Space Elevator Options

[EMac]

While the idea certainly isn't new, the material basis for it is somewhat interesting. I like the graphic...makes it seem like a geosynchronous orbit is nearby versus over 3 times further than the diameter of the earth. I'd like to see the process they'll use to make 26k mile diamond cables.

Space elevator article

[CP]

Very interesting idea for sure and I've wondered the same Emac, how do they know how much transport costs could be with out knowing how to build or deploy one successfully yet.
Another scary thought would be if there are cables stretching from ground to orbit some several hundred miles, if one were to break and begin swinging out of control from the upper end or platform....YIKES! That's one long whippin' nanochain that could do exstensive damage to things from ground level through air space for planes and assumedly, the geo sync sat orbits as well, reaching hundreds of miles in any direction!

[EMac]

Another scary thought would be if there are cables stretching from ground to orbit some several hundred miles, if one were to break and begin swinging out of control from the upper end or platform....YIKES! That's one long whippin' nanochain that could do exstensive damage to things from ground level through air space for planes and assumedly, the geo sync sat orbits as well, reaching hundreds of miles in any direction!

2 orders of magnitude more distance....several 10s of thousands of miles of cable! The designs I've seen are putting the anchor around 60k miles from earth: almost 3 times the distance to the geo orbit (~26k miles). The thought of that thing coming back down is scary. The thought of being trapped up there after an anomaly is horrifying.

I'm sure that they would have some sort of destruct capability for just that sort of scenario. If not - WTF? That cable is as long as twice the circumference of the Earth!

That equals one hell of a lawsuit!

Noodling on this is interesting as well...i.e. how could a self-destruct protocol be done safely? Charges placed every 100m or so (this would mean close to a million charges)? Frangibolt style mechanism (like used to separate payloads from carrying rockets)? Cutting mechanisms similar to an ADD used in skydiving? A rocket attached to the anchor along with a cutter at a set distance so that the majority of the chain goes into orbit around the sun vs earth? How much weight would this add, and how would they be triggered? Would the chain burn-up on re-entry (I'm skeptical if it's diamond, particularly if it's still a long chain given diamond's thermal properties)? It not, that just creates new hazards for future space travelers. The chain is ostensibly static too meaning it can't maneuver out of the way or incoming debris. Considering the velocities from orbiting objects, it doesn't take a huge asteroid to cause massive damage: SWRI & ESA

How do we even lift the chain? If it has to be a continuous strand, 60k miles is 9,656,064,000cm. Assuming ~1cm cubes of diamond stacked, and using 3.51g per cubic centimeter of diamond, this translates to a 33,892,784kg chain. I can't find a simple calculation of weight by volume of carbon nanotubes, but a chain of this material is likely quite massive at these lengths.

If it's not continuous, how will they find the chain's ends in orbit, much less bond the chain's sections together (weakest link in the chain concept), and how many launches will it take just to deploy the chain? How will they keep it under tension? Will the anchor have fuel on board to perform orbital maneuvers (similar to how gliders remove slack in a tow line)?

What kind of electrical effects will need to be accounted for? Depending on the type of chain material chosen, this could make for some interesting experimentation. Towards the sun, the chain will extend past the magnetosphere and a significant portion (~20k miles) will be subjected to the full force of stellar winds. On the back side, it will be encompassed by the field, and will always pass through the ionosphere (conductive). What kind of electrical potentials are developed in such a system? Fenixsmom is onto something with solar storms...massive currents are developed in the ionosphere during these, particularly during strong storms that break the field on the backside (from 100kA nominal to over 1MA during severe storms...how GICs are able to fry EHV transformers). The materials in question, diamond and carbon nanotubes, can serve as insulators (non-doped or non-conductive doped diamond) to semiconductors (boron doped diamond and nanotubes).

...and why did Ogre from Revenge of the Nerds just pop into my head? NERDS!!!!