A spy satellite for the U.S. National Reconnaissance Office has been launched from Vandenberg Air Force Base in California.

A United Launch Alliance Atlas 5 rocket carrying the classified NROL-42 satellite lifted off at 10:49 p.m. PDT Saturday. All systems were going well when the launch webcast concluded about three minutes into the flight.

The launch was expected to be visible across a wide area of California, weather permitting.

National Reconnaissance Office satellites gather intelligence information for U.S. national security and an array of other purposes including assessing impacts of natural disasters.

U.S. officials have not revealed what the spacecraft will be doing or what its orbit will be.

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

(AP)