Then there were two

March 18, 2003 6:58 PM

Seattle PI have picked up the news that there's now competition in the race to build a space elevator. Liftport are the new kids on the block, with a website that only went online about 24 hours ago. I'm watching them build the message board as I type. Nothing like a bit of uplifting science news (pun unavoidable).
posted by krisjohn (14 comments total)

Not really competition. Some of the guys behind highlift are starting a new company now that the nasa funding has run out.
posted by balinx at 7:10 PM on March 18, 2003

My ignorance on engineering needed to do this job is immense, as much as my curiosity ..so a few question for the well informed guys..

a) How does one manage to lift the weight of the cable itself ?
b) Isn't carbon a conductor ? What if a lighting hits the cable, "cosmic freedom fries" ?
c) Wouldn't such a cable require a geostationary satellite or something like that, to keep the top end of the cable
exactly above the bottom end ? That's a 36.000Km cable, unless you connect it to something with engines that can keep it straight.
posted by elpapacito at 7:12 PM on March 18, 2003

There's only one word suitable for describing the space elevator... *HOGH*HOGH*HOGH*!!!

The science behind this thing is bloody ridiculous cool.

a) The cable, if I recall correctly, is dropped down from space.

2) From what I understand, there are a few "lightning-free" areas on earth, where probability of lightning striking is very, very small. One of these in the South Pacific (somewhere near Ry'Leh?) also far from any airline routes, has been chosen for the elevator. (There's also a question of the cable screwing with the ionosphere or generating ridonkulous amounts of electricity by connecting differently charged parts of the atmosphere. From what I understand, this shouldn't be a problem, either. In fact, at some point, they were looking to see if they could harvest energy, but found that the output wouldn't really be worth it.)

iii) Yes, a geosynchronous sattelite is the plan. And yes, that is 36km of cable, which isn't SO bad considering we've built things like transatlantic phone lines in the past. It's more of a problem when talking about carbon nano-tubing, but it's expected that large-scale production of the stuff will be possible by 2015.

All of this is much better explained in the FAQ's over at Highlift Systems.
posted by kaibutsu at 8:42 PM on March 18, 2003

If I remember correctly, the Highlift plan calls for a cable significantly longer then to geosynch orbit. I believe they are talking about a cable that goes about a quarter of the way to the moon, or 96,000kms. (ahh, yes, 91,000, according to this) At 7.5 kg a km (from their FAQ linked above) that makes just under three quarters of a million kg, which is a hell of a lot to get up into space, but not impossible.
posted by Nothing at 9:58 PM on March 18, 2003

Er, that is 7.5 kg per km of cable, I mean.
posted by Nothing at 10:00 PM on March 18, 2003

At last, at last!
posted by interrobang at 10:52 PM on March 18, 2003

From their "Frequent Misconceptions" page:
A number of science fiction stories, including novels by Arthur C. Clarke, Robert Forward, and Kim Stanley Robinson, have involved space elevators on Earth and Mars. These have all been set many decades in the future; the elevator cables were meters and even kilometers in diameter and massed in the billions of tons. In some of them, the horrific destruction caused by the cable breaking and falling was an important story element.

Sounds interesting. Anyone know titles?
posted by Tubes at 11:33 PM on March 18, 2003

The subject of space elevators, raised in earlier discussions.
posted by thijsk at 12:37 AM on March 19, 2003

why are they running SSL with a bogus certificate?
posted by quonsar at 3:55 AM on March 19, 2003

are they planning nanotubes or a wire? Because the wire weight should be enough to drag the thing out the sky...
posted by twine42 at 4:40 AM on March 19, 2003

They're planning nanotubes. They've done a pretty good deal of the math involved (as set out in this report), and have a useful FAQ as well. Short version: the necessary materials aren't available today, but might become available in the pretty near future with a decent-sized R&D program.
posted by Zonker at 4:57 AM on March 19, 2003

I can cope with that.

Space Elevators are a beautiful idea, and one that I can't imagine can fail, assuming we don't confine it to a time frame. But space elevators within 15 years? I'd love to think it's possible. It seems ironic that by that time it works it'll probably cost more to fly to the elevator than it will cost to get up there...
posted by twine42 at 5:04 AM on March 19, 2003

Once the first one is built, the first task should be to build a second one since the cost of getting the material up would be a lot less and provide redundancy. Imagine, a cluster of them.
posted by stbalbach at 5:37 AM on March 19, 2003

Anyone know titles?

Clarke: The Fountains of Paradise

Robinson: Red Mars
posted by SPrintF at 7:16 AM on March 19, 2003