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Questions tagged [fuel]

Questions about rocket oxidizer, propellant, reactive mass, or other fuels used in spacecraft or rockets.

3
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1answer
82 views

Pressurization line (Helium to LOX tank line) chilling while pressurizing LOX tank

I have read that in rockets and launch vehicles Helium is used for the pressurization of propellant tanks. What temperature Helium is stored at? If Helium is stored at room temperature then while ...
6
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0answers
408 views

How long does it take to chill the LOX and RP1 for Falcon 9 V1.1 Full Thrust?

The new version of the Falcon 9 v1.1 Full Thrust, or as SpaceX would like everyone to start calling it "Falcon 9", uses super cooled LOX and RP1 to improve the density of the fuel for better ...
6
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0answers
2k views

Propellant mass calculation

I have been given the following problem: To solve it I used the formulas: $v_e = I_{sp}.g_0$ $M_{propellant} = (e^{\Delta_v/v_e} - 1).M_{final}$ And I assumed that the apogee kick manoeuvre was ...
5
votes
0answers
68 views

What rocket uses the largest percentage of Fuel/Oxidizer before liftoff?

inspired by this question: How much propellant is used up until liftoff? which asks how much propellant (fuel/oxidizer) a typical rocket uses before liftoff. What has been or is the most non-typical ...
5
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0answers
125 views

What is the droplet size that is desirable for pintle injectors?

The pintle injectors tend to generate droplets after impingement of the fuel and the oxidiser stream and I understand that the droplets will be premixed. In such a case, even a larger premixed ...
4
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0answers
72 views

Does the pressurization of tanks prevent “liquid sloshing” during maneuvers?

I'll be the first to admit I know little to nothing about fluid dynamics, especially in a pressure vessel. I was wondering how pressurized rocket fuel tanks don't cause weight-distribution problems ...
4
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0answers
97 views

How much fuel is left in InSight?

InSight probably landed with some fuel margin. Unless it was vented/burned on landing (maybe not a bad idea considering potential leaks down the road), is there some left ? Do we know the ISP of ...
4
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0answers
91 views

Hypergolic slugs with gaseous reactants

Based on points raised in this question about hypergolic slugs. My understanding of a hypergolic slug is that it is a solid or a liquid on a paper patch placed in the combustion chamber and it will ...
3
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0answers
66 views

Falcon 9: how much fuel is left on a booster after stage separation?

If the booster attempts either land or sea landing, how much fuel (RP-1 and LOX) is left in its tanks right after stage separation? Recently, I have heard numbers as high as 30% of its total tank ...
3
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0answers
121 views

Does LOx stay as liquid when entering combustion chamber?

Given the heat from combustion and increased temperature, would the LOx still be in liquid form after emanating from the injector? Or will it instantly transform into gas? Are injectors cooled using ...
2
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0answers
77 views

What fuels would make refueling in space more dangerous/complicated?

I saw the question: Has in-space refueling been done? And was actually beginning to wonder, is refueling and transferring propellant dangerous in space? I understand that this would most likely be ...
2
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0answers
58 views

Is it feasible to take liquid Helium in a Pressure Fed System?

Can liquid Helium be flowed through a heat exhanger to increase its temperature and pressure which will further pressurize fuel-oxidizer tanks.
2
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0answers
104 views

Are there any situations where hot rather than cold propellants might be advantageous?

Given that cryogenic fuel and oxidisers exist, I wonder if the reverse is workable. Are there fuels or oxidisers that have been considered for rockets that must be kept hot to be usable? By hot I ...
2
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0answers
84 views

Would a low pressure container lower hydrogen leakage in space?

Hydrogen, for rocket fuel, tends to leak even through metal containers. Launchers carry hydrogen cooled to liquid in order to save storage space for aerodynamical reasons, but that is unnecessary in ...
1
vote
0answers
43 views

Which is preferred for liquid atomization - gas & liquid shear or liquid & liquid shear?

For generating a spray of droplets, liquid need to be disintegrated/atomized through shear forces. Typical injectors in IC engines and aircraft use shear between gas & liquid at the phase ...
1
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0answers
142 views

How to size Solar Array for Mars Surface

Good morning everyone, I am working on a project for my university where we need to perform a PrePhase A study for a Mars Infrastructure for Propellant production as a means of support for future ...
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0answers
442 views

Could Sodium metal be used in rocket fuel?

For instance, I read that the Hercules X-265 rocket motor used in the Sprint missile was a solid double base propellant that used nitrocellulose with zirconium metal staples and nitroglycerin as a ...
1
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0answers
465 views

How much fuel is necessary for 2nd stage of Falcon 9 rocket to land?

What is the fuel mass nedeed for the 2nd stage of Falcon 9 rocket to land, how much compared with its total fuel mass that it has? Or how much delta-v is necessary? Would it be able for Falcon 9 to ...
1
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0answers
164 views

Are there any complications of the position of the oxidizer injector on Orbitec's vortex rocket engine?

Orbitec's vortex rocket engine injects oxidizer from near the nozzle up the wall of the engine chamber in a vortex. The oxidizer injector being in this position seems unusual. Are there any ...
1
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0answers
99 views

Hazardous Propellant properties

is there a standard how NASA/ESA categorize hazardous propellant properties like flammability, toxicity, corrosiveness etc? Any links, papers, discussions would be greatly appreciated! Regards ...