Tim Dunn

The step-by-step stacking of United Launch Alliance’s final Delta 2 rocket was completed in June at Vandenberg Air Force Base in California for liftoff Sept. 15 with an Earth science satellite for NASA.

A team of United Launch Alliance and NASA engineers worked through Delta 2 launch day fueling procedures during a simulated countdown Wednesday for what should be the second-to-last time before the venerable rocket’s final liftoff next month from California’s Central Coast.