Enlarge / United Launch Alliance's first Vulcan rocket on the launch pad before liftoff in January. (credit: United Launch Alliance) The second flight of United Launch Alliance's Vulcan rocket will take off in September with a dummy payload in place of Sierra Space's Dream Chaser spaceplane, preserving a chance for ULA to begin launching US military satellites on the new rocket by the end of the year, officials announced Wednesday. Tory Bruno, ULA's CEO, announced the change in flight plan for the second Vulcan rocket in a conference call with reporters.