Slashdot Mirror
Space Elevator Update
TheMadReaper writes "The 2005 edition of the Space Exploration Conference in Albuquerque, NM came to a conclusion earlier this week. A large fraction of the conference was devoted to the Space Elevator. Surprisingly, there hasn't been much news coverage of this conference, perhaps because it doesn't have Space Elevator in its name. The most interesting fact I got from the conference is that money is really starting to exist in the space elevator world mainly thanks to the work of Dr. Bradley Edwards at ISR and at Carbon Designs, Inc. The strong nanotube talk was also more promising than last year."
I guess if enough money is pumped into this it will finally get off the ground sooner rather than later.
No, wait. We don't want it to get off the ground do we?
Would be cool to see this in our lifetimes.
So much to do, so little bandwidth.
--
Try Mozilla
Update: Still on ground floor.
What if you happen to get stuck at some weird altitude out of reach of help? If you're stuck high and above, you might have the space shuttle come and rescue you. If you're stuck low, you might have a helicopter come and help you. At other altitudes, you're pretty much fucked.
In the interest of promoting more enlightened discussion, a lot of good information concerning space elevators can be found here.
____
~ |rip/\/\aster /\/\onkey
The music in normal elevators is already driving me crazy...
Imagine going upwards for hundred sof miles while having to listen to Julio Iglesias' songs, performed by some guy on a synthesizer. NOOOOOO!
Jeez, try to imagine the havoc if the cable comes loose from its orbital anchor. Thousands of miles of pure splat! Whatever safeguards the builders promise, the NIMBY factor is so huge, it has no chance of happening.
In a post 9/11 world, space elevators are WMD's
...err wait, I guess in any world there would be mass destruction if one fell.
My bad.
Would somebody explain to me, what happens to this carbon nanotube when lightning strikes it and why it won't "cook" the thing?
That I think this device would be great for the ultimate atomic wedgie???
Well, if the cable is based on land, the're going to have to put it in either Africa or the Amazon, i.e. the third world. I'm sure the residents of these places would enjoy the economic oppurtunities.
A "space elevator" is totally unlike anything ever done before. As I read in a Slashdot post some years ago (referring to nanotubes, the favorite among space-elevator aficionados), "When somebody has built a 40,000 millimeter bridge across a creek on campus, then we can start to talk about a 40,000 kilometer bridge straight up".
The fact that we have not yet achieved one millionth of the task (and in fact fall several orders of magnitude for that) suggests to me that, much as I would love to see a space elevator in place, the job today belongs to materials scientists who are looking at shorter-term goals.
An eye to the future is great, but experimenting on climbers is like practicing the high jump: if you're jumping twice as high today as last year, I wouldn't start drawing any exponential curves. The ribbon is the really, really hard part, and we're currently so far away from it that research energy is better spent elsewhere for a while. 2010 is way, way too close.
Maybe with enough motivation we could get that 40,000 mm bridge by 2010, but somehow I doubt you're going to raise $10 million to build a bridge. The X-prize shot somebody into space for that kind of money.
I'm prepared to be wrong. I'm a software developer, and I've learned that as a consultant I can say, "Your project is doomed" with 95% accuracy before I've even heard your name. Being a nay-sayer is easy. But the real trick is being able to spot the 5% that will actually be profitable, and there are a lot of projects more immediately deserving of this kind of money.
Operating costs estimated at 100 kg/lb, ready in 15 years at most optimistic.
Kilograms per pound? What is that?
Now I know, anything is possible with technology. Science fiction of the 50's is science reality of today. But let's stop the conversation of "is it possible" with that. The question of if the Space Elevator CAN be made seems irrelevant to me.
When it comes to this whole Space Elevator business, the relevant question in my opinion is "would we WANT to make something like that?" To me, it's a novelty idea and nothing more. If people want to get serious about space travel, we need to invest more into the building of in-orbit construction yards (IMHO). Once we get the infrastructure in space to produce the vehicles, we'll find that occasional trips to the "Drydock" from Earth to supply it with raw materials will be far more practical than some 21,700+ mile long elevator reaching into the sky.
-Vendal Thornheart
Even if it breaks down, you'd still have a stairway to heaven.
the LARGEST single stand in the Universe! Wait, maybe not. This is larger By far, they 2nd LARGEST strand in the universe!
How about creating a simulator for a space elevator? It would be great to mess around with values to see how possible this thing really is. The closest thing to a simulator I've seen is this but its sadly lacking.
http://spaceelevator.sourceforge.net, anyone?
Ground floor perfumery,
stationery and leather goods,
wigs and haberdashery
kitchenware and food...going up
First floor telephones,
gents ready-made suits,
shirts, socks, ties, hats,
underwear and shoes...going up
Second floor carpets,
travel goods and bedding,
material, soft furnishings,
restaurant and teas. Going down!
Everyone who is interested in space elevators may also be interested in the book Rainbow Mars by Larry Niven, which features a sort of organic space elevator; a tree that grows from a planet far into space. Nice story.
It will. Apparently lightning is the worst threat to these things....a limitation that will need to be overcome if this project is actually going to happen.
____
~ |rip/\/\aster /\/\onkey
I've read quite a few posts about "riding the space elevator." I'm under the impression (and yes, I RTFA) that the space elevator would be solely used to send cargo up to space. Astronauts would still get up to the ISS by conventional means, and then the space elevator would just be a cheap[er] way to get supplies up to them without worrying about sending up rockets. Unless I missed something, humans wouldn't be travelling on this space elevator at all.
As long as youre wearing a spacesuit theres no reason why you couldn't base jump off to escape... ...Or for the fainter of heart - atmospheric bungee jumping!
Man what a rush.
------
beware he who would deny you access to information, for in his mind he dreams himself your master
My first thought upon hearing of the space elevator was "what happens if it breaks?" Who cares if science suggests it won't be a catastrophe? Most terrorists do not exactly subscribe to the latest scientific journals. A lightbulb will go off in one of their dim minds and they'll try to ram a plane into the cable, or the tower, or whatever, hoping it will somehow dislodge the asteroid from orbit and send it crashing into Washington D.C. or something. It'd make a great scifi action movie, wouldn't it?
