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Space Elevators: Low Cost Ticket to GEO?
Crocuta writes "The current issue of Science
News features a cover story
that discusses the current developments in space elevator technology. NASA has been
working on such devices for many years, but private companies such as Highlift Systems are now jumping on the space
elevator bandwagon, no doubt seeing the huge potential profit in a low cost per pound
delivery system. PhysicsWeb has a somewhat
older, but much more technical article
on the formation and structure of the carbon nanotubes that form the basis of the proposed
tether cables. With a development like this, we could shoot entire boy bands into space and make
the world a better place."
We have enough trouble getting stuck on elevators between floors in 5 story buildings. Could you imagine getting stuck half-way to the moon? They better be sure to put one of those bright red emergency phones on this bad boy.
what about deep space? if we accelerate the payload up the space elevator wont we also get the slingshot effect of the earth's rotation adding to the energy we are putting into the payload to get it flung toward the outer planets at a much higher starting velocity and while using less fuel?
Do not look at laser with remaining good eye.
And I'll say it again. I *love* the idea of a space elevator. But I do not see how it will reduce the cost of going to space as much as some people claim. The maintenance costs for the tower will be tremendous.
Life is like a web application. Sometime you need cookies just to get by.
Those of us already in orbit can't wait for the space elevator to be complete. Finally, we can get some cable TV.
With an object that goes through t the ionosphere you would get a constant stream of free electrons surging through the damn thing. Throw a power station at the base and BOOM. Free electricity. The only question I have is if we pull down electrons in the upper atmosphere would there be an impact?
-=[ Who Is John Galt? ]=-
Imagine asking for the basement, (floor -1), and getting sent to floor 65535 instead :-).
Arthur C. Clarke popularized the Space Elevator and once said "The space elevator will be built about fifty years after everyone stops laughing".
p _1 .htm
http://science.nasa.gov/headlines/y2000/ast07se
My father is a blogger.
This story is a repeat that I've seen at least one other time here on /.. If I recall correctly, the cable is very unlikely to snap, but if a terrorist were to break it, the cable would fall to the ocean and there wouldn't be any devastating impact.
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"A microprocessor... is a terrible thing to waste." --
GeneralEmergency
cant get much lower
Thanks to file sharing, I purchase more CDs
Thanks to the RIAA, I buy them used...
As fascinating as it sounds, unfortunately, Congress will never fund such an endeavor -- as far as they concerned, space is a useless void that we now have no reason to explore after the death of the USSR.
The idea might be feasible -- I prefer the idea of a giant cannon/mass driver/gauss gun to shoot us into space myself -- but the idea of a 100,000km tube supporting an elevator is too farfetched to ever get funding, especially with increasingly conservative US administrations that would rather spend money launching rockets not into space, but into third-world cities, as well as European powers that have their own budget problems due to their social welfare systems that prefer to spend money on Earth and not in space.
The problem with something this tall is that it will inevitably be destroyed, and we will be scattered throughout the earth and forced to speak different languages.
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Some Books to look at:
The 1979 Hugo and Nebula Award winning novel, The Fountains of Paradise by Arthur C. Clarke.
AND...
The Web Between the Worlds, by Charles Sheffield, using the same idea, published about the same time Clarke published his book.
AND...
Of course, Kim Stanley Robinson's Mars trilogy.
LongTail SSH Brute Force analysis tool is here!
Ah, so we should stiffle useful technological advances, and live in fear of terror until the problem magically goes away?
The universe is a big scary place; we won't have the pleasure fully discovering this if we crawl under our beds and hide.
So when to elevator tickets go on sale?
How many gazillion of billions do you think it will cost. If not by any accident, how many terrorists does it take to blow it up? There just is not and cannot be such big amount of capital tied into one physical place. It might be possible to build it - once, if you find someone who is ready to BURN that money. Someone who invested all his money into a dot.com in 1999 is worth economics nobel prize compared to this.
After a cruise through tropical waters, you arrive at a large, anchored platform in the middle of the Pacific Ocean
The very first few lines of the article. The anchor would be a modified oiling platform, not a tower in ecuadro, Brasil or Peru (which, BTW, are NOT anti-american). This platforms are located outside any countries jurisdiction.
There are two kinds of people in the world: Those with good memory.
Somewhat agree, but I have been reading about this since Arthur C. Clarke published 2061: Odyssey Three. I will believe it when I see it working, in person.
