VANDENBERG AIR FORCE BASE, Calif. (AP) - A U.S. spy satellite has been launched into orbit from California.

  

A powerful Delta 4 Heavy rocket carrying the National Reconnaissance Office satellite blasted off from Vandenberg Air Force Base at 11:10 a.m. Pacific time Saturday.

  

As is customary with classified payloads, United Launch Alliance webcast the liftoff only through the period when the aerodynamic fairing covering the payload was discarded.

  

Details of the mission, dubbed NROL-71, were not released.

  

The launch had been repeatedly delayed since late last year for reasons including a hydrogen leak, high winds and a problem with ground communication equipment.

  

The National Reconnaissance Office is responsible for U.S. intelligence satellites.

  

United Launch Alliance is a joint venture of Lockheed Martin and Boeing.

  

The Delta 4 Heavy stands 233 feet (71 meters) tall.