And don't forget it'd be a tremendous icon of Western achievement. You'd better believe everyone in the US, or whatever country eventually builds one, would be proud as hell of it. The media would be going on and on about how it'll usher in a new age for mankind, and so on, and so forth. If terrorists could somehow take it out, wouldn't that have tremendous psychological value? Remember that they chose the World Trade Center and Pentagon to strike at us, two (or three) buildings that symbolized, to them, everything that's wrong with the US. Wouldn't a tower that reaches into the heavens (hello, Tower of Babel?) symbolize that even more?
It's quite reasonable to take terrorism into consideration when designing a structure. While I may be obsessing over the whole "living in fear" deal, its definitely something that needs to be considered.
Andrew Price's list of alternative names:
space bridge space way space rail
In the effort to increase public comprehension of this concept, I offer up "space yo-yo".
...interact with the earth's magnetic field and produce power? If it can produce enough to power the elevator, that would be an elegant solution to one problem.
Forgive my ignorance, MEMS and Nanotech has fascinated me for a while, but I don't know enough of the math behind them to tell if this is true. My grandfather, rest his soul, once told me of something called the Sailor's Rope Rule, which effectively says that the weight a rope can support is diminished by its length. Thus, a 500 lb. rope might support 500 lbs when there's less than a foot or so in length between the pully and the weight, but might only support 250 lbs when there is a good 100 ft. or so... The actual support degradation of course depends upon the width of the rope and the material the rope is made of.
So what I'm wondering is, does the same apply to the weight supported by nanotubes and other molecular chains. I figure it has to be less of a degradation due to the ionic bonds involved, but it would seem to me that, unless some Quantum rule is involved dealing with extremely small-scale weight supporting chains, that they might never overcome this problem due to the sheer thinness of the tubes, chains, etc. It might be extremely strong material, but if it's width is only a few atoms wide, wouldn't this material be, at least in single lengths, more or less useless by the time it got to a respectable length? This is, of course, excluding bundles, which make the most sense, I'm really just curious if the same rule applies to nanotubes as applies to rope.
(In a pinch, some might call it the Nanobahn. Once some drunken shuttle pilot hits it and causes it to fall and wrap around the planet, it will be known as the World Wide Wire.)
Don't blame Durga. I voted for Centauri.
I recall Arthur Clarke pitching the initial concept for a Space Elevator some time back, and revisited the idea in 3001 : The Final Odyssey - in which he depicted planet Earth having a fully functional ( four actually ) space elevator system; which facilitated a subset of human civilisation living in low earth orbits in reduced gravity - thus invoking presumed benefits of doing so.
Anywho. He spoke a couple years ago, subsequent to 3001's release on how at the time of writing, such a feat was nigh on impossible at this stage - as the materials to construct the 'elevator' were yet to be developed. Until now. The carbon molecule Buckminsterfullerene ( C60 ), also known as 'Fullerene', is supposedly strong enough to actually make such a concept a reality - which is in part the reason the space elevator was hurled back into the limelight of late.
I think its a fascinating idea - which until we develop propulsion systems beyond the primative scope of the 1,000+ year old firecracker concept, certainly seems a more elegant way for the species to venture into Space more regulary. Or, at the very least, be the catalyst for what could perhaps become the initial stepping stones to establishing a permanent presence in space which will hopefully later lead to space initiated launches.
How long's a piece of string?
Something I never heared anybody about: Where does the kinetic energy come from that the cargo gains when ascending into orbit? Somehow the cargo needs to gain a huge amount of kinetic energy, because the top of the elevator moves several km/s faster then the bottom. If nothing compensates for this energy, the counter weight would gradually slow down and deorbit, so there must be some kind of propulsion in the counterweight, pushing it prograde whenever cargo ascends and pushing retrograde when cargo descends. Anybody got more info on this?
Such as system needs to have in place some sort of failsafe or redunancy so that such disasters, be they intended, or the result of Teamsters' laziness, do not destroy it all. A (non-Beowulf) cluster of several nano-lines? A sort of web of them so that you could smash through several lines and the thing would still hold?
Don't blame Durga. I voted for Centauri.
Before this gets too far, somebody should call NORAD and ask them how many of the 2500+ satellites and other odd bits of junk traveling at 17551mph (LEO) cross the Equator (ascending and descending nodes) and might present a collision hazard. I could be wrong, but shouldn't the answer should be "Almost all of them."
This reminds me of the asteroid/comet problem, the probability of a significant impact might be low, but it only takes one.
If we don't build one sooner with carbon nanotubes or other conventional means, we will definitely be able to build them once we have molecular nanotechnology (MNT), which there are compelling reasons to believe we will *almost certainly* have within 20 years.
MNT is going to change everything. All you geeks out there better start thinking about it, because once MNT is available, somebody's got to design the products we will manufacture with it--and that somebody is going to be today's generation of geeks. If humanity survives the transition, it will literally be us building the future. Think of the possibilities!
A warning label you won't see on the space elevator:
In emergency, USE STAIRS.
There are some years since I first heared about this space elevator project, but untill now there has been mostly just smalltalk, the fact that the project has some money and the nanotube technology are evolving is a promissing sign, maybe some day I dont need to be stuck at the ground floor..
Bits of News Giving you the latest bits.
Aside from which, manufacturing spacecraft is perhaps one of the most industrially complex things we do. Trying to replicate that in a place more remote, and with far more environmental challenges than, say, Antarctica, would have gargantuan capital costs dwarfing the elevator. In fact, the only way you could probably get the infrastructure up there would be an elevator or something equivalently cheap.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
This is a space elevator we are talking about. Might as well have the sign say "In case of emergency, use stars."
Don't blame Durga. I voted for Centauri.
That's no fun unless you have a snowboard too, man! Cowabunga!
Don't blame Durga. I voted for Centauri.
They have them on Star Trek already.
Don't say these things! You float an idea for a bad movie often enough, and the stupid thing will eventually get made!
I wonder when the space escalator coming out?
THAT'S got to be a long ride.
Over here, one of the major parties lost an election on the basis of a plan to build a canal more than 3,000km long, at a cost of at least $A5 billion, to bring water from the Kimberlies to Perth. It didn't matter to them that it would take less energy to pump sea water against a membrane to get fresh water, and that the membrane would be cheaper to maintain than 3,000km of canal. They had a vision of this connection directly to the water, and that blurred their view of reality.
The space elevator is another one of those connections. It's a Victorian era engineering dream, a vertical railway to the planets, and while it's a beautiful mind picture, it's as much of a dead end as those cast-iron steam trains.
