This biography series, aimed at young adults, profiles important modern-era scientists. The volumes focus on the lives of those men and women who, in the 19th and 20th centuries, made the greatest contributions to scientific knowledge. Each book looks at a scientist - or group of scientists - whose work had a major impact on a particular field. In simple prose, free of technical jargon, each scientist's achievements are discussed, including the scientific principles underlying his or her work. The human drama of scientific work, conveying the excitement and frustration of research, as well as the exhilaration and rewards of discovery, are also depicted. This work provides a profile of Werner von Braun, the designer of rocket engines who developed the V2 rocket (1938) and went on to play a major role in America's first success in space, the satellite "Explorer I", in 1958.