United Launch Alliance said it is reviewing data after one of the solid rocket motors on its Vulcan rocket appeared to experience a problem during a U.S. Space Force mission early Thursday.
The company said in a post on X that teams are analyzing the situation, adding that the rocket’s main booster, upper stage and payload continued operating normally.
The launch marked the fourth flight of Vulcan since its debut in January 2024. The rocket, developed by the Boeing (BA) and Lockheed Martin (LMT) joint venture, is designed to offer a more affordable option in the increasingly competitive launch market. However, Vulcan’s rollout has been slowed by schedule setbacks and technical challenges.
On its second mission in October 2024, a side-mounted booster used to provide extra thrust experienced a small explosion shortly after liftoff. Despite the incident, the rocket completed its mission. ULA did not fly Vulcan again until August 2025.
Earlier this week, interim Chief Executive Officer John Elbon said prior issues had been addressed and described the rocket as ready for regular service. Elbon stepped into the role after longtime CEO Tory Bruno departed in December to join Blue Origin.
ULA is also working to expand operations at Kennedy Space Center by building an additional facility and launch pad, with the goal of increasing its flight cadence.
Once the dominant launch provider for the U.S. Defense Department, ULA now competes with SpaceX (SPACE), Blue Origin and Rocket Lab (RKLB) for government and commercial missions. Among its key customers is Amazon (AMZN), which plans to use Vulcan rockets to deploy satellites for its Project Kuiper broadband network, a rival to SpaceX’s Starlink.