A Norwegian navy ship has set off to locate the remains of the plane that sent legendary explorer Roald Amundsen to a watery grave in the Barents Sea in 1928.The KNM Tyr will drop an unmanned submarine, fitted with sophisticated sonar to scour the sea-bed over an area of nearly 120 square kilometers. A second robot fitted with cameras will work in tandem with the submarine. The search team is heading for Bjornoya, or Bear Island, the area in which it is thought Amundsens plane crashed, and will return to port in Tromso in ten days time. Amundsen took off in a Latham 47 on a mission to rescue fellow explorer Umberto Nobile. All that was found of the Latham was a wing float and a gas tank which now lies in a museum in Tromso. Today’s mission hopes to find more debris, including the plane’s engine, and perhaps reveal the secrets of the great Norwegian explorer’s final expedition.