NASA Still Wants Space Elevator 394
Jerry Smith writes "The Guardian reports 'Each of the groups that will gather in New Mexico is competing to win a NASA prize set up to encourage entrepreneurs to start development work on the technology needed to create a space elevator.' It still might take a while though, progress is slow, so slow."
What happens (Score:4, Interesting)
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The debates purely academic of course - NEVER GONNA HAPPEN.
Re:What happens - FAQ (Score:5, Informative)
http://www.isr.us/Downloads/niac_pdf/contents.htm
LiftPort Group. Company wants to beat NASA. [liftport.com]
Reference Site [spaceelevator.com]
Place a curse on the RIAA/MPAA [i-curse.com]
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Er ... that just doesn't sound right to me.
Let's look at the last (or first, depending on how you look at it) inch of string - just past where you are holding it. Sure, it has the weight of the weight to support, but it also has the wieght of the rest of the string. Each part of the string has to support all the weight of everything that's between it and the other end.
I call your bluff!
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It's been a while since I read anything so stupid. Consider a chain being held up by a 5 km tower and hanging straight down. The link nearest the ground only has to hold its own weight. The link at the top of the tower has to hold the weight of every link below it. The top link will break under the weight of the whole chain. Yes it will break. This little exercise applies to strings, cables, and all other "s
Re:What happens (Score:5, Interesting)
Re:What happens (Score:5, Interesting)
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I'm having bad high school flashbacks; desperately seeking a partner for the last dance.
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Very doubtful. More likely it was an accident or a suicide bomber (who are not crazy, just devoted).
The simple answer to this, is to place it someplace where lots of planes do not fly. A Pacific ocean atoll comes to mind.
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"The simple answer to this, is to place it someplace where lots of planes do not fly. A Pacific ocean atoll comes to mind."
So how do you get crew, workers, and passengers in and out? Submarine? Cruise ship?
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Actually, the groundside station would be the easiest part. The hard part is the orbital station. The way i
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Ass-backwards (Score:3, Informative)
Storm are not problem either - because you do NOT build the thing and attach it to an island. You build it on a floating platform, and the platform is powered. When a storm comes, you simply drive the thing in the opposite direction. The platform can move a coupel of hundred miles to avoid bad weather. This has already been thought of - and the math/engineering works jus
Re:What happens (Score:5, Funny)
That's where the frickin' laser beams come in.
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With sharks attached to them!
Re:What happens (Score:5, Informative)
Most likely, the cable would break, the 99.999% of the cable above the impact point would start to drift upwards, and the 0.001% of the cable below the impact point would fall harmlessly to earth. It would then be a bit of a chore to repair the cable, but not impossible. Fortunately this wouldn't happen, because the cable's base station would be located somewhere in the middle of the Pacific ocean, in the middle of a no-fly zone several thousand miles in diameter. For a crazy pilot to get to the site of the cable, they'd have do evade detection by radar for several hours, and avoid getting shot down by the SAMs or military aircraft whose sole job is to guard the cable against this sort of attack.
Now a question for you: What happens when a plane runs into the Space Shuttle during launch? It only takes on crazy pilot.
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Re:What happens (Score:4, Insightful)
Yup, and for those reasons, such a collision is extremely unlikely to occur. Just as for the reasons I stated above, a collision with a space elevator is extremely unlikely to occur.
There are many unsolved problems to deal with before we can create a Space Elevator. Terrorism (or incompetent piloting) isn't really one of them -- except possibly as a political problem, caused by an American public which has been intimidated into losing confidence in its ability to create anything new.
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The only reason I'd think would be that it's considered one of the high points of american achievement. Not so much anymore, but look at the trouble caused by the wrecks.
For that matter, crashing into the space shuttle is easily doable while it sits on it's pad. If they can hit the pentagon, they'd be able to hit the shuttle. Then you figure in the LH/LOX and solid boosters and you have the potential for a big boom/fire.
The space elevator would easily be safe
if it's a no fly zone (Score:2, Insightful)
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By ship. Or, possibly we allow a few highly secured planes in.
