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| Pong |
 Posted: Thu Apr 17, 2008 2:56 pm Post subject: Integrity of water in space |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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What will happen to a ball of water (say, the mass of sputnik, ~100kg) in orbit?
We know that many comets are water. We know the space shuttle used to "atomize" and eject wastewater; the droplets froze and did not fizzle away into molecules. We know that an accidental icicle formed on the shuttle, did not boil off or sublime perceptibly, despite cycling through sun and shadow.
Am I right to assume my hypothetical ball would last just as long in orbit as most artificial satellites do?
I understand that liquid water in vacuum will violently boil, until the loss of vapor cools it to freezing. That's not really the question, and we can imagine this ball of water was pre-frozen at sea level before exposure to space.
I'm going to pose more interesting, related questions as the thread progresses. |
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| Pong |
| Posted: Sun Apr 20, 2008 3:46 pm Post subject: |
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Forum Senior
Joined: 08 Apr 2008
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 Ball's still in my court. I'm trying to get a reality check here.
OK, next question:
We've got a ball 'o ice in orbit, about the size of a large igloo. An astronaut bores into it, and hollows out a little room. Plug the entrance, and pressurize the cavity with a hose or (daring) by breaking seal on spacesuit, inside.
Does the ball explode? Why didn't the spacesuit explode?
Our astronaut, now in pajamas, complains the room is too chilly. So another astronaut delivers a heater & battery, plugs that into some solar panels dangling off the ball.
Now the walls melt some don't they? And the ball must lose as much heat as is put into it. Is our astronaut about to die? |
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| sunshinewarrior |
| Posted: Mon Apr 21, 2008 5:22 am Post subject: |
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Forum Ph.D.
Joined: 26 Sep 2007
Posts: 825
Location: London
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| I'd imagine that ice does not have the toughness built into a space suit, and so would not survive being pressurised from within. |
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| Ophiolite |
| Posted: Mon Apr 21, 2008 7:29 am Post subject: |
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Forum Radioactive Isotope
Joined: 25 Jul 2005
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Location: Scotland
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Comets - which do contain a lot of ice - are perfectly satisfactory for interstellar travel. They contain reaction mass for propulsion; water for consumption and farming; organics for food production. If I was a creationist I would be arguing that such a fortuitous combination of features smacks of intelligent design. 
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The Universe is not only weirder than we imagine it is weirder than we can imagine. J.B.S.Haldane. |
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| Pong |
| Posted: Mon Apr 21, 2008 4:41 pm Post subject: |
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Joined: 08 Apr 2008
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@Ophiolite. You know where this is heading. Ball of liquid water, containing habitable air bubbles. Before we leap to habitation and travel, though, I want a better understanding of our construction material. From an engineer's perspective, and even a builder's perspective.
I arrived at the ball of water when challenged to design a self-sufficient orbital colony. "Just water" seemed more to the point (sustain life in space) than gee-whiz aerospace models of spaceships and elaborate steel structures. I reckon that if we simply amass water, and keep it liquid, nature will take care of most other problems.
In case anybody missed the jump, I'm proposing a ball of mostly liquid water, with large air bubble(s) in it, having a naturally frozen shell. This thread, I wanna learn how the shell works in space, or doesn't.
| sunshinewarrior wrote: |
| I'd imagine that ice does not have the toughness built into a space suit, and so would not survive being pressurised from within. |
Doesn't this depend on the thickness of the ice? Atmosphere pressure is nothing like popular sci-fi, more like a very flat tire. But the problem is crucial. And even if my idea works in a vacuum, we still have the problem of stray nuts & bolts hitting it. Then what happens?
Suppose we make an ice composite with reinforcing fibre. That could be vegetable fibre - 15% wood pulp yields "pykrete" 3000psi compressive (like concrete) and better tensile than concrete. Or embedded wire & rebar as in reinforced concrete, over the top IMO and I see that as a cheat. I'd rather use pure water without any additives.
My first thought was to put the water in a bag. Like a spacesuit or some of our new ISS module designs. But the bag must be manufactured, it can't self-heal, it requires maintenance, it just seems like excessive packaging. Is that really necessary?
