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Japan starts space elevator experiments

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Re: Japan starts space elevator experiments

#51
post #28

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.

Surely friction is an issue at much faster speeds? I guess the fastest trains go 400+ KPH, with the fastest being maglev. I assume, though can't tell from the article, that the space elevator has physical contact with the cable, and I can't think of how one could reproduce maglev tech when going vertically.

So, there's surely a safe speed limit built into the materials being used? It's probably faster than the speed they're starting out with, but I kinda assume it can't be fast enough to shorten the trip to hours from days.

As an aside, moving people is probably not the most profitable use of the thing for the foreseeable future, as cool as that sounds. Getting a satellite into orbit for a tenth the cost is revolutionary (though they mention the cost compared to the shuttle, which is much more expensive than rocket transport...so they may be cherry-picking numbers to make this seem more revolutionary than it is).

Anyway, I can't think of how they could accelerate much beyond the fastest non-maglev train speeds without tearing apart the cable and car, but I may be underestimating the strength of carbon nanotubes, and whatever other component materials they're using. Perhaps there's a materials nerd here who knows.

Re: Japan starts space elevator experiments

#52
post #44
post #28

Earlier quoted context omitted.

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.

Not sure if this would work, but how about using a wire with evenly-spaced metal beads, then using a magnet (a large one like used in MRI machines) to pull up the cart? You'll probably have to turn the magnet on/off at a specific frequency, depending on the momentum of the cart, which could be a challenge.

Re: Japan starts space elevator experiments

#53

Earlier quoted context omitted.

Is humor against HN rules? I regularly see such posts being downvoted and it doesn't make sense to me.

No, it’s not against the rules, but downvotes aren’t there to enforce the rules. It’s just a culture thing. HN tends to be more news and factually focused than reddit/Twitter/etc. People here just prefer to stay on topic, especially since humor is very different between people and can be very hit or miss.

yup, coming here and the top comment actually being something insightful or some point worthy of discussion instead of some sarcastic comment or joke like elsewhere is what makes this place.

Re: Japan starts space elevator experiments

#54

Earlier quoted context omitted.

Shouldn't we just knock the people out for the 8 day trip?

And how exactly do you plan to 'knock out' people safely for eight days, or even just a few? Heck, even for just a few hours without medical equipment and personnel?

The medical technology for human stasis doesn't seem particularly unattainable, when compared against building a carbon nanotube tether into orbit. Some mammals are able to hibernate for months.

Re: Japan starts space elevator experiments

#55
post #14

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 :)

I believe the expectation regarding carbon nanotubes in the sphere of space elevators is that they would be woven and layered into a sheet of human scale; these sheets would be used to construct a curved ribbon for the gondola to climb.

You could apply the same principle and weave a bootlace from them, but the limits of current technology would render that an exceedingly expensive bootlace.

Re: Japan starts space elevator experiments

#56

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.

Stairway to Heaven is about 8 minutes long, so they better work hard on speeding the elevator up to match that.

Re: Japan starts space elevator experiments

#57

Earlier quoted context omitted.

Shouldn't we just knock the people out for the 8 day trip?

And how exactly do you plan to 'knock out' people safely for eight days, or even just a few? Heck, even for just a few hours without medical equipment and personnel?

I think the safety/ease of sleep makes people think anesthesia is about as easy to manage. In reality, it requires a highly trained professional to be monitoring 24/7, and even that involves very significant risks.

Re: Japan starts space elevator experiments

#58

Earlier quoted context omitted.

Is humor against HN rules? I regularly see such posts being downvoted and it doesn't make sense to me.

Most humor can be categorized as "insubstantive comments" and those are discouraged. It is possible to crack a joke here and get it upvoted, but it's hard to pull it off. I even once had a joke upvoted by quite a lot,* like 50 points or something, but most jokes are downvoted not because humor is forbidden, but because insubstantive comments are discouraged. Some humor is downvoted for being uncivil because a lot of…

Well said. That's about as succinct a sum-up as I've heard. This might actually belong in the FAQ as it might save some folks a bit of confusing cultural acclimation upon arriving at HN from parts distant such as reddit or slashdot (is that still a thing?).

At any rate, way better than "harumph! HN hates fun!"

Re: Japan starts space elevator experiments

#59

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.

[deleted]

Re: Japan starts space elevator experiments

#60
post #56

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.

Stairway to Heaven is about 8 minutes long, so they better work hard on speeding the elevator up to match that.

Only if they want this to be a fancy burial service where we slingshot your corpse into space for kicks.
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