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Although the basic platform dates back to the mid-’70s, the RS-25 rocket engine has undergone so many improvements and upgrades that it now is elevated to the same iconic status of an exotic Italian sports car.
“It is the most complicated rocket engine out there on the market, but that’s because it’s the Ferrari of rocket engines,” RS-25 engineer Kathryn Crowe says in the above video that highlights some of the intricate challenges the propulsion team faces in developing NASA’s new Space Launch System (SLS) rocket that will be powerful enough to eventually take man to Mars.
Echoing Crowe is Martin Burkey of the SLS communications department, who writes on a NASA blog, “The RS-25 makes a modern race car or jet engine look like a windup toy.”
Burkey notes that the RS-25 works within an incredible hostile environment, handling temperatures ranging from -400 F on top of the engine to 6,000 degrees where the fuel is burned.
“The bottom line is that the RS-25 produces 512,000 pounds of thrust. That’s more than 12 million horsepower,” writes Burkey, noting that the RS-25 has about the same weight and size of two engines found in the F-15 fighter jet but produces eight times more thrust.
In order to generate that much thrust, the RS-25 requires a lot of fuel. It takes four insanely powerful turbopumps to move the liquid hydrogen and liquid oxygen fast enough to keep up with the power demands. The main shaft in those turbopumps will rotate at 37,000 rpm.
RS-25 testing has included night firings. The daytime shot comes from the most recent test. NASA photos
Rocket engines can be somewhat finicky if the fuel and oxidizer don’t flow smoothly, so plenty of testing is on the schedule. The most recent firing took place August 13 at the Stennis Space Center in Mississippi and lasted 535 seconds–about the time needed to send a spacecraft up some 200 miles. Only one engine was tested at this time. At some point NASA will fire four RS-25 engines together, which the number of powerplants needed to help bring the SLS rocket up to more than 22,000 mph.
If you want to watch a time-lapse video of a RS-25 being assembled, check out this link.
