SLS Development RS-25 Engine Ignites for Successful Full Duration Test Fire #6

The world's most efficient rocket engine came to life again today, unleashing 512,000 pounds of thrust and a thunderous roar across southern Mississippi and NASA's Stennis Space Center during a 535-second full power test fire. The same engine that powered the space shuttle so reliably for years, the RS-25, will again be employed for NASA's Space Launch System, upgraded to meet the new requirements for what will become the most powerful rocket in history. Photo Credit: Mike Killian / AmericaSpace

The world’s most efficient rocket engine came to life again today, unleashing 512,000 pounds of thrust and a thunderous roar across southern Mississippi and NASA’s Stennis Space Center during a 535-second full power test fire. The same engine that powered the space shuttle so reliably for years, the RS-25, will again be employed for NASA’s Space Launch System, upgraded to meet the new requirements for what will become the most powerful rocket in history. Photo Credit: Mike Killian / AmericaSpace

The most efficient rocket engine in history came to life again this afternoon under clear blue skies, unleashing over a half-million pounds of thrust and sending a thunderous roar across southern Mississippi and NASA’s Stennis Space Center during a 535-second full duration test fire. The same engine that powered NASA’s now retired space shuttle fleet so reliably for three decades, Aerojet Rocketdyne’s RS-25, will again be employed for NASA’s enormous Space Launch System (SLS) rocket, upgraded to meet the new requirements for what will become the most powerful rocket in history, and today’s sixth test fire (in a seven-test series) helped advance the path to Mars further under highly instrumented and controlled conditions.

“It is great to see this revered engine back in action and progressing full steam ahead for launch aboard Exploration Mission-1 in 2018,” said Julie Van Kleeck, vice president of Aerojet Rocketdyne’s Advanced Space & Launch Programs business unit.  “The RS-25 is the world’s most reliable and thoroughly tested large liquid-fueled rocket engine ever built.”

The RS-25 comes to life for an Aug. 13 test fire at Stennis Space Center for NASA's SLS program. Image Credit: NASA

The RS-25 comes to life for an Aug. 13 test fire at Stennis Space Center for NASA’s SLS program. Image Credit: NASA

America’s next generation heavy-lift launch vehicle, the SLS, is quickly manifesting into reality. Its solid rocket booster was test fired earlier this year, NASA’s Pegasus transport barge has been made larger to support moving the colossal rocket, acoustic sound-suppression testing is occurring, F-18 Hornet fighter jets have carried out flight tests for SLS flight software developmenttest stands are being built or modified, KSC’s iconic Vehicle Assembly Building (VAB) is being upgraded to support SLS, launch pad 39B is being prepared, the rocket’s Mobile Launch Platform (MLP) and Crawler Transporter are being prepared, and both qualification and flight hardware for the first SLS vehicle itself are being constructed for an inaugural 2018 launch on the Exploration Mission-1 (EM-1) flight with NASA’s Orion deep-space multi-purpose crew capsule (which itself conducted its first flight test last December).

The 535-second test fire, carried out by development engine #0525 on the historic A-1 test stand, went off without issue—something that has come to be expected of the RS-25 engines. The RS-25 was the first reusable rocket engine in history, as well as being one of the most tested large rocket engines ever made, having conducted more than 3,000 starts and over one million seconds (nearly 280 hours) of total ground test and flight firing time over the course of NASA’s 135 space shuttle flights.

The engines proved their worth time and time again, but the RS-25 now requires several modifications to adapt to the new environment they will encounter with SLS and meet the giant 320-foot tall rocket’s enormous thrust requirements.

Today’s test fire will provide engineers with critical data on the engine’s new state-of-the-art controller unit—the “brain” of the engine, which allows communication between the vehicle and the engine itself, relaying commands to the engine and transmitting data back to the vehicle. The new controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine’s health and status, thanks to updated hardware and software configured to operate with the new SLS avionics architecture.

“We’ve made modifications to the RS-25 to meet SLS specifications and will analyze and test a variety of conditions during the hot fire series,” said Steve Wofford after the first test fire earlier this year, manager of the SLS Liquid Engines Office at NASA’s Marshall Space Flight Center in Huntsville, Ala., where the SLS Program is managed. “The engines for SLS will encounter colder liquid oxygen temperatures than shuttle; greater inlet pressure due to the taller core stage liquid oxygen tank and higher vehicle acceleration; and more nozzle heating due to the four-engine configuration and their position in-plane with the SLS booster exhaust nozzles.”

Today's RS-25 test fire, the sixth in a seven-test series focusing on upgrades made to the engine to support the new requirements of NASA's massive SLS rocket. Photo Credit: Alan Walters / AmericaSpace

Today’s RS-25 test fire, the sixth in a seven-test series focusing on upgrades made to the engine to support the new requirements of NASA’s massive SLS rocket. Photo Credit: Alan Walters / AmericaSpace

For shuttle flights the engines pushed 491,000 pounds of thrust during launch—each—and shuttle required three to fly, but for SLS the power level was increased to 512,000 pounds of thrust per engine (more than 12 million horsepower). The SLS will require four to help launch the massive rocket and its payloads with a 70-metric-ton (77-ton) lift capacity that the initial SLS configuration promises.

