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200 votes
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Nudism in space: Why wear clothes anyway?

Clothes require laundry because they have accumulated dirt and other materials from the environment and their wearer. If the astronaut was not wearing those clothes then that material they captured ...
Brian Tompsett - 汤莱恩's user avatar
87 votes

Nudism in space: Why wear clothes anyway?

Clothing performs essential duties on the station in addition to modesty. They are an easy way to organize stuff. In addition to pockets, clothing is festooned with velcro strips for attaching tools, ...
Hobbes's user avatar
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56 votes
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If an astronaut threw a cup of coffee into space, would it freeze, or boil off into gas?

This was tested nearly sixty years ago. Using a very large cup filled with 95 tons of water. An empty second stage of a Saturn I under test was used. Only the first stage should be tested but with ...
Uwe's user avatar
  • 49k
44 votes
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Can/should you swim in zero G?

Two major problems present themselves right away. As the human body is almost neutrally bouyant with water, one might think that there are no issues with the actual movement in water. But this is only ...
Quietghost's user avatar
  • 2,476
38 votes
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Can you take a bath on Mars?

Short answer, No different from Earth in floating. Buoyancy in water or any fluid is based on the weight of water displaced. Floating is based on the weight of the item displacing water. This is ...
Josh King's user avatar
  • 2,429
31 votes

If an astronaut threw a cup of coffee into space, would it freeze, or boil off into gas?

It would not freeze into a block. It would quickly expand and boil, but not in a rolling boil. Without pressure, bubbles would form throughout the coffee and expand rapidly, causing it to spray out of ...
Mark Foskey's user avatar
  • 11.1k
29 votes

Is there any economical way to move the water from the Martian poles to the people?

You don't care about transporting H₂O. You want to transport hydrogen and oxygen atoms, and if that includes a few other atoms as baggage, that's no big deal. One easily available atom is carbon, as ...
MSalters's user avatar
  • 1,644
28 votes

What does space have to do with providing "fresh water ... without the need for aquifers or pipes?" as Steven Kwast suggested?

The speech is available in full here: https://dc.hillsdale.edu/News/Latest-News/The-Urgent-Need-for-a-U-S-Space-Force/ It's extremely general and non-technical. He talks about getting water from the ...
Organic Marble's user avatar
26 votes

Nudism in space: Why wear clothes anyway?

In addition to capture of contaminants, such as dead skin, hair, sweat, etc, and abrasion/cut protection, clothing forms a basic thermal layer that allows the human body to better regulate its ...
Adam Davis's user avatar
  • 1,103
23 votes

What is the difference between an astronaut in the ISS and a freediver in perfect neutral buoyancy?

An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by ...
Organic Marble's user avatar
22 votes
Accepted

What is the difference between an astronaut in the ISS and a freediver in perfect neutral buoyancy?

A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that. If you ...
Uwe's user avatar
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19 votes
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Why was it necessary to monitor the water quantity in the space shuttle?

Water was used for many purposes in the shuttle. The particular application you are asking about is the Water Spray Boiler (WSB), part of the Auxiliary Power Unit / Hydraulic (APU/Hyd) system. This ...
Organic Marble's user avatar
18 votes

Nudism in space: Why wear clothes anyway?

A picture might be worth a thousand words. Just imagine this situation without clothes:
Eric Duminil's user avatar
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16 votes
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Will uncovering the ice deposit in Utopia Planitia improve the climate on Mars?

Well, let's see how we can try to calculate that. First of, we need to find out what is the mass of the column of air on Mars and then find out how much mass the sublimation of ice will add to it and ...
gromain's user avatar
  • 766
16 votes

What is the difference between an astronaut in the ISS and a freediver in perfect neutral buoyancy?

The viscosity of the surrounding medium has a lot of impact concerning your ability to move. If, for some reason, your body starts rotating, you'll come to a rest quickly in water, but it'll take a ...
Guntram Blohm's user avatar
16 votes

Earth Launch System with Water Propellant

Electrolysis-based propulsion becomes practical only once you've reached orbit, where you can power the electrolysis with solar panels and where you don't need enormous thrust. Whatever you'd use to ...
Camille Goudeseune's user avatar
13 votes

Is there any economical way to move the water from the Martian poles to the people?