The key reasons why it will (deservedly) fail;
There are also safety and technical reasons why the elevator is not a good idea, and I'm sure others will explore them. It's a shame, because it is a lovely concept, but it's better to keep it as a beautiful fiction than to divert energy, money and other resources from projects with a chance of success.
Let it go.
"I've got more toys than Teruhisa Kitahara."
Don't worry, once it's struck by lightning once it'll never happen again. So don't hop on the thing until lightning hits it.
They will have to embed super conductors in the nanotubes. But the problem of collisions will still exist. The elevator threads will have to be self repairing and maintaining.
A space elevator, or beanstalk, has two big problems for construction: 1) materials that are strong enough, and 2) getting it to stay up.
The first we're getting close to being able to handle. The second is just a matter of having a counterweight that balances the 22,500 miles of cable from the equator (more on that later) to the top. Without the counterweight, the ground end drags it down.
That means that we really need to build this sucker from the middle out: extend equal masses out and in (or up and down, if you prefer) from geosynchronous orbit. That's a very expensive proposition. Whether it's cheaper to ship carbon for nanotubes up or go and fetch some carbonaceous asteroids down to our orbit I'll leave as an exercise for the reader.
A poster above was concerned about the terrorist target of something like this. The one consolation in this one is that you can't build it on US or European soil: it needs to be at the equator. At least one SF author (I forget which) posited an elevator whose ground-level terminus was an upside-down Y to two islands straddling the equator some hundreds of miles apart. Not the silliest thing I've ever read, but I'm not sure it makes much sense. Tethering one end down will be tricky enough.
So it won't be Imperialist America that's building it... but that's not to say it won't have protestors. It'll cast a shadow pretty much across the entire planet. It will likely change weather patterns in the region.
It will create the most valuable real estate in the world.
It's going to end up in some place where technology and resources are accessible: Brazil, Equador, Congo, Somalia, The Maldives, Indonesia, Malaysia, or some Pacific Island are all candidates, my money is on a spot just south of Singapore -- there's enough high-tech industrial nations close enough to justify it there. Brazil is my second guess.
And who knows, maybe we'll find Saddam building WMDs up there. (obligatory Funny whoring)
Design for Use, not Construction!
If it does get here in a reasonable amount of time, can it be used to pull high-currents of energy out of the earth's magnetic field by running a wire up and spinning it end-for-end through our field? Think of it as a generator with Earth's magnetic field in space as the magnets.
There was once a cable-link between the space shuttle and a satellite. They were rotating about eachother and the middle of the cable melted due to the inducted electrical energy across the length of the steel cable (get out your intergrals and ti92 to figure out the actual field energy).
Anyone else with thoughts here? -geek
Given all that, I'd imagine that a terrorist would turn their minds to any one of an infinite number of easier, but still spectacular, available targets. How well guarded are your local dams?
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Let's never build anything because the terrorists might blow it up! That'll show 'em!
[ home ]
Can't we just build a really, really, tall lightning rod next to the 62,000 mile space elevator? :)
Understanding is a three edged sword. - Ambassador Kosh Naranek, Babylon 5
I'd love to take a ride with her up a space elevator! I must... become... a rocket scientist at once!
I think you want this,
http://en.wikipedia.org/wiki/Space_elevator
"Due to its enormous length a space elevator cable must be carefully designed to carry its own weight as well as the smaller weight of climbers..."
Quite a bit of good stuff in there. Perhaps Zonk should have linked to it at the start.
Heck, if it could be made into a conductor, that would be cool, because it would allow very thin cables, probably as large as one very thin wire is today, that actually contains hundreds of separate conductors. Think of very thin network cables that can carry an entire 1kb packet in one clock (that's eight thousand wires, plus a few more) in a cable that is no thicker than a modern day Cat-5e.
But honestly, as far as this space elevator is concerned, what exactly is the practical reason that it is discussed so often?
Ground-breaking is right! Mr. Wonka's ingenious solution to base the elevator on a weave of microchocolate fibres is to be applauded. However, once the sun shone on this, the chocolate string melted and the elevator hit like a meteor.
Next time, Mr. Wonka, consider using Oompa-Loompa hair fibers. Or maybe you can beam astronauts into space with that TV ray. Who cares if they come back from their mission 1 inch high?
Don't blame Durga. I voted for Centauri.
Virtualy every sentence in your post is filled with paranoia. The sad thing is, this is COMMON of thinking patterns these days.
We are all going to go someday.. Live your life in fear, but that's not much of a life.. sheesh, start singing that song .. "don't worry .. be happy"... It's acapella after all !.. and maybe turn off the propa.. (I mean news) once in a while.
waiting for ad.doubleclick.net
I find it interesting that they have you take the elevater, just to make you walk down a flight of stairs. I would want to talk to the person that thought up that floor plan. I mean did the even think about handicapped people, I don't think so. Then again they rarely have any customers, I wonder if it has anything to do with that.
Think about it. Such a conference is completely ridiculous. The technology is not there, not to mention the fact that the actual research and implementation of such a device would require hundreds of billions of dollars, if not a number in the trillions, even before getting into zoning issues. The cost of building a SE is too much, and there is currently not enough commercial demand for the concept. It would take at least 20 years before construction would be ready to begin... And what about lighning? Imagine a huge conductive rod in the sky... Let's take a ride! Not to mention the fact that such an object might change earth's rotational velocity! And, btw, no such 'elevator' would use cabling... Now, let's think. Who actually has the resources to pull off such a venture, besides the government? 1.... 2.... 3.... You guessed it! Microsoft. Let's give em even more control over our planet than there already is. People, start thinking before posting such "out of this world" rubbish. I would love the concept, but you really have to consider the downsides of the idea, and put more thought into it before posting it on a site that tens of thousands read a day.
Due to financial difficulties, the light at the end of the tunnel has been turned off.
Is it just me, or does the idea of a space elevator seem more science-fiction than fact, despite the amount of "scientific proof" that it's possible?
As much as I'd like to, I just can't envision a literal space elevator. Sorry.
Real programmers can write assembly code in any language. -- Larry Wall
Apparently some people have this notion of a space elevator as a giant column, which if left unsupported would come crashing down like the Tower of Babel, destroying all in its path. However, the actual designs being considered are more like long ribbons which stretch up into space. The space elevator has to be very strong and very light per unit length, or it would be phsically impossible (ie, we cannot use steel, because it could not support its own weight).
