George H. Ludwig was the former chief research scientist for the National Aeronautics and Space Administration's satellite systems and director of operations for the National Oceanic and Atmospheric Administration. He played a key role in adapting solid-state scientific research instruments for America's first satellites: Explorer I, II, and III. George H. Ludwig was born on November 13, 1927, in Sharon Center, Johnson County, Iowa, a son of George M. and Alice G. (Heim) Ludwig. After graduating from high school in Tiffin, Iowa, in 1946, he served in the U.S. Air Force, where he received training as an aviation cadet and attained the rank of captain. A member of Phi Beta Kappa honor society, Ludwig completed three degrees at the University of Iowa: a B.A. cum laude in physics, 1956; an M.S. in physics, 1959; and a Ph.D. in electrical engineering, 1960. On July 21, 1950, he married Rosalie F. Vickers, and the couple had four children. While a graduate student during the late 1950s, Ludwig, in collaboration with Prof. James A. Van Allen, established one of the first spacecraft instrumentation laboratories, with its special techniques, equipment, and performance requirements. He was principal developer of the cosmic ray and radiation belt instruments for Rockoon and the successfully launched Explorers, I, III, IV, VII and, in some cases, their spacecraft structures and subsystems. The space-based instruments were all transistor, a first. He also served as a research engineer at the Jet Propulsion Laboratory in Pasadena, California for a five-month period following the October 1957 launch of Sputnik I by the Soviet Union, in order to adapt Iowa scientific instrumentation to the Explorer satellites. He was one of the co-discoverers of the Van Allen Radiation Belts. Upon completing his doctorate in 1960, from the University of Iowa, Dr. Ludwig joined the Goddard Space Flight Center (GSFC) in Greenbelt, MD as chief of the new fields and particles instrumentation section. Later he was chief of the information processing division and associate director of data operations. The Goddard Space Flight Center (GSFC) was established on May 1, 1959 as NASA's first space flight center and research laboratory. Its first 157 employees were transferred from the United States Navy's Project Vanguard, but continued their work at the Naval Research Laboratory in Washington, D.C., while the center was under construction. Dr. Ludwig served as Project Scientist for NASA's Orbiting Geophysical Observatory 1, 3 and 5, nicknamed "Street-Car", which carried more than 60 instruments to conduct a wide variety of space science investigations. During his 12-year career at Goddard his positions included Project Scientist; Head, Instrumentation Section; Chief, Information Processing Division, Mission and Data Operations Directorate; and Associate Director for Data Operations. In 1972, Dr. Ludwig joined the National Oceanic and Atmospheric Administration, which was created in 1970. Dr. Ludwig became Director of Systems Integration for the newly established National Earth Satellite Service in 1972 and, three years later, was named its Director of Operations, becoming Technical Director in 1980. In 1981 he became Director of the National Oceanic and Atmospheric Administration's Environmental Research Laboratories, a position he held for two years. Over the next ten years working in Washington D.C. and Boulder, Colorado, he directed the design, construction, and check-out of the Television Infrared Observation Satellite TIROS-N/NOAA polar-orbiting satellite system and many of the evolutionary improvements to the Geostationary Operational Environmental Satellite (GOES) system. Dr. Ludwig returned to NASA as the Assistant Chief Scientist, NASA, Washington DC. He directed a critical examination of NASA space research data management. He retired in 1984. From 1985 to 1991, Dr. Ludwig was a Senior Research Associate at the University of Colorado in Boulder, and from 1989 to 1991 Visiting Senior Scientist for the California Institute of Technology, stationed at NASA Headquarters. Dr. Ludwig led efforts to define the data and information systems for the Global Change Research Program and early-Earth Observing System. He consulted on space research and Space Station design. Among his specialties were designs of radiation-detection instrumentation and orbiting geophysical observatories. In 2004, on James Van Allen Day, in celebration of Dr. Van Allen's 90th birthday celebration, Dr. Ludwig presented a lecture on his contributions with the Iowa Group in the 1950s. He finished the book, Opening Space Research; Dreams, Technology, and Scientific Discovery, published by American Geophysical Union, shortly before his death.