Photos: Atlas 5 on the pad awaiting liftoff on NROL-52

The United Launch Alliance Atlas 5 rocket that will boost NASA’s latest communications relay satellite into space is targeting an Aug. 20 liftoff at 7:56 a.m. EDT (1156 GMT).

Ready to deliver 1.5 million pounds of thrust Thursday morning, an Atlas 5 rocket was rolled from its assembly building to the launch pad today for its national security satellite-deployment flight.

Using a new, uprated main engine for the first time on a rocket of its kind, a United Launch Alliance Delta 4-Medium+ vehicle will soar into space Wednesday night carrying a $566 million Air Force communications satellite.