Oh, you don´t have to come with excuses to get support for that. 
This is probably the most comprehensive article I’ve seen on the space elevator. It also has a link to a related article discussing the economics of the venture. Some of its facts and figures conflict with Tuckerfan’s which is what made me recall it.
The project seems to be faced with enormous obstacles although by no means insurmountable. However, money should be the least of the obstacles. Consider, for example, the dubious benefits gained with the nearly $100 billion spent on the war and occupation of Iraq. RickJay’s pessimistic, albeit wildly inflated and uniformed, guesstimate of a trillion makes the venture seem like a bargain in a cost/benefit analysis.
By the way, does chump change mean the same as chicken feed or is it money that only fools would spend?
Now THIS is bizarre :eek:
But very very interesting, one of the most original ideas in megascale engineering I’ve ever read about. Really neat. :>
Man, I hate being a naysayer, especially about something as exciting as this, but the notion that this will be built in 15 years is insanity.
But this is a common failing. Anyone remember the plan to build giant space cities in the Lagrange points? Gerard K. O’Neill published a book about it, and it became all the rage. We could even doing it without new breakthroughs! Put a mass driver on the moon, shoot rock into space, shape it into giant toruses, put a big mirror at the end to shine light inside, and you’ve got an artificial world big enough for 20,000 people to live inside! Farms, rivers, you name it. Once the mass driver is in place, you could shoot up as much material as you wanted, and make the thing as big as you wanted. The rock shields the inhabitants from cosmic rays. Spin it, and the people inside have gravity.
As a thought experiment, this was really neat. But there were people back then (in the 1970’s and early 1980’s) who were seriously predicting that we could build these things within 20 years. I remember claims of dozens of these being built by 2020, with millions of people living in space.
The thing is, these grand visions are so large that you lose sight of the details. Something as simple as building a vehicle that could move rock to a mass driver reliably in the lunar dust could have stalled the idea for years. At the time, I thought that we’d be lucky to even have started construction on a mass driver by 2020, let alone have cities in space built.
This space elevator is more of the same. Sure, we’re on the verge of solving all the scientific problems, so that it is at least possible to build. But we are nowhere near solving the engineering and logistical problems that need to be solved to build something like this. To say nothing of safety and protection from terrorism.
We’ll be lucky to see a prototype tether in our lifetimes.
Why 62,000 miles? Shouldn’t it just be long enough so that the “counterweight” is in geosynchronous orbit (about 22-23,000 miles up)?
The counterweight is not the only thing hanging on there; if you want to keep the counterweight at a stationary orbit you have to compensate for the weight of the cable, it´s tension and the climber(s) pulling it down, so an extra lenght of cable is used extending further up effectivelly pulling the thing up and keeping it balanced on a geostationary orbit.
The upper end of the cable is held in place by centrifugal force, right?
What happens if terrorists attack the elevator and manage to break the ribbon? Will the cable, the payload, and whatever poor schlubs are working on the elevator go sailing off into space?
Because, ummm, you’re talking about
BUILDING AN ELEVATOR INTO SPACE!!!
You do realize that nanotubes are just about the least of your technical and administrative problems, right?
Look, I get excited by whatever freaky new shit is on the cover of Popular Mechanics, too, but I also notice that 99% of all the PM covers never come to pass. To suggest that this sort of thing could be done for $10 billion is insanity and ignorance on a scale I did not think existed. That’s only eight months of NASA’s budget, so let me ask a simple question; could NASA, by themselves, pull this off without raising their budget by a single dime?
I would honestly be quite surprised if, for $10 billion, you could even just design the elevator car. Prof. Bradley can blithely comment that the car will be powered by using lasers aimed at photoelectric cells, but that’s a huge engineering challenge right there. You have to design and build and test and perfect some pretty honkin’ lasers - I mean, how much energy does it take to move 13 tons at several hundred miles per hour straight up? You have to design and build and test some fairly complex photoelectric cells and power conversion devices. You have to figure out how to aim the laser, since even in good conditions the elevator is going to sway according to prevailing conditions. You have to figure out what you’re going to do about beam degradation caused by clouds, humidity, refraction, etc. And I would be truly amazed if the station at the top of the tether cost less than a hundred billion dollars. The International Space Station, which is basically just a bigger version of Skylab, has thus far cost what, $20 billion? You’re going to design a goddamn elevator into space for half the cost of the ISS? It is to laugh.
So let’s say you succeed is building all these nanotubes - which even according to your cited article still is not precisely a done deal. You still have to build the orbiting station, at a cost of a hell of a lot more than $10 billion. You have to figure out a way to successfully string the nanotube tether to it, which isn’t going to be easy - hell, that ALONE is a monstrous undertaking. You still have to come up with solutions to the issues of lightning, inclement weather, static, wind, meteors, corrosion, and a dozen other things that have never been tested under the astoundingly extreme conditions you’d be asking this thing to survive in, and even if the ribbon survives it’s going to want to move, vibrate, and bend. You are going to pay billions of dollars to build the Earth station; the engineering for the tether’s anchor alone (you have to tie the nanotubes to something awfully strong, right? Can you imagine the force involved?) will cost a billion or more. You’re going to have to spend billions and billions on the elevator. Billions and billions on a system of radar and warning devices to ensure the tether doesn’t get nailed by a satellite or various space junk. According to the linked article thy’re going to float the bottom of this thing off the coast of South America - you’ve got to build that big ol’ boat, too, and it’s going to be gigantic and unlike anything ever built before. I’d be pleasantly surprised if you could just build that for $10 billion.
