SPACE: Vulcan competes second flight despite SRB anomaly.

United Launch Alliance’s second Vulcan Centaur lifted off Oct. 4 on a test flight needed to certify the vehicle for carrying national security payloads, but may have suffered a problem with one of its solid rocket boosters.

The Vulcan Centaur lifted off at 7:25 a.m. Eastern from Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida. The liftoff took place near the middle of a three-hour launch window after an initial half-hour delay to provide additional time for pre-launch checks.

The first countdown attempt was halted 1 minute and 51 seconds before liftoff. Tory Bruno, chief executive of ULA, said on social media that a “transient on a redundant data system” triggered the hold, and controllers resolved the issue and reset the countdown for the second attempt, which resulted in liftoff.

ULA said that the vehicle’s performance was nominal in the early stages of flight. However, the separation of the two GEM 63XL solid rocket boosters (SRB) took place nearly 30 seconds later than the timeline the company provided before launch. About 35 seconds after liftoff, there appeared to be material coming off one of the boosters, whose plume changed appearance, suggesting damage to the SRB’s nozzle.

Other reports claim the engine bell might have blown or burned completely off. But the Centaur second stage successfully reached orbit.