A classified satellite for the National Reconnaissance Office was launched into space Tuesday night aboard a Boeing Delta 4 rocket. The Boeing Delta 4 rocket blasted off at 8:30 p.m Tuesday. The purpose of the mission was not revealed, but the National Reconnaissance Office builds and manages the nation's spy satellites. It was not immediately known whether the satellite entered its planned orbit. Calls to the NRO were not immediately returned late Tuesday. 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 launch signals a military shift to cheaper space boosters.