Questions tagged [fuel]
Questions about rocket oxidizer, propellant, reactive mass, or other fuels used in spacecraft or rockets.
364
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2answers
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Alternative propellants in nuclear thermal rockets
Many years ago, I read a science fiction story "Rocket Ship Galileo" in which a nuclear powered spacecraft used zinc as a propellant. Apart from the fanciful nature of the story itself, I ...
3
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1answer
199 views
How much fuel could a rocket save by launching from an airship/blimp?
What could the Kozlov’s Aerosmena project blimp add to fuel saving if space rockets were launched from it? Where would you place the rocket and airship on this chart?
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4answers
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Why RP-1 and not Methane for Falcon 9's Merlin engines?
I've seen methane described as the best of both worlds---the worlds being hydrogen's energy density + pain-in-the-ass factor and RP-1's lower energy density + ... ease of use?
And this has me ...
-2
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3answers
193 views
energy needed to accelerate in space
I was thinking about possibility of cargo transport between, say, earth and mars when a “pusher” accelerates propulsion-less cargo vessel, which is catched and decelerated at the other end of ...
2
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0answers
32 views
SpaceX Dragon: How many fuel tanks?
I've read that Dragon carries 1380 kg of MMH + NTO propellant. This mass would be split among the various tanks, and I'm wondering---how many of them are there?
Pictures from the manufacturing floor ...
2
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2answers
103 views
Can Pyroxene and other silicon compound be used as a theoretical spacecraft fuel?
I have been reading this patent : https://patents.google.com/patent/US3137599A/en
This lead me to this paper: https://www.jstor.org/stable/44682837?seq=1
The first uses Polysilane, which basically ...
1
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0answers
41 views
Is CO + O ==> CO2 a possibility for propelling rockets off Mars? [duplicate]
Perseverance, the Mars rover, includes an experiment called MOXIE. This is a technology demonstration to show that Mars' atmospheric carbon dioxide can be broken into carbon monoxide and oxygen. ...
12
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1answer
3k views
Why is an inflatable balloon inside a fuel tank not used to prevent fuel from “sloshing around”?
After seeing all the Starship failures, having something with a membrane keep things in place seems like an obvious solution. Has it been considered or tested - or do we simply lack a material that is ...
2
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2answers
207 views
Why is hydrogen better than helium as remass?
I just watched a very good YouTube video on why nuclear engines might be useful, and it also goes into why Hall Effect thrusters are super good at squeezing obscene ISP out of things.
During the video,...
36
votes
3answers
5k views
How do you reliably blow up a rocket that was built not to explode?
NASA, and I'd imagine most space agencies around the world, demands abort systems of its commercial partners capable of destroying a rocket should it venture too close to populated areas. Note that ...
3
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1answer
98 views
Could another fuel be used in the SpaceX Starship header tank?
A memory of hexane and water in a separatory funnel brought to mind the issue of helium and LNG in the header tank while the Starship flips and does its powered landing.
There was discussion of the ...
4
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1answer
146 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. ...
1
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0answers
39 views
What is the O/F ratio of ethanolamine/H2O2?
I've just read this question What is the products of a catalyzed reaction between Hydrogen Peroxide and Ethanolamine with Copper(II) Chloride? and although its a very good question and an excellent ...
2
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1answer
68 views
Potential Fusion Drive system calculation issue
I will start off by saying that this is an entirely hypothetical drive system with plenty of handwaving and optimistic physics. My question I think is fairly simple and may just be something that ...
7
votes
2answers
209 views
What happened to tripropellant rockets?
IIRC, tripropellant rockets can deliver superior performance compared to bipropellant rockets (at the cost of added complexity). Now, I know that there is the Li/H/F combo, but it isn't used because ...
3
votes
1answer
76 views
How do I calculate thermochemical properties of mixed gases?
I'm working on a rocket project, and my design of engines is stalled. I need to be able to calculate the Cp, Cv, and R for mixtures of O2/CH4 (stoichiometric or fuel-rich mix) and CO2/H2O (result of ...
