The test of a solid-fuel booster designed for the Artemis program mission ended in failure. During firing, its nozzle broke.
Close up slow motion footage of the unexpected event(s) during Northrop Grumman’s BOLE DM-1 stb test today. @NASASpaceflight
Rewatch the livestream here: https://t.co/c3mHSLrzV2 pic.twitter.com/FcrZXjwLVD
— Jack Beyer (@thejackbeyer) June 26, 2025
On June 26, Northrop Grumman conducted a fire test of a solid rocket booster designed for the SLS rocket, which would be used in the Artemis IX mission. The test was conducted at a test site in Utah.
Initially, the test was conducted in normal mode. However, ten seconds before the end of the fire, an incident occurred: the booster nozzle broke, accompanied by the formation of a large amount of debris. The booster itself did not explode and continued to operate.
Jim Kalberer, vice president of propulsion systems at Northrop Grumman, commented on the incident as follows:
“Today’s test allowed us to push the boundaries of large solid rocket engine design to meet stringent performance requirements. Although the engine proved itself well under harsh conditions, we noticed an anomaly at the end of more than two minutes of operation.”
It is evident that the incident is similar to the accident that occurred during the second launch of the Vulcan rocket in October 2024. Then, one of Northrop Grumman’s solid-fuel boosters also suffered nozzle failure, which led to a reduction in thrust. Fortunately, it was compensated for by the first stage of the rocket, which prevented an accident.
The solid rocket booster used in the test was intended for use on the Block 2 version of the SLS rocket. Its operation is scheduled to begin with the Artemis IX mission. The booster’s design is based on the design of boosters previously used for the Space Shuttle program. The main difference is that it consists of five segments instead of four. Changes were also made to its design, increasing its thrust compared to the version used in the current SLS modification.
At this point, it is unclear whether the incident with the booster will have any long-term consequences. NASA’s current budget proposal involves abandoning the SLS after the Artemis III mission in favor of cheaper launch vehicles. It is possible that the destruction of the booster nozzle could be used as an additional argument in favor of abandoning the extremely expensive rocket.
