NASA’s Space Launch System (SLS) program and Core Stage prime contractor Boeing were ready for the big moment of the rocket’s Green Run campaign and the biggest moment in the 10-year old program, a static firing of the stage. After a year of test cases at the Stennis Space Center in Mississippi, visits from hurricanes, and waves of the COVID-19 pandemic, an eight-minute long, flight-duration Hot-Fire test was planned for January 16 to demonstrate the readiness of the new rocket stage for its first launch.
The firing lasted only 67.7 seconds, well short of full-duration and the minimum two minute duration firing NASA said was necessary to complete the test. The abort was triggered by a Major Component Failure indication on Engine 4.
Four veteran Space Shuttle Main Engines (SSME), now equipped with upgraded computers and adapted to meet SLS performance requirements, supported this crucial test of the rookie stage. The Hot-Fire test was planned as a full flight duty cycle to demonstrate the real-world performance of the large, complicated rocket; the renamed Aerojet Rocketdyne RS-25 engines will be put through a set of circular and sinusoidal gimbaling experiments that will help demonstrate operating margins predicted by analytical models.