Report: Space Elevators Are Feasible 374
Daniel_Stuckey writes "It's the scourge of futurists everywhere: The space elevator can't seem to shake its image as something that's just ridiculous, laughed off as the stuff of sci-fi novels and overactive imaginations. But there are plenty of scientists who take the idea quite seriously, and they're trying to buck that perception. To that end, a diverse group of experts at the behest of the International Academy of Astronautics completed an impressively thorough study this month on whether building a space elevator is doable. Their resulting report, 'Space Elevators: An Assessment of the Technological Feasibility and the Way Forward,' found that, in a nutshell, such a contraption is both totally feasible and a really smart idea. And they laid out a 300-page roadmap detailing how to make it happen."
Re:Flying pigs (Score:5, Interesting)
As bigjarom mentioned, what's holding us back right now from cheap lift via skyhook is that we haven't quite gotten our carbon nanotube strength up high enough. It's theoretically quite possible.
After that, it's just a question of how do we get enough materials and probably some sort of ribbon* making facility into GEO to actually do the laying. One idea I have is that rather than having to ship all materials to GEO, only to drop it towards the earth, you have a descending constructor that you supply. Though the orbital mechanics of resupplying it can get quite hairy...
*Modern design philosophies has the cable being more of a flat ribbon than circular.
Re:Plenty of scientists (Score:2, Interesting)
Which is really too bad. I was looking forward to seeing how they would handle the problem of harmonic resonance in the cable, and wind blowing the cable, and cable breakage (which would be a matter of when, not if), and what technique they were proposing to get the cable up there in the first place.
Re: Why would it be infeasable? (Score:5, Interesting)
weight of elevator is pulling up, not pushing down (Score:4, Interesting)
Connected to a platform in space, the mass of the platform is to spin with the Earth's rotation. Centrifugal force is actually pulling on the elevator 'cable'.
Re: Why would it be infeasable? (Score:5, Interesting)
Financial gain may be the most likely reason for advancement now, but it won't take more than another 50 to 100 years for it to become a necessity due to any combination of pollution, population, warfare, and resource depletion. Humans have always been really crappy at innovating unless we absolutely have to. When we aren't faced with some kind of crisis, we tend to get really good at perfecting known technologies and ideas, but that's about it.
So yeah, space exploration is pretty much out of the question as long as people (both investors and consumers) are more interested in mobile phone games and reality TV. As soon as shit hits the fan again -- and it will -- we'll see another big leap in advancement.
Re:Rockets won't be loved at (Score:5, Interesting)
I've seen proposals that talk about using a ribbon that is only just barely larger than is needed to support itself for the initial strand. Send it up in a conventional rocket (at the time this was discussed, they talked about using a Saturn V or possibly even the Space Shuttle; these days a Falcon 9 Heavy would probably be enough or even more-than) to geosync and have it unspool in both directions from there. Grab the lowered end as it reaches earth. Then, send up a small climber, carrying another, possibly even smaller strand of ribbon. Join it to the first one. Now you have a stronger ribbon. Repeat (potentially with increasingly large builder-climbers) until you have a strong enough ribbon for whatever you want to do (send up people, or ISS modules, or other satellites, or parts for a Project Orion-style nuclear pulse rocket to be constructed in space... you get the idea).
I don't know how feasible all the steps there are, but it's worth considering as an alternative to sending up the entire thing all at once.
Re:Flying pigs (Score:4, Interesting)
Perhaps it hasn't been addressed much, but from what I've seen part of the 'protection' is that you would be more or less continously extruding new cable(on the order of a couple miles a day!), so as time goes by the cable WOULD be refreshed.
Besides that, if you're sensible you're going to orient your ribbon so it's the narrow end that's facing most probable impacts, highly limiting it's cross section. Then you have to factor in that this material will be the strongest material used in space to date; it should be quite resistant to those effects.
speed of light (Score:4, Interesting)
Speed of Light: 299,792,458 m/s (meters per second)
Great Pyramid Grand Gallery: 29.9792458N Latitude
coincidence?