Photos: Atlas 5 launches navigation craft from Cape Canaveral

An early bird rocket launch from the Florida spaceport will take to the skies before dawn Saturday when an Atlas 5 lofts a classified U.S. government satellite.

United Launch Alliance engineers filled a Delta 4-Heavy rocket with super-cold liquid hydrogen and liquid oxygen propellants Friday at Cape Canaveral Air Force Station during a practice countdown before the heavy-lifter’s scheduled liftoff in June with a top secret U.S. government spy satellite.

United Launch Alliance plans to introduce a new payload fairing design on the next-generation Vulcan rocket, which will fly with composite parts made by Switzerland-based Ruag Space, the company’s chief executive said Wednesday.