North Korea is believed to be preparing to test a Taepodong-2 missile from a launch pad at Musudanri in northeastern North Hamkyong Province, a Seoul newspaper reported Wednesday. ''A U.S. reconnaissance satellite has recently detected the movement, from a missile factory near Pyongyang, of a train carrying large cylinder-shaped objects, believed to be rockets for the Taepodong-2 missile,'' the Chosun Ilbo quoted a South Korean government source as saying.