The Space Elevator

[Cybergod]

Hiya guys, a bit OT here but still related to the SMAC SP...

Here's a quote from the "Focus" magazine, UK

"Taking a trip to the top"

You're taking the lift to outer space. You climb in, press 'top' and off you go. At your juorney's end, you step out into space and weightlessness. Planet Earth is a blue globe beneath you and the stars look so close you could touch them.

Sounds crazy, but members of the Advanced Projects office at Nasa are working on the idea. By the beginning of the next century, they predict that we may be sending equipment and people into space - not by rocket or even by a space plane, but in electromagnetic vehicles, travelling along a cable made from an incredibly strong but weightless carbon material known as buckytubes.

The space elevator was first imagined by Russian space pionner Konstantin Tsiolkovsky at the beginning of the 20th century. The modern incarnation calls for the construction of a 50km tower somewhere on the equator, because this lines up perfectly with the so-called geostationary orbit, 36,000km above the planet. At this height, a satellite orbits Earth once every 24 hours, thus appearing to 'hover' over a single spot on the Earth's surface. The cable would reach from the tower to geostationary orbit and be anchored to an asteroid, specially moved into orbit around the Earth as a counterbalance. The orbital motion of the asteroid would keep the cable taut.

Would-be travellers should take sandwichess as a ride up to geostationary orbit would take around five hours - even though the lift-cars, should they get off the ground, are planned to be travelling at thousands of kilometres an hour.

So what do you think? This is almost EXACT description of the Space Elevator from SMAC (an anchored asteroid, etc.) - could it be something there? I future catching up with today, sci-fi catching up with reality?

[Fitz]

"Konstantin Tsiolkovsky"

IIRC, this is the guy is quoted in the voice-over for the Space Elevator SP. I love the video for that one two.

"In one moment earth, the next the heavens."

Or something like that ...

I assume the buckytubes are a string of buckyball carbon structures, or a variation of the buckyball structure in a tube format.

[Googlie]

Officially attributed to Zak, of course (from blurbs.txt):

##The Space Elevator
#PROJECT27
In one moment, Earth; in the next, Heaven.
^
^ -- Academician Prokhor Zakharov,
^ "For I Have Tasted The Fruit

G.

[bondetamp]

the stars look so close you could touch them.

We need a really tall elevator or that!

[Chowlett]

I believe Konstantin Tsiolkovsky is the man on the Theory of Everything -

"The Earth is the cradle of the mind - but one cannot stay in the cradle forever." - Konstantin Tsiolkovsky, the Father of Rocketry, Datalinks.

Correct me if I'm wrong.

[Xian]

actually there was a book written in 1979 (ill get the name in a second) that wrote about that, so no, nasa did not bite Firaxis

[johndmuller]

Presumably the thing that makes this worthwhile (aside form it being a cool scientific thing) is that you could recover (some of) the energy used to accelerate the cars when they arrive at the other end using some sort of electromagnetic process. Seems like it might be possible to reap a lot of the benefits without having to have the cable; instead we would need to be able to electormagnetically "catch" a fast moving transport. The Mag Pod would probably have to be maneuverable to rondezvous with the "gloves" of the Space Station and the Earth Station. There might need to be some funny trajectories to keep the Space station from getting nudged out of orbit unless there was balanced traffic going up and down to Earth and back and forth away from Earth (say to the Moon's similar installation). I think that the stupendous construction costs and risks of the Space Elevator would pay for a hell of a lot of research into Conical Decelerators.

[Avenoct]

Well, I don't like the idea first off, but maybe I'm missing something. What would be important for the cable would be to be Frictionless not Weightless per se. I had no idea that buckeyballs had been made into chainable 'buckeytubes' either, but that much seems possible. If the cable is affected by the atmosphere at all, it's essentially like having the asteroid in the atmosphere in terms of orbit....not a good thing. the friction on the cable will produce drag. I suppose that if the friction was minimal, the asteroid could have constant thrust to balance that, but even if you tied the moon to the earth, it would be slowed down eventually by the cable friction, so that's the issue I see.

