Questions tagged [chemistry]
Questions regarding the application of chemistry in space exploration, for example the composition of rocket propellants.
70
questions
2
votes
0answers
58 views
Dinitrogen tetroxide decomposes to nitrogen dioxide at room temperature, but rockets that use it are usually said to use N2O4 and not NO2 - why?
To the best of my understanding, both dinitrogen tetroxide and nitrogen dioxide are usable and perform quite similarly as oxidizers, but rockets that use either are almost always said to use ...
3
votes
0answers
81 views
Why didn't propylene fly? (Vector)
Ars Technicha's Rocket Report: SLS has technical problems, Vector—yes, Vector—is back links to Vector restarting operations under new ownership which says:
One thing they did wrong was the technology ...
10
votes
1answer
2k views
How hard is the hardest ice in the solar system? Is it in Pluto's ice mountains?
NPR's Pluto Has White-Capped Mountains, But Not Because There's Snow includes the following:
"Initially, it seemed logical that this high-altitude frost could form like on the Earth," says ...
2
votes
1answer
75 views
Why maintain nominal engine inlet mixture ratio for a gas generator engine?
I was reading up on gas generator cycles and came across the following paragraph talking about fuel or oxidizer rich gas generators and the different mixture ratios for the main combustion chamber ...
2
votes
1answer
48 views
Specific Heat Ratio for a perfect gas mixture
I am reading Rocket Propulsion Elements by George P. Sutton & Oscar Biblarz, 9th Edition. In the fifth chapter, I was introduce to the specific heat ratio k for the perfect gas mixture, Eq. 5-7:
(...
12
votes
3answers
504 views
Phosphine, yes — but where are the organic compounds on Venus?
There has been much speculation in recent news about the finding of phosphine on Venus, and what may be producing it.
At the same time, when we look for clues of life elsewhere in the Solar System, we ...
1
vote
0answers
140 views
Can Chemical Engineer work on something related to space?
I am an undergraduate student (scientific section) living in Qatar. I have a big interest in astronomy and astrophysics and have participated in the IOAA (International Olympiad on Astronomy and ...
2
votes
1answer
89 views
Demonstrating molten oxide electrolysis on the Moon, what would require the most power, keeping it molten or driving the electrolysis?
It seems that oxygen may be extractable from oxides in lunar regolith using "some variant of the" molten oxide electrolysis.
Assuming that solar energy is used in a lunar setting, what would ...
3
votes
1answer
51 views
How to predict reaction of propellants at chamber temperature and pressure? [duplicate]
I would like to understand how to calculate the complete reaction of propellants at chamber temperature and pressure.
For instance taking ethyl alcohol (75%) and LOX combustion with mixture ratio of 1....
3
votes
1answer
164 views
Why might krypton have a lower utilization fraction than xenon for ion propulsion, and what can be done to improve it?
A comment below Why will Starlink satellites use krypton instead of xenon for electric propulsion? links to the 2011 preprint A Performance Comparison of Xenon and KryptonPropellant on an SPT-100 Hall ...
6
votes
2answers
374 views
Sabatier reaction oxygen to methane ratio for Mars ascent propellant
The Sabatier reaction is as follows:
$$\mathrm{CO_2 + 4\: H_2 \rightarrow CH_4 + 2\: H_2O}.$$
If water is electrolysed
$$\mathrm{2\:H_2O \rightarrow 2\: H_2 + O_2}$$
the global reaction becomes
$$...
6
votes
2answers
402 views
Have light gases like hydrogen or helium been explored for ion propulsion?
This answer and discussion in comments below this answer mention that for an ion of mass $m$ and charge $q$ accelerated by a voltage $V$ the momentum it receives (impulse) is
$$p = \sqrt{2mqV} = \...
1
vote
0answers
69 views
What is the most efficient way to go to Titan? [closed]
With ionic motors? or chemical engines? liquid propellant (LH2) or gas? What is the most compact way to make the trip? in the smallest possible rocket, for example the SS-520-5 is a 2-stage rocket, 11....
1
vote
0answers
196 views
Is there any practical application of trinitramide N(NO2)3 in rocket propellants
In 2010 researchers at the Royal Institute of Technology (KTH) in Sweden announced the discovery of new compound, trinitramide N(NO2)3, which could revolutionize production of solid rocket propellants....
0
votes
1answer
83 views
Is it possible for aluminium alloys in a explosion in space or on earth to become pure elemental powder particles? [closed]
If you have some kind of explosion, is it then possible for aluminium alloys to become powder particles?, is yes, can they become pure elemental aluminium particles?, or will they always be aluminium ...
