A pathfinder test article of United Launch Alliance’s (ULA) Vulcan Centaur rocket is seen at Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida on Aug. 26, 2021. The pathfinder booster is undergoing a series of fueling tests to validate the infrastructure in place at the launch pad and allow the launch team to rehearse countdown operations before the Vulcan’s first flight.

A pathfinder test article of United Launch Alliance’s (ULA) Vulcan Centaur rocket is seen at Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida on Aug. 26, 2021. The pathfinder booster is undergoing a series of fueling tests to validate the infrastructure in place at the launch pad and allow the launch team to rehearse countdown operations before the Vulcan’s first flight.

A pathfinder test article of United Launch Alliance’s (ULA) Vulcan Centaur rocket is seen at Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida on Aug. 26, 2021. The pathfinder booster is undergoing a series of fueling tests to validate the infrastructure in place at the launch pad and allow the launch team to rehearse countdown operations before the Vulcan’s first flight.