 Complete the following phrase:  Schmidt planned to study without interruption, therefore volunteered at age 18 for military service in 1937. He began serving with an anti-aircraft battery of Luftwaffe at Vegesack near Bremen. In World War II, after brief service on the Eastern Front during the invasion of the Soviet Union in 1941 including the Siege of Leningrad, he returned to Germany in 1942 to work as a trainer and advisor at the Ministry of Aviation. During his service in World War II, Schmidt was awarded the Iron Cross 2nd Class. He attended the Peoples Court as a military spectator at some of the show trials for officers involved in the 