During a test firing on June 26th in Utah, a new version of the solid rocket booster designed for NASA's Space Launch System (SLS) experienced an anomaly. Northrop Grumman conducted the first demonstration test of the Booster Obsolescence and Life Extension (BOLE) version at its Promontory, Utah, facility. The booster, horizontally positioned, fired for slightly over two minutes, mimicking a launch. Approximately 100 seconds into the test, exhaust emanated from the side of the nozzle, followed by debris scattering, as captured by NASA's webcast. The webcast audio included an audible reaction from test controllers: “Whoa!” followed by a sigh.
Despite the incident, the motor completed the test burn. Initial post-test comments from NASA and Northrop Grumman officials did not address the anomaly. However, Jim Kalberer, Northrop Grumman's vice president of propulsion systems, later stated, “While the motor appeared to perform well through a harsh burn environment, we observed an anomaly near the end of the two-plus minute burn.” The company withheld further details. Kalberer emphasized the test's significance, saying, "As a new design, and the largest segmented solid rocket booster ever built, this test provides us with valuable data to iterate our design for future developments."
The BOLE design, featuring carbon fiber composite casings instead of steel, is intended for SLS missions beginning with Artemis 9 in the 2030s. It boasts a new propellant and performance improvements exceeding 10%, adding five metric tons of payload capacity. However, the BOLE's flight status remains uncertain due to NASA's proposed FY2026 budget cancellation of the SLS after Artemis 3. While the Senate's budget reconciliation bill suggests funding for Artemis 4 and 5, it does not address the program's long-term future. This incident marks the second nozzle-related issue for a Northrop Grumman solid rocket booster in under a year. In October 2024, a nozzle detached from a GEM 36XL booster on a United Launch Alliance Vulcan rocket launch. Although not preventing mission completion, ULA attributed this to a manufacturing defect addressed in February through corrective test firings.