79

Standard atmospheric pressure at sea-level Earth is just 14.696 psi. Compare that to 340 or 300 psi (23.14 and 20.42 amt, respectively). The difference in internal tire pressure in Earth's atmosphere and absence of atmospheric pressure in vacuum of space is only 4.3 - 4.9%. Tires would experience far more dynamic pressure environment due to friction heating ...


33

Part of this is also discussed in the How can Mars have dust storms with such a thin atmosphere? thread, but yes it would be abrasive, and direct evidence for this can be appreciated in all kinds of aeolian formations on the Martian surface, like the dunes of the Nili Patera region or the ones in the Lyot Crater, just to name a few of the most well know ...


28

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 ...


27

Temperature and Humidity Control (THC) system is a part of the International Space Station's (ISS) Environmental Control and Life Support System (ECLSS). Thermal Control System (TCS) is a component part of the THC system and subdivides into the Active Thermal Control System (ATCS, PDF document) and Passive Thermal Control System (PTCS). From a PDF document ...


26

That's not a Ziploc bag, but the retroreflector's dust cover. Here is a larger image of it removed:     And here's an image with the cover still attached to the retroreflector:     The clue is in the use of the red markings along the edges of the part in question, in spaceflight commonly used to indicate parts that need to ...


25

There is one area of exploration on Earth that approximates conditions on Venus, namely that of deep oil and gas mining, and a few additional areas of technology, near avionics engines, and even auto engines. The stated goal for such electronics is to function at 200 C or higher. The most promising technology for surviving high temperatures is Silicon ...


24

When you compare the waste products of LOX/Kerosene vs hydrazine/MMDH/etc, it is actually not too terrible at full combustion. (End up with CO2 and water, or CO2, Ammonia, and water). However, if say, a fully fueled Proton looses control say 50 seconds into flight and collides with the ground, literally a million lbs of hydrazine is the definition on ...


23

There are no technological barriers, provided one is not too ideological about biospheres. In a comment on the question it is remarked that self-sustaining biodomes have not yet been successful on Earth. This is somewhat besides the point. These exercises on Earth have generally been about creating a self-contained biosphere within a dome, independent of ...


16

There have been several experiments with fish in space; as far as I can tell, all have used water rather than humid air as the habitat. While there is no definitive answer available as of 2013 (lack of empirical research), present research suggests fish cannot really live in space without water. It appears difficult to keep fish alive and healthy in a ...


14

It's not dangerous. The core would never be operated on Earth, and so would not become radioactive like you're thinking. A nuclear reactor on Earth that has been in operation is extremely radioactive due to the fission products, but the original fuel was not. The unburned U-235 fuel has a half-life of 700 million years, which means that its ...


14

The gear boxes are sealed, often a labyrinth seal. Opportunity has been operating for almost ten years with many actuators still working fine.


13

I can see four major factors that determine where a spacesuit can be used: Temperature issues. The temperature on Titan is much lower than on the Moon or Mars, so you'll need more insulation or heating. conversely, closer to the sun you need to reflect the sunlight more to prevent overheating. If you use the suit in a vacuum, you need to get rid of excess ...


13

The ISS has a number of thermal management systems. The most visible part are the radiators attached to the main truss (they are the two sets of 3 white panels just to the left and right of middle, and yes, there's a tear towards the end of the first one on the right side) Those panels are part of the External Thermal Control System (ETCS), if I'm not ...


12

The wheel wells are not pressurized. As @Tildalwave says, pressurization wouldn't make much of a difference. The wheel wells are insulated to an extent: the wheel well doors are part of the Shuttle's thermal shield, and had to be well-sealed to prevent hot plasma from entering the wheel well. This meant the temperature swings were less extreme than they'd ...


12

To answer the last part of your question: yes, it was normal to throw away stuff that was no longer needed. On Apollo 11 alone, the astronauts left behind more than 100 items, including four urine containers, several airsickness bags, a Hasselblad camera, lunar overshoes and a complete moon-landing step. The astronauts left behind as much as possible, to ...


11

We have plenty of metallic materials that could stand the heat of Venus's atmosphere, including copper, nickel, cobalt, iron, titanium, tungsten, and chromium, to name but a few (here's a list of elemental melting points), as well as a large number of alloys including carbon steel and stainless steel. Even the sulfuric acid isn't a huge problem with some of ...


11

You answered that in your question. The basic notion described is often seen on Mars rover style suits as in this image from Wikipedia. The suit itself is the airlock. To go EVA, you climb into the suit from the back, (sort of like an Orlan space suit right now). The difference is that the suit itself seals to the 'airlock' but does not really require ...


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, ...


11

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. If they want to come home, water+carbon dioxide+power can produce methane and oxygen. That's the most likely rocket fuel to get home. On the other hand, dust is ...


10

You have to consider that this is a concept that is still under development. If the suitports will really be used (and I don't see why not, it solves many problems at the same time) on Mars, or anywhere else where dusty environment is a bigger concern than during testing on Earth, they would likely use some sort of a retractable tunnel leading to the ports ...


9

Gills aren't purely for respiration. Fish constantly excrete ammonia and urea from their gills and without sufficient water to wash the waste away this would soon cause death, much like how too small of an aquarium allows these substances to quickly accumulate to toxic levels (which begs the question about how waste and hygiene would be managed in the first ...


8

This is an incredibly complex problem, so the only way I can think of usefully answering your question is by referring you to NASA's Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program and its documentation (PDF). This software complements the NASA's BUMPER-II risk assessment software package that was used for the Orion project (...


7

Feng Shui is not used. The ISS is a science lab and Feng Shui is not scientific. Currently, fluorescent lighting is used. A study is underway to replace this with LED lighting. The Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International ...


7

Unsurprisingly, it worked exactly like it did in shuttle. To assure uniform flow, the capillary restrictors are coiled around a warm water-glycol line to increase the oxygen temperature. Page 2.7-3 The aforementioned oxygen supply capillary restrictors are wound around the line routed to the space radiators and relief valves. The other line is ...


6

There is actually a whole discipline, which deals with such issues (among others), in one way or another: Astrobiology. After reports of Streptococcus mitis on the Moon 1969/1970, the topic become more and more an issue of discussion. Today, there are sets of regulations on how a spacecraft, depending on its target, needs to be sterilized. This had led to ...


6

Since Steve just contributed an answer to this...well, so will I. There's no need to consume and eject mass for heat control. Mars is cold. See, for example, this Science article. Although wind chill on Mars won’t be as tough a problem as previously presumed, heat loss will still be a challenge, Osczevski says. For example, a Mars explorer exposed to 15 ...


6

A vacuum is a pretty good insulator, much better than the air at the altitudes balloons operate at.


6

TLDR: The combination burning of hot kerosene and sun-driven decomposition of any remainder gets rid of it quite quickly. From an environmental point of view, this is the bottom line: It is predicted from indirect photolysis modeling of C9 and C16 paraffinic, naphthenic, olefinic, and aromatic hydrocarbon compounds that volatile components in kerosenes/...


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