In the meantime, the technology is being applied in other areas, such as bridges (the cable material) or fuel re-supply (the power beaming system suggested for powering climbers). They not only have what things might look like, they have seen them work. The major problem is that with an increase in length, an increase in tensile strength is required. Everything else can be bested small scale, and the tensile strength problem has seen great leaps over the last decade (it is actually ahead of the original estimates).

Cost may indeed be greater than the current estimates, but even an increase by a full order of magnitude would be a pittance to pay for the capabilities of a space elevator.

Take any large infrastructure project where size/technology/logistics/political boundaries must be pushed. The Channel Tunnel, the Boston Big Dig, the LHC, Airbus A380, Boeing Dreamliner, the Space Shuttle, Hubble, the ISS. All fairly successful (let’s say) but they blew their budgets and often the timelines as well.

In this case the space elevator folks don’t have a cable implementation, they have a theoretical description of what such a device MIGHT look like and MIGHT be constructed out of. Same goes for the cable cars. They also don’t have much in the way of similar projects to point to, and that means the list of architectural, construction, and engineering firms with experience is exactly zero. This project has such high risks that any such firms might ask to be completely indemnified against project failure (if they agree to get involved at all).

For all that it’s still worth trying. Rockets just don’t seem to have the mojo needed to bring costs and risks down to where sending something into space is no more dangerous, expensive or remarkable than taking an intercontinental vacation.

Linear Magnets perhaps.

or grab on and climb with your hands…. (this may take a while, but would most likely open up a whole new crazy record breaking sport)

The benst part, that makes it so cheap…. is that when things come back down the elevator… the motor can be a generator… giving energy back… keeping your costs down…. So you only pay in energy for the payload lifted, not the elevator itself.

You could even setup some kind of cheap/free/profitable energy system…
Setup another elevator on the moon.
Lift stuff for cheap on moon gravity, fling it towards earth…. then let it drop down the earth alevator under much higher gravity, and collect net power generated for free.
Probably impractical… but the elevator opens up all sorts of crazy ideas.

easiest way to make it safe…. run a whole bunch of tethers.. super redundant… the more the better

assuming we can make the tether…. isnt the main problem, getting a big anchor object (and a tether maker) into orbit ?

I agree, the $9 billion price tag sounds astonishingly low, but that’s the number the group is putting out there. Also, in the 2004 DISCOVER article that I linked to the engineer cites a $6 billion price, so I guess all the dreamers agree that it could be done on the cheap.

@Steve: Yes indeed, the elevator’s nanotube cables could be damaged by all sorts of things! Especially space debris. Some say that if you make the nanotube ribbons strong enough they won’t be damaged. Others say that more drastic measures would be necessary. Again, from the 2004 article:

“Since the dawn of the space age in the late 1950s, low Earth orbit has become a junkyard, with about 110,000 hunks of old spacecraft one half inch or larger hurtling at speeds as high as 30,000 miles per hour. Pieces moving 20 times faster than a high-powered rifle bullet would damage even the space elevator’s superstrong fibers. Edwards’s response: Make the ribbon’s base mobile so that it can dodge the biggest pieces that NASA tracks (a 30- to 60-foot movement would be needed every six days); make the ribbon wider in low Earth orbit, where debris is most plentiful; and regularly patch small gashes.”

That’s a very good question. Most proposals I’ve seen suggest the elevator be built on a floating sea platform, like a mobile oil well. That would allow it to set up shop somewhere far from terrorist or military hot spots, perhaps in the Central Pacific. It would be defended by continuous air and sea patrols, and could–to an extent–move to avoid problems or storms.

A bigger danger might be orbital debris striking the tether, and I have no idea how you solve that problem. The tether is going to provide a pretty big area for impacts, so you have to figure it’s going to get hit often. If the elevator cab were to lose tension in transit, due to a tether break or a power loss or some other problem, it would go into some ballistic trajectory based on how high it was on the cable (and thus its angular velocity). If it was close to the top, it might be very near a geosynchronous orbit. If it was very close to the bottom, it would drop almost straight down. If it were somewhere in between, it would fall like a hurled stone. One could imagine an escape pod for the crew, similar to a Mercury capsule, with a reentry shield and parachutes. Solid rockets could separate the capsule (maybe) and send it on a safe reentry trajectory. If the cable broke while you were near the ground, though, I don’t think there would be much you could do.

Perhaps, if this ever gets off the ground, the system will be built with two redundant cables, so that a break in one is not catastrophic. Once you’ve built one, after all, building the second one is easier because the cable cars themselves can do it. Two cables also opens up some additional possibilities for powering the system electrically.

Anyway, it would all be a supreme technical challenge.

Does the article perhaps mean 9 trillion? 9 billion just seems so small, I’d think if that were true Bill Gates could potential purchase one of his own.

http://science.nasa.gov/Realtime/jtrack/3d/JTrack3d.html