Re:What happens (Score:5, Interesting)
The one thing that does seem far-fetched is the several-thousand-mile-diameter-no-fly-zone-idea..
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Umm, no. Real answer: It depends, and none of the answers are good. See also:
http://www.mit.edu/people/gassend/spaceelevator/b
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Really? And what are you basing that prediction on, other than wishful thinking? I'd be the first to welcome the invention of a nice anti-gravity device (or whatnot) myself, but it would be silly to think that something unforseen like that will be invented just because I think it ought to be, laws of physics be damned. Hell, as long as we're going with 'unforseen inventions' as our Great Whit
Re:What happens (Score:5, Insightful)
Seriously, show me the tech that you propose will make space elevators unneccesary. Show me the orbital equivalent of a transatlantic ship, and more importantly show me that it's cheaper.
Otherwise, I don't see why your point is a valid arguement.
Furthermore, the atlantic bridge arguement is a red herring. This is the equivalent of building a bridge where previously ferries were used. Furthermore, even if we did have cheaper ground to orbit craft, a longer space elevator can be used to give the ascending craft enough escape velocity to clear Earth's gravity well, which is something that ground to orbit craft can't do.
I already did (Score:4, Interesting)
In the last discussion we had. You're getting very close to troll territory my friend.
REPOST:
With all the talk lately about a space elevator, I got to thinking after recent slashdot discussion [slashdot.org], just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp [skyramp.org], (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to the tower launch archive [yarchive.net].
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere [gatech.edu], with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At normal launch accelerations you can get to LEO with very little external propulsion.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005 [space.com], and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years.
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benefit.
Once we have that mastered, we can move to algae pods in orbit for food production, oxygen refining, and fuel production (biodiesel or chemical engines), all of which can be powered by the immense energy of the sun, and use the raw materials abundantly available in space. Whether you ship that stuff back to earth or use it for further colonisation, its a vital step.
The production of automated scouts is also a high priority; a vast amount of surveyor and prospector drones to sweep and map every square inch of every rock and gas in the system, out to the Oort cloud, and figure out what they are made of. I'd err on the side of quantity rather than quality, still no reason not to have either. This could be combined with deep space observatories that would make hubble look like the end of a coke bottle.
So now we have a manufacturing bridgehead, a good idea of what's interesting out there, and a cheap means to launch to orbit. Actual manned system ships would come next, to either colonise or investigate the system. The rest, as they say, is (future) history.
A lot of this would require automation, robotics, right up to the point when we build a larger manufactory from the orginal small one. Robots would als
That's not physics (Score:5, Informative)
If you accelerate something to escape velocity, it does exactly that: escapes the gravitational attraction of the Earth and never comes back, unless it's decelerated by some unspecified means. And escape velocity at 11km height means it will be burned to ashes very quickly, remember the Columbia. With our current technology level, building a ship that can fly at escape velocity at 11km height is much more difficult than building a space elevator.
OTOH, if you want to put something in orbit around the Earth, then you should give it orbital velocity, which means it should have a very high tangential velocity around the Earth. You cannot do that with a vertical tower, unless that tower reaches the synchronous orbit altitude of 36000km, which is the whole idea of a space elevator. Remember, velocity is a vector. It has both magnitude and direction. If you want to reach orbit, it's useless to throw something straight up with a high speed, because it will fall straight down.
Well, you may say, let's make the top of the tower curved, so the ship will be accelerated tangentially. Do the math. Find out how big the curvature radius must be so that the ship isn't subjected to deadly accelerations in order to convert that vertical velocity to orbital, i.e. tangential, velocity. That math has been done even before artificial satellites reached orbit. I have an old book, "Flight in Cosmic Space", written in 1952 by Russian scientist Ari Sternfeld, where he analyzes, among other concepts, the idea you have proposed. A practical accelerator to send a ship into space would have to reach a 100km height and have a curvature radius so great that it would be several thousands kilometers in length.
