Questions tagged [engines]
Questions regarding equipment used to propel a spacecraft or a rocket. Questions about attitude control jets should be tagged "attitude".
532 questions
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What is that extra exhaust on the RS-68
Next to the Roll Control Nozzle on the RS-68 (the engine that powered the first stage of the Delta IV) there is this a tiny pipe exhausting something. I have a basic understanding of how liquid engine ...
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Liquid Rocket Engine Sizing Gamma [duplicate]
I'm working on a rocket sizing problem and in reading a bunch of papers none of them state where and how they derived the ratios of specific heat used in almost all rocket equations. I understand ...
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Use of NaK as a possible bipropellant/tripropellant rocket fuel?
Recently I asked this question about tripropellant rocket engines. In an effort to avoid dealing with hot molten metal or powdered metal as the additive, I turned to NaK as a possible solution.
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Feasibility of lithium or aluminum as a tripropellant liner for ablatively-cooled engines?
Studies have been previously conducted on the feasibility of using metal powder as a tripropellant in rocket engines (i.e. lithium/fluorine/hydrogen or aluminum/hydrolox). For example, this NASA study ...
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What is the meaning of "negative thrust" in a grossly-overexpanded engine?
I recently reread this answer and noticed this term being used (quoted here):
At atmospheric pressure, the exhaust can only be over expanded up to a point before the engine begins producing negative ...
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Why did 65%-92.5% throttle cause excessive erosion of the LEM descent engine?
Wikipedia's article on the LMDE mentions that "operation between 65% and 92.5% thrust was avoided to prevent excessive nozzle erosion." This seems a bit counterintuitive as operating at full ...
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Why exactly do full-flow rocket engine's turbopumps run cooler?
Wikipedia's Staged combustion cycle; Full-flow staged combustion cycle states that
Benefits of the full-flow staged combustion cycle include turbines that run cooler and at lower pressure, due to ...
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How many rockets have been re-engined?
I got curious about the idea from the recent Raptor-EUS question and am wondering now how many rockets, particularly launch vehicles and upper stages for orbital vehicles, have been re-engined?
The ...
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How much thrust could radiators provide?
Usually heat is a waste - spacecraft use substantial mass to get rid of it via radiators.
But what if one uses it for thrust? Why not to make some dumb photonic engine out of it?
Obviously it would be ...
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Is used propellant dangerous for other spacecraft, and if so, for how long?
Does the exhausted propellant of space probes pose a danger - as a cloud of high velocity particles - to other spacecraft crossing it soon after, or does it diffuse quickly enough in the vacuum to not ...
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What are the different types of rocket engine ignitions?
Different rocket engines use different types of ignitions. What are the different type of ignitions and which type is used in which engine. What are the advantages and disadvantages of various ...
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How is the Soyuz's movement along the axes ensured using maneuvering engines?
The maneuvering engines are located outside the ship's center of mass and when turned on, they should create rotation, not movement.
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How do the turbopumps in the RS-25 work?
I was looking at a diagram of the RS-25 rocket engine used in the SpaceShuttle program.
You can see two high pressure turbopumps and a fuel and oxidizer pre-burner. I always thought that the ...
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How are rockets able to keep their centers of mass in line with thrusters?
How can the thrusters of a rocket keep in line with its center of mass seemingly perfectly to not exert any torque and rotate the rocket? For torque to not be exerted, the force vector must align with ...
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Why doesn't SpaceX use solid rocket fuel?
I am curious to why SpaceX wouldn't use more efficient solid rocket boosters instead of the liquid booster they currently have for the first stage of their Starships. At first, I thought this was due ...
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