Questions tagged [merlin-1d]
Questions about the SpaceX produced Merlin-1D engine, used by the Falcon rocket.
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What does "pogo bleed" entail?
At around T-3:00 on every Falcon 9 countdown, we hear the following:
Stage 1 pogo bleed verification
I assume they are referring to pogo oscillation, but what exactly does "pogo bleed" ...
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What is the reliability of the Merlin engine?
I know that Merlin is extremely reliable, at least over 99%. I do know of one time when one failed, on Falcon 9's fourth launch. SpaceX had used hundreds, if not thousands, of them. I assume there is ...
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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 ...
user39728
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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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How hot do rocket engine nozzles get?
What temperatures are encountered by the nozzles of rocket engines like those in SpaceX's Merlin series? Radiative or regenerative cooling, atmosphere or vacuum.
There's plenty of info about exhaust ...
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How much of the Merlin engine is made by 3D printing? [duplicate]
How much of the Merlin engine is made by 3D printing?
Is the nozzle, the valve, the combustion chamber? How about turbo pumps?
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How many parts does a Merlin engine have? And how many of them are made using 3D printing?
Simple question: how many parts is the SpaceX Merlin engine made of?
Individual pieces that can be disassembled and put on a table separately.
And how many of them are made using 3D printing?
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Falcon 9 Merlin 1d thrust calculated through every moment of flight
I am currently trying to recreate the launch of falcon 9 in unity. For the calculations I need the thrust of the first stage (only doing it for one stage for now).
How to calculate it depending on the ...
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Merlin combustion chamber pressure
What is the combustion chamber pressure for Merlin?
I mean the average and the maximum
The Raptor engine was tested with a maximum 330 bar. I would like to compare them
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Is this soot building up on the Falcon 9 interstage?
In the below video of stage separation during Falcon 9's CRS-19 mission, the exhaust of Stage 2's Merlin 1D-Vac impinges on the interstage. It also deposits a black substance on the white paint.
Is ...
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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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From what material and how are the Merlin engines and nozzles of it (sea level) manufactured?
I am specifically interested in the alloy used to build the engine, also about the nozzle: Is it just in one piece or welded using different sections. If they are welded then which welding techniques ...
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Why are the Falcon 9 Stage-1 engines placed with offsets in the octaweb compartments?
Pictures of the octaweb show that the engines are not placed at the center of each octaweb compartment---they are closer to one side than to the other.
See the picture below for an example. Focus on ...
user36480
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What is the function of this Merlin engine's tube, and why is it getting red hot?
In the video of the recent SpaceX Starlink launch, one view of the Falcon-9 2nd stage engine shows a cane-shaped tube that glows red hot at the "handle" end and seems to get hotter over time....
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Are these two length scales in FH exhaust plumes real, understood, and distinct?
The Ars Technica article We can admit it—we’re dazzled by the controlled fury of the Falcon Heavy includes a beautiful photo of the exhaust plume produced by the 27 engines of a Falcon Heavy launch.
...
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What are these big shiny metallic "lumps" on the bottom edge of each Falcon Heavy nozzle?
What are these big shiny metallic "lumps" on the bottom edge of each nozzle of each core of this Falcon Heavy image from the Teslarati article SpaceX reveals Falcon Heavy Block 5 in first official ...
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What is the white spray-pattern residue inside these Falcon Heavy nozzles?
What is the white residue in a spray pattern seen on the inside of each nozzle of each side core of this Falcon Heavy image from the Teslarati article SpaceX reveals Falcon Heavy Block 5 in first ...
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How are 9 Merlin 1D engines packed and able to fit in a Falcon 9 FT first stage?
It was proved by Pirl in 1969 the most optimal packing of 9 circles in a larger one https://en.wikipedia.org/wiki/Circle_packing_in_a_circle. The radius of the larger circle should be ≈ 3.613r (r is ...
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The changes of a throttled Merlin-1d engine
With Merlin-1d being able to throttle down from its full thrust potential, this post about its throttle capability does not mention much of its change in performance. On the Wikipedia page of Merlin-...
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What are these flames on the Falcon 9 booster?
When Falcon 9 was on its way to ascend, flames appeared around the bottom of the booster. What are they?
It seems to begin around about 20:36 in the video, ...
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Actuators for gimbaling of engine in rockets and launch vehicles
For controlling the rockets to stay on course, continuous engine control is require which is done by using gimbal actuators.
What type of gimbal actuators have been used on SSME, Rocketlab's ...
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Why is the exhaust plume of Falcon 9 upper stage shaped the way it is?
The (single) Merlin 1D vacuum engine's exhaust plume has a symmetric shape, comprising of six distinct "inner" plumes. Why does it have this shape?
Is it due to the shape/configuration of fuel ...
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How do you shut off a Merlin-like rocket engine quickly? How quickly can it be done?
After about 36:17 in part 1 of this recording of SpaceX's Hans Koenigsmann's talk at IAC 2018, he narrates the propulsive landing of a Falcon 9 first stage, and ...
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What flame is SpaceX's Hans Koenigsmann describing in his presentation?
At 35:46 in part 1 of this recording of SpaceX's Hans Koenigsmann's talk at IAC 2018, he says something like:
The green stuff that you see is TEA-TEB, that’s the ...
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Why is Rocketlabs having lengthy combustion chamber?
Looking at different rocket engines, L/D(CC_length/CC_diameter) ratio of combustion chamber is very much less compared to Rocket labs. Even the modern age engines like Merlin 1d and Raptor engines ...
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What is the Kerosene/LOX mixture ratio of the Block 5 Falcon 9?
as the title would suggest, does anyone know a calculation or solution to finding the current mixture ratio used on the latest block 5 configuration?
