Questions tagged [fuel]

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

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2answers
368 views

Could H₂S₂O₈ (peroxydisulfuric acid), made in the clouds of Venus, be used for making a propellant?

The salts of the peroxydisulfate ion, S$_2$O$_8$$^2$$^-$, are strong oxidants like the perchlorates that are used in propellants for rockets. In this answer on Chemistry stackexchange is a link to a ...
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1answer
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Why was ramjet fuel used as hydraulic fluid during Saturn V checkout?

Fuel is also used within the engine as a lubricant and as a hydraulic working fluid, though before launch, RJ-1 ramjet fuel is supplied from the ground, it being more suited for this purpose. ...
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1answer
435 views

Why did Orbex choose propane as its fuel?

As a follow up to Are there liquid fueled rocket boosters having coaxial fuel/oxidizer tanks? and thinking about JCRM's answer pointing the issue of having a huge contact surface between inner and ...
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1answer
339 views

Does this Soyuz vehicle burn coal or oil? What is its official name?

This tweet shows the image below and says: Soyuz rocket on its way to the launch pad (on a train of course). Question: Does this Soyuz vehicle (a train engine) burn coal or oil? Does it have an ...
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When would the density Isp product be an important performance metric of a propellant?

The quote NASA is testing hydroxylammonium nitrate in space which is expected to perform 50% better than standard propellants and can be allowed to freeze (hydrazine must be kept liquid). LMP-103S ...
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1answer
135 views

Why would it be “less bad” for hydroxylammonium nitrate monopropellant to freeze than for hydrazine?

Answers to Is it bad if hydrazine freezes on a spacecraft? Is it always kept as liquid, or can it be safely allowed to freeze and then thawed when needed? explain that while the freezing of hydrazine ...
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3answers
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Is the EU really banning “toxic propellants” in 2020? How is that going to work?

This comment links to an archived presentation by Tesseract "The space transportation company offering revolutionary propulsion" says on slide 8: Timing is right Small satellite ...
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1answer
432 views

What is Tesseract's “secret sauce”? (green propellant)

TechCrunch's Tesseract makes spacecraft propulsion smaller, greener, stronger tells us to "ditch the hazmat suits" and https://www.tesseract.space/products-and-services lists the Lyra 22 (i.e. 22 ...
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203 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?
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1answer
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Why alcohol had been selected as fuel for the first American space rockets?

I was surprised to read that Redstone used 75% ethyl alcohol as a fuel. Looks like this idea was abandoned later, and modern rockets use rectified petroleum or liquid hydrogen instead for burning with ...
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1answer
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What “fuel more powerful than anything the West (had) in stock” put Laika in orbit aboard Sputnik 2?

The BBC World Service Radio Witness History podcast Laika, the first dog in space contains a short audio clips from some vintage 1950's British news. At 02:30 in a ...
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1answer
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Why can't an expander-cycle engine be built to use RP-1 or other non-cryogenic fuels?

The expander cycle family of rocket-engine power cycles involve using waste heat from the engine's combustion chamber and/or nozzle to vapourise some or all of the engine's fuel, and using the now-...
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1answer
373 views

How were hypergolic propellants delivered to the Shuttle launch pad?

The Space Shuttle Main Engines used cryogenic hydrogen and oxygen, and this question explains how those were supplied to the launch pad. But the OMS and RCS engines used hypergolic fuels. How were ...
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1answer
175 views

In principle, could the oxygen tanks of an 'air breathing' rocket, be filled during ascent?

(Thinking of SABRE and it's heat exchanger). As I understand it, Skylon would take off with full oxygen tanks. Putting aside engineering difficulties, is there a thermodynamic reason why a hybrid ...
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1answer
659 views

Are rocket engine feed pipes flexible?

Let's restrict this question to rockets whose first stage : run on liquid propellant use turbopump (this may be too restrictive for this question, but it still restrict to many rockets in use today -...
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1answer
260 views

Are the APUs on the SLS SRBs planned to be hydrazine powered?

I recently read that the Space Launch System core stage, which uses renamed / slightly reworked Space Shuttle Main Engines and therefore requires a hydraulic system to service said engines, will use ...
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How does one “dump” or deplete propellant without changing spacecraft attitude or trajectory?

Occasionally one reads about a spacecraft "dumping fuel". It may mean expelling the propellant(s) as a liquid, or depleting them by burning them up. Although usually only fuel is mentioned, often ...
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1answer
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What happened to boiled-off gases from the storage tanks at Launch Complex 39?

Both Apollo and the Shuttle launched from KSC complex 39, and used liquid oxygen and liquid hydrogen as propellants. These cryogenic liquids were held in storage tanks near the perimeter of each ...
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1answer
366 views

Can LOX containing hydrogen peroxide be used as an oxidizer for a liquid fueled rocket?

While searching the internet for designs on liquid fueled rocket engines, I noticed that some bottles of liquid oxygen say they contain some percentage of hydrogen peroxide. Could that be used as an ...
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How does the inter-propellant seal works in kerosene/LOX and UDMH/NTO rockets?

I get that the inter-propellant seal on the SSME LOX HP pump is simply a series of cascading regular seals trying to eliminate bleed-through by venting and letting boil at each stage, so that when ...
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Why will Starlink satellites use krypton instead of xenon for electric propulsion?

The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says: With a flat-panel design featuring multiple high-throughput antennas ...
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1answer
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Why is LOX on top in the Space Shuttle external tank instead of the other the way round? [duplicate]

Why is oxygen placed on top of hydrogen? Does this have anything to do with letting the warmer and not the colder liquid have a non-spherical bulkhead and thus more surface area to reduce boil-off?
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Why did the Americans abandon kerosene after F-1 while the Soviets continued to develop it to very high sophistication?

