The largest rocket element NASA has ever built, the core stage of NASA's Space Launch System (SLS) rocket, fired its four RS-25 engines for 8 minutes and 19 seconds on Thursday at NASA's Stennis Space Center near Bay St. Louis, Mississippi.
The successful test, known as a hot fire, is a critical milestone ahead of the agency's Artemis I mission, which will send an uncrewed Orion spacecraft on a test flight around the Moon and back to Earth, paving the way for future Artemis missions with astronauts.
Engineers designed the eight-part Green Run test campaign to gradually bring the SLS core stage to life for the first time, culminating with the hot fire. The team will use data from the tests to validate the core stage design for flight.
"The SLS is the most powerful rocket NASA has ever built, and during today's test the core stage of the rocket generated more than 1.6 million pounds of thrust within seven seconds. The SLS is an incredible feat of engineering and the only rocket capable of powering America's next-generation missions that will place the first woman and the next man on the Moon," said acting NASA Administrator Steve Jurczyk. "Today's successful hot fire test of the core stage for the SLS is an important milestone in NASA's goal to return humans to the lunar surface - and beyond."
NASA previously conducted a hot fire test of the SLS core stage on Jan. 16. The four RS-25 engines fired together for the first time for about one minute before the test ended earlier than planned. Following data analysis, NASA determined a second, longer hot fire test would provide valuable data to help verify the core stage design for flight, while posing minimal risk to the Artemis I core stage.
During the second hot fire test, the stage fired the engines for a little more than eight minutes, just like it will during every Artemis launch to the Moon. The longer duration hot fire tested a variety of operational conditions, including moving the four engines in specific patterns to direct thrust and powering the engines up to 109% power, throttling down and back up, as they will during flight.
"This longer hot fire test provided the wealth of data we needed to ensure the SLS core stage can power every SLS rocket successfully," said John Honeycutt, manager for the SLS Program at NASA's Marshall Space Flight Center in Huntsville, Alabama. "During this test, the team conducted new operations with the core stage for the first time, repeated some critical operations, and recorded test data that will help us verify the core stage is ready for the first and future SLS flights for NASA's Artemis program." Next, the core stage for SLS will be refurbished, then shipped to NASA's Kennedy Space Center in Florida. There, the core stage will be assembled with the solid rocket boosters and other parts of the rocket and NASA's Orion spacecraft on the mobile launcher inside the Vehicle Assembly Building at Kennedy in preparation for Artemis I.