Eve Fairbanks says I drive a hybrid!LOL
Here are some more links to info on our very own Slashdot:
Here
Here..
Here..
and Here
I can just hear the laughter from outer-space:
"GLeebob, come here quick look what those silly humans are trying. Yup, they're trying the ladder-thingy. Remember when we tried the ladder-thingy..Ooooh, that was a dumb-idea. What will they do next, human-pyramid? Come on humans, bang those rocks together..."
"This isn't a study in computer science, its a study in human behavior"
Here's a nice sized (15MB) report done by NASA. They talk about all sorts of problems that need to be worked out to make get this project off the ground http://www.niac.usra.edu/files/studies/final_repor t/pdf/472Edwards.pdf
free ipod? yeah.
The equator DOES NOT pass through India or Venezuala ..
.. and relatively friendly.
The equator passes through 13 countries: Ecuador, Colombia, Brazil, Sao Tome & Principe, Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia, Maldives, Indonesia and Kiribati.
Equador and Brazil are both relatively close
Why stop with one seemingly improbable concept?
Once the elevator is built, use it to haul pieces of an Orion craft to the top and assemble it there. When it's ready, let it go, flinging it out of Earth's magnetic field. Once clear, light it up and go see the solar system.
This way there's no radioactive contamination of the atmosphere, minimal risk while getting the "fuel" in orbit, and it's a handy way to get a crapload of plutonium out of our hair.
Saturn in fifteen years, anyone?
With reasonable men I will reason; with humane men I will plead; but to tyrants I will give no quarter. -- William Lloyd
Well to be truthful, if it matters, it won't really matter. If the thing is made of "nano tubes" some fucker flies a plane into it all we will do is hose it off and go right back to business.
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Discovered in 1991, carbon nanotubes are long molecular tubes of carbon atoms that resemble cylinders of minuscule chicken wire (SN: 12/16/00, p. 398). The bonds between carbon atoms in this configuration are so robust that, weight-for-weight, carbon nanotubes are at least 100 times as strong as steel. They are, in fact, the strongest material known. A carbon-nanotube string half the width of a pencil can support more than 40,000 kilograms, Edwards notes. That's equivalent to the weight of 20 full-size cars.
How much could spiders' silk hold if it were that thick? I've heard that its quite a bit stronger than steel, but is it more than 100?
The minute I saw it on slashdot, just like the last time, I knew people would go into the "this is just impossible" mode without at least giving it a shot.
Ok, I'll bite. READ THIS (warning, it's a pdf file), and once you do, say it again. I'm not saying this paper is wrong, but it's enough information to realize that there's no one thing preventing it form happening. Not even money, as it would all cost about the same as the International Space Station. The one thing that doesn't exist as of yet is the nanotube wire, which feasbility is clearly only a matter of time. So if the existance of the Space Elevator depends on the existance of a 90,000 Km long nanotube wire (the fabric industry is used to threads this long, again, read the paper), then there's no doubt that it will become a reality.
The space elevator is doing for me what the apollo program did for my parent's genration: It's giving me an overdose of inspiration.
There are two kinds of people in the world: Those with good memory.
Well - he blew it in Bolivia. I bet he'll try again, though.
Stop the brainwash
top floor: shoes, ladies ligerie, space. please mind the gap.
Does anybody remember a /. article a while back link to this story about how carbon nanotubes cannot handle bursts of common, ordinary light?
Yes, that's right! A standard camera flash will cause carbon nanotubes to explode!
Check out the link, there's a neat video showing this effect at work.
I can just see it now, on the front page of the newspaper... Tourist arrested for carrying terrorist device and it's just a FLASH CAMERA!
Yeah, I'm excited that the technology to do this is just now barely within our reach - but it'll be a while before it's squarely in our grasp.
I have no problem with your religion until you decide it's reason to deprive others of the truth.
you and the secretary could get it on, and it wouldn't have to be a quicky.
Evil is the money of root.
I watched someone talk about their plans for doing just this on TV about a month ago. I can't remember what show exactly.
Basically it was a ribbon that started somewhere in the Pacific on some island and went straight up into space attached to an anchor. The ribbon was paper thin but wide and incredibly strong. The reason for it being thin was because of wind resistence which is a major factor especially when its an area with tropical storms. It also had to be a no fly zone since if a plane clipped it, either the ribbon would go or the plane would be cut in half.
