ULA Completes Critical Solid Rocket Booster Test, Advancing Vulcan Return-to-Flight
Summary: United Launch Alliance (ULA) successfully completed a static fire test of its Graphite Epoxy Motor (GEM) 63XL Solid Rocket Booster (SRB) on April 15, 2026, validating nozzle design enhancements and advanced propellant technology. This milestone is a key part of ULA's investigation and improvement work following an anomalous plume from one of Vulcan's SRBs during the USSF-87 mission on February 12, 2026. No firm return-to-flight date has been announced yet.