Re:If a space elevator is cheaper (Score:5, Interesting)
In terms of energy losses, the elevators are generally accepted to be more effecient (admittedly this is theoretical).
It takes enourmous amounts of energy to put anything in orbit. Period. Future technology, in whatever form it takes, will face the same physical limits.
Rocket fuels aren't cheap, and aren't going to get cheaper. Moreover, rockets have a very low weight limit - those commercial launches you mention put up tiny satellites, and even then they cost through the nose.
Show me the advanced launch tech that can put something heavy in orbit today. Oh, right, it's that model of effeciency the space shuttle. Trust me, if that's the cost per pound that a space elevator has to beat, we could make it out of pure gold and still come out ahead.
We don't have anything that can do what a space elevator can. Unless you can show me an example of a launch system (existing or theoretical) that can carry the same weight, then your arguement that "by the time we can build the space elevator, we'll have better tech", is invalid. Seriously, go take a look at stuff like the X-prize craft - these are the "spaceships of tommorow" and they still carry very little payload, to no higher than LEO, for a hefty price.
Re:If a space elevator is cheaper (Score:4, Interesting)
Um. All the first order research was done by the military. In particular the German military.
I'm going to assume you're including the efficiency of the electricity generation in that calculation. i.e. Start at around 35% efficient and get worse from there. It will almost certainly require a dedicated nuclear power station to run.
Rocket fuel is not the expensive part of the operation, the fuel cost is negligible compared to the cost of the administration and infrastructure. i.e. the NASA bureaucracy. The shuttle should of course have been scrapped decades ago and replaced by an unmanned heavy lifter, but that's NASA for you. Atlas V, Proton etc can both handle payloads about as big as the shuttle and for a tiny fraction of the price.
Um, I haven't made that argument. My argument is that by the time a space elevator comes around, rockets and rocket launches will be on a production line and their costs will be amortised over far more launches than currently. Commercialising the launch business will bring cheap space flight, NASA never will.
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Or a tornado... (Score:3, Interesting)
And yes, an aircraft could just aim for it - though I'm sure there would be a lot of r
Nature points up the folly of man (Score:4, Funny)
History shows again and again how nature points up the folly of man. You know that once Godzilla gets a bus caught between two gargantuan fangs that he just can't pick out with his silly T-Rex claws, he's going to be looking for some good dental floss.....
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unbreakable diamond fillament.
on mobility of the tether point (Score:2)
Not true, some designs call for a floating tether point, which can be moved as necessary when the need arises for the cable to dodge space debris. It may not be possible to move it quickly enough to dodge, say, a hurricane; but it need not be absolutely fixed either. On the other hand, it does need to be sufficiently massive to not get picked up out of the ocean and flung into spa
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And yes, an aircraft could just aim for it Oh, noes!!!!11 the terrorist are coming.
I'm still waiting for a giant slingshot. Don't the same hazards apply to your slingshot?
Success is never final and failure never fatal. It's courage that counts. --Abraham Lincoln
We choose to go to the moon in this decade and do the other things, not becaus
Not a troll, more of a rant.... (Score:5, Insightful)
The laws of physics work just as well for any nation.
I am convinced that Man will conquer space. Whether the dominant language is American-accented English, Mandarin, Spanish or Japanese is still uncertain, but your capability remains.
You have a brilliant track record, and a wonderful people. Your achievements have inspired me to a thousand times greater use of my potential, my career, than I would have ever reached without them.
However, from across the Pacific it looks like you're in a kind of perpetual Saturday afternoon over there. Might I diffidently suggest that you, as a country, get up off your arses and start doing what you were best known for again? Your beer is terrible, your automobiles are awful, your cuisine apalling, and your politicians are worse than the French.
But your aerospace engineering is utterly superb, and the hope of the race. Don't let the rest of us down.
Moo (Score:5, Funny)
And his heart was filled with pride.
I said to Mr. Otis, "What does your room do?"
He said, "It goes from side to side."
So I said, "Mr. Otis, if you take my advice,
You'll be the richest man in place.