Here is an experiment: take a standard ribbon, about 2m long, and attach it to the ceiling. Now cut the ribbon or otherwise detach it from the ceiling. Stand back! The ribbon will fall like a rock, and may cut right through you if you are in its path.
Wait, actually the ribbon flutters to the ground thanks to our good friend air resistance. This is similar to what would happen if the space elevator fell; the portion outside our atmosphere would gain enough speed to burn up during reentry, and the rest would flutter to the ground (see here).
I wish people would stop with the unfounded fearmongering, but from the moderation here I see that it is much more popular than the more correct postings.
Look the longest Nanotube is about 2 mm. (I've seen them and know the student making them.) Nanotube fibers are made but they are tough to do. The amount of MWNT (the easy stuff!) made in the US is small. There is no way to make a massive amount of the stuff. Certainly not the amount needed for an 'elevator'. Now let's consider the minor factoid that you will have to drop something heavier than you are lifting. (Or at least of similar mass.) I have single word that this space elevator project does not consider - physics
This message was brought to you by "Lack of Sleep."
Actually, since the ribbon will be essentially stationary with respect to the Earth's magnetic field, very little current would be generated in this manner.
____
~ |rip/\/\aster /\/\onkey
I'm an Engineer for an elevator company. We're not one of the big ones you would normally think of, but we've put in thousands of elevators in the Midwest during the 20 years I've been with the company. The number of them that have music playing in them = Zero. I've ridden elevators in many other cities from coast to coast across the US and have yet to discover any that had music playing in them. I'm convinced it's just another urban legend.
We've got elevators that talk to you and tell you what floor they are stopping at and which direction they're going next, but no music. Can any of you point out any buildings that have music playing in their elevators?
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
Something that has puzzled me, but I am sure someone has brought up in scientific discussions, is orbital wobble. Will this cause the earth to wobble during orbit? You can take a 5 pound ball, and spin it on a flat surface and observe it, now try taping a .5 lb weight on a 6 inch string to it, and spin it fast enough to get the weight to fly out horizontaly. I wonder if the earth will have the same effect.
-William
God is everything science has yet to explain.
This is /. and I want to be nice but honestly replying to each and every post that is wrong, mis-informed or stomp-down ignorant is tiring.
These are expounded in greater detail at our FAQ. See http://www.liftport.com/faq.php
Catastrophe. Yes Bad Things can happen. The amount of damage done is less than might be expected.
Terrorism. The thing is less a target than might be expected.
Elevator Music. Puh-lease, this is the 21st century. You can bring your IPod.
Anything else?
Display some adaptability.
Unless...they actually harnessed that great amount of energy in the capacitive effect of a long, conductive ribbon. Then we might have a much more efficient way of powering the elevator.
Because the nanotube technology is so incredibly expensive (about the only thing more expensive is anti-matter) the only reason to use it it when no other material can do the job.
Thus, space elevators.
There are many other industries that will benefit from nanotube technology, but as of now, nanotubes are only required for a space elevator. That's where the funding for the nanotube industry will come from, which is why there are a few groups working on it. Liftport has even been featured on financial websites such as Motley Fool.
fsh
While doing one on earth is well beyond where we are today, doing a luner one is in our grasp today. The materials needed for that are already here. That means within 7 years, we could have our first elevator in action on the moon.
I prefer the "u" in honour as it seems to be missing these days.
http://spaceward.org/
----------------
Have you tried the ICLOD life?
Catastrophe. Yes Bad Things can happen. The amount of damage done is less than might be expected.
IS less? So this has been tested, has it?
I'll tell you what I'd expect. I'd expect if something went wrong and a "load" plummeted to earth from 5km up it would be pretty difficult to predict what sort of damage it would do... There's one of many possible catastrophes we'd like to hear whay you'd expect the damage to be
Terrorism. The thing is less a target than might be expected.
Again, IS less? This fact comes from where? A poll of known terrorists, or off the top of your head?
Yes, I know... people were executed for suggesting that the world wasn't flat, etc etc... but please - if you want a rational discussion on this thing pushing "facts" like these at us is hardly likely to sway any opinion.
How I used to dream of you and your pussy.
Errr, did I say that out loud?
Holy Christ on a cracker are you a total fuckhead!!!
And people who know, like, a 1000 times more about it than you think it's possible some day.
So shut the fuck up, you backward loser, and let the men work on the future.
We haven't made it to step one - so I call bullshit on the $3 per pound. It's just an confidence trick to get funding.
I think this is where the problem comes in. It is not an inexpensive task to construct something from a point in geostationary orbit. All materials would have to be put in an orbit at that point, as well as crew/robots etc for construction. For the cost of construction and operation over the expected life of the space elevator, could we put the same objects in orbit using convential methods cheaper? If so, why bother building the space elevator? I am by no means an expert on the space elevator, but considering the physics of construction, I don't believe it will work out to be cheaper on a per launch basis.
Of course, others' opinions may vary, and I am sure some will have methods to ignore conservation of angular momentum and orbital mechanics to come up with construction techniques that do not require a geostationary orbit starting point. Unfortunately for me, I am not educated enough yet to figure out how to construct a space-elevator without starting at the geostationary orbit. Please enlighten me if you know how to do this.
I used to hang out on their forum a while back. One solution that was proposed was to "maypole" the tether when it enters the atmosphere - i.e., have it split and have a number of anchor points.
Edwards already had discussed several issues: one, the potential site, has almost no thunderstorms. Also, depending on the type of CNTs that you use, many are very resistive, and would not be the easiest route to the ground, but the most difficult. A risk factor, however, would be water streaming down the tether making a more conductive path.
sed "s/SJW.*$/... never mind. I was about to say something stupid, and also, I'm a troglodyte./Ig"
Several places in the article/notes it mentions that public funding for the Space Elevator is unlikely to be forthcoming. I wonder, though, if they've tried pitching it to the government of Japan? They certainly seem to be bullish on the whole space technology thing...
I don't care if it's 90,000 hectares. That lake was not my doing.
like a 150,000 ft tall elevator could withstand basic weather?
I think not. This becoming a feasible option is about as likely as me bouncing a fart off Jupiter and back...
I am amazed at the lack of vision and basic technical knowledge most of the nay-sayers here on Slashdot display.
