211–220 of 304 posts
> "...six oval-shaped cars, each measuring 18m x 7.2m holding 30 people, ... eight days ...." Whooooa. Let's think about this for a second. Eight days means people need to sleep (and not just sitting up in a chair, no matter how comfy). At 1m x 2m per bed that would be a 15m x 4m space even without aisles to walk between the beds or down the middle or any sort of privacy separators. Also, a bathroom and actual washin…
"And overall, such a tower is a diabolical invention. Rotating in equatorial plane it will knock off everything it encounters. And since any satellite orbit intersect the equatorial plane, sooner or later all satellites with orbit lower than the tower height will be knocked down. At the base of the tower will lay remnants of almost the whole cosmonautics."
I'd assume this closes naive discussions about space elevator, at least until the proponents will explain what they are going to do with the problem of hitting satellites. Yet I see this problem again and again with hardly any progress in this area...
i remember reading here on HN someone explaining why space elevators are not possible. I can't recall why, but he/she had very convincing arguments. Anyone here remember that thread and can link it back here? Thanks
Kelly and Zach Weinersmith discuss space elevators in their book Soonish. The summary of the downsides is: * If would need to be the most precisely engineered thing we've every produced just to stand a chance of being good enough. * Because of that, it will be particularly sensitive to wear and tear. How the maintenance would work is an open question. * It will probably attract terrorists like crazy. * It needs to ne…
> It needs to never get struck by lightning. It is a particularly attractive lightning rod.
Haven't buildings solved this problem with lightning rods?
On another note, I am personally fascinated by space elevators which is why I am somewhat interested in going back to the moon where we can build a space elevator with today's tech, avoid all of these problems, and have a large body of resources to build/fuel spaceships with.
Earlier quoted context omitted.
Most theoretical designs that have been proposed would require a very large counterweight, e.g. a captured asteroid.
Or you just build the cable out beyond geosynchronous orbit. The further out your counterweight mass is, the more force it exerts, so, AIUI, the most mass-efficient way to do it is an extension of the cable.
Earlier quoted context omitted.
The end of this cable would be 36000km up, compared to the ISS's 400km. The first space elevator would primarily be used to shift stuff, rather than people at first - there's no point having convenient transit for people if they've got nowhere to go at the other end.
That's where the end of the cable is, but there's no rule that that's where anyone has to get off the elevator.
Earlier quoted context omitted.
There is - and I don't mean to pun - plenty of space in space. Space stations could be quite roomy.
They'll be roomy just as soon as it isn't exorbitantly expensive to transport material to space. So, possibly sometime after this elevator is operational...
An inflatable "house" is conceptually completely possible.
Airplanes have to be small because of air resistance. Space stations have no such constraints.
Earlier quoted context omitted.
Yeah, just wait 6-7 years and Moore's law should take care of it.
Material science is tough. Check out engine/turbine material science developments. It can take >decade to get new materials into planes.
It's unclear to me if this is real or the continuation of a publicity stunt from Obayashi (who has been getting press about their plans to build a space elevator for years). I'm as excited about the theoretical concept of a space elevator as anyone. But the problem remains that no one can produce a cable even close to strong enough. This article has a good description of the material science problem: http://www.space…
It's unclear to me if this is real or the continuation of a publicity stunt from Obayashi (who has been getting press about their plans to build a space elevator for years). I'm as excited about the theoretical concept of a space elevator as anyone. But the problem remains that no one can produce a cable even close to strong enough. This article has a good description of the material science problem: http://www.space…
Reminds me of Ono Sendai making wetwire jacks to the internet.
I'm curious about space elevator phenomena related to lateral ∆V. At Earth's equator (zero altitude - i.e., on the ground), an object moves spinward at about 0.46 km/sec. In geosynchronous orbit, an object has to move at about 3.07 km/sec. A space elevator car ascending from stationary on the equator to a terminal at geo altitude would require a tangential (lateral) ∆V of 2.61 km/sec. This is in addition to the energ…
Edit: And bowed, basically in equilibrium with lateral forces.