NASA tested on August 13 its next-generation RS-25 engine, the main engine for the rocket that will carry astronauts to the planet Mars. The agency commenced test firing of the engine — the sixth of seven scheduled tests — at about 4:30 p.m. EDT at the Stennis Space Center in Mississippi.
The test lasted about nine minutes and allowed engineers to calibrate the engine and gather relevant performance data.
The previous test, according to CNET, was conducted on January 9, also at the Stennis Space Center.
The SLS is composed of four RS-25 engines and two solid rocket boosters consisting of five components each.
Kathryn Crowe, propulsion engineer on the project, told CNET that the design and optimization of the engine makes it the “most complicated rocket engine out there on the market.”
“It is the most complicated rocket engine out there on the market, but that’s because it’s the Ferrari of rocket engines.
“When you’re looking at designing a rocket engine, there are several different ways you can optimize it. You can optimize it through increasing its thrust, increasing the weight-to-thrust ratio, or increasing its overall efficiency and how it consumes your propellant. With this engine, they maximized all three.”
According to Martin Burkey with the SLS strategic communications team, RS-25 is the most powerful engine ever built. It is hoped that the engine will carry Mars-bound astronauts at the speeds of up to 36,500 kilometers per hour using four turbopumps, each able to produce 512,000 pounds of thrust, equivalent to more than 12 million horsepower.
“The RS-25 makes a modern race car or jet engine look like a wind-up toy.”
“The RS-25 is about the same weight and size as two F-15 jet fighter engines, yet it produces eight times more thrust. A single turbine blade the size of a quarter — and the exact number and configuration inside the pump is now considered sensitive — produces more equivalent horsepower than a Corvette ZR1 engine.”
NASA engineers will conduct extensive ground tests on the main engine and other engine parts, separately and in concert.
Part of the optimization of the engine involved designing and building it to withstand higher pressures and temperatures than any engine before it.
“It has to handle temperatures as low as minus 400 degrees where the propellants enter the engine and as high as 6,000 degrees as the exhaust exits the combustion chamber where the propellants are burned. It has to move a lot of propellants to generate a lot of energy. At the rate the four SLS core stage engines consume propellants, they could drain a family swimming pool in 1 minute.”
[Image: NASA via Space.com; NASA/CNET]