It sounded all well and good but the price was hefty and implimenting it sounds near impossible. It would save us a lot of money in the long run considering how much space shuttle launches cost. I just can't see it being reliable. You wouldn't catch me riding on it, thats for sure.
One thing I do know, if they get it to work then it'll be one of the greatest engineering feats ever. I hope they can do it, but I doubt they will.
Cars will be drawn to the top of the elevator by a team of trained mules, hitched to a rope of a length roughly 1.8 times the circumference of the Earth. We anticipate only minor difficulties obtaining a right-of-way through most nations (with the possible exception of Sweden, because they're lame).
The mules will be fed and cared for by dedicated and highly trained staffpersons. At the end of their useful lifespan, most retired mules will be adopted by loving families everywhere. Unclaimed mules will be shot, as will be unclaimed members of loving families. Irresponsible and gratuitously hostile critics, who clearly do not have the best interests of humanity in mind, will be shot also.
On special occasions and international holidays, children of all races, creeds, colors, and nationalities, clothed in their quaint and colorful native garb, will be invited to throw superballs and apples from the top of the elevator. They will be charged only a nominal fee for this unique privilege. Highly sophisticated surveillance technology will enable all the world to enjoy the festivities!
We are now accepting investments in this historic, one-of-a-kind investment opportunity, not to be missed by the progressive and forward-thinking investors of our great nation. We anticipate incalculable earnings; we also anticipate neglecting to calculate them. Please give us all of your money right now and I promise you'll not regret having been so easily gulled.
"Offtopic, Inflammatory, Inappropriate, Illegal, or Offensive" -- hey, that's me!
Sounds like more of a Shelbyville idea...
"I may be quite wrong." - Socrates
One of the things that I find interesting about the whole process of the Space Elevator principle is the idea that after the first one, it is possible to relatively easily spawn of daughter cables, so that if the first one took 2.5 years, subsequent ones would take less than a year. Not only does this provide for additional capacity, it raises the possibility of selling cables! It also makes the first entrant into the Space Elevator arena almost automatically dominant.
Additionally, you can create a daughter cable, and then use the cable to sling the entire daughter cable to the red planet - suddenly, we have a means to get to Geo Earth orbit, a way to sling stuff to Mars (using the cable) and a way to get down to the surface of Mars, and back up! This is probably the most feasible way that I have heard of to explore Mars.
First Falcon-1 to orbit, then Falcon-9. Then I can die a happy man.
Couple of points :
There are obviously enormous difficulties with building this cable, with having it survive lightning strikes, deliberate damage ( could a single guided rocket with an armor piercing molten jet warhead destroy this wire in one hit? If that happened, wouldn't the $10,000 missile have caused 50 billion worth of damage or more...everyone knows that a project like this is going to cost 10 times the current estimate), the mechanical wear as the spacecraft slowly claw there way up...
A far simpler and cheaper solution is a massive ground based laser array. (which incidentally is how they are proposing to power this thing...why not skip the cable and build a much bigger laser). The beam would vaporize propellant attached to the bottom of the spacecraft, eliminating perhaps 90% of the danger of rocket travel (the rocket blowing up has always been the biggest risk...if it uses a nonvolatile, inert propellant) and reducing the cost to a tiny fraction of current expenses.
Since the laser system would be a large array, it would not have to be built to nearly the quality standards that a manned spacecraft has to be constructed to since if one of the lasers burns out, blows up, ect the rest of the system picks up the slack.
The Monkees weren't a boy band so much as a postmodern satire of the Beatles. You must be capable of holding a grudge for a very long time, if you're still bitter about their "comeback".
Mark Walhberg, meanwhile, never really had anything worth coming back for. The moment he realized this, he changed jobs, finding work as a halfway-decent actor. If all the boy bands made Wahlberg's "comeback", music would be a much better place, and movies wouldn't be any worse than they currently are.
Also, the "let's shoot boy bands into space... without space suits!" comment is older now, but not any more tired, than when it was first made. Remember that you're posting on Slashdot, where we already know you don't like boy bands. Originality is much more important than mindlessly repeating the same inane remarks over and over again. Bandwagoning the editor's own tired "insights" puts me in the mood to space you, ahead of the pop-music chorus line of the week.
At least the boy bands are paid professionals: they can dance and sing better than you or I, they work hard, they maintain wholesome appearances, and they appear to be having a lot of fun. They're getting paid for something they do well, and it's something they enjoy doing well.
