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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3
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1answer
26 views

How many hydrolox engines had a methane variant?

Russia, has developed many rocket engine concepts over the years and its noticeable that they already tried liquid methane as a propellant back in the 90s. How many of their cryogenic engines had a ...
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0answers
24 views

Are there any staged combustion cycle rocket engines under 1000 kN? Is it easier to produce larger engines with this type of engine cycle?

I found that most engines developed with staged combustion cycles are inherently quite powerful. Are there any engines which was developed with the staged combustion cycle with a thrust under 1 MN. ...
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3answers
66 views

What is the exit diameter of the LE-5B liquid hydrogen Engine used in H-II

I've found many documents that leave out the exit diameter of the LE-5B hydrolox engine. If anyone has found the detail in any public doxuments, I would appreciate it. If you can still provide the ...
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2answers
464 views

What is the difference between an engine skirt and an engine nozzle?

I have seen "engine skirt" and "engine nozzle" both used for the bell-shaped end of a rocket engine. Is there a difference?
2
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1answer
92 views

What is the plume effect?

I got introduced to the term "plume effect" in an answer I got here. A simple google search did not explain it, but from the link provided in the answer -- Space Shuttle Technical Conference Volume 1 ...
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1answer
83 views
+50

Is it possible for one to adapt engine data for different fuels wrt liquid rocket engines

Liquid Rocket engine design is quite complicated and idealised and assumed theories rarely get sufficient validation. In an effort to verify/validate newer/untested fuels to be used in engine designs, ...
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0answers
27 views

What impacts do the rocket engine cycles have on the sizing of the components and effectively the engine?

For a given performance requirement, combustion pressure, propellant mixture, etc. How can one vary between the various engine power cycles such as gas generator, staged combustion, expander, and how ...
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1answer
104 views

What parameters drive the development effort and cost of a liquid rocket engine for orbital launchers(LEO - GEO)?

The development cost for a rocket engine drives the cost for a launcher and can be attributed to some basic parameters Apart from the few below, what others may be critical to developing and designing ...
5
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1answer
160 views

What are some of the important parameters to scaling a liquid rocket engine

Liquid Rocket Engines can be clustered together on a stage but their performance, weight and size largely decide and constrain the design of the launcher. Data on the newer smaller launcher engines ...
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1answer
67 views

Are there any other examples of right-angle exhaust diverters?

The Scott Manley video The Only Pilot to Shoot Down A Spacecraft - A Space Ace talks about the ASM-135 ASAT and its successful test launched from an F-15. He shows images from the page The F-15 ASAT ...
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1answer
96 views

Kerosene engine film cooling

So it is clear that kerosene fueled engines use two fluids for film cooling via injection in the combustion chamber, throat, or nozzle. (That is "true film cooling" and not just a fuel rich outer ring ...
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2answers
91 views

Whats the difference between cryogenic and cryo storable rocket engines

I've read about cryogenic storable liquid rocket engine but since it doesn't refer to its fuel, I want to understand the difference between a cryogenic and a cryo-storable engine. The term cryo-...
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1answer
80 views

Where are the 6 22-N OSIRIS-REx engines?

Does anyone could link an image/3D model/photo that shows the 6 22-N engines? Related question: OSIRIS-REx engines location.
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1answer
112 views

OSIRIS-REx engines location

I'm trying to locate all the OSIRIS-REx engines. Here: http://spaceflight101.com/osiris-rex/osiris-rex-spacecraft-overview/ (Propulsion System) I read that there are: 4 x 275 N, 6 x 22 N, 16 x 4.5 N ...
6
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1answer
769 views

What is the status of the F-1B engine development?

In this article https://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ and in several answers on this site a modernized F-1 engine is ...
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2answers
104 views

What factors determine the altitude at which rocket exhaust plumes start blooming hugely?

The images below are from a much larger set of photos in Spaceflight Now's August 8, 2019 article Photos: Atlas 5 paints the sky with spectacular sunrise launch. They show several effects related to ...
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2answers
115 views

How does a Hall effect ion thruster have a sea-level Isp of 800? Operates at 1 atmosphere?