You gotta take that room that goes from side to side,
And make it go to outer space."
And that was good advice, good advice.
Good advice costs nothing, and it may win a prize.
NASA offered me
Four-hundred-thousand dollars, whee!
For good advice.
12m (Score:3, Informative)
Hopefully won't be too hard beating that, my mindstorm robot can do better!
"progress is slow, so slow" (Score:2, Insightful)
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Well, fortunately the NASA can use US Dollars, which are somewhat cheaper than Euros, or even British Pounds.
What're you talking about? (Score:3, Interesting)
slow, so slow (Score:5, Insightful)
It still might take a while though, progress is slow, so slow.
There is of course truth in that statement, especially considering the effective infancy of CNT materials science. Many gains have been made in the past 15 years or so, but it takes time...and thus the quote from the summary. We are today seemingly obsessed with instancy; however, this is to our detriment. Patience, patience!
Slow? But why? (Score:4, Funny)
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They'll have to earn it the old fashioned way (Score:4, Funny)
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Horrible idea (Score:5, Funny)
I have a hard enough time avoiding contact with "other people" in elevator cars -- but the real tragedy will be the music. Girl from Impenema for 72 hours straight? [wikipedia.org]
Aaaraargh.
The only way I could see this working is if they piped in aerosol (-)-delta9-trans-Tetrahydrocannabinol and phillip glass...
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Girl from Impenema for 72 hours straight?
Dude. iPod. Get with the program. :)
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BUILDING a stairway to heaven?! (Score:2)
There's a lady who's sure ... (Score:5, Funny)
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Tie a rope to a Space Shuttle (Score:2)
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The trick is to spin the earth fast enough so the rope will be kept in space under the centrifuge force. You only have to put some sortof breaking system on the rope so you don't fly from earth. Hence the function of the rope.
Slow? No kidding! (Score:3, Interesting)
Yeah, I'm not going to hold my breath on this one.
One step at a time (Score:4, Funny)
Doubtful (Score:3, Informative)
Point is, it would probably not take long before such elevator would be completely useless due to its slow speed and low capacity.
Re:Doubtful (Score:5, Interesting)
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Right... And the mods didn't mod you "Completely Insane"... BTW where is the "Completely Insane" moderation option. I think Slashdot would benefit hugely from that particular one.
Re:Doubtful (Score:5, Insightful)
It's true that we may never see a space elevator -- it's entirely possible that the engineering problems involved in deploying one a simply beyond our ability to solve. But assuming for the sake of discussion that it is possible to deploy one, then there's no question that it would be an order of magnitude more useful than any imaginable rocket-based delivery system. Rockets are a good (if risky) way to get small amounts of material into orbit, but they completely fail to scale up past a certain size. The reason for that is because they have to carry their fuel up into space with them.... the more mass the payload has, the more fuel it has to carry, and the real killer is that you also have to carry more extra fuel to lift the extra fuel. So as the mass of your payload increases linearly, the mass of the fuel you'll need to launch it increases exponentially. At some point there simply isn't enough money in any nation's budget to acquire the amount of fuel they would need (never mind building a rocket big enough to hold it all).
That's why (barring the invention of some near-massless rocket fuel) you'll never see massive amounts infrastructure being lifted into space on rockets. With the space elevator, on the other hand, the problem is neatly bypassed: the elevator "car" carries no fuel at all. Instead, the energy needed for lift is beamed to photo cells on the bottom of the car via ground-based lasers. If you want more lifting power, you simply point another (or a bigger) laser at the bottom of the car... there is no exponential increase in fuel requirements, just more equipment (and more power consumption) back on the ground.
So yes, rockets can get us a nice little "lift the rich tourist into low-Earth-orbit for a few days" industry. But if you want to do Big Stuff, like large spaceships capable of carrying a crew to Mars and back, or solar power satellites, then you'll either need a Space Elevator to bulk-lift all that mass, or some way of finding pre-existing mass already in space and building all the components there.
