole, instead from the equator?

Climbers are stupid. (1, Insightful)

tmosley (996283) | more than 5 years ago | (#26049919)

Honestly, why use climbers? Do we use climbers to go up and down regular elevators? No, because that would be stupid. We have cables attached to the tops of cars, and a counterweight. We should do the same thing with the space elevator. That has the added advantage of keeping all of the moving parts up on the space station (or on the ground, depending on your design), which prevents breakdowns in areas inaccessible repair crews.

Hell, you could probably get away with simply having a big rock somewhere past geostationary orbit tethered to a (very heavy) base station, and simply roll the whole array in and out, with the payload fixed to the ribbon. It would be kept straight by the centripetal force, despite any other forces acting on it. If you HAD to keep it PERFECTLY straight all the time, you could put boosters on the counterweight, but that hardly seems necessary.

Slashdot: News From Tabloids Stuff That DOESNT (0)

Anonymous Coward | more than 5 years ago | (#26049921)

matter.

Obviously, Slashdot doesn't want to tell its readers that
there are NO IT jobs.

I hope this helps.

Thanks for nothing.

PatRIOTically,
Kilgore Trout [exiledonline.com]

Why hasn't this problem come up sooner...? (3, Interesting)

w0mprat (1317953) | more than 5 years ago | (#26049957)

Corrolis force problems were one of the first things I thought of when I first heard about the space elevator, but I'd never seen the issue brought up.

It's a given that a elevator would be tethered at the equator, thus will be traveling at 1600kph, the velocity of geosynchronous orbit is what, 11000kph? Anything climbing from the bottom up will be accelerated to that as it ascends. So the question is how the hell do you mitigate this without literally bending the thing out of shape - burning fuel is silly It's not a trivial velocity, it's 40% of what would put you into LEO orbit anyway!

Despite this, I don't think this is a showstopper, remember Arthur C Clarke told is it will be built...

Anonymous Coward (0)

Anonymous Coward | more than 5 years ago | (#26049963)

surely, the development of any space elevator would have more than its fair share of,...er..., ups and downs... (sorry)

air tube (2, Interesting)

shitbrain (996547) | more than 5 years ago | (#26049991)

Why not went air thorugh the tube to as a correction mechanism? No need for rocket fuel in a structure reaching up from the ground, just blow air. Hell, we even do need air up there for life support and other things. Air supply could even be used to produce rocket fuel in space.

Effect on Earth rotation? (1)

2gravey (959785) | more than 5 years ago | (#26050011)

Am I the only one who thinks that a space elevator based on a tethered weight in space(if it actually worked) would drastically alter the Earth's rotation?
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