Astronatix's SPT-100 lists the following: Stechkin electric rocket engine. Used on Meteor and Gals satellites. In Production. 1.35 kW Hall thruster. Thrust variable 2 to 20 kgf. ...
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0answers
36 views

How does a “hybrid orbital raising system” based on R-4D (N2O4/MMH) + SPT-100 (Hall effect) work exactly? (Intelsat 38 & 39)

Astronatix's Intelsat 39 lists the two engines SPT-100 Stechkin 1.35 kW Hall thruster. R-4D Marquardt N2O4/MMH rocket engine. 490 N. Question: Why is this combination on Intelsat 39 called "hybrid" ...
3
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1answer
119 views

How was sky crane (used on Mars Science Laboratory's Curiosity) tested?

This is sky crane: Mars has 1/3 of Earth's gravity, so how was sky crane tested on Earth? Did they even test it at all? Did they repeatedly do the math, and make sure everything works so that they ...
6
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1answer
159 views

Does central Merlin have a different specific impulse?

On a Falcon 9 booster, does the central engine experience unique variations of its ISP due to its plume bordering the eight other plumes? If there is any influence, how does the ambient relative ...
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1answer
553 views

Does static fire reduce reliability?

I do understand that static fire helps discovering malfunctions, as explained in this answer. A launch exerts an important stress on rockets' engines (high temperature and pressure, vibrations,...) ...
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1answer
495 views

What is the job of the acoustic cavities inside the main combustion chamber?

I am new to rocket engines. I was looking at an image of RS-25 engine's MCC and found these acoustic cavities, and I want to know how they work. Can somebody please explain their working principle? ...
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2answers
631 views

Compressed gas thruster for an orbital launch vehicle?

Is it possible for a compressed gas thruster to be used to launch a spacecraft into orbit? Let's say, it's already moving at 250MPH(111.7 meters/second) relative to the planets surface. Planets ...
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2answers
97 views

Would a nuclear turbojet with a chemical afterburner be a suitable intermediate between a pure nuclear turbojet and a nuclear thermal rocket?

NOTE: This is not the place to question the fundamental veracity of nuclear propulsion in aircraft and spacecraft. For context, in a spaceplane, the higher speeds you can attain under air-breathing ...
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1answer
160 views

Are there any rocket engines in current or former use that aren’t normally restarted in flight, but have the capability for an emergency restart?

(Inspired by my earlier question about restarting a flamed-out RS-25 SSME in flight.) Most rocket engines are not designed to be lit more than once.1 Most first-stage rocket engines, for that matter,...
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1answer
117 views

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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2answers
76 views

Oxidizer Line Pressure of DIY Hybrid Rocket Engine Limits Thrust?

So I’ve seen engines like these which use gaseous oxygen as an oxidizer and then a solid tube as a fuel. But do these types of hybrid engines have any possibility of creating a useful amount of thrust?...
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2answers
163 views

Why did the manned Mercury-Redstone flights carry and use retrorockets?

The Mercury-Redstone programme, a subset of the Mercury human spaceflight programme, used a modified version of the Redstone missile for suborbital flights in space. It culminated in two manned ...
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2answers
94 views

Apollo CSM RCS maximum number of simultaneously active engines?

Reading the RCS subsystem manual, it seems like each RCS quad of the Apollo SM consisted of four hypergolic engines. Am I correct in saying that all four engines of each of the four quads could be ...
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1answer
64 views

Apollo CSM mass, inertia and RCS parameters?

Is there a document specifying the total mass, the 3-by-3 inertia tensor of the Apollo CSM assembly, as well as the geometry of the service module and command module RCS assemblies (in other words, ...
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2answers
1k views

Why could the Lunar Ascent Engine be used only once?

The Lunar Ascent Engine was used during the Apollo missions to ascent from the lunar surface back to the Command and Service Module. There was one risky aspect of that engine: it was not possible to ...
3
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1answer
113 views

Does engine purging cause dry run of turbo pump in a liquid rocket engine? If it occurs, what is the implication?

Does engine purging in a liquid rocket engine cause dry run of the turbopump? If so, does that have any implication for the design, health, maintenance, or operation of the pump? How do we calculate ...
3
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1answer
104 views

Can the ISS boost maneuver engine be heard by the astronauts on board?

In the extremely cool demonstration video Demonstration of Acceleration Inside the International Space Station During a Reboost ISS Expedition 22 Commander Jeffry Williams says near the end at ...
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3answers
791 views

Why doesn't Rocket Lab use a solid stage?

