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.

Air Force meteorologists are expecting good weather to launch the Delta 4 rocket with a military communications satellite Wednesday evening from Cape Canaveral.

SpaceX rolled out a reused Falcon 9 booster for a hold-down engine firing Wednesday at pad 40 at Cape Canaveral Air Force Station, making the first use of the launch complex since a rocket exploded there in September 2016. The static fire test accomplished Wednesday was a key step in preparations for launch of a space station cargo ship Dec. 12.