I want people to think about how they can kill this ice/water ball, and tell me how. |
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| unoscooter |
| Posted: Mon Apr 21, 2008 9:06 pm Post subject: |
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Forum Freshman
Joined: 24 Feb 2008
Posts: 19
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| i do not think you could have ice in outer space. the pressure in outer space is 1.30471256x10^-16 atm and it has an averege tempature of 3 kelvin (-270) so if you were to look at a phase diagram of water you will see that it is in the vapor state. so even it you rased or lower the tempature it could never be a liquid or solid. |
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| Pong |
| Posted: Mon Apr 21, 2008 11:32 pm Post subject: |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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| unoscooter wrote: |
| i do not think you could have ice in outer space. |
Well, there certainly is ice in space now. Plenty of it: Saturn's rings, asteroids, even moons of it. We've dumped water in orbit, and it forms ice. |
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| Ophiolite |
| Posted: Tue Apr 22, 2008 2:18 am Post subject: |
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Forum Radioactive Isotope
Joined: 25 Jul 2005
Posts: 4016
Location: Scotland
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| Pong wrote: |
| My first thought was to put the water in a bag. Like a spacesuit or some of our new ISS module designs. But the bag must be manufactured, it can't self-heal, |
It can if you make it from living tissue bioengineered for the environment.
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The Universe is not only weirder than we imagine it is weirder than we can imagine. J.B.S.Haldane. |
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| Pong |
| Posted: Tue Apr 22, 2008 3:27 am Post subject: |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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| Ophiolite wrote: |
| make it from living tissue bioengineered for the environment. |
Then I'd have to crawl around out there painting on sunscreen and massaging my meatball with lotions wherever it got a little chapped. No thanks and I wanna keep to current technology and capability besides.
You're right though I do have an organic cell model... fairly well developed but just now I want substantial criticism of my first assumptions. So, try and sublime it, rupture it, erode it with solar wind, hit it with an asteroid... |
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| KALSTER |
| Posted: Tue Apr 22, 2008 3:33 am Post subject: |
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Forum Professor
Joined: 08 Sep 2007
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Location: South Africa
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Well, for one thing, fast moving debris or meteors might flash-boil the water if it hits at fast enough speeds. That should cause some serious problems, no?
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"Gullibility kills" - Carl Sagan |
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| Pong |
| Posted: Tue Apr 22, 2008 3:58 am Post subject: |
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Joined: 08 Apr 2008
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We'd get a sudden pressure rise, somewhat more than water geysering out of the hole could relieve. Water isn't very compressible, and ice isn't very elastic. So, cracks all around? Then water's flowing into the cracks and boiling/cooling as it nears the surface? Pressure's dropping then. Ears pop - I'd rate that a failure.
The gaping impact hole. More pressure loss. The bends - catastrophic failure. How quickly does such a hole close up? Does it help if large solids can float into it and help clot it?
EDIT: Reconsidered this scenario. Since we already have a large core air bubble, that should absorb much pressure of impact and internal boiling. So we "just" have the gaping hole to worry about. The inertia of water is much greater than air, so volume loss is going to be relatively slow... I mean, compared to traditional space station designs with, say, a window blown out. Will near-freezing water around the sides flow in, boil, and plug the hole?
My heart isn't set on proving the model can stand that kind of abuse, but it's fun to imagine. I'm more keen to learn if the model is basically stable. |
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| unoscooter |
| Posted: Wed Apr 23, 2008 7:36 pm Post subject: |
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| water in space at any emp is always going to be a gas. it can form ice or water when it comes into a higher pressure like on a planet or maybe even a comet. |
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| Pong |
| Posted: Wed Apr 23, 2008 11:56 pm Post subject: |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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| unoscooter wrote: |
| water in space at any emp is always going to be a gas. |
Please take a reality check. I've given you examples, just Google them or better yet go to any of a hundred NASA pages matter-of-factly describing water ice in space at all pressures. Rings, tiny asteroids, water dumps in orbit, it's well documented and ought to be common knowledge after all these years. |
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| Pong |
| Posted: Sat May 03, 2008 11:25 pm Post subject: |
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Joined: 08 Apr 2008
Posts: 309
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| Could I get an educated opinion on this please? |
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| Steve Miller |
| Posted: Mon May 05, 2008 2:13 am Post subject: |
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Forum Bachelors Degree
Joined: 10 Dec 2006
Posts: 412
Location: Magdeburg, Saxony-Anhalt, Germany
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Hi Pong?
Since when does water boil and freeze in vacuum? This was a false statement you're letting of, absolutely.
And then, further, '...That's not really the question....' Your arrogance amazes me. Or am I missing your
point here?
Matter, not so water, does heat up when being compressed, meaning, the room matter does take in was
narrowed. To create a vacuum, air was evacuated providing more space for other matter, like water, to
expand it's volume.
And that was meaning, the room water would take in was not narrowed but extended. Your thread was
made of false arguments, right?
Steve |
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