Aerojet Rocketdyne and NASA currently have 16 RS-25 engines in inventory at Stennis—14 of which are veterans of numerous space shuttle missions. Aerojet Rocketdyne just recently finished assembly of the 16th engine (engine 2063), one of the space agency’s two “rookie” RS-25s. It will be one of four RS-25 engines that will be employed to power the SLS Exploration Mission-2 (EM-2), the second SLS launch currently targeted for the year 2021. All of the engines have already been assigned to their SLS flights.

The RS-25 engine firing up on the A-1 test stand at Stennis Space Center Aug. 13. Photo Credit: Michael Galindo / AmericaSpace

The RS-25 engine firing up on the A-1 test stand at Stennis Space Center Aug. 13. Photo Credit: Michael Galindo / AmericaSpace

“The engine that was tested today continues demonstration of the new controller’s functionality and the engine’s ability to perform to SLS requirements,” added Jim Paulsen, vice president, Program Execution, Advanced Space & Launch Programs at Aerojet Rocketdyne.  “The new controller provides modern electronics, architecture and software. It will improve reliability and safety for the SLS crew as well as the ability to readily procure electronics for decades to come. We are conducting engine testing to ensure all 16 flight engines in our inventory meet flightworthiness requirements for SLS.”

Engine 0525 will carry out a total of seven test fires in this first series of tests and will fire for a grand total of 3,500 seconds, followed by another 10 test fires with another development engine, which will be put through its paces for a grand total of 4,500 seconds.

Known as the “Ferrari of rocket engines”, the RS-25 can 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.

To put the power of the Aerojet Rocketdyne-built RS-25 engines into perspective, consider this:

  • The fuel turbine on the RS-25’s high-pressure fuel turbopump is so powerful that if it were spinning an electrical generator instead of a pump, it could power 11 locomotives; 1,315 Toyota Prius cars; 1,231,519 iPads; lighting for 430 Major League baseball stadiums; or 9,844 miles of residential street lights—all the street lights in Chicago, Los Angeles, or New York City.
  • Pressure within the RS-25 is equivalent to the pressure a submarine experiences three miles beneath the ocean.
  • The four RS-25 engines on the SLS launch vehicle gobble propellant at the rate of 1,500 gallons per second. That’s enough to drain an average family-sized swimming pool in 60 seconds.
  • If the RS-25 were generating electricity instead of propelling rockets, it could provide twice the power needed to move all 10 existing Nimitz-class aircraft carriers at 30 knots.

“There is nothing in the world that compares to this engine,” added Paulsen. “It is great that we are able to adapt this advanced engine for what will be the world’s most powerful rocket to usher in a new space age.”

Panorama of the Aug. 13 RS-25 engine test fire for NASA's SLS program, from the media viewing area about 2,000 feet from the A-1 test stand. Photo Credit: Mike Killian / AmericaSpace

Panorama of the Aug. 13 RS-25 engine test fire for NASA’s SLS program, from the media viewing area about 2,000 feet from the A-1 test stand. Photo Credit: Mike Killian / AmericaSpace

Photo Credit: John Studwell / AmericaSpace

Photo Credit: John Studwell / AmericaSpace

Photo Credit: Michael Galindo / AmericaSpace

Photo Credit: Michael Galindo / AmericaSpace

RS-25 Engine SLS Mission Assignments. Image Credit: Aerojet Rocketdyne

RS-25 Engine SLS Mission Assignments. Image Credit: Aerojet Rocketdyne

 


VIDEO: Watch today’s RS-25 test fire for NASA’s SLS program

 

Be sure to “Like” AmericaSpace on Facebook and follow us on Twitter: @AmericaSpace

 

Missions » SLS »

4 comments to SLS Development RS-25 Engine Ignites for Successful Full Duration Test Fire #6

  • karol

    EXCELLENT article Mike! One of the reasons why AmericaSpace is without question the BEST site for information about our space program is the exceptionally high quality of the writing produced by individuals such as Jim, Ben, Leonidas, and yourself, et al. The gifted AmericaSpace writers provide in-depth, detailed analysis and information in an easily understandable, clear, unbiased format without cheerleading or cult-of-personality mantra. Your exceptional article Mike provides very exciting, promising news about OUR Orion/SLS, so much so that I’m off to secure another bottle of top shelf Scotch for the Exploration Mission – 1 launch party with Jim, Ben, Leonidas, yourself, Tom V., myself, and the whole AmericaSpace Orion/SLS lovin’ crew!

  • Byron Hood

    Mike, I second karol’s comments above. My wife Karen and I were there, in the same spot that you were. That test was one of the most awesome things I have ever seen – or HEARD! Congratulations, and thanks, to the SLS and RS-25 teams at SSC, MSFC, MAF and Aerojet Rocketdyne for their hospitality this past week. Go RS-25! Go SLS!

  • Arth

    It’s ironic that Boeing/Lockmart (ULA) never proposed to use two RS-25E-s in a man-rated version of Delta IV for CST-100 or the SNC Dream Chaser. They always pushed the Atlas V. I guess maximizing profits & greediness checkmate’s a good vision.