Questions tagged [chemistry]

Questions regarding the application of chemistry in space exploration, for example the composition of rocket propellants.

Filter by
Sorted by
Tagged with
10 votes
3 answers
2k views

Why do CH4 (Raptor) engines produce less soot than RP-1 (Merlin) engines?

SpaceX's Merlin engine, which burn RP-1 and LOX, has soot visible after the first stage lands. Many articles on the web says SpaceX's Raptor engine, which burns Methane and LOX, is clean. ...
user avatar
  • 2,285
2 votes
1 answer
161 views

Perseverance's First Borehole looks like its particles of sand stuck together by something; composition of this material and source of adhesion?

Resampled and sharpened detail from PIA24796: WATSON Image of Perseverance's First Borehole This is reminiscent of a day at the beach digging a hole in wet sand. The walls remain standing as long as ...
user avatar
  • 148k
9 votes
1 answer
245 views

How do they know that the Dragonfly helicopter won't get quickly coated in tholin muck? Any desliming technology for camera lenses or propellors?

From Air and Space's Dragonfly Is the First Aircraft Built for the Outer Solar System; NASA returns to Saturn’s largest moon with a rover that can fly. which I just found in this heavily-sourced ...
user avatar
  • 148k
18 votes
2 answers
2k views

How did the kerosene-burning Black Arrow have transparent exhaust? (seems to just "hover" in photos)

Kerosene + LOX rockets have big, bright exhaust plumes, at least in the atmosphere; second stages are are a different matter: Why is the flame of the Falcon 9's 2nd stage (nearly) invisible? But ...
user avatar
  • 148k
2 votes
0 answers
68 views

Has a spacecraft ever actually sprayed a chemical (or anything) on to another spacecraft intentionally for any reason at all?

The question How many of these six military "orbital threat" techniques have been demonstrated in a (more or less) publicly recognized way? begins: If you are having a good day then under ...
user avatar
  • 148k
5 votes
0 answers
73 views

Is MOXIE's oxygen ready to breathe or is there CO2 and/or CO that would need to be scrubbed?

MOXIE splits two molecules of martian carbon dioxide into two molecules of carbon monoxide and one molecule of oxygen. Breathing elevated levels of CO2 ranges from unpleasant (to say the least and ...
user avatar
  • 148k
3 votes
1 answer
149 views

How did MOXIE "know" that it produced 5.4 grams of oxygen? Did it measure pressure rise in a container or just vent it? Did it use an oxygen sensor?

CNN's Perseverance rover just made oxygen on Mars is great and welcome news! While Ingenuity has been achieving one "first" on Mars Perseverance was quietly achieving yet another. After ...
user avatar
  • 148k
11 votes
1 answer
287 views

How much is known about those liquid metal droplets orbiting the Earth? (e.g. sizes, composition, orbits...) Are any actually tracked?

The question Orbit Guardians - bs, right? mentions a company proposing a smallsat that will capture then give a roughly 200 m/s retrograde "kick" to liquid metal NaK alloy droplets in LEO ...
user avatar
  • 148k
4 votes
1 answer
456 views

If high-test peroxide is most stable when pure, why are most uses of it in rocketry at lower concentrations?

Per the Wikipedia article for High-test peroxide: Hydrogen peroxide becomes more stable with higher peroxide content. For example, 98% hydrogen peroxide is more stable than 70% hydrogen peroxide. ...
user avatar
3 votes
1 answer
120 views

What is the products of a catalyzed reaction between Hydrogen Peroxide and Ethanolamine with Copper(II) Chloride?

I found this article about Hypergols, specifically H2O2. It mentions in table 3 and in the body of the paper that they found that Ethanolamine with Copper Chloride reacted vigorously. In my search for ...
user avatar
  • 41
2 votes
0 answers
22 views

What instruments and techniques measured Mars' atmospheric D/H ratio which suggests (all of) it's water didn't evaporate after all?

The Time article Mars Has Much More Water Than Previously Known—But There's a Catch says: The greater weight of deuterium causes it to behave differently in the Martian atmosphere. While free ...
user avatar
  • 148k
4 votes
1 answer
180 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 ...
user avatar
4 votes
0 answers
193 views

Why didn't propylene fly? (Vector—yes, Vector—is back)?

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 ...
user avatar
  • 148k
10 votes
1 answer
3k 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 ...
user avatar
  • 148k
2 votes
1 answer
128 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 ...
user avatar
  • 665
2 votes
1 answer
63 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: (...
user avatar
12 votes
3 answers
703 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 ...
user avatar
  • 6,882
1 vote
0 answers
303 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 ...
user avatar
2 votes
1 answer
109 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 ...
user avatar
  • 148k
3 votes
1 answer
55 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....
user avatar
3 votes
1 answer
291 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 ...
user avatar
  • 148k
7 votes
2 answers
440 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 $$...
user avatar
  • 367
7 votes
3 answers
1k 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} = \...
user avatar
  • 148k
1 vote
0 answers
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....
user avatar
2 votes
3 answers
328 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....
user avatar
  • 2,145
0 votes
1 answer
88 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 ...
user avatar
1 vote
0 answers
39 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 ...
user avatar
4 votes
0 answers
52 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 ...
user avatar
  • 161
3 votes
1 answer
326 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 ...
user avatar
  • 148k
1 vote
1 answer
308 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 (...
user avatar
  • 148k
3 votes
1 answer
581 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, ...
user avatar
  • 7,050
4 votes
1 answer
395 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 ...
user avatar
  • 148k
1 vote
1 answer
94 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 ...
user avatar
  • 11
4 votes
3 answers
341 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?
user avatar
5 votes
1 answer
247 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 ...
user avatar
  • 26.3k
6 votes
1 answer
185 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? ...
user avatar
4 votes
1 answer
305 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 ...
user avatar
  • 729
5 votes
2 answers
998 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 ...
user avatar
  • 1,744
2 votes
1 answer
109 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 ...
user avatar
  • 4,007
12 votes
2 answers
2k 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 ...
user avatar
  • 121
6 votes
1 answer
807 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 ...
user avatar
8 votes
1 answer
521 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 ...
user avatar
  • 148k
0 votes
0 answers
97 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?
user avatar
  • 2,880
20 votes
1 answer
314 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 ...
user avatar
  • 14.6k
6 votes
2 answers
2k 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 ...
user avatar
  • 4,324
2 votes
0 answers
139 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 ...
user avatar
6 votes
1 answer
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 ...
user avatar
  • 148k
4 votes
2 answers
164 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 ...
user avatar
  • 379
5 votes
1 answer
262 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 ...
user avatar
  • 148k
3 votes
2 answers
295 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 ...
user avatar
  • 379