A Space Elevator?

[Capt Dizle]

Originally posted by Frogger
Which others have we managed?

HGP

[KrazyHorse]

Ah, yes. And the Cloning Vats (run by Miriam, it seems)

[DanS]

Here's a good survey of the state of the art in nanotubes.

http://pubs.acs.org/cen/coverstory/8050/8050chemhighlights13.html

And here's how long we can grow them. 20 centimeters in some configurations.

http://pubs.acs.org/cen/topstory/8018/8018notw5.html

[Gibsie]

Originally posted by Frogger
Ah, yes. And the Cloning Vats (run by Miriam, it seems)

Oh, god, you mean the religious nuts are gonna go into a population boom? Fetch the nerve gas...

[KrazyHorse]

Don't you just love Major Atrocities?

[DRoseDARs]

Ugh, this again.

While I'm certain we're close to being technologically and industrially capable of building such structures, doing so at this point of our history is a HORENDOUSLY bad idea. Obvious that they'd be targets for terrorism and sabotauge, but also the tech would be too new and unproven. Better that they should be built and maintained elsewhere in the Sol System first to earn our trust here on Earth. The main problem is what happens if they are build but later fall: build them too thin and they're impractical (difficult to move larger-enough loads to make it cost-effective) but they'll burn up almost completely in the atmosphere, doing negligible damage on the ground; build them thicker and it becomes much easier to move large loads, but more of the upper end of the cable would survive its trip through the upper atmosphere on the way down, enough to impact the ground/ocean and cause wide-scale damage, depending on how much survives reentry.

As far as being bulit-on (single strand) or stradling (split Y-cable) the equator, having the counterweight centered over the equator makes its orbit stable (re: Frogger and geostationary), plus objects being launched from there get greater *ompf* due to the Earth's rotation at that point. Having a counterweight at the space end of the cable follows the same principle as any other elevator: balancing the weight of the load+car (in this case load+cable). The cable doesn't actually stand upwards from the Earth, rather it orbits the planet in a highly refined balance of its weight. The strain on the total cable is a good bit less than one might reasonably expect, but carbon nanotubes are the best (and only current) material to manage the still-great strain.

[chequita guevara]

Go for it. I want to experience microgravity!

[Provost Harrison]

You're in serious sh*t if that breaks down and leaves you stuck on the 110 937 473rd floor

[Tingkai]

So which approach would be more cost-effective: develop the idea of a space elevator in parallel to the development of these nanotubes or develop better nanotubes first? Can the space elevator idea be developed now even though the nanotube technology does not exist?

[KrazyHorse]

What we need to do is wait for materials research to provide the right stuff to build. IMO it's not feasible to hurry this. Let it proceed at its own pace, with some seed money in promising places.

At the same time put some slight effort into theoretical design, feasibility studies and the like based on plausible future technology. Nothing like an apollo-sized chunk of change, though.

Not yet, at least.

When the right stuff comes along to build it, the smart people will be ready to go right away with some real design work and then construction.

Say in 30? 50? 75 years?

[Tingkai]

We need it done in at least 30 years so that I'll have a chance to use it.

[DRoseDARs]

Tingkai and Frogger:
What you've missed is that nanotubes have already been developed. The problem is mass-production of them and assembly into a super-structure...like a space elevator. The last time a thread was made on this subject, the article involved stated a group needed about $5 billion in order to finance developement and construction of such a structure sometime early next decade.

The technology exists. The materials exists. The need exists. It's just the economic push and development of the industrial techniques that's left to do to make a space elevator.

[KrazyHorse]

DRose: i don't see current nanotubules as strong enough to make the project feasible.

Remember what I said: from 10 cm at the base to 16 metres! at the point of maximum tension. That's way too big, IMO.

Luckily, the maximal width of the "cable" (at 50 feet across, it can hardly be called a cable) drops off rather rapidly with the tensile strength of the building material.

[KrazyHorse]

It's better than steel cable, though; steel requires something like the mass of a small planet...

IIRC, its maximum width would be on the order of 10 000 km

[Willem]

The Internet is such a wonderful thing! Here's the guy's proposal:

Space Elevator