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fund space elevator

How to fund and build a space elevator
  (+10, -4)
(+10, -4)
  [vote for,
against]

A)There is a fund the US started to dispose of nuclear wasater sometime and somehow in the future. This fund is now more than $28 billion US (see nuclear fund link). B)There is a design for something called a space elevator which is basically a cable stretching from the earth to past orbit which is taught due to centripetal force pulling outward(we still need ~25 years of research to build one). The projected cost to build this would be ~$6 billion US (see space elevator link). We could use the fund to research and then build 1-3 of these, ship nuclear waste to space and send floating away so it will not be radioactive when it finally reaches another solar system. As a side benefit we will have a space elevator to explore space (it will be VERY cheap to ship things to space once this is developed, basically ride the cable up like an elevator). Most people in the the aerospace field don't believe we will really get going exploring space till we can get things into orbit much more cheaply.
sagebergcross, Apr 03 2007

nuclear fund http://www.nei.org/...p?catnum=2&catid=63
[sagebergcross, Apr 03 2007]

space elevator http://en.wikipedia..._elevator_economics
[sagebergcross, Apr 03 2007]

Binding energy. http://en.wikipedia...wiki/Binding_energy
Iron is the bottom of the energy hill Quantum. [MercuryNotMars, Apr 03 2007]

Earth-Space Web Earth-Space_20Web
Vernon's idea for something better than an elevator. [baconbrain, Apr 03 2007]

Would this help? Centripugal_20Force
[MaxwellBuchanan, Apr 03 2007]

Nano-planet as counterweight Blue_20Nano-Planet
We can only build space elevators if we follow Django [django, Aug 02 2007]

[link]






       Sounds like a pretty good basic idea to me. [+]   

       As a true halfbaked idea, though, it needs refinement. A huge load of radioactive waste going up the cable requires a few things:   

       1) The cable needs to be absolutely safe for moving such weights, or your container drops and burns up or breaks and you contaminate everybody in the region.   

       2) More difficult - You would need to find a way to prevent terrorist or enemy military attack on a space elevator which is being used for sensitive materials like this. A wire under high tension with a load is pretty easy to break with any significant shearing force from the side, as in .50 machine gun bullets from a plane, or explosion blasts, etc.   

       3) You still need to get all of the waste to the elevator, which is part of the problem now anyway. Building more than one elevator to alleviate this adds up those 6 billions pretty quickly.   

       Being able to use safe, perfectly clean nuclear power everywhere this way would be a huge deal, though.
Smurfsahoy, Apr 03 2007
  

       Isn't it general knowledge that fusion builds up denser atomic elements, and that fission breaks them down? What's to preclude us from using fission waste as fusion fuel then? (it just seems so magical to me though, so if someone could please enlighten me)
quantum_flux, Apr 03 2007
  

       um...won't be me, sorry.   

       Cool idea.   

       I don't know why this question is here but [Quantum] Iron has the lowest potential energy in nuclear reations. You can find charts with all the potentials. It is a somewhat jagged line with Hydrogen on top. If you can get energy out of Iron I would be Keen on hearing about it.   

       A link I just found it calls it neuclear binding energy. Wikipedia has a prettier chart. Here is a link.   

       I think the idea here is even better than you know. I am pretty sure there is heat that comes off of nuclear waste. I am not sure about the mass to energy ratio but it would probably make great batteries for outer solar system work. The level of safety required for this is the same level of safety required for most of the useful things we want to do in space. We require other nuclear materials. [+]
MercuryNotMars, Apr 03 2007
  

       I dont see the weight of payload being a problem at all, its miniscule to the cable and while significant to a shell elevator carrying it up, you can just scale down the size to some well within safety margins.   

       Getting the stuff there is a problem I agree. The space elevator has to be near the equator, the closer the better anyway, so the northern hemisphere countries have to ship south atleast and likely very far east west as there will be few. But this is atleast half unfair qualm with idea bc the waste is going to be have to shipped somewhere. I agree this would likely make it shipped on average say ~10 times further than other methods but once you make containers to ship that are safe, I say get it somewhere that wont be a problem in future.   

       The terrorist thing is, in my view, about as bad as the transportation or actually maybe a little less bad, but would get more attention. I think the easiest way to safegaurd easy attempts at sabatoge would be to have a perimieter of say 50 mile radius and screen anything coming in, this could happen if we put in on a island. Now finally there will be a good multinational reason for missle defense, obviuosly need to get a lot better first. A terrorist flying into it, or shooting at it is just tough, again in theory there could be a missle defense, or maybe missles or laser mounted along elevator which protected itself.   

       Anyway all that is problems with the elevator regardess of how or when its made, my main point is where there is money theres a way (will is overrated).
sagebergcross, Apr 03 2007
  

       How do you teach a cable about centripetal force?
coprocephalous, Apr 03 2007
  

       I don't know. I've been trying to teach the difference between centrifugal force and centripetal force to people, and it hasn't done much good. But I'm gonna try again.   

       "Centrifugal force" is simply inertia, which tries to keep things moving in a straight line, viewed or considered in a rotating system/POV. Scientists tried to make clear that it is not a basic force, like gravity or the electroweak. But people got confused, and somehow thought the name had been changed to "centripetal force", which is the exact opposite.   

       In the case of a space elevator, attached to the rotating earth, inertia is the centrifugal force, as it holds the far end of the elevator away from the center. Gravity is the centripetal force, as it pulls toward the center.   