I'm not moved by the music that's written for them, and I abhor the whole music industry/marketing system that makes boy bands possible and lucrative, but the bands themselves are no more evil than they would be if they appeared under a system of independent copyright-owning artists.
Imagine a songwriter who believes his work would appeal to a certain demographic--highschool girls, for example. So he amasses some capital, hires a group of clean-cut young men and a choreographer, writes some catchy tunes, teaches them the lyrics, music, and dance steps, and hits the road. They work as a team, and work hard. They get lucky, create some buzz, burn an album, collect some royalties from downloads and webcasts (in addition to the take from their touring), and generally have a good time writing and fronting the music.
That's not so bad, is it? No different from the independent rappers, emo bands, country singers, folk artists, &c. that will spring up in our hypothetical RIAA-free utopia. I think boy bands will always be with us, and I don't think they will ever be the problem.
Any sufficiently well-organized community is indistinguishable from Government.
For example, the base tower would have to be 31 miles high, according to this article. Which is 90 times higher than the current tallest structure on earth, the CN Tower in Toronto, Canada is only 1/3 of a mile (about 170 stories) high.
There is also talk about using carbon nanotubes to make up the cable. The pricetag, 40 billion dollars (see 2nd link).
The people on board the elevator at the time might argue with that statement... :-/
Very true, but I meant to say that it's not going to cause a tsunami or collapse on Manhattan.
-Lucas
You don't need to tether the end, you can still get some very healthy benefits with a partial elevator. Deals with a lot of the security issues too. Cargo craft only need to fly to the low end and ride the rotation to the top where they can slingshot off. Using the Earth's magnetic field and solar power means it's self-stabilising too. More detail and better writing at; Free David Brin Short Story
it will be much easier for NASA to make fake photos of future "moon missions."
Evil is the money of root.
who says this is going to have anything to do with the government? Just because NASA tends to have a monopoly on the endeavor currently? I'm sure a private enterprise would erect the structure faster and far more cost-efficiently than NASA could.
Ok, as much as we all laugh at Lance, or whatever his name is, from N'Sync trying to go into space, I think it was moronic of everyone involved not to make sure this happened, that he got up there and back safely, and had one hell of a good time.
The entire space program has been gradually fading from world view, and particularly from the Western world. Yes, there are programs still going on at NASA and ESA and even in China, but it's nowhere near what was hoped for in the 1960s and 70s. Putting a high profile celebrity into space would bring a lot of attention back to the space program. Would it be fleeting? Of course. That's what media attention is nowadays. But it would probably enspire a lot young kids to go to space, just as the early US and Soviet astro/cosmonauts did nearly half a century ago.
Before the canal. Study history in any other country and you'd know about the French, the private sector and how lawyers got a bad name. Study history in America... ???
Fascism should more properly be called corporatism, since it is the merger of state and corporate power.
With a development like this, we could shoot entire boy bands into space and make the world a better place.
:)
To the author: are you channeling the Rice University Marching Owl Band today? We just performed a show in which we advocated the launching of boy bands into space. Is this a great-minds-think-alike thing, or did you spend some time at Reliant Stadium this weekend?
hopefully venus doesn't think we're trying to mate...
aoeu
Or it will just get blown up/flown into/cut down by terrorists.
//m
Think of the space elevator structure as a 100,000-km-long highway that will require ongoing maintenance and repair," says Smitherman.
How unrealistic can an analogy be? If a crack forms in some remote stretch of interstate, there's no danger of the rest of the interstate system suddenly ripping away and falling into space. Repairs would have to happen instantaneously without ever breaking an almost unimaginable ribbon tension. And this wouldn't be a very rare occurrence, either, as the ribbon would present a surface area of five to eleven million square meters on each side (5 to 11.5 cm wide, 10^8 meters long). And remember that it's on the equator, which every piece of orbiting debris crosses twice during each orbit.
And the only mentioned solution for lightning strikes (one of which could be fatal to the ribbon) seems almost totally unworkable, and doesn't take into account that a 100,000-kilometer-high conductive tower would generate its own lightning. Remember the ill-fated (but educational) Space Tether Experiment? And the tether was only a mile long. A space elevator's ribbon would intersect a huge chord of Earth's magnetic field, including both Van Allen Belts. Seems to me that, even if the ribbon didn't immediately blow like a giant flash-bulb filament, you still couldn't get within a hundred yards of the base due to the continuous electrical discharge.