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Well, I can think of two reasons: (1) an elevator would be more fail-safe... i.e. if you ever need to shut down the lasers, your elevator car comes to a halt, puts on the brakes, and waits for the lasers to start again, whereas a free-flying vehicles would fall to its destruction. But more importantly, (2) it's not clear to me how a free-flying externally powered craf
Re:Don't need an elevator for that (Score:4, Insightful)
Energetically, the elevator really starts paying for itself once you bring an asteroid or three into orbit and start using the potential energy stored in them (and their raw and barely refined materials - including fresh water) to raise things like people, finished goods, and supplies into orbit. As long as someone wants those raw materials on the earth enough for it to be worth getting them into GSO, that energy is free for the taking.
As The Man (Heinlein) said, "Low Earth Orbit is halfway to anywhere" (meaning that it's very high in our gravity well, such that you've got about half of the energy you need for escape velocity). Geosynchronous is much further out than LEO is - it's most of the way to anywhere, and that works both ways.
How many "launches" per day? (Score:2)
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Really. And, there are no running costs, no infrastructure to be maintained, no personnel costs. No repairs to the structure of the elevator? Nothing has to be replaced over the 20, 30, 100 years of daily use? And you have to remember this is a 35,000km rail line. How long does it take to get to orbit, how many simultaneous launches are running? And remember it's only going to be able to lift thing
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With an average speed of 50km per hour, it would take about ten hours to get to 500km, which could be a waypoint for transfers to other LEO objects. Getting out to 35,000km would take much longer at that velocity (about a month), but even if the cars were lim
Why build an elevator? (Score:3, Funny)
An artist's concept (Score:4, Informative)
http://www.mondolithic.com/06Gallery08.htm [mondolithic.com]
Pluto! (Score:2, Funny)
Won't work, too many defects in the nanotubes (Score:3, Insightful)
the megacable strength will be reduced by a factor at least of ~70% with respect to the theoretical nanotube strength, today (erroneously) assumed in the cable design.
For this reason I've become quite skeptical. But please, prove me wrong, boy would that be cool.
Really well-made space elevator video (Score:3, Informative)
There is also a very good companion article [ieee.org] on IEEE Spectrum, and a fun interview [newtek.com] explaining how it was made (short answer: lots and lots of Lightwave).
No, I'm not getting paid to promote this or anything, I just enjoy sharing it with friends/family, and thought a few of you would like it as well. Alan Chan's a ridiculously cool guy, I mean anyone who could make a short film entitled 12 Hot Women [atomfilms.com] and get people to play it at pretentious movie festivals... wow.
Where has all the imagination gone? (Score:4, Interesting)
I am feeling SO disappointed with my fellow slashdotters.
I've read through every comment on this thread that is scored 2 or above, and every one of you is seeing less than half of the space elevator's potential. You are all so one-way in your thinking.
Let me try to prime the pump of your imaginations...
Visualize a one pound iron ball, sitting in your hand. How much energy would that ball release on impact if you are on an airplane at 5,000 feet and you drop it out the window? Do you think it might break a car's windshield? Do you think it might put a heck of a dent in a car's roof?
Now drop it from 23,000 miles....
So long as we move enough mass down the space elevator, we can capture enough energy using existing regenerative braking technologies to power lifting side. If we move more mass down than that, the space elevator becomes a power generator. And the beauty of this is, it isn't important what we move downward, so long as we can put some kind regenerative braking on it.
As we begin to explore space elevator technologies, we should also begin to think about how to start nudging a near Earth asteroid into a position where we can get at it easily when we are ready to start dropping things down the elevator shaft. Ion engines might be the ticket. At first it won't matter much what we drop down the shaft, but eventually we'll get more picky.
At some point we'll want to build a solar powered distillery at the end of our string, so we can deliver bottled water mined from comets or icy asteroids to the thirsty. We'd do the bottling at the surface, after running the water through 23,000 miles of water wheels and turbines. And we'd probably build a solar furnace at Strings End to reduce nickel iron asteroids to ingots that would fit special drop tubes.
