Questions tagged [engine-design]
Questions regarding the design or design process for a propulsion system.
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Why is SpaceX considering Methane as fuel for their next engine, the Raptor?
Currently, SpaceX has developed the Merlin 1 family (1B (Falcon 1), 1C (Falcon 9 v1.0), 1D (Falcon 9 v1.1/F9-R/Falcon Heavy), vacuum versions and sealevel versions) which are LOX/RP1 based. (75-...
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Why did it take so long for methane to be used as a rocket propellant?
SpaceX have put methane on the map as a rocket fuel, but they weren't the first to consider its use. The first experiments in building a rocket engine that uses methane date back to 2007.
Now methane ...
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Why did the Soviet Union decide to use 30 small engines instead of a few large ones on the N1?
The N1 was a big disappointment after exploding on every single launch attempt. From what I have read, it seems like most of the attempts went wrong because one of the 30 engines exploded causing a ...
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Why are rocket engines operating above 100% often considered nominal?
It was brought to the attention of the community that right before the crash of Antares the commentator noted:
"Main engines at 108%"
It was noted that other engines were also reported to work at ...
user54
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Why do rocket nozzles flare?
Why do rocket nozzles open wider at the end than, let's say, get narrower?
Let me explain:
A jet engine works by having this amazing thing called a combustion chamber. The combustion chamber ignites ...
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Why are Rocket engines at the base of the rocket?
I don't know much about Rockets, but all that I have seen, from the Saturn V to SpaceX's Falcon 9 have the engine at the bottom. Doesn't this make the Rocket really unstable, like balancing a pencil ...
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Is it common and good engineering for a pair of cables to be easily plugged into each other's connectors in modern spacecraft
Space News's Human error blamed for Vega launch failure
Analysis of the telemetry from the mission, along with data from the production of the vehicle, led them to conclude that cables to two thrust ...
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Why doesn't the US use European rocket engines?
US Companies have been using Russian rocket engines for their rockets for a long time, even during sanctions. But as I was going through the European rocket launches, I felt European rocket engines ...
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Why cool engines with fuel as opposed to oxidizer?
As I was watching Tom Mueller describe the Merlin engine, he said that the RP-1 propellant is pumped through ribs in the nozzle to regeneratively cool the engine. Also, a video about Copenhagen ...
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Would a grinding machine be a simple and workable propulsion system for an interplanetary spacecraft?
I am wondering if any space agency has ever considered using a grinding machine as a propulsion system for an interplanetary spacecraft. This system would not be used to lift the spacecraft off of a ...
user28781
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Why aren't linear aerospike engines in common use?
Linear aerospike engines are an old idea that seem so full of promise. Why are they not widely used today by the likes of Boeing, SpaceX, etc.?
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How realistic would the Sea Dragon engine be to produce given today's technology?
Just learned of the Sea Dragon proposal from back in 1962. From the Wikipedia entry
The first stage was to be powered by a single enormous 80,000,000 pounds-force (360 MN) thrust engine burning RP-...
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Does the NK-33 engine require subcooled kerosene so cold that it turns to wax?
It was mentioned in this answer and in several other places on the internet that the kerosene fuel used by NK-33 engines needed to be subcooled enough so that it reached the same density as the LOX, ...
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What is a "Major Component Failure" referred to in news reports about the unsuccessful Space Launch System core stage test firing?
In reporting about the unsuccessful green run of the SLS core stage, Ars Technica mentions
About 50 seconds into what was supposed to be an 8-minute test firing, the flight control center called out, ...
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Why do pressure fed engines have combustion instabilities?
Reading about the Sea Dragon idea, I came upon this argument against it, which sounds compelling, but relies on more detailed knowledge than I have:
Those are to be pressure-fed to avoid "...
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What's so special about SpaceX's Raptor rocket engine with 300 Bar chamber pressure?
