Wednesday, 24 September 2008

Beam me up, Scotty

Sky hooks are on the way (SMH).

JAPANESE scientists are attempting to build a lift that will take passengers into space, marking the realisation of a vision that has inspired science fiction writers for generations.

The lift's carriages, which will themselves require new feats of engineering, would move up and down 35,000 kilometre-long cables. Those cables would need to be stronger and lighter than any material ever woven.

They would be anchored to the ground and disappear into the sky, eventually reaching a satellite docking station orbiting above the Earth.

Carbon nanotubes to the rescue! Yeah!

1 comment:

The Pook said...

Going up! First floor, haberdashery, space helmets... Second floor, parachutes, escape pods...

Extraordinary new feats of engineering indeed will be required, not just for the carriages, but the whole process.

It doesn't say how thick the cable would be, and I don't have the mathematical ability to work it out anyway, but I imagine that 35,000km of cable will require a very very large drum to unwind from, requiring very large motors, exceptionally accurate gears and ratchetting, and very effective braking. Imagine what would happen, launching it through the atmosphere at the 7 miles a second escape velocity required to overcome gravity, if it suddenly snared or jammed? Even attaching it to a rocket presents a whole set of engineering puzzles. If it's got to be that light, it will also probably be susceptible to damage from the rocket engines, necessitating its connection by cable made of some other material, which means creating unbreakable linkages between that cable and the elevator cable itself.

The above assumes of course that the whole cable is not able to be lifted into space and then "lowered" to earth (which would have its own set of difficult engineering requirements). It would surely be too bulky to lift into space rolled up wouldn't it? But maybe I'm wrong about that?

Even if they can get it up there, it then has to be anchored to something heavier than it that is in permanent geo-stationary orbit doesn't it? (My high school physics is struggling to comprehend all this).

And the lift carriages would need to have the capability of release from the cable, and of flight or at least parachutes and heat shields in the case of the cable breaking or being damaged.

It may go the ways of the flying cars that we were supposed to be driving by now.