In the late 1920s, a young Wernher von Braun bought a copy of Hermann Oberth's book, "Die Rakete zu den Planetenräumen" ("The Rocket into Interplanetary Spaces"). Starting in 1930, he attended the Technical University of Berlin, where he assisted Oberth in liquid-fueled rocket motor tests. In 1933 he went to work for the Army designing and building rockets. The final, biggest rocket was the A-4, later called V-2.