What allows the Raptor engine to have a high chamber pressure of 300 Bar? Compared to other rocket engines which have been or that are now operational, it has the highest chamber pressure. What does ...
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Why is the SABRE engine curved?
Why is the Reaction Engines Limited SABRE (Synergistic Air-Breathing Rocket Engine) curved along it's length?
Illustration of the SABRE engine with the pre-cooler heat ...
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If rocket engines only need fuel and oxidizer, then why there are so many pipe lines on the engines?
If fuel and oxidizer are pumped by turbines to the combustion chamber, then why there are so many pipes around? It should only have a two-cylinder shaped turbine assembly. I doubt there are other ...
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Are nuclear-powered engines the way to go for space exploration?
I often think about the future of humanity and how to achieve it. Despite criticism, the USA and USSR achieved significant scientific breakthroughs, such as:
putting the first man in space
landing ...
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Can ion thrusters be scaled up?
All ion thrusters are quite small. Having read through the more approachable information about them, as they use physics pretty beyond me, I don't understand what it is about them that makes it ...
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Could a rocket engine be designed to use different fuels? (Like LOX+H2, LOX+CH4)
I'm obviously not a rocket scientist, so this might rank among the stoopidest questions around here. I wonder if it is feasible to design a rocket engine which could be reused in space by refilling it ...
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Was the third shuttle engine any different from the others?
The space shuttle used three SSME, organized in a triangle with two next to each other closest to the external tank, and one on top of those. I am pretty sure the first two engines were close to ...
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Performance of a pumpless liquid rocket engine
Basically all rockets that I know of have a pump feeding fuel and oxidiser into the combustion chamber. The turbopump is one of the most complicated and expensive components of the entire rocket. If a ...
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Why is the Russian approach to the aerodynamics of their rockets different?
Russian rockets look like this:
They flare them out at the bottom. With their newest rocket, the Proton, the flared shape is gone but the boosters still have caps that angle in towards the main ...
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Why the non-symmetric design of rocket nozzles?
Although I have seen many perfectly symmetric nozzles, I have also seen designs such as this (Virgin Galactic) which is only symmetrical about one axis:
Why is this?
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Why design new rocket engines instead of using the existing types?
Already in the 1960s rocket engines seem to have achieved near maximum chemical efficiency. What are the reasons for new designs being in demand?
How much better could a new engine design be than the ...
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Is it always one nozzle per combustion chamber and one combustion chamber per nozzle?
When I read about engines like the RD-170 they might have a single turbopump feeding multiple combustion chambers, and each combustion chamber has its own nozzle. Is there, or would it be reasonable ...
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Why aren't expander cycle engines used on lower stages?
Looking at the simplicity of BE-7, I was wondering why dual closed expander cycle engines are not used more commonly and, as far as I know, are not used as lower stage engines at all.
A commonly ...
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How do you confirm ignition in the combustion chamber of a rocket?
Is ignition confirmed using a temperature sensor, pressure sensor or another device?
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What is an "exhausterator" and what does it do?
I laughed when I first saw the word "exhausterator" mentioned, I scratched my head when I saw it the second time, and I came here after the third.
Besides making me feel like maybe technobabble isn't ...
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At what travel distances are ion engines faster and more efficient than conventional fuel engines?
According to Scientific American (February 2009), ion engines start off slow, but build up speed as they travel. At what travel distance would an ion engine (such as an ion thruster, a Hall thruster, ...
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What are the advantages of Ox-rich staged combustion?
In the context of staged combustion, I understand that burning ox-rich creates complications associated with having hot, high pressure, oxidizer. Some engines, notably the RD-170 and RD-180 family run ...
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Pumped propellant propulsion - is it viable?
A recent article on Slashdot got me thinking.
While the article is about using electric turbopumps for moving fuel from tanks to engines during launch phase and is just a small, incremental ...
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Using nuclear detonations for propulsion
The proposed orion propulsion system used nuclear explosions to push against a giant shock absorber and propell it, but from my understanding, nuclear explosions only produce heat and rely on the ...