Would reallly stink if someone flew a plane into the cable too. Protecting it against birds, aircraft, space junk, shooting stars, and other damage seems pretty tough. Surely, if Nasa is talking about it they've worked all that out. Nonetheless it seems like a very strange idea...sortof counter to an aesthetic of physics if you ask me.

-Smack

[Googlie]

And none other than our own Hydro, of the Spartan Chronicles fame, expounded on it (book seven):

**********************************

Dr. Mershadeh continued, pointing at the black thread. "We didn't notice this at first, but it appears to be growing. We have done a little spectral analysis and it is made out of carbon, pure carbon. It appears to be molecularly fused in a process we can't quite determine…"

Dr. Andre Zahrenov, seated quietly in the back, blurted out, "Buckyballs."

All eyes turned to the ancient doctor, a holdover of the old University days. He looked sallow and worn, with a sickly pallor only seen on those about to die, or those who want to die. Had he offered an obscure dismissive statement to the astrophysicist that was a third his age?

Santiago gave him a cool stare with a slightly arched eyebrow, indicating he was required to continue and explain himself. Andre flinched under her gaze.

"Ahm. Buckyballs were discovered in the late 20th Century, and are typically interlattaced spheres formed of covalently bonded carbon atoms. They are uniquely stable and strong, stronger in hardness than diamond and the bonds between the carbon atoms are extraordinarily difficult to sunder. The balls can be of any size, but are exponentially more difficult to form as the size increases due to the care and energy required to form and propagate the bonds. There are variations of buckyballs, and under intense magnetic fields they can form tubes, and these 'buckytubes' can be of any length, limited only by technology and energy. Interwoven buckytubes have been theorized to be the ultimate super-thread, and woven together would form a super-rope."

Andre paused as if he was exhausted, and he thought he was finished.

Santiago, however, wasn't about to let him off the hook so easily. "Very interesting Doctor. I rarely have the time to be lectured on irrelevant molecular physics. What is it for, and how does it impact our situation?"

"I thought it was obvious," he continued quietly. "They are going to use the chondrites as raw material to manufacture a buckytube super-rope. It will be anchored to their battlecruiser, which has the gravitational mass of a small moon due to its gravitational anomaly, and they can apparently control gravity in any case. They will lower this rope through the atmosphere from their geosyncrhonous orbit and anchor it to the ground, probably around Spires: Ascendant. The corded buckytubes will easily be able to withstand the atmospheric friction, and will transmit the heat and electrical energy it collects or ablates to the anchor site, providing free energy. Moreover, they will have cheap and easy access to low and high orbits. By attaching a vehicle to the cord they will effectively defeat the gravity well of Planet, being able to store the kinetic energy of atmospheric re-entry to propelling objects back into orbit.

Colonel, they are constructing, for lack of a better phrase, a Space Elevator. "

*********************************

So there you have it.

Googlie

[Blake]

Originally posted by Avenoct
Well, I don't like the idea first off, but maybe I'm missing something. What would be important for the cable would be to be Frictionless not Weightless per se. I had no idea that buckeyballs had been made into chainable 'buckeytubes' either, but that much seems possible. If the cable is affected by the atmosphere at all, it's essentially like having the asteroid in the atmosphere in terms of orbit....not a good thing. the friction on the cable will produce drag. I suppose that if the friction was minimal, the asteroid could have constant thrust to balance that, but even if you tied the moon to the earth, it would be slowed down eventually by the cable friction, so that's the issue I see.

The cable is at 90degrees the equator, poking directely out into space, because it turns with the earth, there is no friction other than that caused by normal wind in the atmosphere. On a perfectely still day there would be no friction on the cable.

