NASA's SLS rocket engine completes successful hot-fire test
NASA finally got the core stage of its Space Launch System (SLS) rocket up and running for the first time today, completing an eight-minute hot-fire test of its four RS025 engines at the space agency's Stennis Space Center near Bay St. Louis, Mississippi.
Costing over US$20 billion dollars to date, the SLS is the key component of NASA's Artemis program that aims to establish a permanent human presence on the Moon. When completed, it will be the largest rocket ever launched – even topping the classic Saturn V of the Apollo era. In turn, the core stage is not only the largest element of the SLS, but the largest rocket element ever built by NASA.
During the test, which ran for a total of eight minutes and 19 seconds, the Boeing-built stage fed liquid hydrogen and liquid oxygen into four RS-25 engines built by Aerojet Rocketdyne. At peak firing, these generated 1.6 million pounds of thrust. In an actual mission launch, this should reach 2.2 million pounds.
Today's test is the last of the eight-part Green Run test campaign, designed to test the various elements of the system, culminating in a successful hot-fire test. This allowed engineers to put the engines through a variety of flight conditions, including directing thrust and running the engines at 109 percent power.
This test follows on from a January 16, 2021 test, which aborted after only one minute due to a technical problem. With the completion of the successful test firing, the SLS core stage will now be refurbished before being shipped to the Kennedy Space Center for integration into the complete rocket for the uncrewed Artemis 1 circumlunar mission.
"This longer hot fire test provided the wealth of data we needed to ensure the SLS core stage can power every SLS rocket successfully," says 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."
The video below recaps the test firing.