US spy satellite to be launched

VANDENBERG AIR FORCE BASE, California -- A powerful rocket carrying a US National Reconnaissance Office satellite is expected to be launched into orbit Wednesday from a California base.

The Delta IV Heavy rocket is scheduled to lift off from Vandenberg Air Force Base at 1752 GMT, according to United Launch Alliance.

The rocket is set to send a classified spacecraft into orbit for the NRO, which is in charge of US intelligence-gathering satellites.

It's the second time that a Delta IV Heavy rocket will be launched from Vandenberg. In January 2011, a sound wave as loud as a freight train swept over a nearby town. Some people reported hearing the rocket's roar as far as 50 miles (80 kilometers) away.

United Launch Alliance is a joint venture of Lockheed Martin Corp. and The Boeing Co. to provide space launch services to the US government with their Atlas and Delta rocket programs.