If anything my cost estimate was low. This is the biggest engineering project in the history of the human race. It is preposterous to suggest that it could be accomplished for such a meagre sum as $10 billion. We had a thread recently about how building a replica Great Pyramid would cost almost that much. That’s just a bit simpler.
Gest, I did quite a bit of reading and put together some comparative costs before citing the $1 trillion figure. I think it’s a reasonable estimate. This project would dwarf any other engineering project ever attempted. Nothing else is in the same league.
I’ll get excited when they use nanotubes in suspension bridges.
$10 Billion? Not a chance.
Dear lord, if you assume 2000 people working on this thing at $100k (loaded labour rate) for 10 years that alone is $2 Billion. Ok? Besides 2000 people there are brand new engineering techniques to be developed, new fangled carbon nanotube strands that have yet to be manufactured or tested and you need to build the facilities to make all that stuff. Then you need to build, and maintain, a floating platform in the middle of the freaking ocean. Most oil rigs are near the coast and are accessible by helicopters. This thing would be stuck in eth mid of the Atlantic/Pacific. Not very easy to get people out to or back from. That costs even more money.
$10 Billion is a pipe dream.
You’ve got to remember that the folks who are promoting this have a vested interest in generating interest for this project. If they just come out and say, “It’ll cost half a trillion dollars”, then they’ve got no chance of getting even seed capital for feasibility studies and prototypes. So they’re going to take the lowest possible figure they can possibly convince people of, and throw it out there to see if it will stick.
I don’t know if I’d go as far as the trillion dollar estimate RickJay tossed out, but it sure as hell isn’t going to be 15 years and 10 billion dollars. Hell, it cost over a billion dollars to build and launch Cassini, and that thing is the size of a small car and used proven technology. And at that, we had to launch it on a smaller-than-desired rocket and use gravitational slingshots to get it where we wanted it to go.
The shuttle flew a tether a few missions ago to see what kind of current would be built up on it (the thing cuts through Earth’s magnetic field, so it’s going to build up a whopping charge). The small tether they dropped out of the back of the shuttle was lost when electrical discharge burned through it. This is an example of the myriad little technical problems that crop up when trying something really, radically new.
Most engineering is done in tiny incremental steps. A technology is proven, and someone takes it a teensy bit farther. Then operational data is collected, problems fixed, and eventally the new practices make their way into our collective engineering database and are used to make the next incremental improvement.
The space elevator, on the other hand, requires major new techniques in numerous areas. This is ALWAYS wildly expensive. A good example of another fanciful engineering project like this is the Moller Skycar. In broad strokes, it sounds simple enough - use a bunch of engines on pods power the thing. Rotate them down, and you can hover. Rotate them forward, and you fly fast. Use a computer to control it, and you can build ‘highways in the sky’ and everyone can fly! The vision itself is simple, and the engineering known. But Moller has been predicting that his skycar would fly ‘this year’ for at least a decade, and maybe more. The devil is in the details. Fuel consumption. Motor failure. Designing a control system that’s reliable. Weather. Lightning protection. protection from fan blades being thrown. Lower engines sucking FOD off the ground and spitting it through the back engines. Etc. ad infinitem. Too many new techniques and ideas in one machine. It’ll never be practical.
There is too much handwaving analysis in the space elevator concept. “How do the cars climb teh tether?” “Uh, they’ll just clamp on and go up!” “How are they powered?” “We’ll use a big laser!” “How do you get the tether to the ground?” “We’ll extrude it from a satellite!”. Simple in concept, but the unknowns are huge, and any one of them could lead to years of delays and cost overruns.
I think Rickjay is pretty damn close to the cost and timeframe. The cost sounds high, but this project will take decades to build. It takes 5+ years to build a bridge around here, and a bridge is easy compared to this marvel.
I think it is better to overestimate than underestimate. At least in cases like these. It will probably be 20-25 years until such a thing gets built (optimistic outlook), and then it will take 20-30 years to build, test, and open for general use. Hell, 50 years sounds too optimistic.
Place me with the skeptics. This doesn’t sound remotely reasonable. Also, am I the only one thiks it shouldn’t be built, even if we could?
If it snapped the lower section would dig a trench that would make the Grand Canyon look puny when it fell.
Would it fall? If it snapped in our atmosphere I can see part of it falling, but if it came loose from its mooring on the bottom of the ocean, would it even fall? That falling probably wouldn’t cause too much damage, would it? I mean it is only a ribbon, three feet wide, probably only a couple hundred tons in total weight, dispersed in say- a 10 mile long strand.
At what point would the strand have to snap in our atmosphere to cause damage that makes the Grand Canyon puny?
Say 1 mm x 3m x 20,000 km. That’s about 157 million kg, or 157,000 tonnes. Still I’d say that it would burn up fairly quickly on re-entry.
So the entire length of ribbon would fall to earth? Even that which is 190 miles from the surface of the earth?
I’m not sure. Take my numbers as a worst case.
Me either. My physics background is limited. Hopefully Exgineer knows, or somebody with a definate answer comes along, I gotta know now. 
It’s a consequence of tidal forces and orbital mechanics. If it breaks the lower section won’t be going fast enough to stay up and the upper section will be going too fast to stay where it is. Bottom half comes down, upper half moves out.
It couldn’t just drop straight down, either. It’ll lay down in a line trailing the anchor, and that much stuff impacting at orbital speeds will definitely make a mess.
Has anyone seen this? It’s a group working on something called “Airship to Orbit”, which uses a series of huge balloons and ion engines to get to orbit. There are some problems, for sure, but it seems like they’ve got a workable idea for getting into space on the cheap.