This would be easier if so many people did not ...
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Does anyone know how to calculate the KG per second of RP-1 and LOX from the 9 Merlin 1D engines?
as can be seen from the title, I have been through at least 1,000 chrome tabs in the last few hours trying to find some form of definitive answer, but I've found absolutely nothing. Could anyone help ...
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Merlin 1D Engine [closed]
How does the Merlin engine work? How does it's working compare to the working of SuperDraco engine?
To be more specific,
What features of Merlin make it unique and more efficient than other rocket ...
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How did SpaceX achieve such a high Thrust to Weight ratio with the Merlin engine?
Were there specific breakthroughs which allowed SpaceX to get such an incredible thrust to weight ratio? The next closest American engine was almost twice as heavy (199 vs 82), and the next closest ...
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Why does Merlin 1D Vac turbopump drive exhaust go around the nozzle?
In Merlin 1D Vac engine:
the turbopump drive exhaust goes around the nozzle. Why is that so?
The feature also seems to be missing in the first stage engine, as seen here:
(screenshot taken from ...
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What is this jet of material spraying out from Stage 2 during the SpaceX PAZ mission?
This spray seemed to be there throughout the entirety of the Stage 2 burn but was especially visible once Stage 2 cutoff had happened.
As that nozzle uses radiant cooling, it can't be cooling fluid, ...
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SpaceX merlin engine failure
On SpaceX's website, they make a claim that their rockets are the safest and most reliable in the industry. This is because apparently it can complete its mission even if up-to two of its engines fail ...
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How do re-usable boosters handle re-entry damage? [duplicate]
Watching Falcon Heavy's side boosters land, I was amazed that they could withstand the stresses of re-entry yet still fire again for a (relatively) slow, smooth landing.
I see there are heat shields ...
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Pintle Injector Face Shut Off - Merlin
The information and schematic are from the web site Pintle Injector Blog.
A pintle injector is a variable area injector consists of a movable pintle, an annular nozzle and the central pintle nozzle. ...
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Merlin engine stoichiometry
As evidenced by the bright exhaust plume at launch, the billowing black smoke rolling out of the flame trench during static tests, the wispy grey effluent from the Merlin Vacuum engine, and the layer ...
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Where is the TEA-TEB stored for the Merlin engines onboard Falcon 9?
The Merlin 1D engines can restart up to four times, they use the pyrophoric mixture of TEA-TEB (Triethylaluminum-Triethylborane) to ignite the engines. My question is where is this stored in the ...
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What does SpaceX do with all the engines?
SpaceX has had 8 successful launches in 2016 according to a wikipedia article. The launch manifest agrees with that, but leaves out the launch pad failure.
According to another wikipedia article, ...
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What are the differences between the SpaceX Merlin 1D and 1D+ engines?
I am trying to model the Merlin 1D+ using inventor. I was wondering what the major differences between the Merlin 1D and 1D+ were. I find when I search trying to find a 1D+ engine all I come across is ...
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What material is the Merlin 1D made from?
I am working on high school presentation about rocket engine materials and I'd like to have a part about Merlin 1D engine as it is supposed to be reusable, but I can't find anything about materials ...
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GSLV MK2 vs Falcon 9 - Reasons for Huge performance difference
Yesterday ISRO operated the GSLV MK2 launch vehicle, which is a medium lift launch vehicle with a capability to lift 5 tonnes to LEO.
I just compared Falcon 9 with GSLV MK2. Falcon 9 capability to ...
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Can Falcon 9 first stage landing final burn using one, two, and three engines? Tradeoffs?
This question is about the final burn in the landing sequence of the Falcon 9 first stage return to Earth tests.
If I understand correctly, there is usually far more thrust than there is weight at ...
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If it is difficult for Merlin engine to have deeper throttling, could it be as an option a different engine at the center of the rocket?
In the landing procedure for the first stage of the Falcon 9 one concern is that :
Merlin 1D throttling at its lowest level still generates more thrust than the empty mass of the first stage. So ...
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How long does it take to chill the LOX and RP1 for Falcon 9 V1.1 Full Thrust?
The new version of the Falcon 9 v1.1 Full Thrust, or as SpaceX would like everyone to start calling it "Falcon 9", uses super cooled LOX and RP1 to improve the density of the fuel for better ...
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How many engine firings can a SpaceX Falcon handle?
For every Falcon 9 launch to date, the process has been:
Each Merlin is test fired/acceptance fired at McGregor by themselves.
The entire stage is test fired at McGregor.
The entire stage is hot ...
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How can a 9-engine Falcon rocket be cheaper than single engine rockets?
From what I understand, the engine is usually the most expensive part of each rocket, excluding payload.
I'm struggling to understand how SpaceX can have one of the cheapest launchers on the market ...
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How do the Falcon 9 engines re-ignite?
Do they use a tungsten wires or something else?
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Falcon 9 v1.1 Full Thrust Specifications
Does anyone know what the dry mass and mass ratio of the Falcon 9v1.1 Full Thrust Stage 1 is? The best info I've been able to find was by taking the specified burn time and multiplying it by the mass ...
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Falcon 9 engine ignition sequence
On the space shuttle, engine ignition was delayed for the main engines. Not all of them were started at once, presumably to avoid vibrations. How does that work for the Falcon 9? I imagine that the ...
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What are the challenges in Falcon 9 "full thrust" (v1.2) with densified propellant?
SpaceX has announced an upgrade to their Falcon 9 rocket, achieving greater thrusts with, as far as I can tell, the same rocket motors (at least, they apparently still call the motors "Merlin 1D"). ...
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