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RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Mon Aug 22, 2011 1:16 pm
by WolfC
Hi all,
just registered to participate in this topic^^

As was said before, if we stop doing things cause some terrorist COULD destroy it....well then all hope is lost.
We should instead say: "If some terrorist blows it up, we´ll build it AGAIN AND TWICE THE SIZE!" ;)

Also I don´t see a problem with war, look at the ISS, many nations including Russia work there.... thought china was interested in supporting it too.
An orbital elevator would be more expensive and more valuable for every nation as the ISS already is. So lets assume China (and maybe every other tech. advanced country has something going on with it) as well as all the nations already working on the ISS...... what nutjob would piss off all these nations? Some 3rd world country maybe? Somalian pirates maybe? THAT would be a really short and very unsuccessful war :D


The REAL problem is the cable needed for it, currently no known material (MAYBE excluding carbon nano tubes) is strong enough to support it´s weight at that height.
You can only build a structure so-and-so high with an material before it crumbles under it´s own weight, the diameter doesnt play a role in it, as the wider it gets the more it can support, yes, but also the heavier itself gets.

The best building site would be some pacific island near the equator, a swimming platform moves and makes calculating an stable orbit impossible, also the pacific is big so if the cable breaks or gets destroyed, at least the immediate surroundings would be safe.
Depending on the material, parts that were out the atmosphere would burn up in the reentry.
An artificial island would be possible but also more expensive...
Also it is easier to ship large amounts of cargo per ship as it is per truck or rail.

Getting the cargo into orbit would be best made with two different cargo-containers, one for cargo only and one for personal. The cargo doesnt need seats, O2 etc. so the space for the life-support etc. can be used for more cargo. Or an module which could be inserted into the cargo-container....

The next tricky part would be the engine/thruster etc. to get it up there.
The best ATM would be an magnetic rail system (like the Trans-Rapid has), this could get it up and down without burning any fuel/having fuel onboard.
The magnetic rail could also be constructed into the cable thus powered from the ground base... but would make it heavier... thus maybe not doable.
If the powered magnets are build into the cargo container, a large amount of energy had to be "beamed" to it.
One way would be the already mentioned laser or microwaves, it could need focusing lenses as the laser would begin to spread at a distance and it is more ineffective in an atmosphere.
Power could also be transporter trough the cable, depending on the material used, seeing the advances in material sciences and molecular changing of material properties (meta-materials, ceramic glass etc.) it could be possible to build an electric power cable into the cable material, regardless if it is conductive in the beginning.

To help the ascend, the container could be "shot" or accelerated with an big coil-"gun", thus it wouldnt need so much power in the beginning ascend.
Although if passengers or fragile cargo would be aboard it would be needed to operate it with lower power to lessen the g-forces.

The best design would be IMHO a donut shaped platform with the cable running in the middle (with the outer hull covering the whole donut shape), it would be stable and easy to balance it out, also it could be rotated once outside the atmosphere thus providing a bit gravity if needed i.e. for personal.
Also it has a much higher cargo capacity as an container shape, like used for rail transport, so it could transport more/bigger things in a single trip.
It would be not very aerodynamic, that however is not a big problem as it would be more or less "slow", an aerodynamically shaped "Hat" for the donut shape could also be used, providing more space too.
Also this would help slow it down when it comes back, thus the breaking wouldnt need so much energy.

The station or orbital anchor would had to be build before, conventionally, thus this would be the most costly part (eventually). As it would be needed to be so big to not only hold all the cargo but also provide an stable point while the cargo is moving up/down.
An included shipyard would be a good investment too.


All in all, unless we develop some really ingenious engine with which we could fly into space without needing fuel (except energy) and thus make space flight inexpensive, an orbital lift is THE sign of an REAL space age.
It would make a trip cheap (in regard of our current methods)and large amounts of cargo could be transported. Thus making it possible to build real spacecraft, meaning interplanetary vessels.
Which albeit costly nonetheless would mean new sources of resources (Asteroid mining would be a possibility) and just going out there to take a look at our neighbor planets instead of just sending drones.


The next step would be setting up a permanent base on the moon for refueling (He3 anyone;) ) and resupply (water is already there in form of ice and it can be extracted via heating from normal moon dust). Add a few hydroponics and photo-voltaic (they would be very effective, always working at 100% capacity of them)... finished.


