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-68 (1940) German submarine "U-68" was a Type IXC U-boat of Nazi Germany's "Kriegsmarine" during World War II. The submarine was laid down on 20 April 1940 at the DeSchiMAG AG Weser yard at Bremen as yard number 987, launched on 22 October and commissioned on 1 January 1941 under the command of "Korvettenkapitän" Karl-Friedrich Merten as part of 2nd U-boat Flotilla.