Video: X-37B payload mated to Atlas 5

Air Force meteorologists are expecting good weather to launch the Delta 4 rocket with a military communications satellite when the sun goes down Friday evening at Cape Canaveral.

A United Launch Alliance Delta 4-Heavy rocket stands 233 feet tall at Space Launch Complex-6 at Vandenberg Air Force Base, California, ready for liftoff Saturday night carrying a top secret U.S. government spy satellite into orbit.

This photo gallery shows the classified National Reconnaissance Office payload, already encapsulated in the 14-foot-diameter nose cone, being lifted atop the United Launch Alliance Atlas-Centaur rocket at Vandenberg Air Force Base for liftoff Oct. 8.