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185

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 would be released to the environment. In the space station it is a closed environment where such dirt and material would contribute to the accumulated hazards. ...


82

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, pens etc. NASA is working on methods for washing clothes in space. Not surprisingly, they've studied the tradeoffs between including a washing machine in the ...


52

Those are jets of water released by the sound suppression systems installed on the pads and the mobile launcher platforms to protect orbiters and their payloads from being damaged by acoustical energy, reflected from the platform during the liftoff stage of a rocket launch. For example, this is the sound suppression system at the NASA Kennedy Space Center's ...


42

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 partially true. Directional orientation in the water will be very difficult. On earth, when we swim, not only is our chest slightly more bouyant than our legs,...


38

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 ultimately ends up in comparing densities. If the density of the displacing object is greater than the density of the fluid it will weigh more and sink, if it's ...


27

Fundamentally, water is water. In its purest form, it is the same anywhere, except perhaps for the isotopes. However, one of the wonderful things about water is the fact that it's a good solvent, and in fact has many things in it that aren't water. For instance, one could not survive off of ocean water: we humans require fresh water. The one potential ...


25

We know from the nuclear power industry that spent fuel storage pools are pretty safe places to be around, radiation-wise. They're actually safe to swim in, to a point, because they're serviced routinely by human divers. They just can't get too close to the spent fuel. We use these pools for short-term storage because water is a really good radiation shield....


23

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 internal temperature and perceived comfort level. Every human has variations in temperature, and even in a perfectly controlled environment once you place two humans ...


21

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 its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head. Buoyant forces do not ...


20

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 let air out until you sink, the mean density of your chest is still lower than the density of your legs. When you exhale completely some air remains in your ...


16

1) Startup cost. Buying and converting a boat is much more complicated and time consuming than pouring some concrete and welding some steel. 2) Logistics. You will need at least 2 boats. One as the launcher and one as the command centre. You also need to have a reliable comms link to the rocket. You also need to house the personnel and maintain both boats. ...


16

Most US Launchers use a similar water suppression system for the same reasons as the Space shuttle. At some level, if you intend to launch often you do not wish your launcher to destroy the launch pad. A rocket launching usually has between 600,000 lbs thrust (Delta 4's single RS-68) to 7 million lbs thrust (Space Shuttle, or Saturn V range) and that is an ...


16

Capsules like Apollo and Orion are mainly open space internally (the crew cabin); they have no problem floating by themselves (like a metal-hulled boat would). The conical capsule shape by itself will float in either of two orientations: stable 1 (base down, nose up) and stable 2 (nose down). In stable 2, the crew is hanging upside down in their seats and ...


16

Canals on Mars has quite an interesting history, starting with Giovanni Schiaparell. He produced this map of Mars in 1877 It is interesting to compare this map to a more modern map Note that the same general features are labeled, however, the lines that run between them don't show up at the modern image. Giovanni was Italian, and called the lines on these ...


16

Cassini's INMS, the Ion Neutral Mass Spectrometer, is an in situ instrument that measures the neutral and plasma gas composition of what it ingests. It was intended for the measurement of Titan's atmosphere, Saturn's magnetosphere plasma, ring composition, and in fact the composition of icy satellite effluents. Here is a good presentation on the basics of ...


16

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 very long time on the ISS (unless you can get a hold of a wall) and you'll rotate forever in free space. In water, you can move around easily by swimming; ...


15

We don't know yet exactly what caused it, but all tests so far ruled out everything else but the PLSS (Portable Life Support Unit). In fact, just today (Aug. 27, 2013) Chris Cassidy and Luca Parmitano managed to recreate the water leak that terminated EVA-23: Robotics, Science and Spacesuit Tests Aboard Station - Aug. 27, 2013: Flight Engineer Chris ...


13

No the blast clearing technique would not work, it requires gravity and the closed environment filled with one substance (water) of the snorkel to work. Neither are present in Luca's situation. Tidalwave's Video links in his comment, indicate that attempts to blow or shake the water away were counter productive, resulting in water entering Luca's ears ...


13

Indeed the presence of water has been confirmed. The late 1980s mission Giotto confirmed the existence of water on a comet well-known to mankind - Halley's Comet. Wikipedia states: Measured volume of material ejected by Halley 80% water, 10% carbon monoxide 2.5% A mix of methane and ammonia. Other hydrocarbons, iron, and sodium were ...


13

Depends how you look at it. Onboard the International Space Station (ISS), water is definitely a precious resource and several measures were taken to consume less of it, such as recycling as much of it as possible, not washing clothes, reducing tap pressure, conserving it under shower and using wet cloths, using liquid waste vacuum tube on toilets, and so on....


13

Plants don't just need carbon dioxide; like most organisms, they need oxygen to survive as well. They can produce oxygen from carbon dioxide, but that doesn't help cells that aren't exposed to sunlight; if you put a plant in a very low-oxygen environment, it will die. There are organisms that can survive on little to no oxygen (e.g. cyanobacteria, which can ...


13

A picture might be worth a thousand words. Just imagine this situation without clothes:


12

In fact, the Soyuz is designed to make an emergency water landing, and has done so once by accident, when Soyuz 23 landed by accident on a frozen lake. The landing didn't go particularly well, the parachute filled with water and caused the escape hatch to be covered in water. A complete account can be found here, but let's just say the experience was less ...


12

I'll have to dig through the decadal survey and LPI proceedings a few times, so I decided I have to make this answer a community wiki anyway. As soon as there is a decent answer by anybody else, I'll accept it. Three basic mission modes: getting inside the ocean getting onto the surface doing research from low orbit The main goal: determining habitability ...


12

Shortly after this question was asked, it was answered (in the case of the moon, not Mars) on XKCD's what-if. Summarizing that article, for most average people swimming would be the same, as the buoyancy effects are an order of magnitude more dominant than the gravitational effects. Extraordinarily skilled swimmers would notice small difference, but the ...


12

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 nearest surface is to take a breath. Surface tension will become the dominant force governing water flow as you come up for breath. In particular, the water will ...


11

Depending on exactly what temperature the water on Enceladus is, the answer is yes. Bacteria are an obvious choice. But there is a higher lifeform which can almost certainly survive: Tardigrades (Water bears) can survive for days at −200 °C - longer at higher temperatures, and can cope with extremely acid or alkaline environments. They can even survive in ...


11

For a Hohmann transfer to Saturn, I get 15.7 km/s for both burns. The transfer time is also a simple formula. I obtain roughly 6 years. Compare to the lunar ice. It is roughly 2.8 km/s to get to, and the trip time would be a few days, even from Low Earth Orbit. As suggested by the other answer, you could compare to Earth's surface. If we're using some ...


11

TLDR Its much harder to swim fast, even though it might be easier to swim slowly. WHY Your main difference will be due to a reduced hull speed of the swimmer. As noted in the comments section, the phase velocity of a wave would be reduced. This forms a hard limit on the speed that one can swim whilst displacing water. As you swim, you generate a wave. If ...


11

I guess the generic answer for any mass separation system would be that you spin it, but mass separation isn't really effective for electrolysis since that requires larger separation between anode and cathode which leads to protonic ohmic losses, i.e. increased internal resistance. So a more optimal species separation is done not by their mass but by their ...


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