There is no doubt that it will take major developments in material sciences to make a SE practical. The possibility of breakage and sabotage would also have to be studied and mitigated. But right now, this is the only realistic possibility we have of becoming a space-faring species in the next couple of centuries.
An SE could lifts 10s of millions of tons of cargo into space each year. Once a critical mass of material and industry was in orbit it would be possible to colonize Mars and the Asteroid belt. Interstellar probes could be constructed and sent on their way. Trillions of dollar worth of palladium, silver, gold and platnium could be extracted from metallic asteroids to be used in manufacturing.
Is it risky, sure it is - but no more than crossing the Atlantic in a little wooden boat in the 15th century.
Enron looming, oil beckoning...you haven't really fallen for the mad Arab bullshit have you?
The favored name at the third SE conference was 'Space Bridge'. One of the more legitimate concerns about constructing an SE is ensuring that longitudinal tension waves do not wreak havoc with climbers and/or base stations. This is probably solvable, but needs to be attended to. If we do not then 'Yo-yo' might be all too apt. Andy
Geostationary orbit is a long way up.
But getting there is done routinely. Where do you think your satelite tv feed is send from?
We don't know yet if carbon nanotubes have the strength require to be able to handle their own mass over such a distance - or half it if you have an asteroid keeping station at the other end.
The most promissing designs require a counterweight to be placed at the outer end of the cable. This would be a human construction, not an asteroid. The cable will have to support the weight of itself, plus the weight of the counterweight being tossed around in orbit. Typical values for tensile strengths needed are quoted as being in between the range ~65120 GPa. Carbonanotubes have have had observed breaking strains of ~63Gpa, but in theory they could go as high as 120 GPa. Research in these materials are still in it's infancy, so I think it is safe to assume that it will be possible, within 10 years, to prove the feasability of creating a material with the required properties.
Call back when we have the technology to bridge from Singapore to Mexico City in a single span - we'll be a small fraction of the way there.
And really why do we bother even wasting money of this. The whole concept of building a space elevator is insane and ungodly right?
Please go off and live in your mud hut, with your fellow bible thumping right-wing extremists, and let us scientists get on with building your TVs, Cable-networks, internet, computers, microwave ovens, SUVs, trains, airplanes, ...
...and you thought the 80 second ride to the top of your office building was unbearable long!
Mens et Manus
The next trickiest thing since the apollo 13 mission -- jumping out of the malfunctioning ISS with correct velocity/trajectory as to latch on to the space elevator and shimmy down to earth
Mens et Manus
...it was written in this weird language?
Got time? Spend some of it coding or testing
"I like an escalator, because an escalator can never break. It can only become stairs. You'll never see an 'Escalator Out of Order' sign, only 'Escalator Temporarily Stairs. Sorry for the convenience.'" ...thanks for the memories, Mitch.
'If you're flammable and have legs, you are never blocking a fire exit.'
Lets drop below the flash point and consider the grandparent post - the attitude that if enough money is pumped in it will work - that should put things into context. The beanstalk is a grand symbol at this point but it is unknown how it can be done - but people are bringing out plausable sounding dollar per pound numbers from nowhere and getting funding from the same cash pool that voyager is being cut out of. As it may stand soon, it may be possible but isn't going to be worth doing unless there are vast tonnages of other material going up there for other purposes. Even if it becomes as light as a few thousand tonnes per kilometre, that's a lot of rocket fuel getting it up there. Done routinely with small cargoes, but with a large use of resources.
You really have to ask - what's it for? If it is for getting less stuff into orbit than itself into orbit it isn't worth it. If it is part of some other project it may well be worth it. I still think the attitude is to build it because it is some enormous great symbol, which is going to get funding from the bible thumping right-wing extremists mentioned above because they can connect with the idea.
Lets get the materials right first, but we have a very long way to go. As a similar example, room temperature superconductivity hit a snag.
LSD..
WRT the homework, the secret method for achieving clarity is to look for but not be fazed or fascinated by the religious underpinnings, which are always there. You need to be careful to remember that the concept of religion is not to be confused with sacerdotalism. Sacerdotalism is what all of the robes and stained glass is for. Materialism or Strict Atheism is just as much a religion as any form of Supernaturalism, from the world-worshipping Gaia sects who climb Cheops every Solstice and the spectacular demon-deafening funereals in Thailand to the sternest, quietest Quaker enclave, it's just as much religious as the "enlightened" and hard-nosed BMW-driving Rolex-wearing competitionalist YUPPIE or driest, most "rational" paleobiologist struggling to fit "wet" and supple T Rex bones into a 68-megayear timescale because (s)he prefers to believe Orthodoxy than evidence.
First, determine what brand of religion underlies the lessons in your science book. Next, find out if the material makes allowance for any competing memes. If it either refuses to admit that any exist, or if it admits them but then lampoons them with hollow caricatures instead of addressing their very real challenges, first note that this is precisely the method and attitude used by the Church of the Dark Ages, and second realise that what you are facing is no longer science, but religious dogmatism.
Once you detect religious dogmatism, it's much easier to correctly interpret whatever is before you. It doesn't magically make the material complete, but it does alert you to look for the gaps, omissions, and oversights.
You can also turn into squirrel food fairly rapidly by redlining your paranoia and seeing methodological gaps where merely human lapses were the cause. Simply satisfy the innate (if not always acknowledged) human need for controversy with a few manageably small doses of material from a competing ideology, and move on, knowing that your understanding will never be perfect, but that "if you shoot for the stars you may hit the Moon."
Got time? Spend some of it coding or testing
35,786km / 3m == 11,928,666 stops ("I say, that's devilish slow!") at say 30 seconds a stop == roughly 6 million minutes == 100,000 hours == 4200 days == 11.5 years. And probably several hundred new sets of doors plus countless motor and drive assembly swapouts.
Wouldn't take forever, but would certainly seem that way.
Got time? Spend some of it coding or testing
...would be to cable a suspension bridge with this stuff, and use that as a bellwether for issues with the real deal. It'd look kind of odd, because the carbon ribbon would be thread-thin compared with the normal steel cables.
Got time? Spend some of it coding or testing
let your wife do the map-reading. You'll get there quicker even if she's near-terminally dyslexic.