Well, that's it. I'm tired of playing Heinlein. Somebody else can imagine the distribution system for the surplus power.
There are some alternative approaches (Score:4, Informative)
There's the idea of laser launch [wikipedia.org] - instead of providing the energy to vapourize propellant with chemical reactions, you aim a laser at the spacecraft to do the job.
Secondly, there's a variety of space tether schemes that don't go all the way down to the surface; instead, they dip down to an altitude and relative velocity where they could be met by hypersonic rockets. These have the rather large advantage of not requiring super-nanotubes. here [usra.edu] is a NASA-funded study on the idea.
And, of course, there's always Project Orion [wikipedia.org] - explode nuclear bombs beneath a gargantuan steel plate to push the thing along...but somehow I don't see that one getting approved any time soon
Yet Another Money Making Idea (Score:3, Interesting)
Just thinking out loud....
Re:WHY? (Score:5, Informative)
Once you get one tether you can send runners down it with additional strands.
It would be strengthened and grow like a pearl from an initial seed.
The problem is getting that seed line up there.
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To the west of the Earthside station, why?
It doesn't make a huge amount of difference, really. Your station will probably be near the ocean, so it won't get in anyone's way. Picking it up might be a bit of a pain, though.
Any material strong enough to make a space elevator out of will be light enough at the earth end that it will look more like a piece of ribbon fluttering in the breeze as it falls than anything else. It
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Re:"They won't waste time and resources" (Score:4, Insightful)
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Yea, transformers FTW.
Intermediate technologies. (Score:5, Interesting)
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Now crap scenes from that godawful film are reverberating round my head...
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Besides, it will cost you to synchronize two orbits with different R, because, you know, T~R^1.5
build a space elevator to Mars (Score:2, Funny)
Got enough rubber to mix in with the nanotubes? That space elevator to Mars is going to need a LOT of stretch.
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Moreover, even the first ribbon is expected to have a payload capacity of 13 tons, and a trip to GEO will take about a week. The useable capacity is *far* g
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The reporter was somewhat incorrect. The center of mass has to be slightly higher than a normal geostationary orbit, but at the s
Re:Fundamental flaw? (Score:4, Informative)
Actually, all you need is a space elevator that can bring up a few pounds - then you keep running it, loading the mass at the counterweight. Then build a bigger cable, wash/rinse/repeat. Soon you are sending tons up at a time. Yes, it is expensive, but compared to blasting the stuff up into orbit, greatly cheaper.
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Re:Fundamental flaw? THE SE IS NOT IN ORBIT!! (Score:4, Informative)
The SE is a rock on the end of a very, very long string, being whirled around by the Earth's rotation. That's what keeps it up -- what's sometimes called centrifugal force. Pulling inward/downward on the string doesn't cause the rock to fall; if the rock is whirling fast enough, it won't even be pulled down, and when you stop pulling, the rock is still there. There's no real notion of "center of mass" of the SE as a whole. The majority of the mass is well above GEO.
The "rock" will actually be all the construction machinery that was used to build the SE, a few hundred machines that climb it and add a tiny bit of material all along its length while they're going up. They will have a total mass of about 650 tons and be at an altitude of 100,000 km. The CNT ribbon will have a mass of about 950 tons. We'll be able to send up a 20-ton climber with a 13-ton payload every four days, or a 10-ton climber with a 6.5-ton payload every day. (Gravity falls off so quickly that a given climber is down to 50% of its weight when it's 2600 km up. That's what makes it possible to send up smaller climbers more often than you'd expect.)
Re:Occam's engineering. (Score:4, Insightful)
Call me crazy, but I think thats the whole fucking point or R&D.
We dont have the tech now, so we go and try to invent it.
How amazing boring would human society be if we simply waited around for new technologies to fall from the heavens instead of actively searching them out?
When we do get a strong enough carbon nanotube rope to build the elevator, we will. And there's nothing like trying to build something to ensure that your materials are up to the task
Re:Has anyone here read Red Mars? It's FICTION (Score:3, Interesting)
The climbers going u