A classified satellite for the National Reconnaissance Office was launched into space Tuesday night aboard a Boeing Delta 4 rocket.
The rocket blasted off at 8:33 p.m. PT (11:33 p.m. ET) from this Air Force base on the central California coast, leaving a thin trail in the twilight sky.
The purpose of the mission was not revealed. The National Reconnaissance Office builds and manages the nation's spy satellites.
It was the first West Coast launch for the Delta 4 rocket, which has been launched five times from Cape Canaveral, Fla. At 20 stories high, it was the tallest rocket launched from Vandenberg.
The Delta 4 launch signals a military shift to cheaper space boosters.
Last year, Vandenberg launched its final Titan rocket, marking the end of an era for the workhorse rockets in favor of a new generation of rockets such as the Delta 4 and Lockheed Martin's Atlas 5.