Being able to bridge Gibraltar to Africa in a single span would be a comparably technical - albeit much smaller - engineering feat. You would probably have to provide oxygen to keep the cars running at the top of the span if you built it as an arch rather than suspension. But the view would absolutely rock.
A bridge from Perth (one potential Elevator site) to orbit would only have to deal with wind, rain, lightning, corrosion and really big waves for the first dozen or so kilometers, and would have practically all of the tension running along the structure rather than across it. That's an enormous difference in structural problems right there, and it's only the start.
Forex, bridging from a floating platform would mean that unexpected waves could be dealt with by simply maintaining even tension on the cable and riding over (more or less) the peak. You could probably continue operating right through the wave, but I imagine that rubbernecking would significantly impede stuff efficiency for the duration, especially as they watched the wave wander off to engulf Rottnest and then Perth.
In point of fact, the article does discuss something akin to building the bridge you demand, but as a big loopy thing going via orbit rather than as the ultimate engineering response to the Sydney Harbour Bridge.
It'd be a bugger to paint, though.
Got time? Spend some of it coding or testing
The thing's going to be under tension 60x60x24x7 anyway. The problem with tying it off to a fire hydrant is that it and probably a considerable amount of other utility structure would be casually torn out of the ground long before the initial stabilising tension (few hundred tonnes at ground level, I guess) was completely put on.
Got time? Spend some of it coding or testing
There are a lot of engineering problems that need to be solved before a space elevator can be built. There are questions about stability, durability, strength, and manufacturability. Crawlers and control systems need to be designed and built.
But these are all just engineering problems and they can probably be solved or worked around given time, money and current technology. The big breakthrough that's needed is a way to actually build a ribbon that's strong enough.
There's a lot of research now going on with carbon nanotubes. There are people looking at ways to manufacture them in large quantities and high qualities. There are also people trying to figure out how to turn lots of short nanotubes into long, strong fibers. There are even people who think they can manufacture single nanotubes of arbitrary length, which could solve the problem right there.
Once this one big problem is solved, a space elevator is a certainty. The only question becomes who will build it.
It's quite remarkable what a source of information the Internet is. I didn't know about the Tower of Babel (only small bits and pieces) so I looked it up on Wikipedia. From there on I got into different religious interpretation of the bible, then the novel
Snow Crash by Neil Stephenson and now I am currently browsing on eight different tabs containing information about stupidity, Rudy Rucker, Georg Hegel, Black comedy, Ronald Reagan, and street smarts.
Truly, the internet currently is one of the biggest fountain of wisdom of mankind.
"All you have to do is be fragile and grateful. So stay the underdog." Chuck Palahniuk, Choke
Following is a modified version of a submission from last month, relevant to this discussion. I believe Edwards' group is planning on competing in the competition. Hopefully congress will lift the $250K prize restriction, allowing NASA to award larger prizes and truly stimulate research in this area:
MSNBC, Space.com, and Wired report that NASA, in collaboration with the non-profit Spaceward Foundation, has announced its first two Centennial Challenges. The Centennial Challenges, inspired by the Ansari X Prize and DARPA Grand Challenge, are prize contests seeking to stimulate private industry development of technologies relevant to space exploration. One contest is the Tether Challenge, for building the sort of super-strong tether needed to make a space elevator feasible. The other is the Beam Power Challenge, for creating a wirelessly-powered ribbon-climbing robot capable of lifting as large a payload as possible within a limited timeframe. The initial set of challenges in 2005 will award $50K to the winners of each contest. A second set of challenges in 2006 will award first, second, and third place prizes worth $100K, $40K, and $10K. It's hoped that these contests will further space elevator technology and help eliminate the 'giggle factor' surrounding them. Additional contests will be announced in the coming weeks, although Congress currently restricts NASA from awarding prizes of more than $250K; the agency is lobbying to try to get this limit raised to $40 million for future prizes.
How long's a piece of string?
Oh, about, yay long.
If Mr. Edison had thought smarter he wouldn't sweat as much. --Nikola Tesla
You could google it too... but since I just have...
The "Journel of Tribology " covers: Friction and Wear, Fluid Film Lubrication, Elastohydrodynamic Lubrication, Surface Properties and Characterization, Contact Mechanics, Magnetic Recordings, Tribological Systems, Seals, Bearing Design and Technology, Gears, Metalworking, Lubricants, and Artificial Joints. Friction and Wear, Fluid Film Lubrication, Elastohydrodynamic Lubrication, Surface Properties and Characterization, Contact Mechanics, Magnetic Recordings, Tribological Systems, Seals, Bearing Design and Technology, Gears, Metalworking, Lubricants, and Artificial Joints.
No. You can't look at my Sig; it's mine, and I'm not showing you.
There's no way a space elevator can be built with any kind of materials we know about today. Not even close. It's a fun idea to think about, but expect to see it built about the same time we invent warp drives and start learning new things from our Vulcan neighbors. Here are just a few thoughts of why off the top of my head, but there are easily hundreds of reasons more.
Move a wire through a magnetic field, and what happens? A current is induced in the wire, proportional to the change in the magnetic field (or, equivalently, the motion of the wire in a uniform magnetic field). Well, a space elevator is definitely moving, and the magnetic field it moves through is definitely not uniform. These currents would easily be enough to vaporize a steel structure like this. Ok, you say, make it out of something entirely non-conductive (i.e., non-metal). Out of what, rubber? Carbon nanotubes are very conductive, as you CS people should know. Try to build it out of something like diamond and it isn't strong enough. And you have to get something nearly entirely non-conductive, too, a high resistance won't work. If you don't know why, ask your oven, it knows. No known material ends up doing a good job at this.
The minimum energy curve from the ground to orbit isn't a straight line because of the Earth's rotation. The elevator couldn't be straight, or anywhere near straight. Consider that at the Earth's surface, we move around at a "horizontal" speed of about 1047 mph (1685 kph) (4000 mi * 2 * pi / 24 hours), at a geosynchronous orbit we're at 6860 mph (11040 kph). That means to move on a straight line you need to be changing your horizontal speed by a few thousand miles an hour! I.e., you'd need a force pushing sideways on your elevator and tower to keep it straight, but unless you want to put rockets on the sides of it, there's nothing you can do to add that kind of force, so you need to make it curved, like an Archimedean spiral, in fact. But, with it shaped like that, you've got a very tall curved structure, and gravity is still pulling it straight down. So it turns out you need to make it out of a much stronger material than you would for a straight tower on a non-rotating Earth.
