Photos: Atlas 5 rocket soars from West Coast

The 100th rocket in America’s Evolved Expendable Launch Vehicle program, the current fleet of boosters used by the nation to get its critical assets into space, was rolled to the pad Friday morning for a vital mission on Saturday.

A United Launch Alliance Atlas 5 rocket blasted off from Vandenberg Air Force Base in California at 5:49 a.m. local time (8:49 a.m. EDT; 1249 GMT) Thursday on the classified National Reconnaissance Office NROL-55 mission.

A United Launch Alliance Atlas 5 rocket emerged from its vertical hangar Tuesday for the 1,800-foot journey to pad 41 at Cape Canaveral Air Force Station, moving into position for liftoff Thursday with NASA’s Mars 2020 Perseverance rover.