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Benefit of Raptor Engines
I know that the Raptor engines are significantly different from the Merlin 1-D's since they use liquid methane and are cryogenic. However, what exactly enables the Raptor engines to produce a lot more ...
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What NASA documents did SpaceX use to design their engines?
I've watched this (excellent) panel discussion titled 'Our Future in Space'. Bill Nye says at 22:48 that SpaceX got their engine design from work done by NASA, which they developed into a working ...
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Why was the Apollo CM main engine thought to be unreliable on Apollo 13?
When Apollo 13 had most of its internal systems destroyed by an explosion, NASA decided that the best course of action would be to fire the main engine on the dark side of the moon to send the capsule ...
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Why was the NERVA program dropped?
At the very end, NERVA (Nuclear Engine for Rocket Vehicle Application) had developed nearly flight-ready engines able to:
operate for periods in excess of an hour while providing maximum thrust up to ...
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Is there any rule for rocket engine nozzle proximity from each other?
I wonder if there is any rule for how closely you can put engine nozzles to each other. Are there any vibration, heat, etc. constraints when you are assembling two or more engine bells together?
...
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Changes made to ISRO GSLV-D5's CUS and FBTP since GSLV-D3's LH2/LOX CUS failure to sustain ignition?
The launch of the ISRO GSLV-D5 launching India's GSAT 14 advanced communications satellite (weighing 1,980 kg) is slated for 19th of August, 2013, flying in the GSLV Mk.2 configuration with an Indian-...
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Have Air-breathing Engines ever been used on a reentry vehicle, could they be?
For the purpose of this question I would like to assume there is no risk of life for the astronauts, or that the design would only be used for delivery of a non-ethically-sensitive payload. Looking at ...
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Why can solid rockets be both the skinniest and most spherical launch vehicles while liquid fuel rockets have a more limited range of aspect ratios?
Question: Why can solid rockets be both the skinniest and most spherical launch vehicles while liquid fuel rockets have a more limited range of aspect ratios? Are there fundamental engineering ...
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What are the consequences of NASA validating this "impossible" space drive?
A British inventor invented an engine that can provide thrust in outer space without a propellant. This engine has been tested by a Chinese team, and more recently by NASA:
The engine itself is The ...
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Did any rockets use differential throttling instead of gimbal?
It seems the standard approach to control of rockets during launch is either vernier thrusters, or gimbals on the main engines. Sure that works, and is quite efficient, but I wonder about a simpler ...
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Is the concept of the Epstein Drive based on actual theorized scientific research which is considered plausable?
I've always found it interesting when we see real life taking its cues from fictional arts, especially when it comes to Science Fiction technology. There are plenty of examples of classic books, TV ...
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What is that second (smoke) exhaust on a rocket engine for?
In this video of a Korea Aerospace Research Institute (KARI) rocket engine test, you can clearly see a second exhaust where thick smoke comes out.
Is this an essential part of the engine, or just an ...
user10509
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Efficient types of nozzles used in rockets
Is there any other type of nozzle other than common convergent-divergent nozzle (see picture below) which is used in many rockets?
...
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Why did each F-1 engine have dual fuel feedlines?
Each F-1 engine had two fuel feedlines connecting it to the fuel tank as shown in these contemporary photographs and drawings.
The corresponding LOX system only had one feedline.
The engine had a ...
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Disposition of the Oxidizer Tank in Rockets with Autogenous Pressurization
A little while ago, Ars Technica did a big story on the Firefly rocket under development.
http://arstechnica.com/science/2014/11/firefly-space-systems-charges-full-speed-toward-low-earth-orbit/2/
A ...
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Are MMH and UDMH interchangeable?
Can Monomethylhydrazine and Unsymmetrical dimethylhydrazine be used one in place of another for the class of the existing orbital maneuver engines (with reduced performance may be)? Such as Shuttle's ...
user54