 Complete the following phrase:  Roesslers first major contribution to Soviet intelligence came in May 1941 when he was able to deliver details of Operation Barbarossa, Germanys impending invasion of the Soviet Union. Though his warning was initially ignored - as Soviet intelligence had received multiple false alarms about an impending German invasion - Roesslers dates eventually proved accurate. Following the invasion, in June 1941, Lucy was regarded as a VYRDO source, i.e. of the highest importance, and to be transmitted immediately. Over the next two years Lucy was able to supply the Soviets with high grade military intelligence. During the autumn of 1942, Lucy provided the Soviets with detailed information about 