Questions tagged [fuel]

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

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What is the meaning of "aggregate state" within the context of RPA?

I'm trying to make a new entry in the thermodynamic database of RPA (Rocket Propulsion Analysis, http://w.lpre.de/) and you are required to provide an "aggregate state". For CEA (Chemical ...
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Decomposing HTP through regenerative cooling for use in closed expander cycle

HTP or high test peroxide has a long history as a low cost and high reliability oxidiser, and has had a lot of recent attention for its pseudo hypergolic nature when passed over a catalyst bed. ...
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Giving rocket propellants an opposite charge for perfect mixing?

One of the challenges in achieving theoretical efficiency is the mixing of both an oxidiser and fuel. This means separating both propellants from each other whilst pairing them with their counterpart. ...
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Using coolant as 3rd propellant

Rocket engines often have 2 propelants, one of which is used to cool the engine and after that the hot propellant is injected in the combustion chamber. Would make sense to have a third propellant ...
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Silane as a rocket fuel

At about 6:55 into the video Why Moon Mining Will DEFINITELY Be A Thing it is stated that lunar silica (SiO2) could be turned into silane (SiH4), which is the silicon analogue of methane. It also ...
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Does anyone know the stay time, or what characteristic length should be used, for a LOX/LCH4-fuelled rocket engine?

Just what it says on the tin. I need to know either the "stay time" (Ts) or characteristic length (L*) that would be used to figure combustion chamber dimensions used with a LOX/LCH4-...
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1answer
137 views

Calculating total burn time for a rocket under constant acceleration with two propellant consumption rates

I tried posting this question on the Physics side of StackExchange but didn't get any response after a week, presumably because it was lost within the broadness of physics in general, so I'm hoping ...
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Which burning of Solid Propellant is best axial burning or radial Burning?

Which Burning is Better Axial or Radial of Solid Propellant grain used in Solid Rocket Motors? How Someone Determines which to choose according to the Mission requirements ?
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Can ion Thrusters be used for Reaction Control System?

As RCS (Reaction Control System) mainly required less thrust than regular rocket engine can ion Thrusters be used for attitude determination in spacecraft(Orion, Dragon), satellites or even during ...
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Does a cryogenic liquid propellant engine exist capable of using multiple fuels?

For example, a rocket engine which can use both liquid methane and liquid hydrogen.
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Did any Apollo missions have enough fuel left to bring back the LM ascent stage?

A recent question asks why the Apollo lunar module wasn't routinely brought back when returning from the Moon, so it could be used as an Apollo 13 style lifeboat. The answers correctly state that ...
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To what precision were the amounts of the Shuttle propellants known? [duplicate]

A previous question reveals that the Shuttle orbiter was weighed before it was moved to the Vehicle Assembly Building. Presumably, the other dry components of the launch stack (the solid rocket ...
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What's The Gas Discharge After Landing Finished For SpaceShip2?

What's the gas discharge after landing finished For SpaceShip2? Why did they did it right after landing finished while crew were on board.
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How to estimate fuel needed to reach LEO, GEO, and L1 earth-moon? [closed]

I'm doing some calculations about fuel production on the moon. To get a sense of order of magnitudes involved. I'd like to know how much fuel is required to get 1kg of mass to LEO, GEO, and L1 Earth-...
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Would it be practical to catch a rocket's exhaust to reuse it as fuel?

It's been some days that i think that would it be possible to make a ship that looks like this? The idea is to catch the fuel as you go. Would this make any sense or the thrust would be canceled by ...
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Did the flare stacks at LC39 have pilot lights?

The liquid hydrogen fuel in the space shuttles would slowly boil off, while they waited on the launch pad at Kennedy Space Center launch complex 39A or 39B. The hydrogen vapors were removed by the ...
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Use of high energy propellants on an engine designed for low energy propellants

This question is about use of high energy propellants on a rocket engine designed for low energy propellants. In any engine, which is currently working on RP1+LOX, if we change the fuel from RP1 to ...
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In situ Fuel in LEO / MEO

I have been thinking on controlled de-orbiting of Satellites. You can carry a supply of conventional chemical fuel, and use it to apply a delta-V that would de-orbit them. There are also methods of ...
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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 ...
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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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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 ...
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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 ...
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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 ...
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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 ...
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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. ...
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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 ...
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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,...
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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 ...
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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 ...
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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. ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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? ...
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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 ...
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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, ...
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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 ...
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680 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 ...
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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 ...
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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 ...
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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: ...
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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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