3
votes
3answers
182 views
Have any rocket fuel systems actually been explosive, and could have detonated proper?
Never mind that this is the 18th question to have the rocket-explosion tag.
To the question "Would the Dragon escape pod have survived this event?" asked about the AMOS-6 mission, Elon Musk ...
1
vote
1answer
144 views
How much power do radiation-based engines produce
I heard that the Voyager satellites used a radioactive source to power the computer and sensor systems. How much power can this technique produce nowadays? Could it power, say, a fighting robot? ...
2
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0answers
112 views
What is the practicality of using sub-cooled propane in combination with HTP in an amateur engine design? [closed]
Using sub-cooled propane, at approximately -90°C (b.p. -42°C at STP) in combination with >80% hydrogen peroxide, can any meaningful gains be made, whilst considering that this fuel mixture would be ...
1
vote
1answer
89 views
How much easier is it, to explore space from a low orbit satellite, than from Earth?
Note: in this question I'm considering cost in both money and fuel terms, and looking for answers that consider both.
So we know that using chemical rockets to reach the moon, or further into space, ...
4
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2answers
2k views
Rocket fuel cost to launch 1 kg to orbit
I have 2 questions about the cost of liquid rocket fuel to launch (anything) to LEO orbit. Let's assume we use fuels used in commercial spaceflight today (probably LOX+LH2 or LOX+RP-1 etc.).
What is ...
2
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2answers
544 views
Pressure levels inside rocket liquid oxygen tanks?
What is the pressure levels inside rocket liquid oxygen tanks, at launch time?
The question is for the minimum and maximum (known) levels of pressure inside such tanks.
I am asking for any rocket ...
2
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0answers
48 views
How stable is ozone as a compressed gas?
I have heard that liquid ozone is violently unstable, making it unusable in any meaningful concentrations. Would using it as a compressed gas partially solves the problem? What is the mechanism of its ...
2
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0answers
72 views
Why shouldn't Chang'e 5's lander's propellant freeze?
We have just measured the shape of the crater that the returner landed on, which is part of the scientific data collection. Then the returner will [put on a] 'new warm coat' to prevent the remaining ...
10
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6answers
1k views
When has hydrogen peroxide been used in rocketry?
Peroxide is apparently a very good propellant, but I can't seem to find any instance of it being used. Has it ever been used and if not, why hasn't it? What's its downsides?
3
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0answers
32 views
Where would one find information on the fuel properties (temp, max ISP) of non-conventional rocket fuels?
Yesterday's Starship landing saw at least one Raptor burning copper. Given that copper oxidizes with oxygen at the temperatures and pressures found in a Raptor combustion chamber, what properties does ...
5
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1answer
120 views
Burning Up Hydrazine and N2O4 for Safety
Sadly, all the "good" (storable, hypergolic, and having good performance) rocket fuels and oxidizers -- Hydrazine, methylated hydrazine, nitrogen tetroxide, and fuming nitric acid -- are ...
2
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1answer
68 views
What happened to continuously-applied heat barrier coatings in engines?
In Ignition, Clark describes an interesting approach to thermal control in rocket engines using oxygen as an oxidizer and hydrocarbon fuel: A small amount (few percent) of silicone oil or another ...
3
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0answers
89 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
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0answers
65 views
Will you be having rubber or wax with your peroxide? (hybrid engine fuel tradeoffs)
Hybrid engines offer some practical advantages and some budgetary ones that can offset lower ISP, including potentially safer solid fuel to store and non cryogenic storage of some oxidizers like ...
5
votes
1answer
294 views
Why did the Space Shuttle dump excess fuel from the external tank?
In his recent video, Scott Manley mentions that after reaching orbit, the Space Shuttle would dump the excess fuel left in the External Tank before jettisoning it:
...
2
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0answers
38 views
How much hydrazine does an Iridium satellite start with? How much does it use per year?
Iridium satellites use hydrazine and the spacecraft are expected to last at least 15 years.
How much hydrazine do Iridium satellites start with, and if possible, roughly do they use per year?