Canals? It's too cold on Mars for water to be liquid, so canals are not going to work. Pipes? ...would need to be constantly heated, so they would require quite a lot of energy. Hydrogen ...
Philipp's user avatar
  • 9,346
13 votes
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What does space have to do with providing "fresh water ... without the need for aquifers or pipes?" as Steven Kwast suggested?

The article says that the page has been adapted from Kwast's speech, so it's possible someone transcribed something wrong or misunderstood. Taking an excerpt: With the right vision and strategy for ...
GdD's user avatar
  • 20.3k
13 votes
Accepted

Why did Apollo 13 need to ration water?

Water was needed for cooling the electronics of the Lunar Module. To remove excess heat, water was evaporated by sublimator plates into space. Without cooling water, the electronics mounted on cold ...
Uwe's user avatar
  • 49k
12 votes
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Boiling ponds and pools on Mars?

The other answers forget latent heat/enthalpy of phase change, and many neglect pressure rise with column of water. :) Enthalpy of evaporation of liquid water is considerably higher than its latent ...
SF.'s user avatar
  • 55k
12 votes
Accepted

Could a ball of water stay in orbit?

The ball of water in that picture is in orbit; it's just surrounded by (presumably) the ISS. But a ball of water like that definitely cannot survive in the vacuum of space. Below a certain pressure, ...
Mark Foskey's user avatar
  • 11.1k
12 votes

More water in a crater on Mars than the quantity dumped by the river Nile into the Mediterranean sea in 45 years?

The ice-filled Korolev crater appears in Viking imagery taken in the '70s. It took the arrival of suitable radars in orbit (like MARSIS on Mars Express and SHARAD on MRO, ca. 2005-6) to determine the ...
Alex Hajnal's user avatar
  • 1,981
12 votes

Can/should you swim in zero G?

Off the top of my head, two issues for free swimming (no breathing gear) I can think of: Absent a sense of "up" and "down", it would be very easy to become disoriented and lose track of where the ...
Tristan's user avatar
  • 17.3k
12 votes
Accepted

Choosing a specific region to live on Mars, how important will the degree of dust there be, compared with the availability of water?

Water is extremely useful on Mars. You can use it to generate oxygen directly via electrolysis and the hydrogen byproduct can be reacted with carbon dioxide to make even more water. We drink water. ...
user2702772's user avatar
  • 1,074
11 votes

Boiling ponds and pools on Mars?

Here's a phase diagram of water from here. If you find Mars's atmosphere of 600Pa on the Y-axis and track right you'll see that H20 can't be water on Mars. It can only be ice or vapor. In your ...
Dean MacGregor's user avatar
11 votes
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If there is actual ice on the moon, why hasn't it sublimated?

Ice sublimates. So does rock. Yet the planet Mercury is still there. The reason Mercury still exists is because even though rock does indeed sublimate, the rate at which rock sublimates is extremely ...
David Hammen's user avatar
10 votes

Will mining water on Bennu for travelling to Mars not be more economical than mining it at the lunar south pole?

The only reason near-Earth asteroids still have water is that it's bound up in hydrated minerals where it's become part of the crystal structure of those minerals. Freeing it from those minerals ...
Christopher James Huff's user avatar
9 votes
Accepted

How did the Apollo survival kit desalter work?

From Legislative History: Saline Water Conversion Act During World War II, the castaway problem reached such proportions that the military initiated several projects to find ways for providing ...
Organic Marble's user avatar
8 votes

How do space capsules float on water?

The Gemini capsule floated because it had thousands of hollow balls made of extremely thin aluminum, each composed of two half-spheres welded together, the size of ping pong balls, which were embedded ...
Kathy's user avatar
  • 81
8 votes
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Scuba diving in free fall, do I need to worry about the Bends?

tl;dr: The pressure increase due to self-gravity reaches one atmosphere for a sphere of water with a radius of about 1000 km. Since water is still viscous but the average buoyancy along trip would be ...
uhoh's user avatar
  • 149k

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