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Re: SDC or MDC for a Beanstalk

Posted: Sat Sep 27, 2008 12:15 pm
by Braden Campbell
In one of the Time Odessey books (Arthur Clark and Stephen Baxter), the characters take a ride on a space elevator - takes them 12 days or so, becasue its designed for cargo and not people, but it works. They describe the actual elevator as being a "ribbon" - a very thin, very narrow material whcih is sonstantly patroled by "robot spiders" that race up and down it, always making repairs.

Now in a Phase World setting, all you'd have to do is attach cargo pods with a CG generator, and give them a guideline. The elevator could therefore likewise be a thin ribbon of material, whisered carbon buckyballs for example, anchored to the planet below and an asteroid or space staion in orbit.

Such a thing would have less then 100 MDC per any given point.

Re: SDC or MDC for a Beanstalk

Posted: Sat Sep 27, 2008 12:54 pm
by KLM
It is probably rather fragile.

I mean the materials themselves are rather strong, however
the structure itself is under constant and tremendous tension.

Also, it depends on the size of the lift cabins it is designed for.
Your average contemporary elevator cabin, with life support
and things is probably the smallest one - around a ton with
RIFTS 3G technologies and materials.

Such an elevator system would consist two cables, and about
10 MDC damage could snap one.

In bigger systems it could go considerably higher, as well as
they might have several paralell cables or rails, not just a mere
pair.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Sun Sep 28, 2008 1:58 pm
by taalismn
Yeah...and prepare for howling noise from the wind blowing over it...
I have a set of massive radio towers near me, and when a good stiff wind starts blowing through the cable stays....

Re: SDC or MDC for a Beanstalk

Posted: Sun Sep 28, 2008 5:34 pm
by KLM
Talking about air guitar...

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Mon Sep 29, 2008 12:39 am
by Aramanthus
LOL!! I agree with the sentiment so far in the thread. It would have to MDC although fragile. SD weapons shouldn't do anything to it unless you ran an SDC vehicle into it at full speed. That might actually be able to cause some serious fraying in the actual cable. Which could lead to it's severing.

Re: SDC or MDC for a Beanstalk

Posted: Mon Sep 29, 2008 9:34 am
by taalismn
buckyball cables ...or long chain molecules..

Durability versus safety(as in the beanstalk whiplashing into the planetary surface at supersonic speeds)

Re: SDC or MDC for a Beanstalk

Posted: Mon Sep 29, 2008 9:44 am
by KLM
That is why there should be at least two - to support each other in case one of them is snapped.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Tue Sep 30, 2008 2:51 am
by Aramanthus
I agree KLM! Safety is always important and should be at the forefront.

Re: SDC or MDC for a Beanstalk

Posted: Tue Sep 30, 2008 3:54 am
by KLM
Also, if we have a pair of cables (periodically interconnected) and one of them snaps,
we only have to repair a single portion of it - instead of a single cable whiplashing
in its - say - half lenght, which is in the case of Earth's geosyncron orbit (when the
sattelite at the end of the cable stays over one point of the planet surface) is around
20.000 kms. Yepp, well over ten thousand miles.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Wed Oct 01, 2008 2:34 am
by Aramanthus
Also with the two cables it makes it far easier to carry out repairs. Which is very important.

Re: SDC or MDC for a Beanstalk

Posted: Wed Oct 01, 2008 8:51 pm
by gaaahhhh
They said it was a beanstalk cable, but really it's a giant whip.

Re: SDC or MDC for a Beanstalk

Posted: Thu Oct 02, 2008 12:00 am
by Aramanthus
Which is anchored at both ends. One on the ground and the other to a satellite in geostationary orbit. :D

Re: SDC or MDC for a Beanstalk

Posted: Thu Oct 02, 2008 6:47 pm
by gaaahhhh
Aramanthus wrote:Which is anchored at both ends. One on the ground and the other to a satellite in geostationary orbit. :D


...Until one end breaks.

Edit - Who put this section of SDC cable in with the MDC cable? :oops:

Re: SDC or MDC for a Beanstalk

Posted: Fri Oct 03, 2008 1:56 am
by Aramanthus
Don't see that happening unless they have some person messing with contracts. And once it is found out, that person is probably going to be in a world of hurt.

Re: SDC or MDC for a Beanstalk

Posted: Fri Oct 03, 2008 2:38 am
by KLM
gaaahhhh wrote:They said it was a beanstalk cable, but really it's a giant whip.


More like a giant ladder if two cables are used. It has to break on at least two places...

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Fri Oct 03, 2008 2:53 am
by Aramanthus
And who is to say that they don't have some sort of system on the fly which travels up and down the cable regularly to make sure it is not flawed and to correct those flaws when they start to show up in the material.

Re: SDC or MDC for a Beanstalk

Posted: Fri Oct 03, 2008 4:08 am
by KLM
Actually it can be monitored without any moving parts.

Also, it must be flexible, so it can "bend" out of the way of detected meteorites and such,
but solar flares and the like can and do wear them out.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Sat Oct 04, 2008 2:07 pm
by KLM
The easiest part is the lenght of the stuff:
It connects the planetary surface and a geostational sattelite/station.

In case of Earth, it would be about 48.000 (forty eight thousand) km.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Mon Oct 06, 2008 11:21 pm
by Aramanthus
So far the bulk of us seem to be agreement.

KLM, you mentioned the ability to move to avoid asteroids. Would that be the top being able to move? Why not have specialized equipment to intercept incoming asteroids. If we could round them up, we could have a nice supply of raw materials.

Re: SDC or MDC for a Beanstalk

Posted: Tue Oct 07, 2008 1:04 am
by KLM
Aramanthus wrote:
KLM, you mentioned the ability to move to avoid asteroids. Would that be the top being able to move?


While the top geostationary station has to have some manouvering
ability, I guess the elevator "cable" itself is easier to bend out of
harms' way.

Why not have specialized equipment to intercept incoming asteroids. If we could round them up, we could have a nice supply of raw materials.


That too, but not every piece of rock worths dealing with rounding up,
and in the case of a bigger one (like a house) might not be worth to
shoot it - because instead of "stepping" out of one projectile's way,
it might look like dodging a shrapnel cloud.

Just my two virtual cents.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Tue Oct 07, 2008 1:11 am
by Aramanthus
So you are talking about the cables being smart material that does what it's programmed to do? I wasn't actually thinking of shooting them bown but changing the approaching objects orbit to make it easier to capture.

Re: SDC or MDC for a Beanstalk

Posted: Tue Oct 07, 2008 3:03 am
by KLM
Aramanthus wrote:So you are talking about the cables being smart material that does what it's programmed to do?


If you have that technology, yes.

Otherwise, put on a small cable car, with some repair facilities, a solar panel and a small ion thruster
on it, to do the repairs (after all, one cannot dodge cosmic radiation) and bend the cable if neccessary.

Adios
KLM

Re: SDC or MDC for a Beanstalk

Posted: Tue Oct 07, 2008 3:58 am
by Aramanthus
Oh ok! That is a cool way of doing the manuevering! :D