Slashdot Mirror
Obayashi To Build Space Elevator By 2050
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."
It would be easier to believe that "Japan's Obayashi Corp" are out of their mind if we would have a link to this on their own web site.
It probably won't hurt your corporate image too much to bolster some idealism every once in a while.
I was the real korpiq until I woke up clowned.
It's bad enough sharing a lift with 5 or 6 people for 30 seconds, let alone sharing one with 30 people for a week.
I wish them luck and hope the technology is ready before I'm too old to ride the thing.
Forecast for this thread. 56% never gonna happen. 10% certain it will happen. 18% about how impossible it is. and the rest finding a way to blame MS for the failure.
Trying to become famous by taking photos. Visit my homepage please.
1. The fact that we don't have the necessary structural materials yet to actually make a space elevator.
2. Neither Japan nor any Japanese company has the financial solvency to undertake such an effort
2. No no wants to spend a week in an elevator even if it means you get to go into orbit. Christ I can barely make it to the 15th floor without some jackass farting. A whole week. Don't think so.
Every so often some company in need of cashflow creates some nonsensical grandiose concept in the hopes of securing ignorant investor funding (See Moller flying cars). And such companies usually have spent the bulk of the cash on P.R. - hence the slashdot article.
It's bullshit. It's always bullshit.
----- In Your Cubicle No One Can Hear You Scream...
WTF does that last sentence even mean?
The fact that we don't have the necessary structural materials yet to actually make a space elevator.
And we'll continue not having them until someone pays to build a space elevator and does the needed research. By 2050 it's not impossible to think materials will be around to make this feasible.
Neither Japan nor any Japanese company has the financial solvency to undertake such an effort
Possibly, hard to say. They put up some really large buildings. They could get a huge loan.
No one wants to spend a week in an elevator even if it means you get to go into orbit.
I would happily pay 20k to go to said stationary station for a few days. Even if it took a week to get there in cramped quarters.
By then there may be a number of cheaper options to visit pace though, Virgin Galactic is making a go at it. I really only want to go up if I can spend a day or two though, so mere flights up and down do not interest me much...
"There is more worth loving than we have strength to love." - Brian Jay Stanley
You are correct. However some dream that the market will provide in some mysterious way without paying materials scientists to find something that will make it technically possible and some engineers that can turn that it a workable design. Then we need an offplanet project big enough so that the huge project of making a beanstalk is worth it.
These stories bring out a lot of clowns that think you can just throw stuff in the air and it won't come down, and reader, if you don't want to be seen as one of those clowns I suggest you look at the wikipedia page on these beanstalks then read and understand the very simple maths and physics before posting. A rotating frame of reference is a bit hard to get used to initially, so get your head around it before posting stuff that anybody with an engineering or physics background here will scoff at as magical thinking.
Fair enough. Basically, the cable is always going to be stressed to a large percentage of maximum loading. It will also be made of carbon, which is flammable. I suspect that many kinds of weaponry could cause just enough damage to cause it to unravel and fail in short order. An incendiary charge placed against the side of the cable with a swarm of R/C helicopters might work just as well.
In any case, it's the ultimate in single point failure. Yes, you can attempt to secure the cable with missile defenses and other weaponry, as well as elaborate security checks of everyone allowed near it. I just can't see such an effort working when it's so trivial to actually destroy the cable, however.
Even a few 20mm rifle rounds in the same spot might be all it takes.
Aerospace engineer who has worked on orbital tether design speaking here.
A cable with a tip velocity of 30% of orbital speed is feasible with existing materials. Since the center of the cable is at orbital velocity by definition, the tip is then at 70% of orbital velocity at the bottom of it's rotation. A vehicle coming from the ground then needs half the kinetic energy as a full ground-to-orbit one does (Kinetic energy goes as 0.5 times velocity squared). That makes single stage launch vehicles very feasible. If the tip is at 1 gravity, then the cable radius is 516 km, and the center would be at an altitude of 750 km or thereabouts, so it does not see too much drag at the low point. Half a rotation later (12 minutes) at top of the rotation, you can let go, and now be going at 130% of orbit velocity, which is nearly GEO transfer or escape. Escape is 141% of orbit velocity.
If you wanted to get to zero g, then it's a 516 km ride, which beats the fuck out of a stationary elevator. The elevator will be heavy relative to the vehicles coming up and down, but you need onboard propulsion to make up for traffic differences. Anything going up tends to lower the elevator orbit, anything going down tends to raise it. Whatever is left over you need to make up, preferably with an efficient electric thruster. Arrival means landing on a platform that is at one gee. With modern GPS and laser navigation, that should be fairly easy. Make the platform hundreds of meters wide if you need a bigger target. Missed landings just means the vehicle heads back down sooner than it was supposed to. It should not present a safety problem.
Building something like this is a bootstrapping task. Start with a small rotating station, and extend cables from it. Keep adding sections of cable one at a time. Get your cable from near earth asteroids which have carbon, so you don't have to launch the whole thing from Earth. As the thing grows, the velocity to reach it from the ground goes down, so the payload a vehicle can carry goes up.