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193

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. ...


83

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 ...


74

Of the 533 humans who have been in orbit, have any of them been sent into space with enough propellant to actually escape Earth's grasp, should they have chosen to use the fuel in that manner? Has any human ever had the choice to never return to Earth? Apart from the Apollo missions, no crewed spacecraft has had anything like enough propellant to leave ...


37

What radius and rotation would be needed to produce 1g consistently from the floor to a height of about 6ft (2m)? Infinity. Technically there will always be a vertical gradient of artificial gravity. Realistically, people will not care. Even with a radius of 224 m the difference isn't much. The acceleration for anything attached to the structure will be:...


31

Soyuz 11 The crew did not return to Earth in their lifetimes. This interpretation is obviously not what you are talking about though. Instead what is of interest is human's remains that do not return to Earth ever. In this case there is also a definitive answer. Clyde Tombaugh Tombaugh died on January 17, 1997, when he was in Las Cruces, New Mexico, at ...


28

This is exactly how it works and how the orientation of many satellites is controlled. For example, the Hubble telescope has 4 fidget spinners installed, pointing in different directions - although they are commonly referred to as "reaction wheels". Unfortunately a typical fidget spinner is a bit too light to be really useful: We have to compare ...


26

Without a glove, a space suit would basically lose its integrity. It is like not wearing a suit in the first place. Then, the question is what happens next. The closest known resemblance of such a scenario happened during a test of an Apollo space suit in a vacuum chamber: (In 1965, a tube pressurising a space suit of a ...


26

Although this has indeed "worked to bits" on the Physics and other SE sites it's worth looking at, for the sake of Space Exploration, the interesting history behind the analysis of the falling cat. For the fully rigorous description of the cat's righting reflex - perfectly in keeping with conservation of angular momentum - only came about because it was ...


25

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 ...


24

This video published on YouTube on Zero-G: "Movement in Microgravity: Skylab to Space Shuttle" 1988 NASA Weightlessness Footage, starting at 2:10 into it, shows a Skylab astronaut doing a front roll and a spiral roll in the Skylab Orbital Workshop without touching anything to push against to change his orientation. And the same video from 5:45 to 6:00 shows ...


24

The ESA Huygens probe very accurately characterized the conditions at its landing site on Titan's surface and verified measurements made by the Voyager 1 Radio Science (VRS) investigation nearly 25 years earlier. It measured a surface temperature of 93.8K (VRS: 94.0 ± 0.7 K), a surface pressure of 1467 mb (VRS: 1496 ±20 mb), a methane abundance of 5.65 ± 0....


23

This is a pretty broad questions, as it would depend on which gas giant you have in mind. Excluding Uranus and Neptune as ice giants, this leaves us with Jupiter and Saturn in our own Solar system, and they're still hard to directly compare in terms of how hazardous environment they'd represent to an orbiting space station. But they have one deadly thing in ...


23

A -183 C nitrogene-methane mix doesn't make you an icecube on the spot, but it still causes quickly frozen wounds. Your only way to avoid it if your whole body is protected, no $cm^2$ may remain open. You need also oxygen supply. Here comes another problem: methane with oxygen supply becomes an explosive substance. The methane concentation on the Titan's ...


22

The lift force you would need to produce would have to be equal (stable flight) or greater (take off) than the force pulling you back towards the moon. If your mass is average for a male at 62kg, the force from the lunar gravity would be F=ma, = 62kg x 1.622m/s2 = 100N (almost exactly). lift force = 0.5 x density x lift coefficient x area x velocity^2 This ...


21

Many jurisdictions recognize weddings performed out-of-jurisdiction provided that those weddings are legal in the jurisdiction they're performed in. Unfortunately, there's no legal authority with jurisdiction over LEO -- it's kind of a legal gray area. Does any national law system provide a means for marriage officiants to lawfully perform a marriage at an ...


