Questions tagged [engines]

Questions regarding equipment used to propel a spacecraft or a rocket. Questions about attitude control jets should be tagged "attitude".

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Resources where one can find RD-171MV engine technical specifications? (e.g.TWR, Expansion Ratio, Isp, Thrust, Chamber pressure, O:F ratio)

I'm trying to get a hold of various technical specifications for the RD-171MV engine A modification of RD-171M being developed for the Irtysh rocket. Unlike RD-171M it's completely made from Russian ...
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1answer
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Pressure inside Starship CH4 and LOX header tanks during entire Earth-Mars trip and landing on Mars?

What should be the pressure inside Starship CH4, LOx header tanks during the entire Earth-Mars trip and landing on Mars ? The main CH4, LOx tanks should be under 6 bar pressure, because that is the ...
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How many turbine blades, engine seals and bearings do reusable rocket engines have and how are they inspected?

From previous year statements of SpaceX representatives, the most difficult and longest part of used F9 booster refurbishment are inspections of the most volatile parts of the booster's nine Merlin ...
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A question about Nozzle/Extension/Skirt Size

In many rocket engines i see that the thrust chamber and a small part of the nozzle are one piece. Does anyone knows if there's a formula which determines what portion of the nozzle is A ? and how ...
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Difference between 2 pumps on same shaft run by a turbo pump and 2 pumps run on separate turbopumps

So i was trying to understand the working of the Full Flow Staged Combustion cycle(FFSC) and was comparing it to the Staged Combustion Cycle(SC) and Closed Combustion Cycle(CCC) a question came up in ...
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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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What is the Isp of gunpowder likely to be? Could this table be right? Can it even be determined?

There are some unsourced refutations of the value for the Isp of gunpowder in the table shown below can be found under What kind of engine does this Isp = 1600 refer to? Is it cubesat-friendly? Alas ...
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Why is the flame color from the New Shepard engine orange?

New Shepard is described as using liquid oxygen and liquid hydrogen for its propellants. When hydrogen and oxygen burn, as in the Space Shuttle main engines, there is a short conical blue flame, ...
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Are the (relatively) new "all electric" satellite buses like the Boeing 702SP really all-electric? Are RCS and momentum unloading done with ions?

This answer to Can ion Thrusters be used for Reaction Control System? got me thinking about the new "all-electric" class of commercial satellite buses. Question: Are the (relatively) new &...
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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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Rocket propulsion question help

I've attempted this question but once again got this wrong. Here is what I did I knew that the thrust equation was mass flow * (Vj - V0). I also knew that the mass ...
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What makes CAPSTONE-1's eight hydrazine thrusters so "super small, high-performance"? How do they work without any tank pressurization?

The NASA Ames Feature Innovative Propulsion System Gets Ready to Help Study Moon Orbit for Artemis says: CAPSTONE’s journey to the Moon will take about three months, starting with its launch to low-...
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Has Demonstrator-1 2021-006BX demonstrated a hydrogen-oxygen combustion engine fueled by electrolysis yet?

NASA's NASA CubeSat to Demonstrate Water-Fueled Moves in Space says: A NASA CubeSat will launch into low-Earth orbit to demonstrate a new type of propulsion system. Carrying a pint of liquid water as ...
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Technical feasibility of using Raptor engines for Vulcan rocket

According to a recent GAO report (p. 116), ULA's Vulcan rocket's BE-4 engines are "experiencing technical challenges" and there is some concern whether they will be ready / certified in time ...
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If building a liquid propellant rocket engine, with bi propellants, how does the dimensions of my Combustion chamber, affect the efficiency?

If building a liquid propellant rocket engine, with bi propellants, how does the dimensions of my Combustion chamber, affect the efficiency ? but also what is the best C* dimensions for an earth sea ...
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Can "engine" and "motor" be used interchangeably in spaceflight? Are there any cases where they can't be?

Typing "rocket motor" into google returns a page full of links mostly about rocket engines. It seems that The Google has AI-synonymized them. Question: Can "engine" and "motor&...
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What are the various ways that rockets measure the instantaneous thrust of each engine?

@DavidHammen's answer to Engine failure: how to detect? mentions thruster sensors. This intrigued me and so I thought I'd ask about how this is done. Thrust is a critical parameter to know in real ...
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What expansion ratio is the best for mars surface level engines?

What expansion ratio is the best for mars surface level engines? For launches from Earth, first stage nozzles are much shorter than second stage nozzles because of Earth's high sea-level pressure. For ...
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What was the volume of the Rocketdyne F-1 engine's main combustion chamber?

In the specifications of the F-1 available online, I can find its dimensions, weight, thrust, etc. but I couldn't find what was the volume of its main combustion chamber. Is this information available?...
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Conversion of heat into electricity in rocket nozzles

Can we use advanced thermoelectric materials to reduce the temperature of nozzles by converting heat energy to electric energy and reducing the strain on the nozzle material and the coolant while ...
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How could I find the pressure and/or the Isp at the exit of a rocket nozzle if I have data for the throat and comb. chamber?

I've been looking at this for some time and working with CEA which will only give me data points for the pressure, temperature, Isp, etc. for the Injection, Combustion Chamber End, and the Throat; but ...
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Are the engines present on the SpaceX Starship Sea level engines or Vacuum engines?

The SpaceX Starship will have engines that light up in space and propel the ship to Mars. Companies and organizations use vacuum engines in space. However, Starship has to land on Mars, travel back ...
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Why does the RD-0110 Injector have a larger cone spray angle in the outer element rather than the inner element?

