When was the the ship launched ,that along with the Tripitz and the Lützow was a target for  Operation Source ?
Operation Source Operation Source was a series of attacks to neutralise the heavy German warships – "Tirpitz", "Scharnhorst" and "Lützow" – based in northern Norway, using X-class midget submarines.
German submarine U-138 (1940) German submarine "U-138" was a Type IID U-boat of Nazi Germany's "Kriegsmarine" in World War II. Her keel was laid down on 16 November 1939 by Deutsche Werke in Kiel as yard number 267. She was launched on 18 May 1940 and commissioned on 27 June 1940 with "Oberleutnant zur See" Wolfgang Lüth in command.