17

I wouldn't recommend it, and there's several reasons why. First, even if we assumed you'd get chemically pure water out of the exhaust plume, in essence distilled water, it would lack any dissolved minerals and cause you to lose electrolytes. If that was all that was wrong with it, then small quantities wouldn't hurt you, but you'd have to substitute lost ...


16

The test had to start somewhere. There are a number of reasons why they couldn't simply do a 6 person stay, that make it somewhat difficult at least. These include: There is a natural cycle to bring down astronauts from the ISS, in that a Soyuz needs to be replaced every 6 months. While in theory a crew could bring a Soyuz, and bring the old one down, that ...


16

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


15

Yes, of course the fogging could occur, if not mitigated. You'd be exhaling and sweating pretty much same contents of water vapor wherever you are, and in a completely closed system like a helmet used in non-breathable atmospheres like on the surface of Mars would be, in the vacuum of space, or hazardous environments (hazmat helmets, full face gas masks, e.t....


15

It depends how suit is built. And in fact pretty similar thing happend to Joe Kittinger during his (>50 years long standing before it was recently beaten by Baumgartner during Redbull Stratos flight) record jump flight from the stratosphere. Kittinger lost pressurization in one of his gloves while still rising to altitude. He could abort the mission but he ...


14

According to ABC News, yes: But now, as American astronauts spend more and more time in space, they've noticed they're returning to Earth with a surprising malady: They cannot focus their eyes properly after they come home, and for some the problem seems permanent. ... A fifth of the astronauts tested showed a flattening of the rear of the eyeball, ...


13

Vacuum on the skin will not normally cause blood to flow through the skin. It can cause the skin to distend (push outward) from the fluid pressure behind it, and to stretch the capillaries under the skin. Actual vacuum exposures have shown that even 20-30 minutes of exposure do not result in external bleeding - but they do result in massive bruising. Joseph ...


12

The Canadian Space Agency (CSA) was helpful on Twitter (@csa_asc in English and @asc_csa in French language) and answered a couple of my questions. This is in response to a general question in the title: Me: How do astronauts battle loss in blood volume in microgravity? CSA: Astronauts typically combat the effects by wearing compression garments ...


12

It is hypothesized that the only acceleration that can be tolerated for looong time without side effects is the normal acceleration. Human subjects have been exposed to continuous high-G environment at most for seven days at 1.5 G. Although no immediate ill effects were found, extrapolation of the data to longer periods may be dangerously risky. Relevant ...


11

The "Nutrition and Human Spaceflight" section of NASA's Space Food factsheet has some good, basic information with links to specific research and studies. For example: The nutrients astronauts need in space are the same ones all people need, but the amounts of some differ. Astronauts need the same number of calories for energy during spaceflight as ...


11

The biggest risk I foresee is nitric acid. A hot open flame in the atmosphere will cause N2 and O2 to react, creating a number of different molecules such as NO and NO2. These dissolve reasonably well in water and will form acids.


11

Almost certainly not. First of all, astronauts work out for hours every day, specifically to prevent the deterioration of bones and muscles. Moreover, the human energy budget is dominated not by the energy cost of moving around, but by a) maintaining body temperature and b) the brain. Furthermore, just removing gravity from the equation isn't necessarily ...


11

Despite a higher risk of a fire, pure oxygen also has some advantages. First, the internal pressure of the vessel is only a fifth of a normal breathing mix, allowing less structural load on the hull of the spacecraft. The resupply system is also simplified, because a system including nitrogen must have an extra tank for the nitrogen. (If you had them mixed, ...


10

From one NASA study which examined several space shuttle crews: "Energy expenditures were similar before and during flight." However, there was a decrease in energy intake (also noted in this journal article). So the energy requirements seem to be the same, but for whatever reasons the astronauts seem to take in less food and water. So yes, people eat less ...


10

The problem is about a so called 'comfort zone'. In fact it is not radius but a ratio of radius and angular velocity. Nausea or motion sickness is caused mostly by Coriolis acceleration which makes 'artificial gravity' different form nearly homogeneous earth gravity. There is a real expert on topic Theodore W. Hall. Among a lot of staff about artificial ...


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