       Back on topic: There's a space-launch system that's a lot simpler than a space elevator, although sort of related. Vernon wrote it up for the 'Bakery, I'll see if I can find a link. Basically, it's a maglev loop around the Earth, held up by loads running around it at greater than orbital speeds. It could be used to fire containers off into space or maybe into the sun.   

       A space elevator will hoist loads to geostationary orbit, or maybe beyond, but that doesn't get the loads to another solar system, or even out of our own. But some modifications could take care of that, easy enough.   

       Funding a space-launch system as a nuclear waste disposal is a clever idea. [+]
baconbrain, Apr 03 2007
  

       // Gravity is the centripetal force   

       Thank you for the lesson on semantics. However, in the case of a space elevator, the top station is placed beyond geostationary orbit, so that the centripetal force that overcomes its inertia that is termed the centrifugal force, is only in part gravitational. The rest is provided by the super-strong carbon nano-tube reinforced tether. This ensures that when a small load is added to the lift, the station does not get pulled out of its orbit and come crashing down, wrapping the cord around the world like some big kinky world-whip.   

       Oh, just to clarify: sp: taut
TheLightsAreOnBut, Apr 03 2007
  

       //I am pretty sure there is heat that comes off of nuclear waste.//   

       At the site where the building used to be of the only US military nuclear meltdown, there now exists a large amount of radioactive structural debris buried underground. They covered it with enough concrete to stop the radiation from being lethal or unhealthy, so it is like a huge parking lot right now. I'm not sure how far down it is, but it must be at least a dozen meters or so, I'm guessing.   

       Even that deep, the heat generated from the radioactive waste of a backpack sized experimental reactor is enough to melt and evaporate 4 foot high snow drifts. In the winter, it's a deep white landscape as far as the eye can see, except for that one patch of bare, hot concrete, some 50 years later. Pretty impressive. Imagine what the waste of a full scale power plant with little to no shielding in space could provide heatwise.
Smurfsahoy, Apr 03 2007
  

       sounds like the stuff of a great nuclear battery for outer solarsystem work, as I expected. The weight energy ratio I was refering to is like the battery weight to thrust ratio when you recycle this stuff and use it for probes. Though you do have a pretty good slingshot at the end of such a cable, it might begin to not matter once you start taking advantage of gravitational assists how much weight the waste has.   

       This is a brilliant synergy. I would give another bun if Jutta would let you vote twice without changing your vote. nuclear materials are what scientists are itching for in space, even it it is just deterioration at work.
MercuryNotMars, Apr 03 2007
  

       //Isn't it general knowledge that fusion builds up denser atomic elements, and that fission breaks them down? What's to preclude us from using fission waste as fusion fuel then? (it just seems so magical to me though, so if someone could please enlighten me)//   

       I'm no nuclear physicist, but I'll try and take a stab at this.   

       Fusion is the process of smashing atoms together to produce energy. Fission is the process of breaking atoms apart to produce energy.   

       Simply put, small atoms (Like hydrogen, with one proton, or helium with two protons) provide more bang for the buck with fusion, and large atoms (like Uranium, or Plutonium with roughly 100 protons each) give you more bang for your buck with fission. As mentioned earlier, Iron provides the least bang for your buck either way.   

       Fusing say... lead... back into plutonium, or uranium would require a really powerful particle accelerator. Fissioning helium back into hydrogen... well, let's not worry about that just yet since we've been working on getting economically feasable fission since the sixties without any real luck.
ye_river_xiv, Apr 03 2007
  

       Even with $6bn, we still dont' have the technology for the tether. Still, right now we have neither, so [+].
wagster, Apr 03 2007
  

       //we've been working on getting economically feasable fission since the sixties without any real luck// Seems to work fine over here.
MaxwellBuchanan, Apr 03 2007
  

       The big situation here is using funding for one purpose from another source. Although this sounds practical, it is seldom done in any kind of organization with a budget. Steal from Peter to pay Paul kind of process.
the great unknown, Aug 02 2007
  

       Pretty good idea I think. But you need a counter-weight to attach your nano-tube cable to.   

       There is only one feasible way to make such a counter-weight, and that is by implementing Django's legendary nano-planet scheme. Please see the important link to this ingenious and elegant idea (we calculated things with pencils, so rest assured, it makes sense).   

       You get a croissant too, don't worry.
django, Aug 02 2007
  

       Nuclear powered aeroplanes and launch rockets have all been nixed due to the risk of having radioactive materials zipping about in our atmosphere in untested prototypes. I doubt (certainly in the present political climate) that people are going to get any happier about it. It's still a good idea, though.
wagster, Aug 02 2007
  

       There is also another thing which is normally ignored. Actually there is no such thing like nuclear waste. Especially the radioactive materials which are still radiating for thousends of years are not really WASTE in the general sense.   

       The only problem is that we don't know how to get all this remaining energy out of them.   

       You would not send hundreds of tonns of gold to space just because it doesn't glitter the usual way.   

       Maybe in a few hundred or even thousand years this waste could be the only remaining source urgendly needed for whatever purpose there might be (energy production, medical treatments,...).   

       So in my understanding storing them in a secure place (maybe for future use) is a much better approach then sending them to space and loosing them forever.   

       Even for plutonium which is an extremeley dangerous material we maybe once will find a better usage then building A bombs out of it.   

       We don't know if our ancestors will have to mine our waste deposits for whatever purpose!
gutemine, Sep 11 2010
  

       // a fund the US started to dispose of nuclear wasater//   

       I had some of that on sushi once. Scary stuff.
MaxwellBuchanan, Sep 11 2010
  

       Nice +
simonj, Sep 15 2010
  
      
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