OT: About Space Elevators

[geoschmo]

A plane hitting the cable is going to do damage to the plane, but it's going to break the cable as well. The cable slicing through the plane and ramaining intact is just not going to happen. We can't even comprehend materials strong enough for something like that. By the time we can planes will be faster and made of stronger materials too, so the plane will still break the cable.

You aren't going to have thousands of miles of cable falling down though, and it's not going to wrap around the earth. If the cable is that long it could of course wrap around the earth, but that much cable wouldn't fall down.

While the cable may thousands or even tens of thousands of miles long, a break in the cable at above a couple hundred miles is not going to cause it to come crashing down. The reason is that at that length the mass of the cable itself will be enough to keep it in orbit. Remeber that this isn't like hanging a rope fom a branch of a tree. The cable isn't supported by the sattelite at the orbital end. The cable is in effect a sattelite itself.

A break anywhere in the lower couple hundred miles of cable would cause everything below that to plummet to the ground of course. And a couple hundred miles of cable is going to be a problem if it lands on something. But you can limit the risk by locating the ground end carefully.

The literature on the website Baron posted talks about putting the ground end on a mobile ocean platform, like what is used for deep ocean oil drilling. These aren't attached to the ocean floor. This sort of arangment could actually be moved to avoid low earth orbit sattelites and possible sever weather such as a hurricane.

EDIT: Something else I didn't consider, but the website mentions. Parts of the ribbon above a certain altitude falling down will burn up in the atmosphere. So actually you may not get more than 10 or 15 miles of ribbon on the ground, not the hundreds that I was thinking. And the ribbon is heavy in total, but streatched out any particular piece of it is very light. So as it falls that part that survives the trip through the upper atmosphere will be slowed by the lower atmosphere to around the speed of falling paper. You'd have a big cleanup job picking up miles of ribbon cable, but it won't have much physical impact even if it hits something on the ground.

Geoschmo

[ October 09, 2002, 13:13: Message edited by: geoschmo ]

[Puke]

or they could have several parallel runs, that are interlinked at several intervals. say there are three cable runs. elevator cars could attacth around all three, but would be stable if only two held up.

while that might sound a little sketchy, the real advantage would be having the interlinkings between cables, so you would never really lose any. some would go slack, and you would just have to pick it up from where its dangling, and splice it back in.

or you can just go with the "reel some more out" method, which is probably alot easier, and maybe cheaper. the only problem there, is if 30,000 feet of cable come crashing down on the base-station, and sink it into the ocean.

A small battlegroup of cruisers and a AWACS or three, should be fairly capable of keeping air traffic away from it. I can imagine a little (huge) oceanic platform where cargo liners (and maybe cruise ships) come to load and unload cargo, and you would not want a several tons of cable to come slamming down on this.

the real cruicial time to defend it, would be when the elevator car is under 30 or 70 thousand feet, and would be vulnerable to conventional aircraft attacks.

[TerranC]

Originally posted by Puke:
A small battlegroup of cruisers and a AWACS or three, should be fairly capable of keeping air traffic away from it.

I don't think an military presence is necessary. And I think it will create a diplomatic incident if there is a military presence into something grand such as that.

[Puke]

why? its a significant economic interest, the corporation that owns it will be bringing in loads of money for their parent country. not only that, but it is a significant boon to space bourne interests. anyone that wants to use it to put payloads up, will have an interest in defending the thing.

I would sure think it prudent to be able to shoot down any unauthorized craft that strays within 50 miles of it.

im just waiting for the strong-man competitions where individuals try climbing the things into orbit.

[Phoenix-D]

"I don't think an military presence is necessary. And I think it will create a diplomatic incident if there is a military presence into something grand such as that."

Oh no, it's only the largest and most valuble target on the face of the planet. Why defend it?

Phoenix-D

[Taz-in-Space]

What I want to know is how they are going to ground the darn thing. Electricly. Isn't there an electrical charge difference between earth's surface and high altitude? Sounds to me like this would be the Mother of all Lightning Rods!

Who needs terrorists when NATURE itself will take care of the problem.

[Phoenix-D]

Just being that tall would make it the mother of all lightning rods, to say nothing of all the interesting effects it might have on global weather (and vice versa).

However, planes can take direct hits from lightning and keep going; if the car is on the outside, or cleared before a storm, I don't think a hit would do THAT much.

Phoenix-D

[dogscoff]

I can imagine a little (huge) oceanic platform where cargo liners (and maybe cruise ships) come to load and unload cargo,

Heh, that's a good point. HOw to get stuff to/ from the floating platform? Boats, sure, but boats are slow. It would be quite ironic if something this high tech revitalised some older technologies like flying boats & airships.

[Dragon of the void]

Good point about the lightning, Taz.

MAybe they yould even use this power that comes down the cable, it just has to be strong enough. Thus you would not need to "ground" it, you channel the current into your battery.

[dumbluck]

D of the V: Man, that's one honkin battery your talking about!!! Do they even make batteries with that kind of capacity? CAN they even make batteries with that kind of capacity????