Lakes on a space station

[SargeRho]

Something I've been wondering for a while. Let's say you have a ring station in solar orbit, built from materials harvested of an asteroid or whatever.

So people will need water. Lots of it. Would it make sense, or be viable at all, to store at least part of the water in the form of a river or lake on the inner walls of the station, as is seen on essentially every sci-fi ring station?

[Nuke]

id keep the water in ballast tanks and pump it around to stabilize the ring. you might need irrigation canals for agriculture though.

[lajoswinkler]

Pumps would be a must have, as the fluid would otherwise quickly pile on one side and cause the whole thing to wobble.

[Kerbin Dallas Multipass]

Pumps would be a must have, as the fluid would otherwise quickly pile on one side and cause the whole thing to wobble.

Why would water do such a thing?

I think the idea is a torus shaped rotating ring station?

[SargeRho]

Yes, and it's always going to wobble slightly. Water will begin to move towards one part of the torus, causing more wobbling causing more pileup and...you get the picture.

[Nuke]

id hate to write the control algorithms for the ballast distribution system.

[astropapi1]

I think OP is talking about this kind of space station, which would work as a centrifugue:

[K^2]

Pumps would be a must have, as the fluid would otherwise quickly pile on one side and cause the whole thing to wobble.

Common misconception. But the ring station will turn around the center of mass. If one side is heavier, the other side will be further from center of mass, and be "lower" from perspective of centrifugal force. That means water will naturally flow to balance the station. No need for pumps.

If there is also enough of an altitude change to set up a temperature gradient within the ring, you might even be able to get away with having natural weather carry moisture around resulting in lakes and rivers that OP mentions. In fact, in a large enough station, this is inevitable. So you'll either have to do rivers or channels of some sort. The only question is how large is large enough for that, and whether any known materials would allow for a station that big.

With materials we know, we should be able to do up to about 100k in diameter. That can easily allow 1k+ altitudes within the ring. Like I said, I don't know if that's enough for weather to develop naturally, but you'd be able to set up something weather-like semi-artificially. Whether there is any benefit to that, vs a nice controlled environment, I don't know.

[Sillychris]

I think the real concern is the feasibility of waterskiing on these lakes.

[MC.STEEL]

There is also another bother to this do we really need such big stations and who would or can he/they even pay for this?

If the station is big enough i see no reason why not make it have a functional ecosystem.

[Seret]

In a really massive habitat station like that it would be possible to have a much more biomimetic life support system than our current technology. So you could have a proper hydrologic cycle (clouds, drainage, maybe even precipitation, etc). Lakes/reservoirs would be by far the simplest way to store your bulk water, and would do double duty as recreational facilities and sources of biodiversity. Wetlands would filter your water, and the lakes would serve as big sponges for atmospheric gas imbalances.

In short, why would you NOT have lakes? You need the water on board anyway.

[Aghanim]

Raining inside a space station? Now that will be a sight to see!

[lajoswinkler]

Common misconception. But the ring station will turn around the center of mass. If one side is heavier, the other side will be further from center of mass, and be "lower" from perspective of centrifugal force. That means water will naturally flow to balance the station. No need for pumps.

If there is also enough of an altitude change to set up a temperature gradient within the ring, you might even be able to get away with having natural weather carry moisture around resulting in lakes and rivers that OP mentions. In fact, in a large enough station, this is inevitable. So you'll either have to do rivers or channels of some sort. The only question is how large is large enough for that, and whether any known materials would allow for a station that big.

With materials we know, we should be able to do up to about 100k in diameter. That can easily allow 1k+ altitudes within the ring. Like I said, I don't know if that's enough for weather to develop naturally, but you'd be able to set up something weather-like semi-artificially. Whether there is any benefit to that, vs a nice controlled environment, I don't know.

You never did any laundry, did you?

[SargeRho]

Laundry isn't liquid

But yes, I was referring to something like what astropapi1 linked.

Edited April 4, 2014 by SargeRho

[K^2]

You never did any laundry, did you?

