NPR Talks Skyhooks

David writes "NPR's Talk of the Nation this past week featured Brad Edwards, President of Carbon Designs Inc., to talk about their plans to develop an elevator that would lift people to an object orbiting in outer space. The project's homepage details their plans and ambitions. The discussion expands on callers' concerns about such problems as commercial airliners running into the super long cable or if it would act as a conduit for lightning."

Comments

Re:Towers 2.0

[yotto]

*Don't space elevators have to be built along the equator?

I thought this as well, but no, they don't. A rough diagram of a space elevator would be:
O--------
Where the "O" is the Earth. Imagine, right before "tying down" the base of your elevator, you drag i "up" a few dozen degrees to New York. The farther North you go, the more of an angle it will have, but it's not unstable so long as it's anchored.
The first thousand miles of the climb would be like a very steep gondola ride.

*NIX and no Real

[zp]

% mplayer -ao pcm:file=20050603_totn_03.wav 'rtsp://real.npr.na-central.speedera.net:80/real.n pr.na-central/totn/20050603_totn_03.rm'

Should work if one has mplayer but does not have realplayer.

Re:Muzak

[evil_mojo_jojo]

The endpoint is way past geosynchronous orbit, but the counterweight is less than the cable. It's a win because if you put the endpoint out far, you get greater centripidal force for an extra-orbital launch.

Re:Nothing new under the sun

[Calsat]

Tower of Babel, thank you.

Re:wrong concerns

[mbrother]

No, because it's very light and will be spread out over an area. Think of dropping a ribbon off a building. Payloads in transit are a larger issue, but more on the level of a plane crash than a nuclear explosion.

Interesting interview

[drgath159]

Covered a lot of the questions that have popped into my head while reading the previous 947 Slashdot/Space-elevator articles.

Highlights
- Location? Straight south of California near the equator.
- Timeframe? 15+ years
- What if an airliner flew into it? Pretty much screwed. But the location is 400 miles from any air route so shouldn't be a problem.
- How long would it take to get up? A few hours.
- Wouldn't it be a huge lightning rod? Yeah, but that area of the world does not have lightning, so shouldn't be a problem.
- Wouldn't the car that goes up the cable just pull it down and not crawl up it? Yes, but the car is only a few tons and the weight of the cable and weight on the other end was something like a couple thousand tons. So shouldn't be a problem.

There are a lot of "shouldn't be a problem"'s in there that one of them will be a problem. Exciting technology though.

Re:No free lunch

[yotto]

Sorry, but you're wrong.

The current solution to the problem you outlined is to shoot the thing with a laser (a big frickin' laser) on the ground. Keep the laser trained on the elevator car, and on the car convert that light to the electricity you need to crawl up the line.

I wouldn't be surprised if some day some smart engineer figures out a way to use the potential energy of a down-moving car to supply some of the energy to an up-moving car (Not all, of course, gotta pay mister Entropy).

Re:Skyhooks?

[imroy]

According to the Wikipedia article:

The name "Skyhooks" comes from an imaginary device created in the book Charlie and the Great Glass Elevator used to hold the elevator up in mid-air.

Re:Maypoling to avoid sats too

[Rei]

You confuse maypole and hoytether. A maypole is a radial structure where the cables merge at a single point and diverge thereafter. A hoytether is a regularly interconnected series of cables. Maypoles lose equal strength with every hit. Hoytethers lose less and less strength with each successive random hit. The downside to a hoytether is that your mass requirements grow greater and greater the further apart your base cables are. It's not realistic to make your whole skyhook have its component cables be far enough apart that its earth intersection would be safe from lightning/aircraft impacts.

Babel, not Babble

[fbform]

I don't think the space elevator is quite as ambitious as the tower of Babble

At the time, it was better known as Babel. It wasn't named Babble until the people could no longer understand each other.

Later of course, Babel and Mabel got together and had lots of Baby Bels. The runt of the family was nicknamed Deci Bel.

Re:wrong concerns

[1u3hr]

Unless the pilot is a crazed Saudi with a taste for Flight Simulator...

Sorry, this isn't "insightful". Need I say RTFA? Perhaps I do.

• the elevator cable is a few mm wide, and thus invisible from any distance (though the climbers will be larger, but only a few times a day). Not an easy target
• the base will be a platform on the equator in the open sea. It'll be well out of any normal flight paths, anything approaching will be very obvious a long time before it gets close.
• it'll surely have air defence easily able to take out any civilian plane. In case of war, it's a sitting duck, but would probably get a battle group to look after it. In extremis they could release the tether and pull it up 100 km out of harm's way and let it down later (too bad about the platform though).