I have no idea what the "weightless" part is about, after all weightless materials dont exist. It could be that it refers to the fact the cable actually "floats", it is attached to the surface of the earth, but doesn't actually bear any weight because of the perfect balance between centriugal force (from the oribiting astroid) and gravity.

Would reallly stink if someone flew a plane into the cable too. Protecting it against birds, aircraft, space junk, shooting stars, and other damage seems pretty tough. Surely, if Nasa is talking about it they've worked all that out. Nonetheless it seems like a very strange idea...sortof counter to an aesthetic of physics if you ask me.

Again because the cable is not actually moving relative to the atmosphere birds would not be a threat to it. Otherwise it just has to be tough enough to withstand hits from other junk (and remember the thing is harder than diamond)
It would also have regular rockets / turbines mounted along the cable so it could stabilise itself. Additionally it would be a very very good idea to have the thing bristiling with point-defense weapons to destroy any incoming aircraft / astroids / missiles. They should probably be automated and controlled by computers to destroy any incoming threat - no questions asked.

It is VERY bad if the astroid breaks off the top of the elevator, because then the cable falls down, the earth is spinning so the cable gets wrapped around the earth - and it's long enough to go around 3 times. As the cable falls down it'd be like a string of atomic bombs detonating around the equator, a band of earth kilometers wide around the equator would be scorched of all life. There would be enough time for people to evacuate most of the impact zone.

Fortunately it is not a problem if the base of the elevator gets blasted, because at worst the cable just floats off into space. This means any attack against the elevator (aimed at damaging earth) would either have to be an inside job, or down by an enemy with space weapons capable of severing the cable. Bringing down the elevator would be the ultimate act of terrorism.

The thing which makes the elevator so worthwhile is electrical energy from a powerplant can be used to put things in orbit, instead of needing huge amounts of fuel. This is cleaner, more efficent and safer. All that is required is a nice big reliable powerplant. Additionaly by having one 'cable car' go down for each which goes up the energy required is really quite low, especially for orbital manafacturing, where raw materials go up, and finished products down.
However it would also be slower than rockets, it would take about a day (IIRC) to get to the top of the elevator.

[Avenoct]

No really, I WANT to be open minded about this...

Again because the cable is not actually moving relative to the atmosphere birds would not be a threat to it.

but birds move relative to the atmosphere. Hence 1+0 does not = 0.

there is no friction other than that caused by normal wind in the atmosphere. On a perfectely still day there would be no friction on the cable.

Find me a time and place where all layers of the atmosphere at any point are in equal motion, and I'll buy you an ice-cream cone.

The thing which makes the elevator so worthwhile is electrical energy from a powerplant can be...

yeah, but in reference to your disaster example, you could say that cuddling up with an atomic explosion is a good way to get warm, indeed, the best way...but....

Otherwise it just has to be tough enough to withstand hits from other junk (and remember the thing is harder than diamond)

Yeah, but, it's not the destruction of the cable that's the issue per se, it's the effect on either end....ever play 'catch the whip'? or know what a 'clothesline' move is in pro-wrestling? Ouch!

-Smack, the disillusioned.

[Blake]

Find me a time and place where all layers of the atmosphere at any point are in equal motion, and I'll buy you an ice-cream cone.

'fraid the ice-cream will melt before it gets to NewZealand

The cable WILL sway, that is why it has rockets and/or turbines (in the atmosphere), they stabilise it. I also seem to recall that such structures are more stable if they are set to ossciliate...

The point with the atmosphere/wind/bird is that a bird crashing into the cable would do about the same damage as a bird crashing into a building. When is the last time you heard about a solid wall getting 'holed by a bird?

Besides, birds know to avoid things like giant cables, and wind would tend to flow around the cable so a bird with have to be trying to hit the cable. (I'm not saying they wont try to do this...)