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6answers
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Using water as a high density storable hydro-lox propellant
Hydro/lox is an excellent fuel choice and has been used in many engine/rockets with high ISP requirements, however, the two biggest drawbacks of the propellant are its density and boil-off. Could this ...
5
votes
1answer
457 views
Does peroxide spontaneously decompose when introduced into hot combustion chambers?
I understand that hydrogen peroxide (HTP) can be decomposed into superheated steam and oxygen using a catalyst, but I haven't been able to find any information on whether or not it will decompose in ...
0
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0answers
84 views
Preventing hard starts using varied propellant/ O/F ratio?
From what I've heard, hard-starts are a very common, particularly in less refined amateur rocket engines, and the only way to avoid them is to either start the engine on an extremely low flow rate or ...
1
vote
1answer
82 views
Which fuel cell fuels have been demonstrated in space?
Combination of fuel cells and electric motors - whether it has been used as part of an electric pump-fed cycles? gives a short summary of fuel cells and lists the following energy-containing fuels ...
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0answers
92 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 ...
14
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1answer
2k views
Why is butane never used in rockets as fuel?
From what I know, it seems good, so why does no one use butane as a rocket fuel?
24
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2answers
3k views
Why do the contents of the Space Shuttle External Tank not match the mixture ratio of the engines?
The Space Shuttle External tank contains:
629,340 kg of liquid oxygen
106,261 kg of liquid hydrogen.
That's an oxidiser to fuel ratio of 5.92
Meanwhile, the Space Shuttle Main Engine has a constant ...
asked Oct 14 '20 at 12:26
SE - stop firing the good guys
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2
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1answer
220 views
Why can I not use stoichiometry to calculate the O/F ratio of my rocket? [duplicate]
I am attempting to calculate the oxygen to fuel ratio (O/F) for my hybrid rocket engine (paraffin wax and gaseous oxygen). I know I can use the oxidizer to fuel equation to calculate this, but my ...
0
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1answer
85 views
At what time is the Falcon 9 loaded with fuel?
How long before launch are the fuel and oxidizer loaded into a Falcon 9 rocket?
And how much time does it take to load it?
2
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2answers
211 views
Will mining water on Bennu not be more economical than collecting it near the south pole of the Moon?
Bennu is a carbonaceous asteroid that is currently accompanied by the OSIRIS-REx spacecraft that will take samples from it to return to Earth.
Its diameter is 490 m. and it is slightly denser than ...
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66 views
Could the issue of engine coking be solved with corrosive additives?
Many fuels will start to coke, that is they solidify when they're exposed to heat, such as in a regenerative cooling loop, particularly those that are commercially available like petroleum. Are there ...
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1answer
1k views
Have there been rocket engines designed for diesel? What ISP theoretically possible?
Have there been rocket engines or even test engines that have used diesel as a fuel? If so, what oxidizer had they used and what ISP did they achieve? If not, is it possible to say what ISP is at ...
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2answers
1k views
In what ways is helium used on modern launch vehicles?
Helium is a fairly rare material and does not remain in the atmosphere.
I'd like to know the uses of helium on modern launch systems?
Do most launch vehicles use helium in several different ways, or ...
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3answers
805 views
Getting back from the Moon
This link describes the way back from the Moon surface to the orbiting spacecraft. But how could that spacecraft get back to the Earth?
It is a long journey. How much rocket fuel would be needed, in ...
6
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2answers
179 views
Did rockets use turbopumps prior to the V-2?
Did the liquid propellant rockets before V-2 use turbopumps or were their fuel tanks pressurized with gas? Or perhaps were their engines gravity-fed?
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1answer
90 views
When was liquid hydrogen used for the first time in rocket engines?
When it was the first time the liquid hydrogen was used in a rocket engine? I mean for space launches, but it would be interesting to also know about first uses in experimental engines, in military, ...
8
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2answers
2k views
When was liquid methane used for the first time in rocket engines?
When it was the first time the liquid methane was used in a rocket engine? I mean for space launches, but it would be interesting to also know about first uses in experimental [rocket] engines, in ...
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0answers
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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 ...
