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Japanese Begin Working On Space Elevator
thebryce writes "From cyborg housemaids and waterpowered cars to dog translators and rocket boots, Japanese boffins have racked up plenty of near-misses in the quest to turn science fiction into reality. Now the finest scientific minds of Japan are devoting themselves to cracking the greatest sci-fi vision of all: the space elevator. Man has so far conquered space by painfully and inefficiently blasting himself out of the atmosphere but the 21st century should bring a more leisurely ride to the final frontier. Japan is increasingly confident that its sprawling academic and industrial base can solve those issues, and has even put the astonishingly low price tag of a trillion yen (£5 billion) on building the elevator. Japan is renowned as a global leader in the precision engineering and high-quality material production without which the idea could never be possible."
"The first space elevator will be built about fify years after everyone stops laughing."
-Arthur C. Clarke
The meek may inherit the earth, but the strong shall take the stars.
Nor did you RTFWikipedia. It's a held up by a weight at geosynchronous orbit. The only problem is that geosynchronous orbit is so far out there (the red dotted line is the International Space Station, the black dotted line is GEO), so it requires a WHOLE LOT of exotic material.
And as a sub-subnote, this is approximately the cost of developing a complete conventional man-rated rocket launch system. I'm skeptical of the quoted price tag, but it would be extremely cheap if it could be achieved.
If you mod me Overrated, you are admitting that you have no penis.
You have an anchor at the top of the ribbon. It needs to be very massive compared to the payload - so we need a large space station, or a small captured asteroid. You have it in an orbit that's slightly above geostationary, so that it tends to drift into a higher orbit and is kept in place by tension in the ribbon. That way, the top is pulling upwards naturally, and the payload doesn't drag the whole structure down.
Real Daleks don't climb stairs - they level the building.
Technically, a weight in geosynchronous orbit would remain at the same altitude indefinitely with no other forces in effect. A space elevator will require a weight placed in an orbit which will supply tension — otherwise it'd be pulled out of orbit. It would probably be close to geosynchronous, but not quite.
(Actually, I'm not sure we even have a name for such an orbit. It would have to remain stationary above a point on the earth, but it would also have to hold up the cable and the car – in other words, without the tether it'd fly off into an entirely different orbit. Also, whenever the car accelerates it will put an additional tug on the cable – equal and opposite forces, you know. It'll be a tidy little equilibrium problem, and I'm glad I don't have to solve it!)
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Well, no. Modern materials are within a factor of 3 or so of what's required for a space elevator, and known materials with sufficient theoretical strength exist, it just needs to be figured out how to build them. It would not be surprising to have those materials move from theory to reality within a decade or so.
AI, human-indistinguishable androids, and world peace, on the other hand, are not things that people have any idea how to achieve. And FTL drives are prohibited by currently accepted physical theory. To compare a space elevator to any of those is either deliberately being stupid, or a result of profound ignorance about either space elevators or all the other things you mentioned.
A space elevator is certainly not going to be as easy as a Popular Science article makes it sound. But on the other hand it's not anywhere near as difficult as the pipe dreams you named.
If you mod me Overrated, you are admitting that you have no penis.
You're thinking of making a big tower (like a really large skyscraper). That wouldn't work. You have to approach the problem differently.
A simplified explanation of a space elevator is to take a really long, really strong cable (nanotubes), hang a weight on the end (more cable, an asteroid, lots of metal, etc), and anchor it on the equator. The weight goes out beyond geostationary orbit, and the tension of your cable pulls in on the counterweight to keep it from flying away. The tension keeps your cable taut. You can then run "cars" or "trains" up and down the cable on motorized wheels, most likely with electric power (solar, beamed microwave, or conducted through the cable). Your car can travel nice and slow, and be more efficient than a rocket.
If this doesn't make sense, imagine tying a weight to the end of a string, holding on to the other end, and spinning in circles. The weight will be held out at the end of the string and appear stationary relative to (since you're spinning too). Now put a caterpillar on that string that walks to the counterweight and back to you.
In short, the advantage is that you can use electrical power (which you don't have to carry with you) converted to direct mechanical energy to climb into orbit, instead of expelling fuel (less efficient) that you do have to carry with you. Your vehicle ("car") structure is simpler, more robust, and cheaper than a rocket. The elevator itself would be quite expensive, and requires some advances in materials science, but isn't physically impossible.
The meek may inherit the earth, but the strong shall take the stars.
Being groped by space-whores could potentially be worth the wait anyway.
But remember, this is JAPAN we're talking about. They have tentacles.
Still, that amounts to $9.5 Billion USD at the moment. To put it in perspective, we're looking at spending $700B to bail out the banks this week. Over the course of the life of the shuttle, each launch as ended up costing $1.3B. So, for a little over a tenth of the bank buyout, or less than 10 shuttle launches*. Or, if you want to go with incremental costs ($60M), it'd be 158 launches - compared to the 115 launches as of Aug 2006. Still, I hardly think that it'd be fair to compare incremental costs of a dangerous platform with creating a new one with substantially lower incremental costs and hopefully greater safety.