Don't get me wrong--I've dreamed about space elevators since I was a kid reading about Clarke's hyperfilaments, but the more I think about it, the more unworkable it seems.
Oh, that urban legend again? Pencils are hazardous in weightlessness; both NASA and the Soviets used them at first, then both switched to the SpacePen when it became available.
Will the wire generate power?
Yes, but only in the milliwatts.
Tim
Omnia vestra castrorum habetur nobis.
Equator, since (a)the Earth is an oblate spheroid and the Equator is higher than the poles (b) slingshot effect wouldn't apply at the poles. Same logic explains the Russian sea launches which allow rockets to save a chunk of fuel by getting as equatorial as possible and the French using Guyana for Ariadne.
That's an urban legend. See for yourself
//m
Instead of spending billions to perfect a safe, efficient delivery method why not just unravel the world's largest rubber band ball; tie them all together; and shoot the boy bands (one at a time for greater distance) into space?
and what, pray tell, do you think the units are on the Kelvin scale?
I've heard some shorten "degrees Kelvin" to ?Kelvin, or even "Kelvins", in case that's what you're driving at, but it's still degrees, just as "60 Fahrenheit" is short for "60 degrees Fahrenheit".
One thing I never see mentioned by all these proponents of nanotubes as a structural material is that extrapolating the strength of nano-scale covalent bonds to macroscopic dimensions is overly optimistic. "Calculations suggest... based on flexibility... 100x as strong as steel" sure. There are all sorts of materials, if you remove all the defects on an atomic scale, that are super strong. But saying that it is inevitable that we can scale up something from 1 micrometer to 100,000 kilometers is a bit of a stretch. If you made the cable out of solid flawless diamond, it would be stronger than out of nanotubes, and we can already make bigger diamonds than we can make nanotubes. I think a space elevator would be great, but don't hold your breath. There are a lot of details to be worked out in the materials science area before it is really a possibility. But nanotubes do hold promise, just not as much as everyone here seems to think.
.. and get on board with my idea for space rubberband.
Inspired by RoadRunner cartoons and a 6 pack of beer, I was able to sketch out a design that would launch anything we wanted into space without fear of terrorist attack.
1) Dig hole 2 miles deep.
2) Build giant rubberband
3) Stretch giant rubberband over hole
4) Put cargo on top of rubber band.
5) Tie Star jones to rubber band
6) Drop Big Mac in hole
7) Jones drops. At the low point, right when the rubber band stops stretching, special release latch disengages Star Jones from rubber band thus saving Star Jones for next launch.
8) Cargo goes shooting up into space
9) Star Jones eats Big Mac making increasing thrust for next launch.
Yeah, I know I know.. after a few launches I would have to switch it up with KFC, Taco Bell and BK.
[Sadly, a coworker had to help me with the physics]
Anyone know the email to Nasa so I can get them working on this?
Live web cams
So yes, there are many challenges to overcome, but they all, fortunately, seem surmountable.
I know a few Native Americans who might disagree with your final sentence.
"You want a toe? I can get you a toe by three o'clock... with nail polish."
The people on board the elevator at the time might argue with that statement... :-/
na, they would be flung into a higher orbit. IIRC, This whole rig is pulling on the base station. It wants to be in a higher orbit, but the tether keeps it where it is. So if the tether snaps, the station would move into a higher orbit, more in line with its velocity, while the thether would float back to earth, much like paper.
Necessity is the mother of invention.
Laziness is the father.
The site was throwing around numbers like $10 billion - well within the reach of a large corporation. Heck, Microsoft could pay for this baby with cash.
I'm a huge space enthusiast. Huge. I love just about anything that promises to bring the cost of space access to a reasonable (read: below $200 per kilogram) levels. I've been following the X-Prize competition with great interest.
That said, I can't get behind this space elevator push. First, the economics of it won't scale to meet a wide range of demand fluctuations. What if you build it and then find out that demand for it is only a tenth of what you had predicted? There's no way to scale down the sunk costs involved--it's an all or nothing sort of proposition.
Second, it would represent a prime terrorist target. No set of defensive systems could hope to cover against every possible means of attack. Missiles, bombs, lasers, and who knows what else. And we haven't even covered the subject of action by a hostile nation-state, which could presumably marshall far more impressive resources to the task of bringing down a cable.