Any object when heated is going to expand, which is a non-trivial effect even for small objects. Look at concrete bridges, even small ones, for example. Periodically there are gaps in them an inch or so wide, to allow for thermal expansion of the bridge, if those gaps weren't there, the bridge would break. Bridges even only on the order of tens of meters long need these. A space elevator obviously couldn't have gaps, and will be on the order of thousands of kilometers! This means there will be *significant* changes in where the top of the elevator is, which means you need a significant change in the angular momentum at the top of the tower to keep it from collapsing. Of course, that's only if the tower is straight, if it's spiral-shaped, like a real one would need to be, you've got a much more serious problem, because the shape of your spiral just changed! You've got even more of a problem when you consider that the temperatures along different points of the structure will be different, and will be constantly changing, particularly the points near the top--what's the temperature of an object in space in darkness vs. direct sunlight!? And then there's the problem that this will cause the strength of the material the elevator is made up of to change, too! So you end up with an elevator that's longer than it was a minute ago, weaker than it was a minute ago, and no longer the same shape, trying to do the same job!
But that's not all, you also have to consider that deformations only propagate along the structure at the speed of sound in the material. This isn't an issue in a small structure, but one that's 100,000 km high, it's a serious issue! When part of the structure expands or contracts the whole thing won't move instantly! There will be serious waves of compression and expansion propagating through it. The structure will *bend* because it can't move out of its way fast enough for its expansion.
There is a difference between wisdom and knowledge, and it is the difference between productivity and procrastination.
A carbon nanotube-based space elevator might
actually turn out to be a better source of
energy than a means of transportation. All that
would be required additionally is the really big
Leydon Jar to store the charge.
The Space Tethers will be built far sooner and are really much better. These can toss you into space fast so you don't fry in the radiation belts, recycle the energy from payloads going down into payloads going up, and be built with materials we have today.
article
Fittingly, at a space elevator conference last month [September 2003] in New Mexico, the keynote speaker was Clarke, 86, who spoke via satellite. "I do think it may be the way to space. The economics are fantastic . . . I think it'll be built 10 years after everybody stops laughing . . . and I think they have stopped laughing."
Yeah, we've discussed it the other day...
Future Wiki -- If you don't think about the future, you cannot have one.
Everyone knows that when the elevator breaks, you take the stairs. In "The Golden Age" by John C.Wright, there is an episode where the protagonist has to do exactly that.
"Robinson made it up. You know, from his imagination." I had no idea! I thought it really happened and messed up our Mars colonies!!!!!
Don't blame Durga. I voted for Centauri.
We tried this once before but G_d came down and destroyed the Tower of Babel. I'm hiding all my English to other languages dictionaries.
They already tried out this idea on The Simpsons. It didn't go well.
What does this button do...
Space elevator bottleneck is high quality ie high purity high density nanotubes in commercial QTY'S (I calculate at 8 Million lbs or less) I am surprised that as a nanotechnology newsletter you are not yet aware of a firm that has made a major breakthrough in the commercial production of hundreds of "lbs " yes "lbs" per hour of the highest quality known carbon Nanotubes (as grown 97.5% purity 99% + after added refinement) This means the commercial nono era is not years away but here and now Suggest you download the U of C test reports in a 3.9 MB PDF file at the following site I am sure your readers will be ecstatic to view the unfortunately somewhat "highly Technical" report from U of C University posted on the site this week, which includes high quality photos of the Carbon nano tubes (100-200 nm long - flexible)in SWNT DWNT, MWNT and their high density carbon nano fibers stated with "3.5%WT Elastic Modulus (GPA)" I can tell you the quantity and quality need for your space elevator is less than one years production doeable now !!! www.Cleantechnano.com
Don't forget the kryptonite so that Superman doesn't fly into it by accident.
One line blog. I hear that they're called Twitters now.
I imagine that the cable will be inherently light and that it would be more conveinent to have a solid, small counter-weight. A lot of extra cable hanging around might get in the way of stuff. Maybe the receiving staion will need to be radiation hardened, and thus willl provide a good location to hold the weight (as sheilding).
Your idea does win on elegance points though.
..........FULL STOP.
unfortunateson: you can't build it on US or European soil: it needs to be at the equator.
:-D). I think Jerf said it best: http://science.slashdot.org/comments.pl?sid=145575 &cid=12191065
Anonymous: Or at a pole. Just have to put a swivel at the base.
Shimmer: Interesting idea. I've never heard that suggested before. I wonder how practical this is [...]
How is this at all possible knowing that \tau_net = I*\alpha = dL/dt (Newton's second law for rotation and then angular form)?
I think there's a reason you've never heard this suggested before -- because it's fundementally wrong. Angular momentum is a big factor in keeping the ribbon and counterweight aloft. You can't have orbit while just sitting above a pole (there's no force preventing you from flying straight down (up?) into the Earth). Anyhow, you need a force of some kind to counteract the force of mg.
Correct me if I'm wrong... Space Elevators, as I understand them, use ballast to provide tension (ballast can be either more cable stretching past the target elevation, or some localized mass at the 'end', space station, asteroid, etc.). The tension against the ballast comes from orbit, because there is no ballast to sufficiently counteract Earth's gravity without it (unless we had a ribbon long enough to reach some equilibrium point between us and the Sun affixed to the Earth in some way (on a track?) such that it always pointed directly at the Sun -- then we'd need crazy contraptions to sync with the moving base to load and unload it).
That's just some Physics 1 thinking, I'm by no means an expert. However, I see a lot of people on this thread talking about SE without even basic understandings of phsics (maybe that's me?
Read Heinlein's 1953 Revolt in 2100, now more than ever.
Won't there be a huge electrical potential at the earth end of the rope?
Build a theather.
Sell power.
Profit!
Rick B.
the moon is a perfect base for a space telescope.
place solar panels there and beam the energy to satellites.
good place for satellite communication (future belongs to lasar).
Basically, everything except for launching to other planets. That is probably the only stupid idea there is. Any water there should be used for living rather than for for launches. And when ppl talk about sending fuel there, to launch from is even more ridiculus. No sense escaping two gravity wells when you only need to escape one.
I prefer the "u" in honour as it seems to be missing these days.
Exactly what is up there in space that is so important we're willing to sink billions upon billions of dollars into it?
