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35

You bet. Not only gases, but astronaut pee as well! Which could result in spectacular light shows. This happens for several reasons: Spacecraft and the tanks inside them are built to be as light as possible, which means no stronger than necessary. If the pressure inside them gets too high, it must be released to keep the hull from rupturing. The device ...


20

Hydrocarbons are largely interchangeable when it comes to performance, and as long as no single one beats kerosene with a large enough margin, the hassle of changing infrastructure is generally not worth it. Compared to RP-1, butane has slightly (very slightly) higher specific impulse, and somewhat lower density, largely cancelling each other out. Butane ...


16

A good pressurizing gas needs to satisfy a few basic properties: it needs to stay gaseous at the temperatures and pressures your fuel and oxidizer are stored at, so that it won't just condense out when injected into the tanks; it needs to be inert enough to be safe to mix with both the fuel and the oxidizer (since if you're going to have two different ...


12

The two measurements appear to be in disagreement, and so the magnificent thing that is scientific debate is now ensuing on this question. The 2003 observations would suggest, based on the believed lifetimes of methane in the atmosphere of Mars of several hundred years, that Curiosity should have detected it a 6 ppb. Curiosity has ruled out concentrations ...


10

Can electrolysis of water provide fuel for the generator where both water and liquid carbon dioxide is utilized in one self sustaining machine? NO. A 'self sustaining machine' would be a perpetual motion machine, and those are impossible. You have to provide energy from an external source. Electrolysis of water costs energy, about 50 kWh per kg of ...


7

Section 30.4 of this NASA document describes passivation of spacecraft at end of life. The objective is to remove all sources of stored energy including pressurized gases and the way to do it is to vent them to space.


7

The technological solutions are still being tested, but it is possible. NASA's ROxygen generator is being used in Hawaii on rocks that are similar to lunar dust which Erik points out contains oxygen. While it doesn't produce enough for a crew of 4 to survive, it is a first step in developing a solution to a critical problem.


6

There was a proposal by Mars One for a mission to Mars. It suggested using hydroponics to produce oxygen. But a MIT study reviewed it and showed that this model could not work, because the plants actually produced too much oxygen. Thus they would need to vent it, and that would take with it nitrogen. Which if they did not keep sufficiently in the ...


5

note: the question has been significantly modified (potentially improved) - I'll leave this slightly-outdated answer here as-is for reference. There probably are no studies that have shown that carbon dioxide liquifies naturally on Mars. Below Carbon Dioxide's triple point of 5.1 atmospheres it can not exist in liquid phase at the surface. I should mention ...


4

Skylab had 1630 lbm of N2 at launch. That's enough to fill the 12,750 cubic foot habitable volume ~ one and a half times to sea level pressure and temperature even ignoring any oxygen. Shuttle N2 tanks were mission kits so not every mission flew with all tanks. A typical mission, STS-88, had 400 lbm of N2 two and a half hours into the mission. Oddly enough,...


3

There aren't many atomic or diatomic gases at room temperature: H, N, O, F, Cl and the noble gases. noble gases are expensive F and Cl are corrosive oxygen reacts with propellants, so can only be used to pressurize an oxygen tank H is flammable/explosive that leaves N and the cheapest of the noble gases, He. Compound gases also exist (e.g. CO2) but they ...


1

The materials that spacecraft are made of can release gas into space. It's called outgassing, and is a problem that crops up from time to time with satellites and spacecraft. Source : https://en.wikipedia.org/wiki/Outgassing


1

Helium is used for cryo-storage, and enables freezers that are much colder than those making use of nitrogen.


1

On one hand, a biological resource system should be avoided because they are large and energy intensive. On the other hand, it is likely necessary due to the complex biochemical requirements of humans. Recycling O2 and H2O are technically easy. But we do not live on O2 and H2O alone. There are many essential micro- and macro- nutrients which must be provided....


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