Photos: Atlas 5 on the pad at sunset

A United Launch Alliance Atlas 5 rocket powered away from Vandenberg Air Force Base in California tonight to place a classified surveillance satellite into space for the U.S. National Reconnaissance Office. Follow the ascent in our live journal.

A United Launch Alliance Delta 4 rocket climbed into orbit Friday from Vandenberg Air Force Base in California with a top secret spy satellite, adding a new set of eyes in the sky for the U.S. government’s intelligence community and nudging part of the Delta 4 family closer to retirement.

This is the ascent timeline to be followed by the United Launch Alliance Atlas 5 rocket in launching the Mobile User Objective System satellite No. 5 on Friday at 10:30 a.m. EDT (1430 GMT).