Third, it represents completely unproven technology. Better to go with a multistage rocketplane or some variation on that theme. Design one that can be built with the equivalent of off-the-shelf parts and build it with a multi-purpose role. A launch vehicle that could also effectively double as a system for high-speed transoceanic delivery would have great commercial and military applications, and would be developed that much more quickly and economically.
In short, the space elevator is a nifty idea in many respects, but it won't happen until the construction of such a system is relatively trivial. When one business guy turns to another and says: "You know, we're paying a lot of money for pilots for our launch vehicles. Maybe we should just build an elevator and get some high school kids to run it."
In a world without walls, there is no need for Windows.
One of the papers on their talks about the high about of energy a climber will require and how the energy should be transmitted by laser (as nanotubes are very good conductors the resistance over that huge distance is just too much). Anyways there is absolutly no talk about conserving energy. As technically if you had a climber at the top, and assuming it used some sort of rollers to climb up and down. The energy generated by the rollers on the way down should be the same energy required to get back up. (Minues electrical resistance and stuff) Is there any way to save this huge about of energy? It seems such a waist to not atleast try.
Most likely they'll have many Anti-air systems around the elevator. Anything flying gets within 10 miles, and it shoots it down. Period.
It will start warning you 20 miles out though.
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
Bad analogy.
I was one of those people inspired by Apollo. Stayed up late on Sunday night that Summer when I was thirteen watching the fuzzy time on the surface replayed, with Walter Cronkite commentaries.
Fast forward a few years, and watch it all rot.
Maybe an elevator would do better, maybe it will finally get us access for good. I hope so. I fear not.
The living have better things to do than to continue hating the dead.
Why, 'cause you have to expend a fair amount of energry just lifting fuel up as your craft ascends. not to mention heating loss thru the atmosphere/clouds. Just ask yourself what's more efficient riding a bike under your own leg power or having someone shoot a hot laser at your waterpack to propel you by steam....I don't think so..
As far as I've read the "cable" or ribbon will only be at its max diameterseveral inches - our guidance systems aren't that good -the current (USA) tech can hit stuff on te order of magnitude of a jet. The ribbon version of the cable is 1 meter wide by a FEW MICRONS!.
..........FULL STOP.
The units on the Kelvin scale are officially known as "kelvins".
Google sez:
kelvin (K): A unit of thermodynamic temperature, taken as one of the base units of the International System of Units (SI). The kelvin is defined by setting the thermodynamic temperature of the triple point of water at 273.16 K. Note 1: The kelvin was formerly called "degree Kelvin." The term "degree Kelvin" is now obsolete. No degree symbol is written with K, the symbol for kelvin(s). Note 2: In measuring temperature intervals, the degree Celsius is equal to the kelvin. The Celsius temperature scale is defined by setting 0 C equal to 273.16 K.
Note how there is no degree symbol when writing a tempetature in Kelvins.
From:
http://lamar.colostate.edu/~hillger/temps.htm
we can see
The kelvin (K) temperature scale is an extension of the degree Celsius scale down to absolute zero, a hypothetical temperature characterized by a complete absence of heat energy. Temperatures on this scale are called kelvins, NOT degrees kelvin, kelvin is not capitalized, and the symbol (capital K) stands alone with no degree symbol.
Also, the plane could only hit a few miles up. The 'elevator' is more a suspended rope. All they'd have to do would be to extend the cable down further. This would probably also be done for 'routine maintenance'.
I don't read AC A human right
There would be electromagnetic induction due to the space environment outside the magnetopause (the boundary of Earth's magnetic domain; outside that, the Sun's field dominates), but that's a much smaller effect (because the field is so much weaker out there than just over the surface of the planet).
Shouldn't all the drawings have two elevators, one going up, one going down, with the cars being transferred one to the other at the endpoints? Two-way traffic on a single string would be a pain. The redundancy wouldn't hurt either. Heck, why not have a dozen elevators all within a stone's throw of one another.
Nonsense! There's no way that a 100,000-mile-tall tower would have any effect on language.
Er, that is to say, there's no way that a 100,000-kilometer-tall tower would have any effect on language.
...to pretend the other people aren't there.
(Like we do in elevators now)
Cake or Death? Cake Please!
Rubbish. 10 billion is a small fraction of the cost of the ISS, and a space elevator would be *much* more useful. If this indeed turned out to be feasible, it'd get funded in a heartbeat.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Well, of course the Beatles were a boy band. I'm not disputing that! It's the Monkees that weren't a boy band. They were a subversion of the boy band, and we're waaay overdue for another one.
