Photos: Atlas 5 on the pad for X-37B launch

The Atlas 5 rocket emerges from the Vertical Integration Facility for rollout to Complex 41 at Cape Canaveral in preparation to launch the Orbital ATK Cygnus resupply ship to the International Space Station. Liftoff is set for Thursday at 5:55 p.m. EST.

A United Launch Alliance Atlas 5 rocket took off from Cape Canaveral on Aug. 8 with the U.S. Air Force’s fifth Advanced Extremely High Frequency communications satellite, the second launch from Florida’s Coast in a span of less than 35 hours.

Firing into orbit from a barrier island on India’s east coast, a 145-foot-tall Polar Satellite Launch Vehicle lifted off early Wednesday to deploy 20 satellites in a perch more than 300 miles above Earth.