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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.
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? ]=-
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
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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.
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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.
Here are some more links to info on our very own Slashdot:
Here
Here..
Here..
and Here
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.
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
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.
top floor: shoes, ladies ligerie, space. please mind the gap.
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.
How much could spiders' silk hold if it were that thick?
I can't answer that question, but I *can* say you'd need a lot of friggin spiders...
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.
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
Just a minor clarification on the parent...
The "slingshot effect" is only useful for trajectory changes. [cut] Due to conservation of energy, when you approach a planet and slingshot away from it, you end up with the same velocity on the way out as the way in.
This is correct enough, but for those who haven't taken an orbital mechanics class, I thought I'd chip in a little bit more info. The 'slingshot' effect seems to work since you (the object) is changing frames of reference into- and out of the planet being used. (The other frame being with respect to the sun.) Additionally, you have to do the approach from the 'backside' so the planet pulls you forward on your way by (assuming you want to gain speed; otherwise enter on the front-side to slow down).
Once you leave the sphere of influence of the planet itself though, and are only under the dominant effect of the sun (i.e., changed frames of reference) you have changed net velocity (speed as well as direction).
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.
All true, but you missed two points:
BZZT!!! No, you're forgetting that the planet has its own velocity, which a spacecraft can steal. When a spacecraft slinshots around a planet, its velocity on the way out is the same as its velocity on the way in, but this the the velocity RELATIVE TO THE PLANET. If the spacecraft approaches the planet head-on, and does a 180 degree slingshot around the planet, then (ideally) its final velocity RELATIVE TO THE SUN is equivalent to its initial velocity plus two times the planet's orbital velocity. Energy is conserved, because the energy gained by the spacecraft is stolen from the planet.
That's "Mr. Soulless Automaton" to you, Bub.
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.
Will the wire generate power?
Yes, but only in the milliwatts.
Tim
Omnia vestra castrorum habetur nobis.
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?
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?
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So yes, there are many challenges to overcome, but they all, fortunately, seem surmountable.
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.
Microsoft could build this thing *OUT OF* cash!
So of course, this being Slashdot, I get flamed and modded down by geniuses who don't know a fucking winking smiley when they see one.
Sigh... well, not like it matters. Excellent minus 2 is still Excellent, in all probability. And if not, well, it still doesn't matter.
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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.