Video replay: Parker Solar Probe launches atop Delta 4-Heavy

The 75th Atlas 5 rocket rolled to its launch pad at Cape Canaveral on Wednesday, a day before it was scheduled to lift off with a U.S. Air Force satellite to provide warnings of missile launches that might threaten U.S. territories and allies.

United Launch Alliance teams rolled the Mobile Service Tower away from a Delta 4-Heavy rocket at Cape Canaveral’s Complex 37B launch pad Wednesday in preparation for liftoff on a national security mission.

Watch a video clip of the Falcon 9 rocket’s first stage separating and firing its engines to return to Cape Canaveral shortly after liftoff Jan. 7.