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. Von Braun was working on his doctorate when the Nazi Party gained power in Germany. An artillery captain, Walter Dornberger, arranged an Ordnance Department research grant for von Braun, who from then on worked next to Dornberger's existing solid-fuel rocket test site at Kummersdorf. Von Braun's thesis, "Construction, Theoretical, and Experimental Solution to the Problem of the Liquid Propellant Rocket" (dated 16 April 1934), was kept classified by the German Army and was not published until 1960. By the end of 1934, his group had successfully launched two rockets that reached heights of .