RE: Express Elevator to Space: Fiction Or Reality?

mcb1 — Tue, 23 Oct 2018 05:39:55 GMT

This mythical story was about years ago.

Not sure exactly how the end in space is going to to be able to keep the cable suspended, and then there is the issue of weather affecting it within the earths atmosphere.

I've just watched a program about space junk, and they are tracking somehwere in the order of 22,000 items bigger than a baseball at the current moment.

The theory was they are going to improve the technolgy and they expect to track 200,000 items all of which can cause major problems.

At the moment they move the space station and other satellites out of the way of larger debris, but this is going to have a problem that the tether will be the bit that potentally is the biggest problem.

I'm adding this one to the "we'll all be talking to our computers and not using a keyboard".

Mark

RE: Express Elevator to Space: Fiction Or Reality?

jw0752 — Tue, 23 Oct 2018 00:14:38 GMT

Besides the energy needed to lift the elevator and payload there would be a need for energy to accelerate the elevator and payload in the direction of the Earth's rotation on the way up as the elevator and payload will have greater angular momentum the further up it goes. As the elevator descends it will have to be negatively accelerated to compensate for the lower momentum needed the closer to the earth that it comes. Failure to provide these compensatory accelerations will make the system unstable. Further whatever the cable is tethered to in space will also have to have the ability to be accelerated or decelerated as the force needed to lift a mass from the surface will require and equal and opposite force from the tether object and the energy for this force will have to come from the angular momentum of the tether object. If one wants it to stay directly above the Earth anchor point it will need energy and the ability to adjust its orbit. The energy costs of this system are not trivial and if the initial costs are added in it is doubtful that it would be practical. I have seen one version of this or another kicked around for the last 25 years. It makes for a good thought experiment but is in my opinion just that.

John