What is the reason behind America's switch to LH2/LOX, and (USSR's) Russia's decision to stay with it and develop it to spectacular technical sophistication such as the Oxygen-rich staged combustion ...
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1answer
261 views

Is Cryogenic Rocket Fuel Still Liquid When It Flows Through a Regeneratively-Cooled Nozzle?

For a rocket engine that runs on (deeply) cryogenic fuel like LH2, e.g. SSME, is the fuel kept liquid throughout the entire length of the regenerative cooling circuit in the nozzle? Or is it allowed ...
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2answers
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How could a hydrazine and N2O4 cloud (or it's reactants) show up in weather radar?

Question: How could a hydrazine and N2O4 cloud (or it's reactants) show up in weather radar? Tweet: This is what an ‘anomaly’ looks like on weather radar. Tweet (with GIF): Dragon's static fire ...
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Can a rocket refuel on Mars from water?

Can a rocket run only on hydrogen and oxygen? Could a rocket, rover, and electrolysis machine be sent to either of Mars' poles to excavate ice to make hydrogen and oxygen to refuel an unmanned rocket? ...
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1answer
101 views

How to find an optimal number of propellent tanks?

My idea: If the propellent mass to tank mass ratio remains constant when increasing/decreasing the amount of propellant then you could increase $\sum \Delta v$, by splitting the propellent tank and ...
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2answers
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Break Away Valves for Launch [duplicate]

I forgot to hang up the fuel pump and broke it off and costed around 80 dollars to replace. While there I wandered could this be adapted to a rocket in some way? How much fuel capacity would be saved ...
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1answer
231 views

What rocket system launch contained the highest amount of propellent potential energy?

In regards to rocket launches, what rocket launch contained the most potential energy (joules/btu/etc.) in its thrust propellant to achieve is basic mission? I'm not as much concerned with ...
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7answers
5k views

Pre-mixing cryogenic fuels and using only one fuel tank

A methalox engine is fed from two cryogenic fuel tanks. Why can't the methane and oxygen be mixed as gases, in the desired proportions, and then chilled to a temp that liquefies both? From a single ...
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151 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 ...
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1answer
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How much propellant is used up until liftoff?

How much of the total propellant mass (fuel+oxidizer) of the first stage/boosters is usually burnt between ignition and liftoff?
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Fuel vs food on the trip to Mars?

How much food for each person is need and fuel per various engine to go to Mars on the current 9-month trip there then 3 months on Mars and the 9 months back? Can time be saved on the trip to and from ...
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1answer
115 views

What are ways to store hydrogen for electric propulsion without a heavy pressure vessel?

This comment points out that any advantages of using low-mass ionized atomic hydrogen (i.e. protons) for electric propulsion if you had a fixed acceleration voltage and plenty of electrical power ...
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1answer
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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 ...
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1answer
385 views

What type of propellant does Spacex plan to use in Starship for long duration missions?

For long duration missions such as ones to mars what type of propellant would be best suited?
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Cheapest rocket to go to space?

Have you ever heard of the old movie Salvage? The TV movie, “Salvage,” aired on January 20, 1979. The film begins with Harry successfully bidding for a vintage bi-plane and then reselling it in pieces ...
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1answer
247 views

Are there any hypergolic solid/liquid fuel combinations?

Could the principal of hypergolic fuels be applied to hybrid rockets? And if so, are there any known hypergolic solid/liquid combinations?
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1answer
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Scoutleader looking for understanding of fuel burn for getting away from earth gravity Vs. fuel expended when traveling from A-B in space

I am a layman scoutleader and like to discuss the amount of fuel needed to get from earths gravity to the thrust needed in space to get from A-B. Is there a spreadsheet that would give course ...
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1answer
225 views

What methods are proposed for storing cryogenic fuels (esp. hydrogen) in space for months or years?

Current Launch vehicles and upper stages must only keep their fuels for minutes or hours, so they are only insulated to keep boiloff to a few % per day - I've seen 21% per day quoted for Centaur on ...
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2answers
187 views

Hypergolic Propellant Combination

Is Rocket Grade Hydrogen Peroxide and Liquid Hydrogen a hypergolic propellant combination? I recall, seeing the combination somewhere on the www, however I couldn't retrace the source where I saw it.
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0answers
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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 ...
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1answer
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Was there fuel consumption budgeting for Apollo 11 Lunar module?

Did the astronauts aboard Apollo 11's Lunar Module have any stated or imposed limitation or restriction on the amount of fuel they could use while in lunar orbit and performing landing maneuvers? I am ...
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0answers
559 views

What is the best fuel for bottle rocket? [closed]

I want to modify my firework bottle rocket to fly a mile high. What will be the best fuel for this? Could fuel used in space rockets be scaled down to work in a large bottle rocket?
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2answers
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What are some notable cold gas thruster propellants, and why?

Cold gas thrusters are a very simple and reliable form of thruster that operate only by spraying a compressed gas, without any chemical reaction. What are the most common, performant, or otherwise ...
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0answers
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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 ...
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1answer
12k views

How much fuel does the Falcon Heavy use? What is the price RP-1?

Does anyone know how much fuel the Falcon Heavy can hold, the RP-1 fuel and liquid oxygen as oxidizer, and how much of that will it use to get to a certain point? I don't know how i would calculate ...
10
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1answer
498 views

Why did the MarCO space probes use fire extinguishant as their propellant?

In many news articles, it's mentioned that the MarCO spacecraft, launched with InSight, used fire extinguishant as the propellant for its cold gas thrusters. I originally assumed that this was ...
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2answers
155 views

Propellants used for different Mars landers [till 2018]

What propellants have been used by lander to land on Mars surface?
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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 ...

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