Personally, I would think the creation of on-planet infrastructure would be more valuable. There are still places within the United States that don't have electricity or telephones. I only have to step outside my Austin Residence to tell you the horrors of our local highways. When we have billions for the research and development of a space elevator, but the cost of toll-free roads linking Houston/Austin/Dallas is considered 'prohibitively expensive' there is something wrong.
That said, I'm a big fan of the space program. If we can create a good, cheap means of moving our astronaughts from turf to their destinations, by all means, more power to you all. I've seen ideas for space catapults and high altitude launch sites that seek to break the initially high cost of lift-off. While these ideas aren't the best of conserving energy, energy on this planet is - at the end of the day - relatively abundant. Solar, wind, tidal, geothermal... all sources of energy that have not been sufficently tapped. Better to sink $5 billion+ into new forms of renable and recoverable energy techniques and another $5 billion on a launch site than $10 billion on a massive space penis.
But that's just my two cents.
How many times can you use the words "space elevator" in the description of this article?
The Chronic *WHAT* les of Narnia!
Lets just borrow wonder womans lasso.
Here's a fun business. Convince the government to provide backing for a private insurance fund to cover the losses for the 40,000 mile diameter area which would be partially leveled by the whiplash of a broken cable from the space elevator. That way, you could collect the premiums and go bankrupt (Mansion and estate in Florida not included) when the work by the corrupt contractor involving contaminated nanotubes causes a twenty thousand mile long whipping cable to fall to Earth at high velocity, tearing down and killing everything in its path...
To get government backing for corrupt corporate schemes, the main criteria is some kind of suck up to a power group. A fundamentalist approach seems best here. By claiming the great need to protect Christians from the hell cable and the chance that pornography would be lifted into the heavens and offend the angels, the savings plans of tens of thousands of uniformed retirees could be leveraged to provide backing for a reinsurance plan, which would limit liability for the original insurer to the cost of the actual nanotube which broke. The important thing here, politically, is the emphasis on values.
But just think about the funding! Huge amounts of money from the government to corrupt Texas corporations! It can't be built, you say? Well, even better! Much better, in fact. Building things costs money, big money. Look, here's the plan. We take billions per year to "research" the space elevator, hire nine or ten "scientists" and give a few grants to some university nitwits, and viola, at least a billion per year to the stockholders, and all we really have to produce is a few artist's conceptions and press releases in Omni or Wired or something.
THIS, my friend, is the future of NASA. Not building things. What have you been thinking?
When you are spanning a canyon for a suspension bridge, you first span it with a light rope. This rope is used to haul a heavy rope across. The heavy rope can then be used to haul a steel cable across. (At least that's the way it used to be done before the invention of the helicopter.)
To build the space elevator, you would do the same sort of thing. You would have to start from geostationary orbit. You would drop a line from orbit, with either a relatively massive anchor satellite, or an active anchor satellite (rockets to hold it in place). Once the initial line is down, a small climber can pull a thicker line up. Then a larger climber can pull an even thicker line up, etc, etc.
So, only the initial piece needs to be launched using conventional means.
"I'm not impatient. I just hate waiting." - My Dad
So this cable to space, which is kept at tension by the force of a weight pulling away from earth from somewhere above geosynchronous orbit, is "on a sea."
Right. And it's anchored to what, exactly? The water? Won't it flip around a bit?
... at cleantechnano :)
How exactly did parent get flamebait?
dbIII is uninformed and spouting FUD. I mean, jeez, look at his rant on keeping things in 'geosynchronous low orbit'? Or where he says that the only parts of the cable in free fall are the endpoints?
dbIII clearly doesn't understand the theory that a space elevator is based on, or basic orbital physics for that matter...
"We have to go forth and crush every world view that doesn't believe in tolerance and free speech." - David Brin
Now, go over there in that dark corner and cower in fear, and the rest of us will trailblaze the future.
...horizontal speed. The higher you get, the faster you're going to be traveling *before* you even start falling.
-2A
The revolution will not be televised... but it will have a page on Wikipedia
Um, the forces transfered through a bridge are perpendicular to the force transfered along a space elevator, the physics are totally different, the comparison makes no sense.
-2A
The revolution will not be televised... but it will have a page on Wikipedia
Once again, man is looking at this problem from the standpoint of brute strength - ie building a "cable" so strong that it can overcome not only its own weight, but the forces of nature within the atmosphere. Most of such an elevator" would be within the Earth's atmospehere, which is a mechanical bull of a place to be if you are a 150km long cable stretching from the ground all the way into space.
Whatever the answer is, it is going to be a hell of a lot more elegant than the use of nothing but brute tensile strength - like dredging and pumping half of the mass of the planet into space, bringing space to us - now that's elegant.
How would the SE be defended against would be terrorists ?
Who would control the SE ?
Who would get to use the SE ?
The science problem are big enough, the social\behavioral\cultural ones are bgger imo.
Cover it with a non wettable surface like a lotus leaf so there is no path for elecricity to travel.The drops of water will simply bounce off the rope. And a few clinging drops will not matter. as they do not provide a continous path.
We should offer a prize to the first person to genetically engineer a self replicating microbe that can knit carbon nanotubes, helix style. Then we build CN farms all over the country, jobs galore.
Let's nickname the elevator 'UPS' (since it carries stuff up). Only Slashdot readers would know it was short for 'Ultimate Phallic Symbol'.
A Russian professor has accused the United States of stealing ideas for a "space elevator" from a famous Russian engineer. http://mosnews.com/news/2005/04/13/sibir.shtml
Who in turn stole the idea from K.E. Tsiolkovsky.
I say the Russians stole the idea for manned rocketry from Robert Goddard. Nyah.
Display some adaptability.
As a nanotechnology site you may be interested in visiting a site of a firm that has made a major breakthrough in the commercial production of hundreds of "lbs " yes "lbs" per hour of the highest quality known carbon Nanotubes (as grown 97.5% pure) This means the commercial nono era is not years away but here and now Suggest you download the U of C test reports in a 3.9 MB PDF file at the following site I am sure readers will be interested to view the unfortunately somewhat "highly Technical" report from U of C University posted on the site this week, which include high quality photos of the Carbon nano tubes (200 nm long - flexible ) in SWNT DWNT, MWNT and their high density carbon nano fibers U of C report says " elastic Modulus 3.5 %WT Gpa" www.Cleantechnano.com