Photos: Delta 4 launches on secret NROL-45 mission

China launched the fourth in a series of high-resolution Earth-imaging satellites Saturday, expanding an orbiting fleet of reconnaissance craft that likely serve the Chinese military.

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.

United Launch Alliance and Boeing teams worked through the weekend on closeouts of the Starliner crew capsule, inspections and final outfitting of the Atlas 5 rocket. A launch readiness review Tuesday approved the continuation of final preparations for liftoff from Cape Canaveral Friday of the first Starliner spacecraft on an unpiloted test flight to the International Space Station.