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Comment by blahedo | Hacker News Reader

> "...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 washing facilities of some sort are mandatory, and a kitchen with at least minimal food-prep capabilities (even if it's mostly pre-made); modern airplane galleys only need to deal with trips in the tens of hours.

18m x 17.2m is really really not a lot of space for all that.

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Seems doable, to pick a random example: https://en.wikipedia.org/wiki/HMS_Endeavour 30m long, 8.9m beam, complement of 94.

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.

”Obayashi envisages a space elevator using six oval-shaped cars, each measuring 18m x 7.2m holding 30 people, connected by a cable”

I can’t see how one would read that other than as each car holding 30 people.

You would need an extra comma to make it six cars holding 30 people in total:

”Obayashi envisages a space elevator using six oval-shaped cars, each measuring 18m x 7.2m, holding 30 people, connected by a cable”

I read it as the entire elevator carrying 30 people, and this article seems to confirm it (https://www.zmescience.com/research/japanese-space-elevator-...)

Having 30 people in one car including gear, provisions and sharing sanitation seems absurdly small if not logistically impossible

But the original sentence is ungrammatical either way. Under your interpretation there’s still a missing “and”: “each measuring 18m x 7.2m and holding 30 people”.

The missing "and" is a tiny grammatical error, whereas the missing "," Someone mentioned is a large grammatical error. Tiny grammatical errors are OK -- language grammars change over time because many people start making the same tiny grammatical error until it becomes part of the accepted grammar of the language.

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.

It's an elevator to _space_. There are going to be some comfort compromises, especially on these early iterations.

Comparing to a typical submarine, it's three times as much space per person. Submarines typically have 30 square feet pp, 18m x 17.2m for 30 people is 93 square feet.

7.2, not 17.2, so about 46 sqft per person. Point taken, but if a submarine is the point of comparison... yeah, that's really really not a lot of room.

8 days of uncomfortably close quarters on ascent may be a good way to psychologically prepare folks for a perhaps slightly-less cramped orbital experience.

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

Not to mention the existence of 'capsule apartments'...

There's one practically derelict building of capsule apartments, it was a failed experiment. Capsule hotels are a thing, but not apartments.

Don't actually need much for 8 days. Provide video games, pizza, and a relief tube. People do it all the time.

Hey, Stephenson had people living long-term in spaces that size, in Seveneves. That didn't turn out so well, but eight days isn't that long.

Tube beds could be close packed, and people could sleep in shifts. Also, one can survive just fine with just a washcloth and towel, and a source of warm water.

Beds can stack.

Astronauts wear diapers, painfully lose their fingernails when working in spacewalks. Having to bunk in submarine style accommodation for little over week is nothing.

okay i had never heard of the fingernail thing. that sounds awful. I wonder if later designs helped? My immediate thought is: fill those finger spaces with clay like material -- to spread the load across the whole surface of the finger, not just the nail.. but yowtch. glad I never chose that career.

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

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.

Interesting thought. Note that getting off 300 km up would not put you in orbit; you would lack the orbital velocity required for that. So if you get off there you'd have to burn around 8 km/s of delta-v, which is quite a bit of fuel to haul up.

For efficiency you'd want to go higher. There'd be a point much higher than 300 km where detethering would put you into a highly elliptical orbit where the periapsis is 300 km. Then you'd just have to burn retrograde to circularize. Off hand I'm not sure what the math for that would be but it should be pretty simple algebra.

Actually the cable will extend well beoynd that point. 36Mm is the altitide where the elevator would be travelig at orbital speed. Jump out any lower and you will drop back to earth. Unless you jump very hard (using rockets or something).

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

But it's still an apt comparison. People live for long periods on the ISS, and the amount of space isn't likely to get any bigger during their mission.

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...

The slightly counter intuitive point is that you only have to transport wall material.

An inflatable "house" is conceptually completely possible.

Airplanes have to be small because of air resistance. Space stations have no such constraints.

Inflatable, sure, but not a balloon. Micrometeors/space junk are a threat, and more so for bigger inflated objects.

Yeah, the walls need to be strong enough. Whatever that means long term.

The mathematical argument of 2D vs 3D still holds.

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.

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.

General anesthesia kills 1 in 100,000 patients, and that's with medical personnel standing by in actual hospitals, much less a skeleton crew of people strapped to a spacebound elevator.

We don't understand ourselves or our bodies anywhere near as well as we can understand or advance materials science. My money is on new cables before reliable stasis.

So far, for humans, that lives within same realm that warp drives occupy in science fiction.

No, we don't even know if warp drives are allowed by the laws of physics. We have a pretty good idea how to do hibernation: Saturate the tissue with some cryoprotectant and freeze it very quickly. The problem is that we don't have a cryoprotectant that is sufficiently non-toxic and we can't freeze anything as big as a human quickly enough.

Of course we know. Bend space and don't travel faster than light. We JUST need exotic matter of sufficient energy density to carry around.

Yeah and since nobody knows whether the exotic matter needed actually exists, we don't know whether bending spacetime in the required way is physically possible.

On the other hand, we can successfully freeze and thaw bunny kidneys.

And some way of resolving the resulting time travel paradoxes.

If bears were capable of warp drive, then I would agree with you.

If bears will be the ones to take space elevator trips, then we're set.

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