Video: Delta 2/SMAP pre-launch news conference

A replay of the United Launch Alliance Delta 4 rocket launching on the NROL-45 satellite-deployment mission for the National Reconnaissance Office from Vandenberg Air Force Base, California.

The U.S. Air Force has identified the launch of a next-generation GPS navigation satellite for the first in a series of competitive rocket procurements between United Launch Alliance and SpaceX, service officials announced Wednesday.

Four magnetic explosion probes in a towering stack atop an Atlas 5 rocket rode a fountain of flame off the launch pad and into Earth orbit Thursday night for a $1.1 billion NASA science investigation into a universal force of nature.