 They missed Wernher von Braun's research group which voluntarily surrenderd to the US Army on May 2, 1945, and most of the Peenemünde scientists who preferred working on the British or American side.In addition, the US Army was able to capture and remove more than 100 completed V2-s and assembled components, together with all relevant documents for the design and manufacturing, from the Mittelwerk before they handed it over to the Soviet army by July 1945, as agreed earlier during the Yalta Conference.As the only experienced rocket scientist the Soviets convinced Helmut Gröttrup, the head of the group for developing the V-2 control systems from 1941, to set up the "Institut Gröttrup" in Bleicherode, and also hired more German scientists to build the "Institut Rabe" for reconstructing the V-2 and other German weapons.