Actually, I have, and my laundry machine has loose bearings in the outer ring specifically to self-balance. The reason clothes don't self-balance is because they get stuck to the walls and each other. Anything that's free to move around the perimeter, however, will improve balance.

I can tell you more, given a spring, such as wheel suspension, there is a minimum spin speed at which the system self-balances. But in free space, any rotation with free flowing liquid or other free-moving mass is going to self-balance.

Would you like to see derivation of that from the first principles?

There are a lot of things you might know better than me, but mechanics isn't one of them, trust me. I'm happy to explain further to satisfy your curiosity, but you ought to leave any hope of proving me wrong on this at the door.

[einsteiner]

It is not wise to argue with K^2 when it comes to physics and math.

[K^2]

There are branches of both where I'm going to be pretty lost, and there are definitely a few members on this board who can teach me many things on these.

Oh, and I don't mind arguments and questions. Everyone is going to learn something from a well structured argument. I just get a little cranky when people are snarky about it.

[Brotoro]

As I recall, Von Braun's wheel shaped space station design incorporated a pipe partially filled with water that was supposed to automatically shift to balance the station's rotation.

[lajoswinkler]

True, laundy isn't liquid, but I don't see what mechanism would evenly distribute water along the torus if uneven distribution occurs. K^2, can you explain it more thoroughly?

I know there are liquid mirror telescopes, but I think the stability of rotating fluid systems have much to do with viscosity and the actual scale of the system. I really think a watered Standford wheel without smart pumps would get into trouble because of its size.

[Runboy]

The station would not wobble as some people say it would,because the water moving to one side changes the center of mass so that one "side" of the station travels faster than the other,which then creates increased centrifugal force @ the side that is moving faster,pulling the water from the side that has more water and therefore less centrifugal force keeping the water on that "Side" towards the side that is generating more centrifugal force because it is traveling faster,therefore creating an effect that makes the water even itself out if there happens to be more water on one side of the station.

[Kerbin Dallas Multipass]

I'd like to just leave these here:

[jwenting]

Raining inside a space station? Now that will be a sight to see!

it will come as a surprise to some no doubt. But it's not unheard of for large buildings to have weather systems, including clouds and rain. Think the Boeing factory in Seattle, things that size are large enough for it. A torus style space station would be many times larger.

[Stargate525]

it will come as a surprise to some no doubt. But it's not unheard of for large buildings to have weather systems, including clouds and rain. Think the Boeing factory in Seattle, things that size are large enough for it. A torus style space station would be many times larger.

And the VAB down in Florida. If the HVAC goes off there, they get a nice little cloud system. And Hitler's magnum opus that he had planned in Berlin would have been big enough inside to not only form clouds, but produce significant rain.

With materials we know, we should be able to do up to about 100k in diameter. That can easily allow 1k+ altitudes within the ring. Like I said, I don't know if that's enough for weather to develop naturally, but you'd be able to set up something weather-like semi-artificially. Whether there is any benefit to that, vs a nice controlled environment, I don't know.

It is. You'll get clouds for sure and, if not rain per se, foggy condensation and mist. If you allow enough evaporation so that the 'sky' is warm and muggy, it would be trivial to install condenser fins along the ceiling and force traditional rain, if you wanted.

The bigger question, I feel, is how you're going to maintain structural integrity of a vacuum with water essentially free to roam around. Our stuff isn't terribly waterproof at the best of times, and I can't imagine how you would go about repairing corrosion caused by your groundwater soaking against your outer hull for a decade.

[KASASpace]

Something I've been wondering for a while. Let's say you have a ring station in solar orbit, built from materials harvested of an asteroid or whatever.

So people will need water. Lots of it. Would it make sense, or be viable at all, to store at least part of the water in the form of a river or lake on the inner walls of the station, as is seen on essentially every sci-fi ring station?

Why build a ring, when you can build a cylinder!

O'Neill Cylinder time, now.

[DJEN]

Why build a ring, when you can build a cylinder!

O'Neill Cylinder time, now.

I prefer Kalpana One to the cylinder.

Also, Bishop Rings.