The cheap way to the stars - by escalator

[Karmadillo]

http://www.guardian.co.uk/spacedocumentary/story/0,2763,1041360,00.html

If climbing a stairway to heaven sounds like too much hard work, then a conference of 70 scientists and engineers opening in Santa Fe today may offer hope of a more leisurely way into space.
In two days of discussions, the scientists aim to turn into a reality an ambition that has been around for at least a century: the creation of a space elevator that would deliver satellites, spacecraft and even people thousands of kilometres into space along a vertical track.

Engineers say that recent advances in materials science - particularly in the development of carbon nanotubes - mean that such a system, which first gained widespread attention when the science fiction writer Arthur C Clarke described it in his 1979 novel Fountains of Paradise, is no longer pure science fiction.

Mr Clarke - who once said a space elevator would only be built "about 50 years after everyone stops laughing" - was due to address the scientists at the Santa Fe conference today by satellite link from his home in Sri Lanka.

The American space agency Nasa is no longer laughing. It is putting several million dollars into the project under its advanced concepts programme.

more...

[acerbic]

1. The cost in perspective

"None of it is really extravagant," said Dr Edwards, who estimates it would take about $7bn (£4.4bn) to turn the concept into reality.

That's about 8% of $87bn... the estimate is probably optimistic but still: the stupidity of the current priorities is depressing. :-(

[GAspnes]

2. knowing how I feel about heights

I'd never ride the damn thing. But it would be an amazing (and easy!) engineering feat.

[FDR2004]

3. probably the greatest in the history of the world

why haven't I heard of this before??

FDR2004

[GAspnes]

4. it was science fiction, at one time

put a satellite in geosynchronous orbit, 22,500 miles above a point on the equator.

The satellite hovers over the same point, yes? Now, start dropping a rope from it. The rope heads towards Earth, falling down. Of course, this changes the center of gravity of the satellite (essentially moving it into a lower orbit, where it would start moving relative to the surface of the earth). So, you need to simultaneously push an equal mass rope away from the earth to balance out.

After a while, you have a rope 'hanging' from the satellite all the way to the surface, and another rope sticking out 22,500 miles farther as a counter-weight. Start climbing the rope from earth, and run out as much additional rope from the satellite outwards as is needed to counter-weight you. You climb the rope into orbit, as slowly or rapidly as you wish.

Once at the satellite, you can continue to climb into a 45,000 mile orbit and jump off from there.

The tricky bit is making a rope that can support its own weight over a length of 22,500 miles. Carbon nanotubes are looking like a good candidate.