If this happens, it would probably be one of the biggest space transport breakthroughs ever.

http://news.yahoo.com/news?tmpl=story&u=/a...pace_elevator_1

I think the best part is that he has also thought up a way to actually get the elevator into space without the need for dropping it from an asteroid in orbit. I am skeptical, though, since there have been many other announcements about many other breakthroughs, of which there have been nothing.

If only I had ten billion dollars...

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Eeahh, I'm not too sure.

The Arthur C. Clarke novel quoted as "The Foundations of Paradise" is actually titled, "The Fountains of Paradise". This is a very seminal book on the subject by a well known landmark in Science Fiction.

One wonders what else they got wrong.

The winds may be fair in the proposed location now, but maybe climate change will change all that.

And, scissors beats cable.

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The Space elevator has more obstacles to overcome than can be solved in fifteen years. It includes:
- the fact that carbon nanotubes are highly flamable
- the debris in orbit has to be cleared out [scissors beats cable]
- the starting point on Earth has to be above the weather [and lightning]
- the cable has to be able to handle the electric current it will develop sweeping through the Earth's magnetic field
- carbon nanotubes haven't been manufactured in any great length yet [a process has to be developed to do this cheaply]
- it will take a LOT of cash to start the project.

I imagine that it will be built this century if we survive.

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I wonder, would the construction start in space or on Earth? I think I know the answer to that...stupid question <_< .

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A better question: how far would the elevator extend?
Would it extend just to the end of earth's atmosphere?
Would the ISS be at the other end?
Would it end very close to the moon?
Also, where would the elevator base be on earth?
On the primeridian or Internat'l D-L? Probably not.
On the equator? Probably...where?
Africa?
Asia?
S. America?
Pacific?

In the final book of Clarke's ODYSSEY series, there are four space towers (not necessary elevators) equally spaced apart on earth's equator. Does this seem likely to happen in reality?

I think the main problem is making the whole cable.

I don't think carbon nanotubes can carry a current...but I'm not sure. Carbon isn't a metal, or even a semi-metal. If it did carry a current, could it be used for power?. Also, it could be coated with a flame-retardant (which would hopefully not add too much weight).

For debris, smaller objects shouldn't be a problem, ISS can withstand hits of objects up to a quarter-ince in size. In Robinson's Red Mars, they slowly "wobble" the cable back and forth to avoid Phobos and Deimos hitting it, maybe something like that could apply here for larger objects, like satellites.

I'm sure it will take more than 15 years, but it's still better to try than to quit before we start.

A lot of questions. Basically, an elevator would stick out all the way past GEO and stay up by centripetal force. The far end, if engineered properly, would be moving faster than escape velocity, so any spacecraft could just be flung off without the need for propellant (except to slow down).

This particular elevator design would end at 62,000 miles (100,000 km), well short of the Moon. (Another point, the Moon's gravity could cause instabilities that would have to be balanced by something else, probably attitude jets). Other designs end at other altitudes, but it's still the same idea.

Note: It would be impossible to have the other end at the Moon because the Earth rotates much faster than the Moon orbits.

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The space elevator conference in Washington just wrapped up... did anyone attend?

http://www.isr.us/spaceelevatorconference/

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And the difference in electric charge between space and Earth, and that's an awful lot, with an unbound amount of charge in space. So when the current starts flowing it won't stop unless something gives (the cable).

Cheers.

Here's another great resource for space elevators:

http://en.wikipedia.org/wiki/Space_elevator

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I don't think NASA could find it's own rear-end with both hands in 15 years. The only hope for a space elevator is if a private firm develops it, and 15 years might be a little to soon.

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The Earth is bi-polar.

I always invisioned it starting in the 22,300 mile geostationary orbit, and reaching down to someplace on the equator.

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The Earth is bi-polar.

I don't think a space elevator would be completely built by NASA, but if they committed to a certain amount of launch business every year, it would give private investors more confidence that there's a marketplace for a space elevator.

The folks planning on building an elevator need to get a commitment from anyone launching anything into orbit that they'd buy if the space elevator could deliver launches for X price. If launches cost $3,000/lb right now, and some entrapreneurial companies think they can get it into the $1-2,000 range, the space elevator would need to offer a launch in this price range.

Let's say they can line up $2 billion a year in launch business, and vastly undercut the traditional launch business, the investors would take it very seriously.

Anybody want to try a back-of-the-envelope calculation?

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There are several sets of costs to take into account:
- The cost to manufacture the ribbon[s].
- The cost to launch and deploy the initail set-up
- The cost of the cargo-car
- The cost of the initial orbital platform
- The energy cost per trip
- The annual maintenance of the system
- The consumables for the passengers [if any]
- The cost of insurence in case of disaster
- etc.

Of these, there isn't any way to accurately estimate the cost of the ribbon. Assuming that a manufacturing process is found, lets be hopeful and say it will cost about $1000 per meter. Ribbon cost: $80,000,000,000 for a ribbon to geosynchronous orbit, and a ribbon for a counterweight.

The cost to deploy and set up should be about $10,000,000,000

Lets assume the cost of the Cargo-car to be cheap [$200,000,000]

Let's assume the cost of the initial platform to be $25,000,000,000

The energy cost per trip could be zero!

The annual maintenance of the system is a tough one to guess. Let's give a WAG of 15% of the total system cost.

Lets ignore consumables and insurance for now.

So the cost of the set-up is $115,000,000,000 with about $18,000,000,000 per year maintenance and operation costs.

Let's assume the cargo-car can make one trip per week [50 per year]. This means that each trip would need to yield $360,000,000 profit. This would require the car to carry 180 tons to make it pay if the profit was $1000/lb.

Another way to look at it is that we can start bulding this system profitably if it costs less than $10 per meter to fabricate a ribbon that can support itself plus about ten tons. I think that will be quite a few years off, and will require some serious advancement in nano-technology.

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Have a look at www.liftport.com!

I've posted this before and everyone seems to ignore it for some reason

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My god! Its full of stars!

We're not ignoring it, it's a very interesting site. You might want to list it as http://www.liftport.com, so people can link to it directly.

Great calculations Antoniseb, I was actually thinking what it would take from the other direction. How big is the current launch market, considering everyone switched to a space elevator at, say $2000/lb. How many pounds were launched into space in 2003?

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I think it'll be a little while before the technology can be made cheap enough to make the option viable. Right now, there's no existing market for carbon nanotube production, and I think if scientists worked on finding other uses for this material, and worked on building up an industry based on this, then in about a decade we could make the effort worth the cost. Otherwise, no one with the financial means to make it possible will pay all that much attention.

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Carbon is a good conductor and its conductivity increases with temperature (unlike most conductors)which is why its used for brushes in electric motors.

Space Elevator ...nice idea but science fiction for a half century

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