Video: Liftoff of Atlas 5 on NROL-55

A SpaceX Falcon 9 rocket is standing more than 20 stories tall on pad 40 at Cape Canaveral Space Force Station, ready for blastoff with the Turksat 5A communications satellite.

SpaceX’s first Falcon Heavy rocket is set for liftoff Tuesday from NASA’s Kennedy Space Center in Florida, and the heavy-lift launcher will head on an easterly course over the Atlantic Ocean atop nearly 5 million pounds of thrust.

In the span of two weeks, United Launch Alliance technicians performed the basic buildup of the Atlas 5 rocket and then mated the advanced GOES-R weather satellite that will be hauled into space on Saturday.