Space elevator unlikely due to static electricity?

[ehkzu]

I've read a bunch of articles about space elevators. Main problems they discuss seem to be ribbon strength & dodging space junk. However, a system-level software engineer friend (i.e. very technical but not in this area) insists space elevators aren't possible due to static electricity buildup along the ribbon frying it/elevator/cargo/everything. I keep wondering why I wouldn't have seen this discussed in the articles I've read, though of course there's always the danger of the Golly Wow World of the Future syndrome ignoring stuff that would invalidate the whole concept.<br /><br />2nd question: What about a lunar space elevator? Even if static electricity is a valid issue regarding a space elevator over an iron core massive-for-an-inner-planet planet with a substantial atmosphere, wouldn't it still be possible to do one for the Moon? Plus the advantages of nearly no orbiting space junk and much less material strength needed for the ribbon.<br /><br />I know this begs the issue of just what you'd do with a lunar elevator. I assume moon-based observatories and mining the moon for materials used in orbital structures mainly.

 

[alpha_taur1]

Why bother with a space elevator on the Moon? There is no atmospheric resistance there. Actually a space cannon would work quite well with the moon, at least for some inanimate cargoes. <br /><br />For Mars supply, put a container in a highly elliptical orbit around the sun, so that it comes close to both the Earth (or moon) and Mars, and it then would be a question of docking with it at both ends. It should be possible to match speeds roughly with an Earth orbiting satellite taking advantage of the Earth's rotational velocity around the sun. Orbital correction could be made using power from the docking spacecraft at both ends.

 

[nexium]

We have tested some electrically conducting tethers orbiting at about 17000 miles per hour. The space elevator will experience less than 1000 miles per hour with respect to the upper atmosphere so the static build up should be much less. I suspect the static electricity can be delt with sucessfully.<br /> An elevator needs to be almost 60,000 miles long. To the moon abut 260,000 miles long. But the stress is a bit less. Neil

 

[nexium]

My guess is a super conductor is needed to get even one megawatt from a tether. At one hundred ohms per kilometer, the heating loss of 100 amps is one megawatt per kilometer and the voltage drop is 10,000 volts per kilometer. The tether will be close to failure temperature at one megwatt per kilometer, in vacuum, I think.<br /> Why can't a tether attached to the moon reach almost to the Earth other than the strength of materials problem? Isn't the distance to L2 more than 300,000 kilometers from the moon and L2 rather unstable? Neil

 

[alpha_taur1]

Here's an interesting link on the Space Elevator concept. Actually they're looking at the Geosynchronous altitude (around 42,000km) rather than the Lagrange points. That way, I guess there would be minimal energy expended in launching a satellite, because the Earth's rotational velocity would provide the correct orbital velocity. <br /><br /><br />http://www.isr.us/SEConcept.asp?m=2 <br /><br /><br />The idea of power generation is interesting. Which would be the greater effect, the generation of electricity through the motion through the Earth's geomagnetic field, or static electricity?

 

[ehkzu]

So L4 and L5 match the Moon's elliptical orbit around the Earth, with the same--what is it, 29+ days?--period?<br /><br />And it sounds there's no inherently stable location for a lunar elevator. <br /><br />Hey, I wonder if a low-orbit space tether's possible?

 

[nacnud]

<font color="yellow">Hey, I wonder if a low-orbit space tether's possible?</font><br /><br />Google: lunavator

 

[vogon13]

Seems like a clever engineer could design space tether to use power generated to loft payloads.<br /><br />Also, still think space elevator only has to descend to altitude attainable by Spaceship One. Give it a place to dock and you've got the cheapest access to solar system I can imagine. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[alokmohan]

When nanotech is ripe we may not have these problems at all?

 

[alokmohan]

Now I understand.

 

[vogon13]

I was assuming geostationary tether arrangement and Space Ship One launch from equator underneath tether. Sorry for not elucidating assumptions. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[ehkzu]

That was interesting. Along with the lunar rotovator idea being thunk up back in the 70s. <br /><br />Makes you wonder why this stuff hasn't appeared in any sci fi shows yet. They jump straight to antigrav/ftl yada yada without any of this cool & vastly more possible stuff being considered.