38

Spooky This one is subjective. To some, just finding an abandoned spaceship would be spooky. I'll say there's probably not a lot that has to happen to evoke this feeling. Rusted Actually, unless your spaceship never had a breathable atmosphere or the atmosphere was vented before the spaceship was abandoned, rust is totally possible on the inside and ...


15

'Organics' usually refer to organic compounds. From Wikipedia: http://en.wikipedia.org/wiki/Organic_compound There is no single "official" definition of an organic compound. Some textbooks define an organic compound as one that contains one or more C-H bonds. Others include C-C bonds in the definition. Others state that if a molecule contains ...


14

Probably not any more likely than on Earth. Actually, Curiosity's (MSL) rover's wheels are made out of aluminum and they've been grinding through iron oxide rust that gives Martian regolith and the whole planet its color for quite a while now. And Spirit and Opportunity (MER) rovers also use several tools, among which even grinders, made out of aluminum. So ...


13

This took a fair bit of investigation! Arm Strength The Mars Science Laboratory Robotic Arm (RA) is 2.2m in length, is made of two arm sections (an upper arm and a forearm) and is controlled by 5 actuators. These consist of (among other things) a brushless DC motor and a planetary gearbox to step down the motor speed and increase torque. Two of these ...


12

No, I don't think so. Combusted hydrazine smells like ammonia, because it is ammonia, plus nitrogen and hydrogen. Unburnt hydrazine also smells like ammonia, but has a sharp sting to it that, if you smell it, you should leave that building.


10

What is meant by 'Organics' when discussing space exploration? It means compounds that contain carbon, except possibly for some simple carbon compounds such as CO2, carbonates and cyanides that historically have been deemed to be inorganic. In the 19th century, carbon-containing compounds were classified as organic or inorganic based upon 19th century ...


10

Often, electrical systems prone to whisker growth are coated with a 2-3 millimeter layer of polymer (called a conformal coat); this not only prevents growth of whiskers, but also prevents any loose electrical contacts from creating short circuits. There are many benefits that are associated with doing this. Another likely cause of crystalline whisker growth ...


10

I'm going to start off with a warning: if you want to get started with model rocketry, it is about a thousand times safer and easier to start with off-the-shelf solid rockets. Don't even consider trying to build your own liquid fueled engine until you've learned a lot more. That said, reaching the RP-1 specification from commercial kerosene is probably ...


9

Chlorine is a relatively rare element, so the concentrations of it is not going to be high anywhere. It is also very reactive, so all of it is likely to only occur as a part of different chemical compounds. Chlorine is especially likely to react with sodium as it one of the most common elements, and also has a very low electronegativity. That makes sodium ...


9

450-455s Isp is typical of H2/O2; according to the Huzel and Huang data, a hydrogen-beryllium mix combusted with oxygen can hit ~540s. The numbers in that table are for moderate chamber pressure and expansion ratio; higher values are possible. According to Wikipedia: The highest specific impulse for a chemical propellant ever test-fired in a rocket ...


8

The Merlin engines are ignited with a mixture of triethylaluminium and triethylborane (TEA-TEB); according to Wikipedia: Triethylborane is strongly pyrophoric, igniting spontaneously in air, burning with an apple-green flame characteristic for boron compounds. Thus, it must be handled and stored in nitrogen or argon.


8

Non-hypergolic liquid fuels i.e.: LH2, LOX, Methane etc are all kept as pure as possible. One of the major advantages of these is that they burn clean. Any additions are potentially problematic: Complex combustion by-products, different density ratios leading to separation, and differential storage requirements etc seem to have outweighed any potential ...


7

Two big ifs here. IF we achieved viable commercial fusion power (other than the sun) and IF He3 was an indispensable part of this process. But for the sake of argument, let's say He3 is the fusion fuel of the future. I'll quote John Schilling's comment from Rand Simberg's Transterrestrial Musings blog. Helium-3 mining on the moon simply does not pass ...


7

Conformal coatings mostly, just like on Earth. A thin polymer layer impedes problematic whiskers principally by confining them to the inside of the coating. Theses links confirm that NASA has a large interest in the study of conformal coatings and likes to use them. The first one includes pictures of whiskers that formed under coatings towards the end. ...


7

As pointed out by @Thomas, this nice thesis Radiation from High Pressure Hydrogen-Oxygen Flames and its Use in Assessing Rocket Combustion Instability - Ph. D. Thesis, Fiala, T., 2015 discusses this phenomenon. The term $\color{blue}{\text{blue radiation}}$ is suggested as the best available. While there are several narrow spectral lines int the near UV (...


7

If we have a pressure shock front travelling very fast through the material it is an explosion. The reaction inside the explosive is started by the sudden pressure rise, not by a temperature rise. But when the solid rocket fuel burns, we have a nearly constant pressure inside the rocket and no travelling shock front. The thermal conductivity of the fuel is ...


