Space Elevator - Could We Do It?

Question

'Elevator to Space' or 'Death-o-Swing'?

During one of my ever increasing day-dreams; I remembered something I heard in respect to a theoretical 'Elevator to Space' and I was wondering what you guys think about this.

looking at the diagram added, the first thing noticed was the counterweight - not to mention the gravitational barrier that we will need to overcome initially with the weight of the cable alone I don't think its plausible... However,

Assuming we could;

1. How far out would it have to be at the end of the cable to escape the earth' gravity, enough to then let centrifugal forces take over? is it even possible?

Assuming that could be done;

2. Do you think it will be a matter of weight to keep the cable upright - or distance? (obviously a mixture of the two - but how much centrifugal force increase would be expected

This is my Main Quarrel;

3. Wouldn't even a small weight, attached to a tether eventually off-centre the rotation of the earth and potentially change its orbit and relationship with The Sun and our moon... Killing us all :( Or could a secondary elevator on the opposite side counter the effects?

I can only imagine this has been dreamt-up already. but it has had me thinking ... which is always dangerous :)

and I thought why not start a discussion... any thoughts are welcome, thanks, Everybody :-P

Answer 1

Yes a space elevator is perfectly possible and current technology I have heard it said that technology exists to put one on the moon right now and would cost an estimated $10 Billion or something.

1) An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,786 km altitude) https://en.wikipedia.org/wiki/Space_elevator#Physics

2) I think it is a matter of tensile strength in the material the elevator is made out of.. the cable would need to hold its own weight with the centrifugal force trying to throw the cable away from earth, so the cable needs to be able to not snap at this long distance.

3) The idea is to attach solar lifts to the cable and these then travel up and down the cable transporting goods without having to worry about burning fuel to break the earths escape velocity. I think the forces are so small in comparison to the things like asteroid / meteoroid impacts, the moons and tidal influence on us that these are causing more distortion to our earths orbit than the space elevator would. However I would be interested to know the impact, I'll see if I can find some more info.