As time advances, mining maybe even terraforming colony's on Mars, seed-/generation-ships to discovered hospitable planets........etc. unless we screw up first and end our race for the stars face down in the dirt. Which is sadly a possibility with humanity ;)




RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Mon Aug 22, 2011 5:06 pm
by Data
Ohoo, I like this topic more and more....a new recruit. Welcome to the forum, WolfC.

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Mon Aug 22, 2011 9:57 pm
by tjhkkr
We should instead say: "If some terrorist blows it up, we´ll build it AGAIN AND TWICE THE SIZE!" ;)

And they get a bomb twice the size...

Welcome to the Boards WolfC

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 6:56 am
by Facedrop
And to think that some people, not naming any names, disapprove of OT discussions.

Welcome to the forum!

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 7:50 am
by WolfC
We should instead say: "If some terrorist blows it up, we´ll build it AGAIN AND TWICE THE SIZE!" ;)

And they get a bomb twice the size...
Well yes, maybe but the point I wanted to get at is that terrorists want to instill fear and panic to cripple a society. I dont say "Just dont have fear" , they are a threat and being afraid is a normal reaction.
Soldiers under fire have fear and those who aren´t afraid are fools BUT you have to control yourself and keep the fear in check, otherwise you´d endanger yourself and your buddys.
The same apply to an society. We have to be aware as an global society* that terrorists are an threat but at the same time must watch out that they dont get in control of our lives... that´s their goal. (I.e. disturbing our lives, our advancement).

*with global society I mean esp. us western country´s but also any other country under this threat.


Hope I´ve written halfway understandable, my english is quite good I presume but not perfect ^^

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 10:49 am
by Igard
WolfC, your English is great as is your introduction to the forums. Welcome aboard.[:)]

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 3:02 pm
by tjhkkr
Indeed, you English is better than my own...

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 5:24 pm
by Canute0
an Space elevator to build and maintance would need alot resources. And the places where you can build it are limited too and mosttimes not at High-tech ownership.

But an space Elevator isn't that fragile like you would think, since the Cable need to hold a strong force it is very strong.
You can fly a plane against it and you just would scratch the outer structure around the cable.
Sure you can launch a tactical nuke at any on the anchors to cut it, but when people get this tool at their hands its too late anyway.


RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 6:33 pm
by WolfC
Thanks Igard and tjhkkr :)
I just have sometimes the feeling that the structure of my sentences is a bit off but mostly it is the same as in german^^

Back on Topic... before our offtopic thread becomes more offtopic :D :
That the material of the cable would have to be very strong is of course true,
but it would be already under alot off tensile stress from just standing.
Because of that it would be easier to break then the material would be under normal conditions.... a crashing plane would regardless of the cable make a mess on the ground, falling debris and fuel...
Depending on the size of the cable it would be however more or less an very difficult target to hit directly, even hitting it only with the wings would be difficult.
To avoid accidents it would be also an no-fly zone, so it should be obvious if someone has ill intentions^^

RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Tue Aug 23, 2011 9:26 pm
by Canute0
Why do you think it would be difficult to hit the cable with a plane ? The cable dont move, and its a very big target at the vertical.
Basicly it would be the same manover like to take down a plane, and most planes hit the middle of the landing rollway at the middle :-)

The cable need to have safety reserves. Weather even the few 10-20km at the ground can add some extra pressures to the cable. Sometimes it need to hold the Anchor at space when some spacecraft pilot made a mistake at docking. Or just other possibles accidents.

I dont think a plane could cut a nanotube-cable structure. but without real not existance numbers about the cable we can't say anything about it.


RE: OT Discussion: Feasibility of an Orbital Elevator

Posted: Wed Aug 24, 2011 1:10 pm
by Shark7
First off, welcome WolfC, and don't worry about your English, it is quite understandable. I'm just glad this is written language and not spoken on these forums, as I doubt many of you, including my fellow USA countrymen, could understand me. [;)]

Back to the topic at hand. I would assume that not only would the cable be extremely strong, but it would likely have some sort of shielding structure around it. Perhaps a series of rigid rings with additional smaller cables with the main cable and lift inside. Basically, I can't see building something like this without taking some precautions to protect it from accidental aircraft or space-craft strikes.