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Questions tagged [restartable-engine]

A rocket engine, or other impulse engine, which is designed to be fired more than once.

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Why didn’t the space shuttle’s engine-out checklists include steps for attempting a relight?

Throughout much of a space shuttle ascent, even a single SSME failure would have left the mission’s intended orbit out of reach and forced some sort of abort; a two-SSME-out situation would have left ...
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How do you read an Engine Throttling specification of 3-5:1 in percent thrust load?

I was looking at the CECE engine by Aerojet, however I am not sure how to determine the trust range of percent thrust range of the engine. How I can translate the throttling spec into a percent load ...
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Is there an upper stage main engine that is human ratable and may out perform the Common Extensible Cyrogenic Engine performance by Aerojet?

I am fasinated by Aerojet. The CECE, has a total qualified burn time of 10,000 seconds and with a total of 50 restarts. The LOX/LH2 engines have a great performance with a specific impulse of > 445. ...
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Chilling during restart of Spacex first stage engine [duplicate]

As I know that all the liquid rocket engines go through chilling process for different components (like pipes, engine, injector plate, etc.) before starting the ignition. At the time of launch the ...
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169 views

How long does Augmented Spark Igniter fire?

The heroicrelics.org page J-2 Rocket Engine Augmented Spark Igniter mentions that The ASI operates continuously during entire engine firing Does this how all spark igniters function in rocket ...
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198 views

How is a spark plug igniter of rocket different from one used in IC engines?

US20120103302 shows a spark ignited prechamber combustion system typically used for IC engines. It basically consists of a chamber which has a input of premixed fuel-air mixture and a spark plug to ...
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269 views

Which is the preferred mode of liquid rocket engine cutoff - fuel lean cutoff or fuel rich cutoff?

When a bi-propellant liquid rocket engine receives a command to shut down, will the fuel gets cut off first and then the oxidiser - a fuel lean cutoff? Will the oxidiser gets cut off first and then ...
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When this F9 2nd stage engine suddenly moves upon shutdown, is it moving along the rocket's axis?

The GIFs are made from frames of the live broadcast of SpaceX JCSat-16 2nd stage around the time of the second engine cut-off (SECO-2). It looks like the engine moves outward axially as the thrust ...
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Have reliable, restartable LH2/LOX engines ever existed? - ever used? [duplicate]

I just wrote the following paragraph as an edit to this answer: Using LH2 for regular burns to maintain ISS altitude would require a whole new set of engines that may not yet exist anywhere. While ...
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What ever happened to SpinSat - did it work?

I can find several descriptions of what the SpinSat satellite was supposed to do. I can find some nice images of it being deployed from the ISS also. But I haven't been so successful in understanding ...
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How does an Electric Solid Propellant rocket work?

I saw the section in Wikipedia about Electric Solid propellants but I can't figure out what it really is, and how it works. It sounds like a solid propellant rocket that you can start and stop ...
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Why is TEA-TEB chemical ignition used instead of spark ignition?

Both the Saturn V and the Falcon 9 use TEA-TEB to ignite their kerosene-fueled engines. TEA-TEB is pyrophoric, igniting spontaneously on contact with air. This poses handling issues; it must be stored ...
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What causes the green flash during Falcon 9's ignition?

Right before Falcon 9's engines start, there's a green flash. I assume it's some kind of chemical ignition. What makes the flash the color green?
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Why were there green ignition flashes after Falcon 9's landing?

Whenever Falcon 9's engines start, there's a green ignition flash. During the latest landing there were similar green flashes right after touchdown: 1st stage landing (3 camera angles): ...
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How often can liquid hydrogen engines be restarted?

A proposal for lunar development, LunarCOTS, relies on a reusable shuttle running on LH2 and LOX to work. It lands, is refueled on the lunar surface, and then takes off again. Presumably it could sit ...
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What limits the number of times that a liquid fueled rocket can restart?

I know the upper stage of the Falcon 9 can be restarted once, thus allowing an additional thrust for some circumstances that might require it. However, I don't really understand the mechanism that ...
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Practical limits to a restarting a main rocket engine in orbit? [duplicate]

With current technologies, are there practical limits on the number of times a rocket engine can be restarted while still remaining in orbit? Given sufficient fuel, could an engine be designed today ...