Questions tagged [fuel]

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

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Need help with 'Tsiolkovsky's Rocket Equation': What's the maximum weight of my rockets command module?

A civilization wants to transport a command module towards another planet that is passing by. Their planet has a radius of 6'800 kilometers and weighs about 9 × 10^24 kg. They have no stronger engines ...
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Is it possible to use gases instead of liquids as fuel in a rocket engine?

Im reading about rocket engines and I have a question about is it possible to use fuels in the form of gases than a liquid in a rocket engine?
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Ion Drives specific impulse somewhat of a false economy?

I've been working through a thought experiment with a friend of mine, with some of my previous questions already being (very helpfully) answered on here :) Here's the current issue I have though - ...
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VASIMR - Propellant usage data?

So I am using the VASIMR data of approximately 5N of force per 250kw of power draw. As far as I can see, this scales fairly linearly, so 500kw would result in 10N of force. (Might require two engines, ...
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Looking for fuel mass per kg payload data for Ion drives

I'm looking for some information on what the fuel/propellant mass per kg of payload is for ion drives. Hall X3 or VASIMR or whichever is currently the 'best' that we have available. This isn't for ...
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Looking for figures for contemporary interstellar engine options

So I have already done... a lot of reading on this subject lately. A lot. You wouldn't believe. My maths is... functional, probably far above 'average', but when it gets into the realms of the 'rocket ...
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Would it be possible to use electrically charged plasma to drive a vehicle to space? [duplicate]

Electrically charged plasma is not extremely difficult, at least in materials needed. I was wondering if it would be a practical substance due to its high energy. I also thought that, if it remained ...
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Why is the Space Shuttle's External Tank fuelled through the Orbiter's main engine plumbing system?

This answer states that Space Shuttle's External Tank (ET) was fuelled (this process is known as Tanking) through the Orbiter's main engine plumbing system with the Tail Service Masts (TSM). One ...
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Are there examples of a spacecraft designed for transitions from supercritical to liquid+gas mixtures?

The question What happens when supercritical fuel tanks deplete below critical point? suggests some possible scenarios when the pressure of a tank is in danger of dropping below the supercritical ...
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Why would oxygen be stored as a super critical fluid?

Organic Marble just answered a question about Apollo 13 in terms of the storage of Oxygen, and posted some fascinating stuff, including the fact that Oxygen was stored as a super-critical fluid. I ...
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How does a NTR with an afterburner perform at a stoichiometric mixing ratio?

The LANTR entry at Encyclopedia Astronautica describes how a sample nuclear thermal rocket performs at various mixing ratios of LH2/LOX. It does however stop before reaching the stoichiometric ratio ...
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Maximum speed of rocket propellant flow?

In reading this question (Limiting factors of liquid rocket engine thrust), it prompts me to ask if there is an upper limit in how fast the propellant/oxidizer can be pumped into a combustion chamber ...
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Chandrayaan 2: How has life of the orbiter increased from 1 year to more than 7 years?

https://timesofindia.indiatimes.com/india/chandrayaan-2-orbiter-has-life-of-7-yrs-95-of-mission-accomplished-isro/articleshow/71026990.cms The ISRO Chairman has reported that the economic use of fuel ...
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Why RFNA is used in orbital rocket and why it leaks?

The red fume can be seen in some ballistic missile tests and of course here for the case of Chinese KZ-1A orbital launcher. i wonder what's the usage and why it leaks.
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What is a propellant burner trailer?

CNN and NPR have pointed out that the US president recently tweeted a surveillance photo of an explosion of a rocket on a launch pad. One of the items identified in the photo is labeled as a ...
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What is the ideal propulsion for an inner solar system spacecraft?

I've seen the X3 ion thruster named as the future for traveling between planets. Would the ideal spacecraft have only one propulsion? Or would it have multiple sources such as hydrazine and solar ...
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How is it that “blow-down” propellant storage systems work in micro/ zero-gravity?

A "blowdown" pressure system is something that is extensively utilized on Earth -- with tons of applications ranging from kegs to high-tech hydraulics. This architecture focuses on adding a ...
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Why don't we use Cavea-B

Raiz Aerospace raised an interesting question during one of his KSP Realism Overhaul play throughs. If the RCS propellant Cavea-B is better than hydrazine and less toxic why does no one use Cavea-B, ...
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Could H$_2$S$_2$O$_8$ (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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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 ...
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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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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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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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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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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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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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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?