Obayashi To Build Space Elevator By 2050 488
mattr writes "Japan's Obayashi Corp. has announced plans to build a space elevator by 2050. They are famous for wrecking skylines with the over-sized bullet train station in Kyoto, the world's tallest self-supporting tower Tokyo Sky Tree and just recently, the beginnings of the Taipei Dome. It will take a week at 200 kph for your party of 30 to reach the 36,000-km-high terminal station, while the counterweight [swings along at] 96 km high, a quarter of the way to the Moon."
Re:Is that so? (Score:5, Informative)
Well, here's [obayashi.co.jp] a list of some of their previous projects.
Re:English? (Score:5, Informative)
WTF does that last sentence even mean?
It's just the editors being up to their usual standards of quality. The elevator cable doesn't end at the geostationary station (at 36000 km); it continues beyond it for another 60000 km, and terminates in a counterweight. This counterweight is supposed to be positioned 96 THOUSAND kilometers from the surface, hence the mention of the quarter of the distance to the moon.
Not well thought out (Score:4, Informative)
Furthermore, using the term 'elevator' is clearly an attempt to dumb-down the technology (kind of like called a Philosopher's Stone a 'Magic Stone').
Don't have a citation, but I believe that even using carbon nanotubes, the tether cable needs to be about 10 metres thick. This would mean that the project would require some 36 x 10 ^ 8 cubic metres of carbon nanotubes. Idaho Space Materials makes about 50gms per hour - at a cost measured in hundres of $ per gram.
I don't know that this is all practically do-able yet.
More Detailed Article. . . (Score:5, Informative)
. . . is located here [mainichi.jp]. It includes a bit more about the proposed construction, starting date, and other interesting bits.
Re:How to install it? (Score:4, Informative)
It's a cool idea but requires a material that does not exist yet fabricated to lengths not yet possible while requiring techniques to get things up the beanstalk that have not yet been developed. However carbon nanotubes, if they prove to be strong enough, are highly conductive so the power for a climber may be able to be delivered from the ground without any weird laser or microwave wireless power advances required.
Anyway, just ignore the "possible now" or "indian rope trick" freaks and enjoy the cool newtonian physics thought experiment while hoping this doesn't create too many scams on the fringes.
Just treat it like cool SF with some real world constraints and a minor bit of handwaving to ignore a few of the more inconvenient real world constaints. Such a massive (pun intended) project needs to be just a tiny fraction of the mass intended to be moved beyond geostationary orbit for it to be worth doing instead of just using rockets. The "indian rope trick" fanboys in paticular forget that a hell of a lot of mass has to be moved up there by rockets in the first place just to get started. Unless we are lucky enough for a relatively small asteroid to sit for long enough at a lagrange point for us to catch it and slow it down enough for it to be used as a counterweight then truly vast amounts of mass have to be accelerated to very high velocities to build a beanstalk. Even with the captive asteroid option that's still ludicrous amounts of fuel to get it to where it can be used.
Wrecking Skylines? (Score:5, Informative)
Really? With the train station in Kyoto? Seriously? I've been there, both in the train station and in the surrounding area. It's big, but it's not exactly skyline wrecking unless you happen to live in an apartment which directly faces it. There are plenty of other buildings nearby which are close to the same height and once you get about two blocks away, you can't even see it from the street. If you don't believe me, here's a picture [obayashi.co.jp] from above which shows the surrounding area. Plenty of other 8+ story buildings in the area. Here's a view [tripadvisor.com] from the top of the hotel in the train station. What skyline is it that they're destroying exactly?
Kyoto is a lovely city. It has myriad beautiful temples and gardens and the nearby country-side is lovely. People flock to it to see the cherry trees when they are in bloom. But none of these things are very tall. Most of the famous temples aren't even visible when you're half a block away from them, nevermind part of the skyline. It does not now have an impressive skyline and if it ever did, it must have been centuries ago, and although the train station big enough to be clearly visible for a couple of blocks around, it's not exactly a sky-scraper. Honestly, its width and shininess stand out as much as its height. So, if the person writing the article thinks that the Kyoto train station (which has far more non-shinkansen platforms than shinkansen platforms) is too big or too shiny, then fine, but saying that it wrecks the skyline is just dumb.
Re:Counterpoint (Score:5, Informative)
Most railways in Europe are owned and operated by state-sponsored monopolies. In The Netherlands there are small openings for other railway companies and they are generally cheaper, more reliable and providing much better service.
Fun case: Deutsche Bahn wanted to extend their high-speed network into The Netherlands (to the North) where the current monopolist has no intention of providing service. But since they aren't allowed into Germany they were able to block the new railway into The Netherlands through lobbying. The northern provinces of Holland were quite mad but couldn't do much about it.
Materials science 101 (Score:5, Informative)
No quotation marks needed. The problems in designing very strong materials have been known since WW2. The challenge can be expressed very simply: the more the strength depends on having a complete covalent structure (in CNTs the bonds have some ionic characteristic owing to the p-hybridisation but the same logic applies) , the greater the weakening effect of even a single fault. If a cosmic ray unzips a few bonds, the stresses will concentrate on the bonds on either side, and the split is likely to propagate. In strong metals we fix this with alloying components, very crudely like the gravel in concrete, which stop those dislocations from extending right through the material, but equally adding alloy components reduces the ultimately obtainable strength from a perfect structure. It is a tradeoff, as usual.
Re:Is that so? (Score:5, Informative)
The climber has to have food, toilets, sleeping facilities if you are going to take a week to get to GSO, so it's going to have to be more like a mini-hotel (or at least a mini-space station) than an elevator car.
Like a 'mini hotel'? You've never travelled across Russia by train. Those trains have toilets, sure. Sleeping facilities, sure. Dining cars, sure. But 'mini-hotel'? No. It'd be very cool if the 'space elevator' had coal-fired samovars in every carriage though!
Re:Counterpoint (Score:5, Informative)
Umm, no.
Below the terminus at GEO, the elevator is moving at less than orbital speed. Above the terminus (all the way to the counterweight), it is moving at more than orbital speed.
This can be taken advantage of to deploy things to positions in LEO (release something at just the right altitude along the space elevator, it'll drop down to a perigee at the altitude you want it, then a small boost from a conventional rocket, and you're in a circular orbit in LEO. At much lower cost than a rocket from the ground.
Likewise, it can be used to toss things into the outer system - the counterweight is moving at far above escape speed (~7000 m/s at 96000 km), so you can just let something go there, and it'll be heading off in the general direction of Jupiter. It won't go as high as Saturn's orbit without a higher counterweight, of course, but lower aphelions are possible by releasing at a lower altitude than the counterweight...