Wouldn't a large cone spray angle in the inner element (oxidizer) impinge with the outer element spray cone (fuel) and facilitate better atomization and mixing? Here are the RD-0110 Injector specs:
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Hypergolic Engine Diagram

Does anyone have any hypergolic rocket engine diagrams, preferably labeled but it's fine if they aren't? Thanks!
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Engine thrust gain with altitude [duplicate]

As you climb at launch, atmospheric pressure falls, causing thrust to rise. The thrust gain I'm talking about here is due to the increased ratio of nozzle pressure to atmospheric pressure. I'm going ...
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Open source liquid rocket engine

Is there an open source bi-propelant liquid rocket engine that would have all the documentation, computations, test results and 3D design files (CAD) freely accessible?
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Highest Isp achieved with nitrous oxide as oxidizer

What is the highest Isp achieved on orbital rocket for an engine that used nitrous oxide as oxidizer? Both hybrid and liquid engines can be considered. Not considering nitrous oxide monopropellant ...
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Is it possible to launch a rocket with steam by using a fission reactor?

The idea is to use a fission reactor to turn water into steam pumping it outside the reaction chamber through heat pipes.
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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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Attitude control with cold gas thrusters

Consider the cold gas thrusters on a Falcon 9. There are two thruster pods on stage 1 and two on stage 2. Each pod has four orifices to fire along the x, y, and z axes of the scacecraft. By varying ...
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Cooling the nozzle extension of a nuclear salt water rocket (NSWR)

The nuclear salt water rocket(NSWR) uses a plutonium salt (at least to my understanding) dissolved in water as its fuel. The mixture is kept stable by filling the fuel tank with boron carbide, which ...
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Why are the rocket plumes on SN10 different colors?

At about 7:53 (T+2:30) in this official video of the SpaceX Starship SN10 test flight, the engines are shown in the lower right, with clearly different colors in the plumes. The one on the right is ...
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Why are Starship's tanks curved the way they are?

Since Starship has to feed its engines in two kind of situations : -during ascent, acceleration is colinear to Starship's longitudinal axis. -at the end of the belly dive, acceleration is normal to ...
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Can Falcon 9's engines be ignited more than 4 times if there is enough TEA-TEB?

SpaceX's Falcon 9 uses TEA-TEB as a ignitor for its Merlin engines. My question is if the rocket has more TEA-TEB, can the engine be shut down and restarted more than 4 times?
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Can nuclear thermal engine designs be shutdown in such a way as to be restartable, in space?

Nuclear thermal rocket designs have a working temperature of 2000k or greater. Shutting such a reactor down won't stop that heat production instantly - it'll take quite some time to cool. Do current ...
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Are nuclear thermal engine designs limited to about twice the Isp of existing chemical rocket engines? If so, why; what's the limiting factor?

Discussion below With Ultra Safe Nuclear engines and hydrogen propellant, how far to Mars could you get and still be able to return to Earth in an emergency? including a comment that suggests that the ...
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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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Solid state thrust vectoring

Usually thrust vectoring for the whole rocket is done by changing the orientation of individual engine(s) by hydraulic/electric actuators. So in this system the engine simply moves and with it the ...
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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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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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Why are rocket engines shaped like a bell rather than a gun barrel? [duplicate]

When blasting matter out of a spacecraft engine for thrust, it seems like you'd want as much velocity in one direction as possible. Why do spacecraft engines (e.g., Apollo CSM) have big bell-shaped ...
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Sources for values for realistic thrust calculation exercise?

I want to use this simplified equation to calculate the thrust of multiple different real engines: $$F = \dot{m} V_e + (p_e - p_0) A_e$$ Source: https://www.grc.nasa.gov/www/k-12/airplane/rockth....
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What is this ring-shaped part falling from Starship SN9 after launch?

The picture shown is a screenshot during the recent launch of SpaceX's SN9 from a live stream, and I noticed that a black ring fell off the exhaust/engine. It only shows up for around a frame or two ...
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Could New Horizons' thrusters' ISP be as low as 157 sec?

A discussion below How much of a deep space spacecraft's structural mass is useless dead weight after launch? Any plans to shed it in the future? has lead to https://nssdc.gsfc.nasa.gov/nmc/...
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How many ion thrusters would be needed to accelerate a 1000 tonne craft at 9.8m/s²?

If we assembled an array of today's best ion thrusters in orbit, (the x3?) how many would be needed to accelerate a 1000 tonne spacecraft at 1g? I'm thinking Space Tug, for repeated Mars missions. ...
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Rocket engine with lowest Isp to reach orbit

Which engine with the lowest possible specific impulse has reached orbit propelling a given rocket? There is a page at Wikipedia that compares orbital engines but some engines are missing Isp value ...
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How can firing a Space Shuttle OMS engine below 21 km cause its nozzle to "collapse"?

This answer to Can the space shuttle use OMS engines during landing? says: No and quotes Section 3.7 of the Orbital Maneuvering System Workbook; OMS 21002 October 10, 2006, Final version, USA006500 ...
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How do pressure-fed engines stay cool?

Does anyone know how pressure-fed/hypergolic rocket engines cool themselves down? Do they regenerativly cool themselves? Thanks!
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Are there any hand-sized rocket engines?

Are there any rocket engines that are small and light enough to be held in one or both hands? Gas, liquid and hybrid designs are fine but solid motors are excluded (with the exception of solids that ...
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What happens to ablative nozzles after a test fire?

For example RS-68 engine If you make a test fire of an ablative nozzle engine then the fire will consume the coating of that nozzle. That means you have to replace the coating or the entire nozzle. ...

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