(AP)—An Atlas 5 rocket carrying a classified satellite for the U.S. National Reconnaissance Office blasted off Thursday from the central California coast.
The launch vehicle's main engine ignited on time for a mission described only as being in support of national defense.
"We've just seen a successful liftoff," United Launch Alliance commentator Don Spencer said after confirmation of upper stage ignition and separation of the aerodynamic fairing covering the payload about 4½ minutes into the flight.
As is customary during such secrecy-laden missions, a webcast of the launch ended at that point.
It was the fourth launch this year for the NRO, which operates the nation's system of intelligence-gathering satellites. The launch was delayed six weeks due to launch range equipment problems.
For the first time on an NRO flight, the rocket's excess capacity was used to boost 11 tiny satellites for other customers.
Called Cubesats, the small satellites will conduct research on subjects ranging from space weather to tracking maritime shipping containers.
In addition to the Army, Aerospace Corp., NASA and Lawrence Livermore National Laboratory, the Cubesats include projects by the University of Southern California; University of Colorado, Boulder; California Polytechnic State University, San Luis Obispo; University of California, Berkeley; and Kentucky's Morehead State University.
Explore further: Global roadmap for better understanding space weather released