Table of Contents
- 1 What is a Merlin Vacuum engine?
- 2 What happens to the Merlin Vacuum engine?
- 3 How much horsepower does a Merlin engine have?
- 4 What is the difference between the Merlin 1D and Merlin Vacuum?
- 5 What’s the difference between SpaceX’s Merlin 1D and 2nd stage engines?
- 6 Why does the Falcon 9 have such a large nozzle?
What is a Merlin Vacuum engine?
Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9 and Falcon Heavy launch vehicles. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. Propellants are fed by a single-shaft, dual-impeller turbopump.
What happens to the Merlin Vacuum engine?
The rocket has now burned enough fuel (thus decreasing its mass) that the center core engines can throttle down. The side cores separate and fall into the ocean, while the center core’s nine Merlin engines continue to burn for approximately 30 seconds. The second stage separates from the remaining first-stage core.
Why are they called Merlin engines?
Following the company convention of naming its piston aero engines after birds of prey, Rolls-Royce named the engine the Merlin after a small, Northern Hemisphere falcon (Falco columbarius). Two more Rolls-Royce engines developed just prior to the war were added to the company’s range.
How much horsepower does a Merlin engine have?
| Specifications: | |
|---|---|
| Rolls-Royce Merlin I | |
| Horsepower: | 1,030 (768 kw) |
| RPM: | 3,000 |
| Bore and Stroke: | 5.4 in. (137 mm) x 6 in. (152 mm) |
What is the difference between the Merlin 1D and Merlin Vacuum?
Wikipedia also says that the Merlin Vacuum Engine is larger than the standard Merlin 1D. That got me thinking… are there more differences? What are the differences between the first stage Merlin engines and the second stage Merlin vacuum engine?
What is the throttle range of the Falcon 9’s Merlin 1D engines?
According to the October 2015 revision of the Falcon 9 User’s Guide, the Falcon 9’s first stage Merlin 1D engines have a 70\%-100\% throttle range, while the second stage Merlin 1D Vac engine has a 38.5\%-100\% throttle range.
What’s the difference between SpaceX’s Merlin 1D and 2nd stage engines?
I know that there’s a difference between SpaceX’s Falcon 9 1st stage engines and the 2nd stage engine, since that stage is specifically tuned for vacuum. Wikipedia also says that the Merlin Vacuum Engine is larger than the standard Merlin 1D. That got me thinking… are there more differences?
Why does the Falcon 9 have such a large nozzle?
Since the Falcon 9 second stage mounts a single engine, in the same diameter body as the first stage (with its cluster of 9), there’s plenty of room for the large nozzle. This reddit threadincludes some inconclusive debate about how much different the vacuum engines actually are.