Questions tagged [fuel]

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

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2 answers
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Calculating propellant mass from total impulse

I have a simple question about how to calculate the total propellant mass used by a satellite in space. From Simulink, I have a graph of thrust VS time, so I could integrate this to calculate the ...
13 votes
1 answer
1k views

How do propellant transfer technologies work?

I'm new to the aerospace world, and I was wondering how the ISS or other rockets were refueled in space. I've found some information, but most were patents and I wasn't able to understand them well. ...
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2 votes
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What is the most powerful solid rocket fuel (highest isp) and it's combustion temperature

I wanted to know what the most power full solid rocket fuel is. I do not mean theoretical once like metallic hydrogen. Are solid rocket fuel mixtures prepared in a non-ideal mixture? In other words, ...
3 votes
0 answers
54 views

Does Juno have enough fuel to push itself into a more elliptical orbit reaching out to Himalia? [duplicate]

Does the Juno probe have enough fuel to push itself into a highly elliptical orbit around Jupiter so that its apojove would be at Himalia's orbital distance to study Himalia better? Would a gravity ...
1 vote
0 answers
92 views

What are better ways to deliver heat directly to propellant in a Thermal Rocket design for use in launch than UV such as in the Nuclear Lightbulb?

Most advanced, high-power engine concepts that I came across aren’t suited for atmospheric launch, so I got curious about what kinds of engines could launch a very heavy craft from the surface of a ...
0 votes
0 answers
49 views

A hybrid micropropulsion system for CubeSats

I am curious about how much potential would a hybrid (electric & chemical) micropropulsion system have for CubeSats. The chosen propellant is water due to its non toxic nature, cheap cost and high ...
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7 votes
1 answer
867 views

Nitrogen trifluoride as a high density oxidiser

Nitrogen trifluoride (NF3) is a liquid between 66K and 144K and has an incredible density of 1.885 g/cm2. It has a pretty great specific impulse, although combustion temp is a bit high, and AFAIK is ...
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2 votes
0 answers
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Paraffin wax in solid motors

Paraffin wax is often used in (at least hypothetical) hybrid motors, mostly with N2O or HTP. Could it not, however, be used in a conventional configuration? Running at O/F of 12.4, 60 bar chamber ...
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2 votes
2 answers
111 views

How do you calculate fuel usage ratio for rocket acceleration vs deceleration using a fixed total amount of fuel?

If a rocket is accelerating and then decelerating to stop at a destination (not necessarily continuous acceleration), and you want to use a given total amount of fuel, how do you calculate the amount ...
1 vote
1 answer
161 views

What rockets use a methalox propellant?

I’ve found that the SpaceX Raptor rocket engine and the BE-4 rocket engine use methalox (Liquid Methane and Liquid Oxygen), is there any other rocket engines that use a methalox.
17 votes
3 answers
3k views

What is the best chemical rocket fuel from a purely specific impulse standpoint?

A variety of different rocket programs use a variety of different fuel types. Researching this, the main fuel combinations I saw were: RP-1 / LOX (SpaceX's Falcon rockets, early stage Atlas and Saturn ...
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How to calculate combustion temp? [duplicate]

I was reading about a propellant combination using ethanolamine(19.9% propellant fraction w/ 1% Copper Chloride) and 90% HTP(80.1%). I am trying to design a hypothetical engine around the propellant, ...
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-3 votes
2 answers
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Why isn't oil used for rockets? [closed]

Most people know that when you add oil to a fire, it grows rapidly and becomes more powerful. So, why isn't added into the propellant just before it comes out of the engine?
12 votes
2 answers
2k views

Could a Mars rover go to Phobos or Deimos instead?

Could a Mars rover go to Phobos or Deimos instead of going to Mars? The choice is made after launch, and no further modifications can be made to the rover. Could it land safely? Up to what point could ...
29 votes
2 answers
5k views

Ultimate fate of rocket propellant in space?

For many trajectories using engines with moderate ISP such as chemical or nuclear-thermal rockets, the exhaust velocity vector of various space operations is such that the rocket exhaust will end up ...
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10 votes
1 answer
349 views

What happens to the propellant in a wet dress rehearsal?

The Artemis 1 mission is going to do a wet dress rehearsal where the rocket will be filled with propellant and the launch sequence will continue until almost the last second. The launch sequence will ...
1 vote
1 answer
114 views

What is the equation to find how much fuel you need to reach a velocity? [closed]

Theoretically, I need to launch a rocket, and I need to find how much fuel I need to reach a velocity however I do not know the equation.
3 votes
1 answer
582 views

What is the equation for fuel equals distance for a rocket? [closed]

Theoretically, I am trying to launch a rocket from space and trying to figure out how much fuel I would need to get to a certain distance.
-7 votes
1 answer
143 views

Why is monopropellant used?

