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NASA Still Wants Space Elevator
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."
Money is expensive, so expensive.
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!
Don't forget GPS. And satellite TV. And high-speed intercontinental data backbones. And weather forecasts based on satellite imagery. Even 'failed' missions such as Beagle 2 resulted in significant scientific advances (in that particular case, reducing the size of a mass spectrometer from the size of two desks to something the size of a Kirk-era tricorder prop).
how do you get there to go into outer space?>
every day http://en.wikipedia.org/wiki/Special:Random
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.
I don't care if it's 90,000 hectares. That lake was not my doing.
The very concept is much like building a bridge across the atlantic ocean in 1900. Better methods will happen, which are largely unforeseen at the moment.
I suggest you read Slashdot
actually, slow accent is one of the goals of the space elevator. instead of the challenger and columbia accidents, imagine if the astronauts had had a big red 'emergency' button that they could have pressed which would have stoped the shuttle in mid-air, while an emergency tech crew could have sent up spare parts, or gotten the astronauts to safety? one of the design goals of the space elevator is to have sufficient tensile strength so that a shuttle car could actually *stop* and suspend on the elevator, if necessary. as it is now, we have to hop on the top of a freakin 10 story tall liquid hydrogen/oxygen fueled *rocket* to get into orbit. doesn't sound particularly safe to me. the elevator is a design blueprint that could feasibly re-engineer the entire concept of access to space; in particular, engineer it with much improved safety procedures.
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.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
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.
I don't care if it's 90,000 hectares. That lake was not my doing.
We are talking about a space elevator here, something thats so far beyond our current capabilities its like the Wright Brothers talking about building a 747 (in both cases the concepts and capabilities exist, but in severe infancy). When we have the capability to actually build one of these things, a thousand mile multilane undersea highway or mass transit system will be childs play.
The initial seed ribbon will not support very much, obviously. Beyond that though, even the early ribbons are expected to lift up to 200 tons. This is by no means a limit, merely what is expected to be the safest and most economical course of development. Once the initial ribbon goes up, it is pretty much inevitable that much larger ones will follow.
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* greater than with any existing means of launch. (The shuttle can deliver less than 4 tons to GEO, and it certain can't launch 50 times a year.)
This is a bit too simplistic however, for two reasons. As things go up the ribbon, they get lighter. In actuality, you can get much more out of the ribbon by sending multiple climbers up at appropriately spaced intervals. Second, many things only need to go to LEO, so the frequency of "launches" could be much greater.
At least that's the conclusion of Nicola M. Pugno:
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.
Any sufficiently advanced libertarian utopia is indistinguishable from government.
Hey guys, somebody better call up NASA and ESA real quick! They think they're going to build one of these fancy "space elevators", right? Well I'll have you know that some guy on the internet uncovered a fatal flaw in their plans. And he got modded informative! Alert your Congresscritters everyone, we don't want to be wasting time on an idea that's obviously flawed.
Mr Pugno seems to be confusing bulk and nano technologies.
... let alone to an active MNT material whose design and properties we don't yet know. Even if the basic lattice structure is modelled after today's passive nanotubes (which is unlikely), the composite properties will be quite different.
MNT doesn't seek to make ribbon-type materials through bulk materials processing, but by constructing atomically perfect lattices out of individual atoms or out of small molecular assemblies. You can think of nanofactories as extruding an atomically-perfect ribbon by design.
However, that's not the end of the story either. Even if you nanofactured a perfect ribbon, it wouldn't stay perfect for long, but would suffer environmental damage over time and a certain amount of spontaneous self-decomposition as well.
That's why the MNT community is keeping active MNT materials in mind, ie. ones where you're not really extruding a perfect passive component but a live lattice of interlinked and self-repairing nanomachines. While there are many variations on this theme being suggested, this general approach seems to be essential for keeping the elevator cable healthy.
Needless to say, Pugno's strength reductions don't apply to such a perfect lattice material
"When we do get strong enough carbon fiber filaments (or diamondoid nanotech or whatever) to produce a space elevator, then we can start building it."
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
Come read my stupid blagablog. Rants and Giggles
Why couldn't you ship everything by boat? Heck, you could put most of the machine shops inside a boat. The only reason for flights would be for people or stuff you forgot. The reason for flying people is that it's cheaper to pay to fly them than to have them sit idle on a boat for two to three weeks. Though you could probably just send the machinists in with their ship, have them work on the way.
Actually, the groundside station would be the easiest part. The hard part is the orbital station. The way it works, you don't build up, you build it in orbit and drop it down.
As for hitting it with a plane - well, the thing's going to be 22,000 miles up. Most planes don't fligh more than a couple miles up. If the line is severed, only a mile or two will drop, the rest will sit there until the satellite can drop more. As for the dropping, the line will be so light that it'll more drift down than crash down.
I don't read AC A human right
Also, why would a terrorist want to attack it?
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 safer than the shuttle.
I don't read AC A human right
It still might take a while though, progress is slow, so slow."
It's not slow, it's incremental.
This is an important distinction. Incremental advances allow for a stable and mature system to emerge.
Stable and mature are good things in this environment.
Display some adaptability.
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.
Do not mock my vision of impractical footwear
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.
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
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 "stuff" used to build bridges.
Anarchists never rule