Bigger objects do present more of a threat, which is why the cable, especially near the base and astroid need to be capable of blowing them into little pieces, so the little pieces just bounce harmless off the cable. Ofcourse security would have to be very very tight to prevent lunatics setting off bombs on the astroid.

And altough the thing is potentially dangerous that is no reason not to build it. That's like not building skyscrapers because if they collapsed more people would get killed.

Besides mankind already has enough nukes to pretty much destroy the surface of the earth, so whats the danger of putting up a structure with the potential of 'nuking' the equator. I mean, it's only the equator


Not to get all starry eyed (excuse the pun) but a space elevator would literally open up the stars to mankind, finally allowing humanity to throw off the shackles of gravity, herald a new erald of prosperitey, blah blah.

[Blake]

I should also add that the astroid is slightly above the geo-sync orbit, so it exerts a slight force on the cable, keeping it taut, with corrections by turbines / thrusters even the strongest winds should present no problem - keep in mind that only a tiny fraction of the length of the cable is in the atmosphere anyway.

Depending how heavy the astroid and cable are the astroid may have to be significantly above the geo-sync orbit, in which case it has a pseudo gravity, and any object not tethered to the astroid would get flung of into deep space - this is not nessecarly a bad thing because then it can be used like a slingshot.

[Mr. President]

I actually think a space elevator would be a good idea. The objects going into space don't have to carry fuel, which is a major problem with rockets. The further a ship has to go, the more fuel it needs to carry; but the more fuel it carries, the more fuel it needs to carry to move the original fuel. But with an elevator, the lifting is all done by the cables. I'm only a first-year engineering student, so I don't know the full mechanism. But I think it could work.

Of course, you would need to prevent it from swaying in the breeze. If size and cost do not matter, you could build the shaft as a non-free-standing structure; ie. build the 50-kilometre tower and support it by attaching thousands-kilometre long girders and cables to the earth on all sides. The rocket booster thing sounds a bit iffy to me; you'd need fusion power (which they're incidentally trying to develop at Lawrence Livermore Laboratory, where my Astrophysics lecturer used to work) to generate enough energy to keep them working continuously, as you'd need to.

You'd also have to protect it amazingly well. It would almost have to go in South America, since no other equatorial region is friendly enough to the US such that they would have confidence building a space elevator there. It would pretty much have to be in a military base to prevent sabotage. You could launch weapons satellites (scoff at me for now; but I read in National Geographic that they're looking at firing lasers from satellites as a new super-weapon. Just think of the possibilities: you could hit any point on the surface of the Earth!) in geosynchronous orbit near the top of it to shoot out any rogue satellites or airplanes.

To diverge a little, it seems we're almost getting ahead of Alpha Centauri's science, before the 21st century has really started. They've already decoded the human genome, cut and pasted animal and plant genes, begun working out how to build quantum computers (which our game never even touched), started thinking about travelling faster than light and using giant membranes to trap the sun's energy, begun working on fusion power, plus a whole lot of stuff we don't even know about yet. Any science fiction games Firaxis makes from now on are going to have to be pretty damn good to beat real-life science!

[Avenoct]

Btw Blake, love the new Spamatar.!

O.k. I'll just continue pestering here

I should also add that the astroid is slightly above the geo-sync orbit, so it exerts a slight force on the cable, keeping it taut,

This is kinda what I'm talking about. Centripedal force and Orbital force are different, but you'd need to get some centripedal force on that asteroid or the Orbit would degrade. In other words, there would have to be some continuous thrust on the asteroid, though probably very small. Simply putting it outside the geosynch orbit won't add constant centripidal force....it will only add at the beginning, but once the tether it taut, that force becomes nil. I think.

Get what you bargained for Cybergod?

How thick is the indestructable cable supposed to be?

And yeah, I agree that science is proceeding both faster, and in unexpected directions such that sci-fi writing always misses the mark. It's just funny that a game written in '97 to portray the future or 103 years later actually portrays the future of 3 years later in some things.

-Smack