1
vote
0answers
37 views
How can 3He be mined on the moon? [duplicate]
Now I know how it is detected, but what would the mining process be like? given that there is a lot on the moon but not concentrated, so you have to process large amounts of surface to extract a ...
4
votes
0answers
48 views
Hydrocarbons of Titan: Potential Applications
Imagine in the future that some space agency or corporation has deployed a manned mission to Saturn's moon Titan with the intent of collecting samples of its hydrocarbons. This is to be accomplished ...
3
votes
1answer
91 views
Are Mars' atmospheric CO₂, O₂ and CO in equilibrium? Are sunlight or chemical reactions involved?
According to the NASA JPL video linked below the top five gases comprising the martian atmosphere include CO₂, O₂ and CO. Do the proportions reflect some chemical equilibrium? Are sunlight or chemical ...
1
vote
1answer
177 views
What is a lithium fed GIT? How does it work?
This answer to What is the maximum speed an ion engine can propel a spacecraft at? mentions the following:
Lithium fed GIT (gridded ion thrusters) have demonstrated 50,000 - 80,000 seconds of ISP (...
1
vote
1answer
300 views
Which scientific articles together give proof of all the chemical elements found on Mars?
Wikipedia about the elemental composition of Mars:
Based on these data sources, scientists think that the most abundant chemical elements in the Martian crust, besides silicon and oxygen, are iron, ...
4
votes
1answer
223 views
Are there fuel cells for methane + oxygen? Could there be?
Hydrogen + oxygen fuel cells powered the week-long Apollo missions to the Moon and Shuttle missions to orbit, and there is a industry trying to build itself around hydrogen-fed fuel cell-based road ...
1
vote
1answer
93 views
What is the heaviest chemical element that has been recovered from beyond cis-lunar space? [closed]
Material has come to Earth from deep space (beyond cis-linar) and been subjected to scientific analysis both in the form of meteorites, and via robotic sample collection spacecraft and robotic ...
4
votes
3answers
181 views
Options for making rocket fuel using the Moon's natural resources
Based on what is known about the chemistry of the lunar surface through remote sensing and surface exploration, what raw ingredients are likely to be available that can be used to make rocket fuel?
5
votes
1answer
187 views
Are rocket fuels and LOX pure or are there additives?
I wonder whether there are any small amounts of additives in rocket fuels such as hydrogen and kerosene, or to the liquid oxygen, or if they are absolutely pure (barring any unintentional ...
6
votes
1answer
150 views
What would a candle flame look like in low gravity?
We know what the flame of a candle looks like on Earth in 1g and what it looks like in weightlessness. But do we have an idea of what it would look like in Lunar (0.166 g) or Martian (0.38 g) gravity? ...
2
votes
1answer
212 views
What would be the performances of chlorine trifluoride as an oxydizer?
Inspired by this comment
Assume that a particularly deranged moustache-twirling villain with way more time and resources than is reasonable decides to build a satellite-launching rocket using ...
5
votes
2answers
588 views
Sources of Xenon or other noble gases in space?
Xenon is a common choice for ion thrusters, though other heavy noble gases could work due to their low ionization potentials.
I got thinking about building or refilling future space travel ion ...
2
votes
1answer
82 views
Molecular propellant in ion engines
This question was prompted by discussions on this question. Can there be an advantage to using a molecular propellant in an ion engine, as opposed to noble gasses or iodine? (Although iodine actually ...
5
votes
1answer
664 views
Removing perchlorate from Mars surface soil
It's known that there's a lot of perchlorate contained in Mars' surface soil.
But could we take the toxic part out and make it become plantable?
If so, how might this be done in a practical way on ...
6
votes
1answer
654 views
Density of propylene when used as rocket fuel, and advantages (if any) over RP-1?
Recently Vector space from USA has said that propylene is a better choice of fuel than RP-1. See Ars Technica's After a decade of testing, propylene rocket fuel may be ready for prime time
Why is ...
7
votes
1answer
464 views
How quickly might a Titan rover or drone get covered in oil and dirt? Will it need windshield-wipers?
These questions and their answers address some potential aspects of a rover on Saturn's moon Titan.
Titan rover survival challenges
What are the technical challenges in building a Titan rover that ...
0
votes
0answers
78 views
Is abundance of chemical elements in the asteroid belt / solar system real through higher concentrations?
Given humanity would be once able to access any minerals in the asteroid belt and moons of planets, would be there some chemical elements (if stable isotopes exist) still considered as rare?
