I don’t understand why you’re assuming that any perturbation on the tower will be self-accellerating. It’s NOT a “pencil balanced on it’s point” situation. As far as I can tell, the effects of the moon, sun and an imperfectly spherical Earth will simply mean that the top end will wobble about a bit.
Thats the one I keep remembering.
Hundreds of miles of cable rather than 10s of thousands.
We have the manpower though, and that manpower can help make the money, materials and technology happen. 12.5 million people are unemployed in the US. Creating a space elevator would create jobs and a new paradigm of research and technological advances.
The interesting thing about nanotubes is that they are produced by the ridiculously simple technology of a candle flame and are found in soot. The expensive part is filtering out all the other stuff from the soot. I think we’ll see a breakthrough in the next few years with a system able to produce nanotube filaments of unlimited length from a pyrotechnic source.
If we had this, a system that could produce industrial quantities of filament to order, on location…how difficult is the rest?
As for the value of it, the most worthwhile project would be unlimited power from solar panels in space. Make the mass of the counterweight was a huge farm of solar panels. Constant access to the sun and ship the power down the filament. The crawler would have to be a Faraday cage, so no leaning out the window.
Hey, while we’re stimulating the economy, can I have a gravity train?
Because it’s not a situation where the thing just wobbles a bit.
Here is a brief discussion of some of station keeping operations for satellites in GEO and GSO. Also, the ground tracks for satellites are “small wobbles” but they still cover a heck of a lot of ground. Pretty picture of ground tracks.
The only obstacle is inventing the materials that can withstand the heat and pressure of the Earth’s mantle and core!
Ok, be kind if completely wrong, but it seems that something on this scale might have some interesting side effects. Would any kind of electric current be induced in this elevator (if anchored? or maybe even if not)? Carbon nano-tubes can be semi-conductors, and even though it’s moving with the earth’s magnetic field, not sure if there are other fields surrrounding the earth that could cause it, interaction with particles from the sun, etc… Or maybe static electricity build up on it?
Hey, if they can do it in The Core…
Actually, despite the amazingly rendered animation on the wiki page, you don’t have to go through the core. You can also do diagonals. Of course, even at a diagonal we’re talking several miles down, and you really ought to create a vacuum for best efficiency, but at least it won’t fall on you when it fails…
It’s entirely possible I’m missing something important, but I don’t see the problem here. If you have a space elevator, getting fuel to GEO for station keeping shouldn’t be much of a concern. And I don’t see why the ground tracks are significant. Is there any reason why the anchor point has to precisely align with the ground track? We’re talking about cables, not rigid towers. A bit of swaying at the top shouldn’t matter, at least compared to the kinds of forces you’ll already be dealing with.
Not that I expect a space elevator to be built anytime soon, but as I understand it, the primary challenges are engineering and materials problems, not fundamental flaws in the physics of the concept.
I think this would only work in vacuum-- Air resistance would be prohibitive on Earth. But it’d be a good complement to the Space Elevator for slowly-rotating, airless worlds like Luna or Mercury. Between elevators on Earth, Mars, and the gas giant moons, and pinwheel skyhooks on Luna and Mercury, you could go anywhere you want in the system except for Venus, and honestly, who wants to go to Venus anyway?
The way I recall it, the wheel rotates at the VERY top of the atmosphere, space bascially. You “just” jump up 50 to a 100 miles high to catch the ride.
If we could build large quantities of nanotube sheets, I think I’d rather see something like an Orbital Balloon.
First, you build a balloon big enough and light enough that it can climb to 140,000 feet. There, you assemble a much bigger one, which isn’t affected by weather and turbulence and which stays up all the time. It’s basically a floating waypoint. Then at this one, you build a truly humongous balloon (over a mile long) that is so light it can climb even in the rarified atmosphere above 140,000 ft. You put an ion drive on this one so that as it climbs it very slowly accelerates until it’s eventually in orbit. To come down, you just decelerate, and let it float back down slowly through the atmosphere.
It’s a pretty cool concept, and it’s actually being built right now. The company has had contracts from the military for building the suborbital waypoint station, and has been test-flying its balloons for years. Unfortunately, they recently had one of their big ascender balloons ripped apart in high winds, but they’re seriously funded and have large facilities and are continuing work.
Here’s a PDF describing the concept in detail
Anyone want to poke holes in this idea?
Yes. “Modern Marvels” on history channel shows a design for a space elevator we could build right now. If the elevator is anchored in say, Ft. Worth, and the cable snaps at the bottom, your house in Idaho could get swiped. (!)
If cable breaks up top, not only will a flaming cable come down but the elevator in space would crash too, giving us a blast as big as an asteroid on the surface.
Can’t build it yet.
Good points, but wouldn’t the fact that the tether is anchored to the ground limit how far the it could deviate from it’s orbit? It still seems to me that all perturbative forces would do would add a small amount of extra strain on the tower.
I live under an airport approach path, and have a couple dozen large jets flying over that could crash into my house every single day of the year. I don’t lose sleep, even though it’s a fact they sometimes do crash into houses.
What makes you think the elevator would crash like a meteor? We can’t put parachutes on the things?
You don’t even need that really.
The thing is going to be so lightweight per foot of length its going to be more like falling kite string than falling steel girders.
The broken cable would demolish an airport if detached from the ground.
If detached from the top, the ship or platform would slowly enter orbit falling, heating up and BOOOM! Parachutes would flame up too.
Check historychannel.com Great show!
ehh?
If detached from the ground, the counter weight or station in space would enter a higher and higher orbit, pulling the cable with it. The idea is that there is tension on the cable.
If detached from the top, the cable would fall (burn up?) and the station would still just float off into space. Unless of course there was the ability to slow it’s orbit down.
Well, I’m confused. I’m talking about what would happen if the crawler fell, and we would certainly build in some safeguards to keep it crashing like an asteroid. It wouldn’t really be that big anyway.
If we’re talking about the nano-fiber ribbon, I don’t see how it’s going to hit me with more force than a string of yarn floating down.