Any sufficiently well-organized community is indistinguishable from Government.
Sure, it all sounds like it will work, but have they thought about how they plan to deal with the Vermicious Knids?
I don't care if it's 90,000 hectares. That lake was not my doing.
which brings us to our next point. The base station is not anchored in space, it is anchored in earth. There is NO leverage from which to pull things (never mind, that you would have to pull them at escape velocity to in the first place.
Again, not a big deal. The 'elevator' climbs the cable to the station. Yes, we still have Newton's laws, meaning that the cable is pulled down. But, the angular acceleration of the station (remember, its being spun in a big circle, and pretty fast to boot) will keep the station from being pulled back to Earth. Sure, there will be a limit to the amount of mass you can haul up this thing, as you will have to keep the inward force on the cable less than the 'centrifugal force' (yes, I know its ficticious, but its a useful concept in this case). Too heavy of a load and it will just pull the cable in, anything less than that and it will just climb.
As for needing to get to 'escape velocity'... Not true. escape velocity is only for a ballistic projectile. Or, more simply, one that does not have the benefit of continious force. Imagine climbing a ladder, do you hit EV to make it from one rung to the next? No, what if that ladder extended to the altitude of Geosyncronious orbit? Would you need to hit EV to keep going up the rungs? No, it would take a large amount of energy to climb, but you would never need to be going that fast. Technically, one can make it into space traveling at 1 m/s, as long they have some way to keep being pushed up.
Necessity is the mother of invention.
Laziness is the father.
There's and interesting, informal dicussion group for this kind of thing at space-elevator@yahoogroups.com
This would let us put cows in orbit! Imagine, fresh milk in space.
The thing is that towing asteroids around doesn't seem like anything we're all that likely to do until we have a space elevator as a jumping-off point.
Tim
Omnia vestra castrorum habetur nobis.
The irony of a flamewar about "degrees" vs. "degrees kelvin" is truly humorus.
It has also been a long day of staring at poorly designed C++ code <sigh>, so maybe it's not that humorus.
That's too disturbing, even for a hardened cynic like myself.
Any sufficiently well-organized community is indistinguishable from Government.
This is a pretty funny post, but it bugs the crap out of me that everyone thinks this is a strike. It's not. The port owners closed the ports after a work slowdown of 50%.
In other annoying news, President Bush mispronounced the word "nuclear" 473 times during his speech the other night.
Yes, this is a repeat, and they pretty much have determined that this stuff will break up into small pieces with the biggest problem being breathing it in when it lands.
It's not as easy as it seems, because if you just chuck a satellite out the door, that puts it in an orbit designed to bash into your cables, but you can lift a rocket with maneuvering-orbits quantities of fuel rather than escaping-the-gravity-well quantities of fuel, which is a big win, and use it for a "bus" to deploy small satellites. (It's too bad you can't just chuck stuff out the door - there are lots of things you can do with a bunch of cheap nanosats.)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Eh?
How many missles travel at 24,000 miles an hour?
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
The cool thing is that, should somebody detach the thing, it'll fall up
"We returned the General to El Salvador, or maybe Guatemala, it's difficult to tell from 10,000 feet"
interstellar starships are created from genetically engineered trees grown in orbit.
Perchance, were any of the trees named Tsunami?
"We returned the General to El Salvador, or maybe Guatemala, it's difficult to tell from 10,000 feet"
BZZZZT. Wrong. one, the materials used are going to be heavy.. carbon nanotubes will have weight comparable to diamonds..
BZZZZT!! Wrong. This ribbon is lighter than tissue paper. I don't care about the 1 k rotational velocity at all. It would be slowed down by air drag to just a few miles an hour. Throw a piece of tissue paper out of the window of a fighter in a dive at mach 2. Will the tissue paper stike the ground at Mach 2 and kill someone? No. Of course not. Neither would this.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
I was not concerned about only 1km of cable falling. It seems obvious to me that there is the potential for a lot more than that to fall (although no nearly enough to wrap around the earth). The point of noting the weight of a 1km section of cable was to emphasize the immense surface-area to weight ratio this material has. It's lighter than tissue paper. It doesn't really matter how long a section falls, because it's going to have the falling properties of a crepe-paper streamer.
Additionally, those concerned about the cable wrapping around the planet, remember that the entire structure is revolving at the same tangental velocity as the Earth's rotation, with it's center of gravity on a stable GEO. If it falls, it will fall more or less straight down (give or take a bit for winds). Most likely the part that does fall will land in the surrounding oceans.