Of course, the article does at least mention a number of issues - we need to industrialize a carbon nanotube production process that makes a cable that'd 4 times as strong as the best lab result to date. There's all sorts of issues with a pod that has to go 22k miles, straight up.
I heard a snippet of a speech by Reagan today about SDI and how we now finally have the missile defense stuff he proposed. They talked about him not realizing the difficulties and state of the art, at which I laughed a bit when, in the speech, he talked about it possibly taking 'into the next century'. Anyways - this topic reminded me of the SDI program - nice goal, but might end up being slightly out of our reach at the moment. Especially for a 'mere' 9.5B. Probably end up being 100B*, and an additional 40 years.
*Still cheap at the price.
I don't read AC A human right
actually it's the center of mass that is relevant. The device would be considered in GSO because the center of mass would be there, or minimally lower (a few feet).
There would be roughly evenly distributed mass from earth to GSO, Maybe slightly increasing as it goes up to GSO, and then a large weight beyond GSO.
The idea is to not have it pull up on the ground, or press down (much). Last thing they need is to have a huge chunk of the terminal flung into space.
Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
Can we please not use the word "Boffin" to describe scientists. Its a words used by the British tabloids, usually out of ignorance, and in a derogatory sense.
Sir Arthur C. Clarke, when asked about when the space elevator would be constructed, he said something like:
Probably about 50 years after everybody quits laughing.
link.
Don't shut the idea, the idea is pretty good, yet the implementation is going to be tricky, with a space elevator, sending a kg. into space will be way more cheap than what is cost nonadays.
DON'T PANIC.
This is exactly how all the people considering this intend to do it. The problem is that the strength of cable required to support its own weight for that distance is huge. It has been determined that a ribbon shaped like a giant flat golf tee (can't think of a better description) will be best.
In short, your plan is the same as the best plan that mankind has so far, but we still don't have a suitable material to make the cable from.
Justin.
(Incidentally, geostat tends to be much higher than 100 clicks (qv 'Low Earth Orbit').)
You're only jealous cos the little penguins are talking to me.
The best counterweight is... another elevator car. If you have multiple tethers and superconducting cable (or another means of transmission), you can use a large fraction of the potential energy of the descending car to power the ascending car.
If you bring net mass down from orbit, you can actually make an energy profit (just on the elevator, I'm not saying that it would offset the costs of hauling propellant, etc, for asteroid miners and such).
No, it's your references which are wrong: if you could get to C your trip (from your view) would be instantaneous, from Earth it would take 4.3years.
As I understand it the popular plan is to not actually attach the bottom end - you have it float around at fairly low altitude over the middle of the Pacific and reach it by conventional aeroplane - at least for the first one, perhaps when the technology's tested we can think about having one with train lines running there. Anyway, with such a "floating" elevator there's no need for absolute precision - if it moves a few tens of meters who cares. Just stick some thrusters on it so that it can be actively stabilized.
I am trolling
So don't tie it down. There's nothing about the design of the space elevator that requires it to be tied to the earth in any way. If there's a storm coming, pull it up (or fold it up) about a mile or so above the clouds.
The best way to build a space elevator would be to begin at GSO and build outwards from there, keeping equal mass towards and away from Earth. You can then maintain a stable CoG by having masses at the top and bottom of the elevator structure that can be added or removed as needed. Note that in this design, the elevator is NOT tethered to the ground and is in fact in orbit with a portion coming near the ground. Some form of thrust, likely ionized gas propulsion, would be needed at the top to counteract drag and other wind acting on the lower section of the elevator.
Ignorance is Bliss -- And the Opposite is True -- Genius is Madness
At a distance of (iirc) about 2/3rds of the way to geosynchronous orbit, an object dropped off the elevator will be in an elliptical orbit that just barely misses the atmosphere. Anything lower than that will re-enter. With rockets, of course, you could drop things lower and/or achieve round orbits.
Launching from beyond geosynchronous orbit ultimately robs the earth of its rotational energy (something that happens all the time anyways because of tides), so that's not really a big deal for the elevator as long as it can handle the additional tension. It would be a great way to launch things towards the rest of the solar system without wasting fuel.
Wikipedia has an indirect link to a 2002 paper where a microscopic nanotube was found to have a tensile strength of 0.15 TPa, which is easily strong enough. Even if that was wrong, I see no reason to expect the theoretical calculations to be so far off as to make a perfect structure lack enough strength. Whether they would last long enough to be useful in a space environment, with all the high energy radiation there, is something I wonder about. Can they be repaired in place as fast as they decay, or how much of a cable's life would be spent hauling up its replacement?
It does seem much too early for the Japanese (or LiftPort) to be getting serious about building a space elevator. I suspect that is more for the buzz, and the genuine hope is that the research dollars they generate will pay off in more mundane uses of super strength materials.
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