Northrop Grumman recorded a $71 million charge in its first quarter of 2026 tied to a recurring flaw in the solid rocket boosters used on United Launch Alliance’s Vulcan Centaur rocket.
The charge stems from an anomaly during the February 12 launch of the USSF-87 mission, where one of four GEM 63XL boosters shed debris approximately 65 seconds after liftoff. Although the payload reached its intended geosynchronous orbit, United Launch Alliance later classified the event as a significant performance anomaly.
This marks the second time in four Vulcan flights that a GEM 63XL booster has failed, following a nozzle detachment during the Cert-2 mission in October 2024 that was traced to a manufacturing defect in an insulator.
In its quarterly filing with the Securities and Exchange Commission, Northrop specified the charge covered the evaluation and implementation of corrective actions for the solid rocket motor anomaly occurring in the first quarter of 2026.
Despite the successful payload delivery, the Vulcan rocket remains grounded as the U.S. Space Force, Northrop, and ULA continue investigating the root cause, with no timeline established for return to flight.
At the 41st Space Symposium, Space Force officials indicated they are evaluating a configuration of the Vulcan that omits the GEM 63XL solid boosters entirely, enabling launches of lower-energy missions such as those planned for the Space Development Agency’s missile-tracking and communications satellite constellations.
Lt. Gen. Philip Garrant, head of Space Systems Command, stated that if the rocket does not rely on solid propulsion, there is no technical barrier to launching, emphasizing the service’s commitment to keeping such missions on track.
Separately, U.S. Space Force Col. Eric Zarybnisky revealed at a media roundtable during the Space Foundation’s Space Symposium that the force is actively considering using the Vulcan for lower-risk missions that do not require the solid boosters, though specific mission profiles remain undefined.
These lower-risk flights would likely involve lighter payloads or lower orbital destinations, reflecting a strategic pivot to maintain utility of the grounded vehicle while investigations continue.
The repeated booster issues raise questions about the reliability of the GEM 63XL design despite prior redesigns following the 2024 nozzle failure, suggesting deeper systemic or production challenges may persist.
Why is the Vulcan rocket grounded despite the USSF-87 mission succeeding?
The rocket is grounded because the booster anomaly, while not preventing mission success, is classified as a significant performance issue requiring investigation before ULA and the Space Flight will authorize another launch.
What missions could the Vulcan fly without its solid boosters?
The Space Force is considering using the Vulcan without GEM 63XL boosters for low-energy missions, such as deploying payloads for the Space Development Agency’s missile-tracking and communications satellite constellations, which do not require the extra thrust the solids provide.