What is not known is if or how the cable will disintigrate into individual nanotubes. If this happened, there may be some danger related to inhalation of the particles. Research is being conducted into this issue, and the designers are working on a way to insure that in the event of a catastrophic failure, the material tends to break into rather larger pieces, which couldn't be inhaled.
That's why the carbon nanotubes are such a big deal. In fact, they're THE deal. According to the Science News article, a nanotube strand half the width of a pencil can suspend 40,000 kg. The question, then, is how much such a strand would weigh, per km. If 100,000 km of it (that's how long it needs to be) weighs 40,000 kg or more, you're shot.
According to "Physical Properties of Carbon Nanotubes", the tubes can have varying densities (makes sense, when you understand what they look like). Let's pick the largest density listed on the page: 1.40 g/cm^3.
Assume a pencil is 0.50 cm wide. So our nanotube strand is 0.25 cm wide. Cross sectional area is 0.053 cm^2. So the total volume of one strand is 10^8 * 0.053 cm^3, or 5.3x10^6 cm^3. Its mass would be about 7.4x10^3 kg, then. Or in English, 7400 kg. Significantly less than 40,000 kg. This single strand could hold up three more strands just like it, AND bear another 10,000 kg of strains.
And of course, a space elevator would consist of thousands of these strands. Kim Stanley Robinson was right; this thing would be ridiculously stronger than needed.
Lately democracy seems to be based on the skybox, the Happy Meal box, the X-box, and the idiot box.
KSR described the destruction of the Martian space elevator in - um - Green Mars, I think. Or maybe Red Mars. Anyway, his research seemed to be pretty good, so if you want to believe a fictional account, the elevator, severed at the top, would be dragged down to the planet by the weight below, falling faster and faster over a period of days. It would wrap around the planet 2.5 times in the Earth's case, and fall faster than it could burn up.
When it hits, it demolishes anything in a lane several meters wide. The lane will trace the equator, of course. Countries affected would include Borneo, Malaysia, a few Indonesian islands, Kenya, Uganda, Congo, Gabon, Brazil, Colombia, and Ecuador.
Anyone in the forecasted strike zone would be well advised to get the hell outta there. But come back in a few days. Once everything's cooled off, you're now in possession of your very own diamond mine.
I suspect the authorities would try to work things in such a way that any material harvested from the fallen cable would be used to pay for construction of the replacement. That would be the biggest damage - financial loss of cheap transport between Earthside and space.
Lately democracy seems to be based on the skybox, the Happy Meal box, the X-box, and the idiot box.
Read the faq on the site. It states that it is very light.
At any rate, this is as thin as tissue paper. Even lead in the thickness of tissue paper is quite light. And this isn't nearly as dense as lead.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
Ow. Ow ow ow.
First of all, I used the right pi. I supposed a pencil was 0.50 cm wide, halved that to get the width of the nanotube strand listed, then halved that again to get its radius, 0.125 cm, which I rounded to 0.13cm (for ease, though, not for signifidigits). pi*r*r = 3.14 * 0.0169 = 0.053 cm^2, as I said. Close enough to your figure. Hey, who knows what kind of pencil they use at Science News...
Of course, I then said the line was 10^6km long, or 10^8cm long, which means in my universe there are 100 cms to the km for some reason. So yeah, I should burn for that. Meanwhile, though, you might want to run away from that 700000-kg carbon strand falling out of the sky. Yeck. Maybe a carbon nanotube strand is even less dense than a single nanotube? Or they don't use chiral nanotubes in such strands? Surely one of my assumptions had to be wrong...
Lately democracy seems to be based on the skybox, the Happy Meal box, the X-box, and the idiot box.
The Martian elevator didn't burn up. Earth's atmosphere is significantly more "there" than Mars', so maybe it would be enough to burn it up, or maybe it still wouldn't be enough.
Also, the Martian elevator was a long strand counterbalanced by an asteroid at the far end. The cable was effectively cut just beneath the asteroid, thus making it horrifically off-balanced.
Even so, I really like your idea of failsafes, particularly chopping the cable up. I'm not sure boosters could brake the cable enough to prevent serious damage - maybe they could. You'd certainly want boosters along the cable anyway, to push it out of the way of any really big rocks or satellites.
Lately democracy seems to be based on the skybox, the Happy Meal box, the X-box, and the idiot box.