The most efficent fuel, liquid hydrogen, is a bipropellant. So, why don't we just use bipropellants? Some monopropellants, such as hydrazine, are toxic. Wouldn't it be easier to just use bipropellants ...
10 votes
3 answers
2k views

Why do $\text{CH}_4$ (Raptor) engines produce less soot than RP-1 (Merlin) engines?

SpaceX's Merlin engine, which burns RP-1 and LOX, has soot visible after the first stage lands. Many articles on the web say SpaceX's Raptor engine, which burns methane and LOX, is clean. ...
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1 vote
1 answer
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Using Chimborazo as a rocket launching platform

Please consider this. Chimborazo is a sleeping volcano at 01°28′09″ S 78°49′03″ W. Its peak is 6263 metres above the sea level and because it is very near of the equator, the peak is more than 2 ...
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1 vote
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Fuel profile for Apollo 11

I downloaded a dozen of NASA documents about post-flight analysis of Apollo 11 mission, but I cannot find a table or a plot of fuel usage and remains; Some of the documents which I found: http://www....
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3 votes
1 answer
184 views

How to convert bi-propellant fuel into Delta-v (for ex., for JWST)

The following news gave the details on the quantity of fuel embarked on JWST: NASA gives green light to fuel the James Webb Telescope. The Webb telescope’s spacecraft bus, built by Northrop Grumman, ...
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5 votes
1 answer
172 views

How are JWST tanks baffled to dampen slosh?

After JWST slews to a new orientation, it then needs to “settle” sloshing fuel in the tanks before Fine Guidance System (FGS) can acquire the new science target. The time needed for slewing, settling ...
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6 votes
1 answer
450 views

Can the higher oxides of nitrogen, like nitrogen pentoxide, be used as oxidisers in rocket engines?

Both nitrous oxide (N2O) and dinitrogen tetroxide (N2O4) are used in storable propellant combinations, so, simply as a continuation, can the higher oxides of nitrogen (N2O5, N2O6, etc.) still be used ...
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24 votes
1 answer
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What is "anti-geysering" and why would you turn it off 70 seconds before launch?

Today Rocket Lab launched the Electron from Launch Complex 1 Pad A in New Zealand, and there was something about ...the first time a helicopter will be stationed in the recovery zone offshore to ...
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2 votes
1 answer
106 views

Solid metal fuel for nano satellite thrusters

A South African company is developing a solid metal fuel thruster that was initially researched by NASA but was not further developed, an electric reaction could be used to vaporise solid metal fuel, ...
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17 votes
3 answers
3k views

Why don't Raptor engines use CH3Cl instead of CH4?

The boiling point of CH3Cl is -24 degrees Celsius, whereas the boiling point of CH4 is -160 degrees Celsius. The density of CH3Cl is 2.3 g/cm3, whereas the density of CH4 is 0.6 g/cm3. CH3Cl is polar, ...
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18 votes
2 answers
5k views

James Webb telescope; limits to propellant lifetime?

There is a comprehensive article on Wikipedia on the James Webb telescope. It includes a statement regarding the operational lifetime being nominally five years and optimistically ten years. However ...
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0 votes
1 answer
100 views

Tilted exhaust gases from the rocket nozzle after sonic boom [closed]

Our solid propellant rocket, on test, produces sonic boom. Right after, the plume of exhaust tilts sideways. This will definitely have a gimbal effect during flight. The propellant chamber has one ...
2 votes
0 answers
46 views

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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2 votes
1 answer
86 views

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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4 votes
0 answers
57 views

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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7 votes
1 answer
1k views

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 ...
8 votes
0 answers
250 views

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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6 votes
1 answer
363 views

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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2 votes
1 answer
379 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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2 votes
1 answer
201 views

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 ?
2 votes
1 answer
238 views

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 ...
5 votes
1 answer
335 views

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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4 votes
1 answer
659 views

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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4 votes
0 answers
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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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7 votes
0 answers
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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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1 vote
0 answers
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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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18 votes
9 answers
5k views

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 ...
3 votes
0 answers
107 views

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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8 votes
1 answer
518 views

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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5 votes
2 answers
138 views

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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6 votes
2 answers
264 views

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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3 votes
1 answer
290 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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