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Japan starts space elevator experiments

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Re: Japan starts space elevator experiments

#41

Post by Shivetya »

Barrin92 wrote: post #36
blahedo wrote: post #29

> "...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…

six oval shaped cars with those measurements each is about 780 square meters in total. The average Tokyo condo is about 65 square meters (for a family of three). Somewhat unpleasant for 30 people but not really that small. Like 3 people in one Tokyo apartment density wise.

to be safe I would suspect any one of the three cars must be able to support all persons on the trip. they are pretty much of out reach of help shortly after leaving.

it might be interesting to see what type of personality tests them use before allowing anyone to actually board one of these should they ever come into existence.

Re: Japan starts space elevator experiments

#42

Post by macspoofing »

yohann305 wrote: post #15

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

I'm not sure a space elevator is 'impossible' in the way that faster-than-light communication is. I suspect they argued that the engineering challenges will never be solved - which is a fair argument.

Re: Japan starts space elevator experiments

#43

Post by ghaff »

mLuby wrote: post #28
ourmandave wrote: post #3

The cars would travel at up to 200kph and arrive at the space station eight days after departure from Earth. These early cable experiments are important, but someone should also be working on the composing an 8 day Elevator Muzak score that won't drive you insane.

Weird to me that they aren't accelerating till the midpoint and then breaking till the destination at a constant 1g. Gets around the space sickness by providing artificial gravity and should take ~hours rather than ~days.

Because it would require you to reach an improbably high velocity (especially for pulling yourself up a cable)--and you'd do so relatively quickly using an improbably large amount of energy in the process.

Re: Japan starts space elevator experiments

#44

Post by p1mrx »

mLuby wrote: post #28
ourmandave wrote: post #3

The cars would travel at up to 200kph and arrive at the space station eight days after departure from Earth. These early cable experiments are important, but someone should also be working on the composing an 8 day Elevator Muzak score that won't drive you insane.

Weird to me that they aren't accelerating till the midpoint and then breaking till the destination at a constant 1g. Gets around the space sickness by providing artificial gravity and should take ~hours rather than ~days.

That trip would only take an hour, but I don't think you could build a cable and drive system capable of operating at 18 km/s.

Re: Japan starts space elevator experiments

#45

Post by curiousgal »

blahedo wrote: post #29

> "...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…

How much space would they get on the ISS either ways? It'd be a good practice.

Re: Japan starts space elevator experiments

#46

Post by toyg »

blahedo wrote: post #29

> "...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…

You forget this is Japan, where tons of people sleep on trains almost every day - often on their feet.

Re: Japan starts space elevator experiments

#47

Post by twic »

ghaff wrote: post #24
pier25 wrote: post #16

I know nothing about physics... but wouldn't the space station need to counter the cable tension?

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.

Re: Japan starts space elevator experiments

#48

Post by pilsetnieks »

ourmandave wrote: post #3

The cars would travel at up to 200kph and arrive at the space station eight days after departure from Earth. These early cable experiments are important, but someone should also be working on the composing an 8 day Elevator Muzak score that won't drive you insane.

I think copyright won't apply after the first half hour.

Re: Japan starts space elevator experiments

#49

Post by krallja »

curiousgal wrote: post #45
blahedo wrote: post #29

> "...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…

How much space would they get on the ISS either ways? It'd be a good practice.

They’re not going to ISS, they’re going somewhere in geosynchronous orbit.

Re: Japan starts space elevator experiments

#50

Post by monk_e_boy »

Torkel wrote: post #14
sandworm101 wrote: post #2

Carbon nanotubes are cool, but i will believe space elevators possible once someone shows me a carbon nanotube rope i can climb with. I'd settle for a bike or motorcycle chain. A nanotube-based shoelace would be worth a noble prize or two.

Given strength and size and other properties that carbon nanotube ropes would need have... Wouldn't a carbon nanotube shoelace be like the worst idea ever? ...strong as a steel cable, but so thin as to be hard to see and handle. And brittle and not so good at bending. => First it slices up your hands when you tighten it and then it breaks when you tie it :)

Its going to be very interesting when carbon nanotubes are combined with cloth.

Ripstop cloth is a mix of plastics and line giving a fexible cloth that is very very strong. Its also airtight so you can inflate it (for a time - its not 100% without a bladder)

Inflatables wings. Hulls.

https://youtu.be/WgABFvqE8lY

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