$10 billion and 15 years?
I’d say thats far to optimistic. I would guess at the very least $20 billion and 25 years. It’ll get done eventually, but underestimating the challenges it’ll bring isn’t doing anyone any favours.
That doesn’t mean I won’t be ecstatic if they pull it off.
Chump change.
Am I right in thinking that weight won’t be much of a problem because of centrifugal force? (or does the earth not spin that fast)
Whada you mean no new physics? As I understand it, to build a 62,000 mile long space elevator you need 62,000 mile long strands of carbon nanotubes. However, nanotubes today are only manufactured in little piles of dust that cost a gazillion dollars. Explain a way to efficiently make long strands of nanotubes and I’ll start getting excited.
When I first heard the idea of a this years ago, my thought was “how the hell are they going to protect this thing”?
It seems to me like it’s going to be awfully difficult to prevent some numbnuts from flying into this, either accidentally or intentionally. I would think this thing would be lit up like a massive Christmas tree to prevent accidental collision, but how in the world can this be protected from someone looking to cost the U.S. a few billion bucks?
Not saying it shouldn’t be built, I’m just wondering if it’s going to have to have an armed fighter plane flying around every few thousand feet of it’s length.
The articles I’ve read in the past have all mentioned that need. I don’t think that the plan is to have fighter planes constantly flying around the thing, but more likely a “no fly” zone around it, along with lots of EAM (Elevator to Air Missiles) with a long enough range and power that they could take out anything headed for the elevator.
The conference on space elevators takes place in a couple of days. And last years presentations can be found here.
Expendable launch vehicles built from conventional materials have significant advantages over a space elevator built from conventional materials. Would one not expect, then, that expendable launch vehicles built from carbon fiber nanotubes would have a significant advantage over a space elevator built from carbon fiber nanotubes?
There is a hell of a lot to do beyond coming up with a few nanotubes, folks.
Fifty years and a trillion dollars and that’s if we’re lucky. And I’ll bet money on it.
That’s like saying a horse has a significant advantage over a car because a horse can eat grass.
The beauties of a space elevator compared to an expendable rocket are as follows:[ul]
[li]Larger payload capacity, it can haul thousands of tons of cargo with no propellant, whereas a rocket needs a ton of propellant or more to lift a pound of cargo.[/li][li]Longer life. If the space elevator’s carrying tons of materials into space on a daily basis, it beats a one time use rocket.[/li][li]Enviromentally benign. A space elevator can be solar powered.[/li][li]No need for exotic heatshields for returning items.[/li][/ul]
RickJay, what leads you to believe that it’ll be so complicated and expensive?
What kind of space elevator are we talking about here?
The two types I know are the one which is anchored to the Earth and on the other extreme of the cable there´s the Mother of All Counterweights; and the other is the thing that spins around and one end of the cable enters the atmosphere at regular intervals.
The counterweight one
It is to be positioned off the coast of Ecuador on a thing similar to an oil drill. Every so often they change it as to avoid space debris from tearing it. It would also be a counter-weight type deal.
Also, the current fiber is one percent Nanotubes and the rest polyfibers. Ideally they would need 50/50 or more of the carbon nanotubes.
Unbelievable Tuckerfan… that was my exact post almost… good thing the last part is alright still.
OK, so I should have checked the link… 
Now I see what kind of space elevator this would be; I´m a bit curious about this:
A piece of paper, for the record, is about 0,02 cm thick; now that is some thin “cable” they´ve got there!. Turns out it is more like a ribbon after all.
Anyway, the whole affair seems of a much smaller scale than I thought, though 13 tons is a respectable weight, however how long would it take to the elevator to reach the top floor?, I mean, if it takes two months then the scheme looses a bit of interest. For the sake of argument let´s say a 62 mph climb speed, that turns into 1000 hours of travel, roughly 42 days. :eek:
The quoted speeds that I’ve seen on other sites indicate that a trip up would take 7 days.
OK, not that bad after all; but is that a round trip or just a one direction ticket? Well, as long as it´s slow but dirt cheap it´ll be OK; though I wouldn´t be thrilled about hanging by a thread for a week. 
Talking about threads, this ribbon, 3 feet wide, I think that would take quite a load from winds, no matter how calm the area may be, there´s always some wind and the ocasional storm; and there´s a lot of canvas there…
I may sound pessimist, but this is one of those things that I don´t buy easily. :dubious:
That’s the trip up, if the space elevator’s like the elevators in the WTC, then the trip down will be a bit faster…
Well, the theoretical limit for nanotubes strength is something like 300Gpa, and the engineers say they only need 160Gpa out of them for the elevator to work, so if the engineers are saying that including a healthy margin for safety, the actual limit to get the thing to work (in a vacuum) might be as low as 80Gpa. Bump it up to 200Gpa and you’ve really got things covered. The big issue is going to be getting the money, IMHO. I say we mug Bill Gates.