68
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SpaceX merlin engine failure
The Falcon 9 can shut off a faulty engine, re-configure the remaining engines (change thrust levels, vector direction) and update its flight profile in real-time. This happened on the SpaceX CRS-1 ...
- 12.6k
50
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If rocket engines only need fuel and oxidizer, then why there are so many pipe lines on the engines?
While an ideal engine would just ingest fuel and oxidizer and produce exhaust gas real world engines will have some combination of regenerative cooling, film cooling, turbine exhaust, hydraulic power, ...
- 25k
20
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How hot do rocket engine nozzles get?
Direct measurement is difficult; I've seen some optical methods used but can't put a hand on them at the moment.
Here are some calculated inner and outer wall temperatures for the Space Shuttle Main ...
- 189k
18
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SpaceX merlin engine failure
The engines can be vectored to manage this. They actually have had an engine failure and still made it to orbit in the CRS-1 mission. Note that there are some points in the mission that an engine ...
- 122k
15
votes
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Merlin engine stoichiometry
Fuel-rich operation is common in hydrocarbon engines and improves specific impulse, although there's some confusion about the mechanism by which that occurs.
According to Sutton & Biblarz' Rocket ...
- 172k
14
votes
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Why does Merlin 1D Vac turbopump drive exhaust go around the nozzle?
The turbopump exhaust in the Merlin 1D vacuum versions is directed into the nozzle where it acts as a cooling layer between the very hot chamber exhaust and the wall of the nozzle extension. The ...
- 172k
11
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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 @RussellBorogove points out in his excellent answer, Isp or "mass-specific impulse" is the number that expresses the relationship between thrust and mass flow rate.
Mass specific impulse with ...
- 151k
11
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When SpaceX claims to build 4 engines/week, which engines do they mean?
Revisiting this question 4 years later, it seems clear that while they had this estimate of the engine build rate, they did not hit it.
There was an Instagram post of the 400th completed engine Dec ...
- 80.5k
10
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What is the white spray-pattern residue inside these Falcon Heavy nozzles?
I believe it is residue from the TEA-TEB starting fluid.
Triethylaluminum combustion produces aluminum oxides, Triethylborane produces boron oxides. Both are shades of white and grey, matching the ...
- 6,417
9
votes
SpaceX merlin engine failure
Per the specs on the F9 page it has about a 1.4 to 1 thrust to weight ratio at takeoff and it goes up from there as the vehicle burns fuel getting lighter and the engines start to generate more thrust ...
- 1,196
8
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Pintle Injector Face Shut Off - Merlin
Here is an image on how this can be done.
It can be done using a sleeve that covers the central pintle. The sleeve also has a "bump" in it that controls the gap around the annular gap. So the sleeve ...
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8
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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?
I think uhoh's answer (7607000/2570=2959 Kg/s) is in the ballpark.
Here's another (less precise) approach:
First stage has 245,620 L of liquid oxygen and 146,020 L of RP-1 fuel (1)
Let's assume ...
- 2,113
8
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How did SpaceX achieve such a high Thrust to Weight ratio with the Merlin engine?
As I understand the two major items are continuous refinement of the design, and 3-d manufacture of key components of the engine. The Merlin is the most recently designed engine used on a large scale, ...
- 122k
8
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What are these big shiny metallic "lumps" on the bottom edge of each Falcon Heavy nozzle?
They are bumpers, to prevent damage during gimbaling. These were added after an incident in testing where engine nozzles were damaged after they banged into each other.
The bumper functions as a ...
- 130k
7
votes
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What is wrong with this burn time calculation?
The equation works for a straight-line burn with no gravity losses, but the first-stage burn of an orbital launcher arcs from vertical to nearly horizontal, and loses velocity to gravity.
To compute ...
- 172k
7
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What are the differences between a standard Merlin engine and the Merlin Vacuum engine?
There are several reasons for having deep throttling in the vacuum engine but not the first stage engine.
(1) The first stage cannot use a large expansion bell, and couldn't even if the mechanicals ...
- 71
7
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From what material and how are the Merlin engines and nozzles of it (sea level) manufactured?
Tl;Dr; Nickel-cobalt with a copper cooling jacket.
Spacenews interviewed Elon Musk where he said
"....
The hardest part of the engine to mass produce is the electro-plating of nickel cobalt on ...
- 3,857
6
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What is this jet of material spraying out from Stage 2 during the SpaceX PAZ mission?
The thing circled in the photo is a LOX vent. The puffy white snow-like stuff is solid oxygen. It was described at T+1.05:25 in the Iridium-6/GRACE-FO webcast.
- 12.9k
6
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What flame is SpaceX's Hans Koenigsmann describing in his presentation?
The jumping flame was the gas generator exhaust.
You can see that as the bronze-ish coloured smaller cylinder on the side of the engine in this picture of Merlin 1D engines in the factory.
You can ...
- 80.5k
6
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What are these flames on the Falcon 9 booster?
I think that is exhaust gas recirculation. Exhaust products gather in the low-pressure area around the base of the rocket.
The gas generator exhausts are grouped in a ring around the center engine. ...
- 130k
6
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How are 9 Merlin 1D engines packed and able to fit in a Falcon 9 FT first stage?
Your radius number for the Merlin is too large. By measuring photos, people have estimated the diameter to be about 0.9 m.
- 130k
5
votes
Actuators for gimbaling of engine in rockets and launch vehicles
SSME & Merlin use hydraulic actuators. For instance,
The engine is gimballed through two planes by hydraulic actuators for
vehicle pitch, yaw, and roll control. - Space Transportation System,...
- 6,417
5
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How does SpaceX plan to achieve reusability of the Falcon 9 *second* stage?
One possible thing which might help is to switch to methalox on the second stage to get additional performance to pay for grid fins and a heat shield. The subscale raptor engine they tested back in ...
- 221
5
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Can Falcon 9's engines be ignited more than 4 times if there is enough TEA-TEB?
The engines can most definitely be ignited more than 4 times.
Every engine is separately test-fired at McGregor after it is built. The entire booster is then again test-fired at McGregor before being ...
- 20.7k
4
votes
What does SpaceX do with all the engines?
... are producing at the RATE of four Merlin 1D engines per week.
That is the key. They have had two stand downs due to loss of vehicles (CRS-7 in flight, AMOS-6 during a test). During that time, ...
- 80.5k
4
votes
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How do you shut off a Merlin-like rocket engine quickly? How quickly can it be done?
The Merlin is throttled by modulating the propellant flow to the gas generator and thus the turbopump speed. Engine shutdowns are carefully orchestrated and timed affairs but I'm reasonably sure it ...
- 189k
4
votes
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What is the Kerosene/LOX mixture ratio of the Block 5 Falcon 9?
You're on the right track to finding the ratio; unless a particular ratio is published by the engine vendor, the best you can do is divide total propellant mass consumption as you're doing here.
By ...
- 172k
4
votes
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Falcon 9 Merlin 1d thrust calculated through every moment of flight
I'm going to bang this out in English units because that's what I have a feel for and so am less likely to make an embarrassing mistake.
Let's use the thrust equation for non-airbreathing engines, ...
- 189k
3
votes
Merlin 1D Engine
The Merlin Engine is a gas generator cycle engine which uses liquid Oxygen(LOX) and refined Kerosene(RP1) as its propellants.
The SuperDraco engine is a pressure fed cycle engine which uses mono-...
- 4,305
3
votes
The changes of a throttled Merlin-1d engine
For the SSME throttle % means % of rated chamber pressure (Pc). % thrust isn't a good metric because it varies with altitude. Thus your % throttle would increase during ascent even though you changed ...
- 189k
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