US Space Force Halts ULA Vulcan Launches
The U.S. Space Force has suspended all missions for United Launch Alliance's Vulcan rocket. The halt is pending an investigation into a potential issue with the vehicle's solid rocket boosters. The suspension complicates ULA's efforts to increase its launch cadence and presents a challenge for the Department of Defense's launch schedule.
The anomaly on the February 12 USSF-87 mission occurred about 20 seconds after liftoff, when one of the four Northrop Grumman GEM 63XL solid rocket boosters (SRBs) showed a visible malfunction. Despite the issue, the rocket's two main BE-4 engines compensated, and the mission successfully delivered its two Geosynchronous Space Situational Awareness Program (GSSAP) satellites to the correct orbit. This marks the second time a Vulcan rocket has experienced this type of failure. A nearly identical issue, later attributed to a manufacturing defect in a booster nozzle, occurred during the rocket's second certification flight in October 2024. That earlier failure prompted a lengthy investigation and delayed Vulcan's certification for National Security Space Launch (NSSL) missions. The investigation into the latest anomaly is expected to take "many months," according to Col. Eric Zarybnisky, the Space Force's acting portfolio acquisition executive for space access. ULA is forming an investigation team with Northrop Grumman, the booster manufacturer, to inspect the spent hardware and determine the root cause before flights resume. The boosters, GEM 63XLs, are the longest single-segment solid rocket motors ever produced, standing over 72 feet tall. Their monolithic design, cast as a single piece, is intended to enhance reliability by minimizing joints and hardware, making the recurring nozzle issue a significant engineering concern. The grounding disrupts an ambitious 2026 launch manifest for ULA, which aimed for 18 to 22 Vulcan launches to address a backlog of more than 80 missions. Critical upcoming payloads, including a GPS III satellite and the first Next-Generation Overhead Persistent Infrared (OPIR) missile-warning satellite, now face potential delays or reassignment. With Vulcan sidelined, the Space Force must rely exclusively on SpaceX's Falcon rockets for its critical national security launches. This situation highlights the strategic importance of having multiple certified launch providers and puts pressure on ULA to resolve the issue to maintain its competitive standing in the NSSL program. The suspension also impacts major commercial customers, chiefly Amazon's Project Kuiper. Amazon has booked 38 Vulcan launches to deploy its low-Earth orbit broadband constellation, a direct competitor to SpaceX's Starlink. These delays could affect the deployment timeline for one of the largest satellite constellations ever planned.