7

Absolutely, it's the same as heating up metals with a blowtorch. The colour of the flame tells you what is present. Wikipedia actually has a handy list giving an indication of the significant elements present: Orange-yellow (sodium) Yellow (iron) Blue-green (magnesium) Violet (calcium) And Red (atmospheric nitrogen and oxygen)


7

The spectrum you show from Titan was taken using the IRIS spectrometer aboard Voyager 1. Of course Voyager 2 had one as well. A huge amount of work went into developing and optimizing the design in order to develop a precise optical instrument that would survive both the high g-force and vibrations of launch, and the years in a space environment while ...


7

Perchlorate contamination is a problem on Earth. Essentially, there is a series of water treatments and bioremediation, the process of using biological systems to fix the problem. Here is a detailed summary of one effective approach. The short answer is this: Engineers know how to do this on Earth, and the Martian solution is likely to be an adaptation of ...


6

I believe electrolyzing would take at least 286,000 joules per mole of water. See this Wikipedia article. A mole of water would give ~16 grams of oxygen and ~2 grams of hydrogen. So to make a million grams of propellent we'd need at least (1,000,000/18)*286,000 joules. That's about ~15,888,888,889 joules for a tonne of propellent. According to this NASA ...


6

That is the beauty of rocket engines, you can put almost whatever you want into them, and they still kinda work. (That said, I see that as beauty, engineers just scream in terror.) Joking aside, there is actually a little bit of truth in that, rocket propellant specifications are not that strict. For example, the original specifications for RP-1 just ...


6

The Moon would be a much better place most likely. As you said, 220 pounds of Helium-3 in a mass of many many tons of rock, makes it so that even a few tons of equipment to be dropped on the Moon would vastly reduce the price to return it home. Lifting 220 pounds from the Moon to return to Earth is relatively easy, all of the Apollo missions did it, and then ...


6

The theoretical limit is set by the specific energy of the reaction of combustion of the propellant. Knowing specific energy $e$ of given substance, we can put a cap on obtainable specific impulse $I_{sp}$ by assuming 100% of conversion of chemical energy to kinetic energy. $$ I_{sp} = {v_e \over g_0} $$ $$ E_{chem} = e m \geqslant E_k = {1 \over 2 }{ m ...


6

First we have to go back to the chemical equations, and this time, include the standard enthalpy of combustion. Hydrogen: 2 H$_2$ + O$_2$ → 2 H$_2$O + 572 kJ/mol Methane: CH$_4$ + 2 O$_2$ → CO$_2$ + 2 H$_2$O + 889 kJ/mol Dodecane: 2 C$_{12}$H$_{26}$ + 37 O$_2$ → 24 CO$_2$ + 26 H$_2$O + 15,026 kJ/mol Ethanol: C$_2$H$_5$OH + 3 O$_2$ → 2 CO$_2$ + 3 H$_2$O + ...


6

There are a number of rocket fuels that can be made from moon rock, discussed in some depth in this answer and the linked papers. Aluminium and liquid oxygen seems to be perhaps the leading contender. None is as good in various respects as "normal" fuels like kerosene and liquid oxygen, and there are some engineering problems, but they are possible. There ...


5

Yes, there is phosphorus on Venus, just like on Earth. The elemental composition is not that different. However, you can not find many phosphorus compounds in the atmosphere, due to few of them being gasses even at Venus high temperatures. The one you use as an example, Phosphine, suffers from the fact that Venus almost completely lacks hydrogen. Phosphine ...


5

Iron, while abundant in weight percents only accounts for 2% iron in martian soil samples. This is not sufficient concentrations for a strong naturally occurring exothermic reaction. And if you are interested in "local" sources of aluminum on the surface, it's about 10% but already in an oxidized form. Source also see Inspecting Soils Across Mars


5

Virtually all chemical reactions take place in a liquid or gaseous phase. Uncontained gasses aren't a likely candidate for life, so we're looking for solvents for life-related reactions to take place in. A good solvent is (a) common, (b) dissolves a wide variety of substances, and (c) is liquid at a wide range of temperatures. Very few liquids meet even ...


5

Life depended on water is what we know. Until we find life not dependent on water we don't know what to look for. We have to act within our experience. Cosmic exploration is expensive and the risks are high. To minimize the chances of failure in looking for life it's less risky to look for "life as we know it".


5

It's actually not that far-fetched, but non-biological processes involved with creation of such breathable atmospheres likely wouldn't be sustainable for a very long time. Let's imagine a largely water ice world that was first formed beyond its host star's snow line but later swapped orbit with another body that orbited within the star's Goldilocks zone. ...


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