An eventful, highly productive career ended with the death of James Preston (“Pres”) Layton in December 1992. His career in rockets, which spanned 50 years, is a chronology of developments in the U.S. space program. Layton was instrumental in the development of rocket technologies ranging from the first jet-assisted take off (JATO) boosters used on aircraft to space nuclear power and propulsion. His work on JATOs, during World War II, involved both testing of solid-fueled units on naval aircraft in the Pacific and developing advanced liquid-fueled systems at the U.S. Naval Academy's laboratory under the direction of Robert H. Goddard, the father of American rocketry. It was Goddard who inspired Layton to devote his life to rocketry. In 1948, as chief of propulsion for the Glenn L. Martin company, he became crew chief in charge of testing the first big U.S. rocket, the Viking series. Layton subsequently joined the research faculty at Princeton University where he served from 1951 to 1976, taking a brief leave in 1955 to earn a Masters Degree at Purdue University under the direction of Maurice Zucrow, another American rocket pioneer. As Chief Engineer of Princeton's Guggenheim Jet Propulsion Center, he created the nation's foremost university rocket research facilities, where he conducted the first experimental evaluation of liquid ozone as a rocket propellant. Later Layton led Princeton's Advanced Systems and Mission Analysis Laboratory, which conducted pioneering studies of space nuclear power and propulsion systems. During this period, at the Lawrence Livermore National Laboratory (on leave from Princeton), Layton helped develop and test the world's first and only nuclear ram-rocket. During his career, Layton performed many responsible consulting tasks for industry and government in the U.S.A. and abroad. He was chief technical consultant to Mathematica, Inc., whose analyses formed the basis for the current Space Shuttle design. He conducted an AIAA assessment of New Space Transportation Systems; and chaired a projection of space activities into the 2000 to 2020 time period for the National Research Council. More recently, he designed environmental and communications satellite propulsion systems for MATRA Espace and RCA Astro-Electronics. Layton was very active in the American Institute of Aeronautics and Astronautics (AIAA) and the International Astronautical Federation (IAF). In 1985, he served as International Program Committee Chairman of the 35th International Congress in Stockholm. Layton was a Fellow, American Astronautical Society, Associate Fellow of the AIAA, and a Member of the International Academy of Astronautics.