20
votes
1answer
302 views
Rock flipping operation
After the recent announcement of complex organics being found on Mars within the curiosity rover's meager 5cm drill depth, I had an idea about artificially increasing it:
Is curiosity rover's arm ...
5
votes
2answers
1k views
What are the energy-to-mass ratios of some fuels/oxidizers, when including the oxidizer?
Energy-to-weight ratio is an important parameter. We would like it to be high so we don't have to carry around much fuel.
Maybe you've heard some of the numbers for common fuels. Hydrogen is about ...
2
votes
0answers
131 views
Speculation. Will this “turning-co2-into-O2” zeppelin work in Venus? [closed]
Background: Me and a friend are trying to "colonize" Mars and Venus. He has Mars, and I have to "colonize" Venus. So, my intention was to do a slow terraform by creating zeppelins that convert CO2 ...
6
votes
1answer
1k views
What would a “water” landing on Titan be like? How viscous is the liquid?
The abstract to the recent paper Never-EVER Land - A Titan Flyer Concept is shown below.
I've asked about the need for the aircraft to remain in flight continuously and land only at the end of it's ...
4
votes
2answers
140 views
What is the process to produce a chemical composition spectrum of a celestial body?
I have come across this spectrum, which depicts the chemical composition of Titan's atmosphere:
Taken from here.
I would like to know how do scientists generate such spectra, starting with capturing ...
5
votes
2answers
241 views
Got Milk? Why is the term “colloid” used in “Colloid or Electrospray thruster”?
From this answer to the question "Difference between colloid thrusters and electro spray thrusters" I've extracted the following:
According to the Wikipedia article Colloid thruster they are the same ...
3
votes
2answers
238 views
What is a pickup ion?
I've been reading several publications about Titan's atmosphere and chemistry, and the term "pickup ion" kept appearing here and there (see this publication for example).
I looked it up and found the ...
3
votes
1answer
78 views
How (if possible) can we assess the isotope variations on martian soils?
I'm personally interested in the biological implications of different isotope variations on biology. This can be tested on earth by separating them and just observing, but determining the isotope ...
6
votes
1answer
10k views
Can I make my own RP1? [closed]
Is it possible for me to buy kerosene from a local store and then try to refine it to the extent where it would be considered RP1. If so how would I do it? For those who are wondering me and a group ...
7
votes
1answer
111 views
Meteor color hints at chemistry
This recent meteor over the midwest. Reports described it at blue / green. I have seen blue / white, red and yellow meteors. I presume red means iron, green means copper. Can meteoritics or meteor ...
2
votes
1answer
130 views
What is $C_p$ in the fuel efficiency equation?
On page 94 of Ignition! an equation for "Frozen equilibrium calculation":
$$
c = \left[ 2H/M \right]^{1/2} \left[ 1- \left( {P_e \over P_c} \right) ^{R/C_p} \right]^{1/2}
$$
All quantities are ...
1
vote
2answers
239 views
Chemical Fuel Improvements
With advances in chemical engineering, could chemical propulsion have a fuel (or fuels) that would allow it to compete with newer, more advanced form of propulsion (such as electrical or nuclear) or ...
2
votes
1answer
298 views
What proportion of a rockets fuel remains unburnt?
Presumably liquid rocket combustion is never 100% efficient, so what proportion of fuel does typically remain unburnt, venting into the atmosphere, and does this vary for different rocket designs and ...
31
votes
7answers
7k views
Do things get dirty in space?
I'm writing a computer game involving space exploration, where the player will come across space ships/stations that are hundreds/thousands/tens of thousands of years old. I'm also trying to make it ...
8
votes
3answers
4k views
Is there a maximum Isp for “exothermic chemical reaction rockets”?
The question Is there a maximum $\text{I}_{sp}$? reminded me that I once read somewhere that the maximum possible $\text{I}_{sp}$ for a rocket engine based on expansion driven by exothermic, ...
11
votes
5answers
2k views
What limits burning speed of solid propellant?
SRBs and missiles use grain to regulate thrust over time, as only exposed surface of the propellant burns.
But what causes propellant to burn only on the surface, and regulates the speed at which the ...
10
votes
1answer
3k views
What is the cause of the blue light from LH2/LOX rocket engines?
Below are some screen shots from circa June 2016 launch (or re-launch) videos by Blue Origin (video link) and SpaceX (video link). The New Shepard burns $\text{H}_2$/$\text{O}_2$, while the Falcon 9 ...
6
votes
1answer
4k views
What causes the green flash during Falcon 9's ignition?
Right before Falcon 9's engines start, there's a green flash. I assume it's some kind of chemical ignition.
What makes the flash the color green?
