Going Up?

An AC points us to this article about the space elevator concept, once solely the realm of science fiction but now coming a bit closer to reality. The main problem seems to be the lack of some material with the ludicrous tensile strength required. Oh, and an asteroid to anchor it. And the willpower to actually build it. Check out the slashdot discussion of an earlier spacescience.com article on this idea as well.

Comments

You've got it all backwards

[roystgnr]

Do you realize how much energy our Sun is spitting out every second? And how little of that energy happens to impinge on this tiny planet for us to use?

How about matter? I'll spare you the numbers, but it wouldn't take a very large asteroid to supply our entire civilization's structural metal requirements for centuries, and to provide enough mass of everything else to make the phrase "precious metal" an oxymoron.

There's a nice Kuro5hin discussion going on right now about overpopulation, including the question of what is a "sustainable" population for humanity. The answer isn't encouraging; our fossil fuels won't be around in a few centuries, our fissionable metals will give us a few centuries more... and then what? Solar power? Not concentrated enough, unless you've got a plan to reduce our population 10-fold, or pull in extra power from space. Fusion? That's better (assuming we get it working eventually), but then you run into the problem that the cleanest fusion fuel, He3, only exists in quantity on the Moon and outer planets. Even if you don't see the value of going into space to support life there, eventually we'll want to leave this planet to better support life here.

The solar system has the resources to support quintillions of people; unfortunately for us an insignificant fraction of those resources happen to be on Earth.

An elevator to nowhere. Imagine how silly it'd look.

So anyway, like I said, you've got it exactly backwards. It would be an elevator to everywhere.

Space Teathers and elevators

[GryMor]

I have attended several panels by Dr. Robert L. Forward on the subject of space teathers and elevators using current materials. Interested parties should check out his company, Tethers unlimited Inc as well as his personal site. I don't know where he will next be lecturing, I last caught him at VikingCon 17 (Western Washington Universitie's SciFi convention).

For More Info

[Cheshire Cat]

An interesting article, but a little light on the details. There is a really good piece on how space elevators work here.

What if you get stuck

[Travoltus]

on the 150,000th floor?

I doubt there's enough Mentos in the world to get ya out of that situation :)
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63,000 bugs in the code, 63,000 bugs,
ya get 1 whacked with a service pack,

Space travel isn't feasible

[Animats]

Why space travel doesn't work:

• Chemical rockets. Chemical fuels aren't powerful enough for useful space travel. Even with the best possible fuels, you either need disposable stages or have tiny payloads for the size of the craft. Heinlein pointed this out in the 1940s.
• Nuclear rockets. Too messy. The NERVA program made real progress, but open-cycle nuclear reactors spray radioactive waste. Closed-cycle ones are too heavy, and messy if they crash land. Orion, the A-bomb powered spacecraft, was even worse in that regard. Still, if you launched from, say, halfway between Cape Horn and Antartica, where South Africa once tested an A-bomb without bothering anybody, it might work.
• Antimatter propulsion. Dangerous, but feasible. Antimatter can be contained in electric and magnetic fields. Portable containers for antiprotons have been built. If anything goes wrong, all the energy comes out as gamma rays. Another one of those "the launch site had better be really remote" launch systems.
• Laser launch. A big laser on the ground heats up water in the spacecraft to make steam. May be feasible for mini-spacecraft.
• Antigravity. We have no idea how to do this. But it might not require new physics.
• Beanstalks, tethers, etc. Requires really good materials in huge quantities, along with some other big-time means of space travel for the construction.
• Winged launch. The Pegasus rocket was launched from a B-52, and souped-up fighters have made it to the edge of space. Helps the fuel problem a little, but not as much as is really needed.
• Cheap, dumb boosters. The original Von Braun plan: mass-produce lots of cheap disposable rockets, build a big space station, and operate from there. Boosters have been mass-produced as ICBMs, but never got cheap enough.

And that's the way it is.

Re:What's the american degree for -1?

[tesserae]

Your idea isn't basically wrong, but it's an extreme case. What you can do is make life easier by changing the diameter of the cable to match the local loading: at geosynchronous orbit, where the loads are highest (because the entire cable is "hanging" from GEO, both inwards and outwards) the cable is largest, and it tapers down as it goes each way. This reduces the total weight of cable needed, and also reduces the necessary strength of materials by a huge factor.

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Cool as this is, think about physics and politics

[human bean]

As anybody working in the fields of mechanics and material science can tell you, this is a lot farther off than it looks, folks. Just the logistics of flying the orbiting mass (yes, flying, you maybe though satellites stayed up there without guidance and thrust?) twenty-four by seven FOREVER (with what this puppy has to mass, believe me, you don't want this thing's orbit to degrade, ever.). Using a little thought and imagination, the list of "safety related" items goes on and on.

Also, the thought of having one doorway to outer space, under the control of some political force or another, does not strike me as safe. Considering the kinds of mass destruction that can be wreaked on the rest of the work from orbital heights means that this would not only be the space elevator, it would also be a major weapon. Lets face it, once something is in orbit, landing it in a particular spot is not that difficult. For those who do not believe, go get a copy of Navigation for Space Flight, by Prentiss Hall, I think (it's been a while). At the kind of energy levels we are talking about here, you don't have to be precise.

Besides, I want my OWN fricking orbital shuttle. I've got places to go besides Clarke orbit.

Megascale Engineering

[tamnir]

If you are found of Dyson spheres, beanstalks, spacehooks, terraforming and other stellar husbandry, check out the following site, full or ressources on these topics:

Megascale Engineering

Megascale engineering is about building/creating or using structures on a extremely large scale, at least 1000 kilometres in diameter, often incorporating highly advanced and/or speculative technology. Typical examples are orbit-to-ground Beanstalks, moving planets, Dyson Spheres and Stellar Husbandry.

There has to be a practical reason...

[Gendou]

Sure, Arthur Clarke's vision of an artificial ring around the earth is a great idea, but it's a bit far off.

And this wouldn't really be a step in the right direction. Sure, research into new materials/engineering techniques would be fruitful, but what is this really?

An elevator to nowhere. Imagine how silly it'd look. :-)