Rocket Scientist. Having helped Germany bomb London during World War II, he then was a major part of America's project to land men on the moon. Raised in Hanover from the age of two, he developed an interest in rockets after hearing a lecture and seeing a test of a rocket-driven railroad car. He became part of a group of amateur scientists directed by Albert Pullenberg, then studied mechanical engineering at the University of Hanover with a major in diesel fuel injection. Drafted into the German Army in 1939 (a Nazi Party member, he became such in the same involuntary manner as did thousands of others), he was assigned to horse-artillery and participated in the early part of the Battle of France. Apparently not a very good horseman, Dannenberg was discharged from the army in 1940 thru Pullenberg's influence then assigned to Peenemunde as a propulsion specialist. Becoming Walter Riedel's deputy, he was present at the initial test of the V2 rocket on October 3, 1942, the first launch of a man-made object which achieved escape velocity and reached outer space. The V2 inflicted much damage on England during the final year of the war; when the scientists at Peenemunde realized that the German cause was lost they made a conscious decision to surrender to American troops rather than be captured by the Soviets; thus, the Russians found the facility empty, the men and rockets in American hands. Dannenberg was part of "Operation Paperclip", the shipping of captured Nazi scientists to the United States. Initially the group was at Fort Bliss, Texas where Dannenberg used the captured V2s in propulsion research; transferred to Redstone Arsenal in Huntsville, Alabama at the start of the Korean War, he was a developer of the Redstone missile and later worked on the Jupiter IRBM at the Army Ballistic Missile Agency in Detroit. In 1960 he moved to the NASA Marshall Space Flight Center in Huntsville where, as deputy manager of the Saturn program, he helped develop the propulsion system for the Saturn V which carried the first men to the moon in 1969. Upon his 1973 retirement, Dannenberg received the NASA Exceptional Service Medal, then later was professor at the University of Tennessee; in 1990 he was awarded the Durand Lectureship and in 1995 received the Herman Oberth Award. Throughout his later years he remained an advocate of continued American exploration of outer space.