Space Elevator

[kirkster501]

Why can't such a thing be built?

https://en.wikipedia.org/wiki/Space_elevator

 

[Louis D]

Mostly the material for the cable would need to be lighter and stronger than anything out there right now.

Then there would be the issue if it broke, and thousand mile long sections of it came down on populated areas after drifting around the earth.

[ronin]

Materials just are not up to it at this time. Arthur C Clarke - The Fountains of Paradise, 1979.

If I recall you would have to buit it both upwards and downwards. Start with something in geostationary orbit (bit far out) then run the same mass down to earth and outwards to maintain the forces.

[michael8554]

Then there's the version that rotates about the centre point.

With the right dimensions and rotating the right way, apparently the end is moving slowly enough to pick up a load when it kisses the earth and then slingshot the load out into space, a win-win situation.

Michael

[Stu]

I've never quite got how this fits in with the different orbital velocities which occur at different distances from the earth. My understanding is that the higher the orbit, the slower the speed, so whilst I get the fact that one end is at the geostationary orbit, I don't understand how this would overcome the fact that at each level up the tube or wire, there should be a different orbital speed which would cause it to oscillate horribly.