I was just reading about the Scout, an all-solid rocket, and thought of Rocket Lab's Electron, which seems to have a similar mission of deploying small payloads to orbit. I understand the engines to ...
2
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1answer
129 views

What kind of methane-fueled rocket engines exist?

I have heard of methane being a strong contender for Mars and beyond. Methane is a cryogenic fuel and is said to have a high specific impulse, and work with closed- and open-expander cycles. I have ...
8
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1answer
303 views

Why don't all SSME turbopumps gimbal with the engine?

The SSME low-pressure pumps (both fuel and oxidizer) are mounted to the vehicle structure and don't gimbal. The high-pressure pumps are gimbaling with the engine, so the propellant lines between low-...
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2answers
1k views

Why does the Superdraco exhaust seem so under-expanded in this photo?

The Ars Technica articles From zero to 100mph in 1.2 seconds, the SuperDraco thruster delivers Dragon was destroyed just before the firing of its SuperDraco thrusters both include this "file photo" ...
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6answers
9k views

Why aren't air breathing engines used as small first stages?

I am wondering why we don't use jet engines as first stages. Most small rockets, like the Electron, can lift off with a small thrust. In the Electron's case, 192 kN. Why can't we replace the 9 ...
7
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1answer
287 views

Are turbopumps lubricated?

It is easy to find data about rocket engine propellant, but quite difficult to find information about other fluids used in rocket engine. For engine using a turbopump, this pump turns at quite high ...
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1answer
106 views

What is the O/F mixture ratio and the ISP for the SuperDraco Engine by SpaceX?

Is it safe to assume a mixture ratio of 2.16 with an ISP of 313 s for the NTO/MMH, SuperDraco Engine manufactured by SpaceX? I am referencing the 2.16 propellant mixture ratio, and estimating or ...
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1answer
184 views

Could this satellite wobble in orbit creating additional orbital angular momentum?

This question asks if this type of steam engine would work: Could a steam Engine outperform other electric producing devices in space? this not a sterling engine since it has far less moving parts. ...
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2answers
153 views

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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3answers
224 views

How much of the exhaust speed is due to combustion and how much is due to the injection?

The thrust $F$ of a rocket engine is given by $$F=\dot{m}v$$ where $\dot{m}$ is the mass flow and $v$ is the exhaust speed. Now the first factor, $\dot{m}$, is almost entirely due to the turbo pumps (...
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1answer
119 views

Could rockets benefit from Reaction Engine's Air-Breathing Rocket Engine in terms of payload?

While I get that one is a vertically launched rocket and the other is a space plane, is it even wildly possible that there could be a vertical intake version of the SABRE engine? Maybe it can be used ...
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0answers
214 views

Could a steam Engine outperform other electric producing devices in space? [closed]

What would be the Specific Impulse of a steam-based propulsion system like this model in space? Are there any types of engine that works this way? Could 2 tanks be designed to rotate slowly in space ...
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1answer
81 views

What types of engines are able to go from Earth orbit to Martian orbit? [closed]

What engine is the most efficient in fuel and/or time to go from Earth orbit to Mars orbit and back again that are not capable of launching from the ground?
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1answer
140 views

Is there any combustion chamber and nozzle cooled with liquid oxygen instead of fuel?

There are many rocket engines for liquid propellants which use the fuel (rocket petrol or liquid hydrogen for instance) to cool the walls of the combustion chamber and the nozzle. But are there any ...
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0answers
130 views

Why does Orion's Jettison Motor, have four nozzles but eight Attitude Control Motors arranged in an octagon?

Spaceflight 101's Orion Spacecraft Overview shows the following tests for the escape system. Why are there eight ACS thrusters arranged octagonally? Is it just to reduce cosine losses or does this ...
5
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1answer
230 views

NASA's RS-25 Engines

I am developing a FSX-based space flight simulator FSX SpacePort. I've been trying to get the detailed specs on NASA's RS-25 engine, namely, what were the ramp-up times for this engine? As in, how ...
2
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1answer
199 views

How do you determine what the temperature will be in the combustion chamber of a rocket engine?

I am guessing it is dependent on the fuel and oxidiser and the chamber pressure but is there an equation that would calculate the chamber temperature?