Rudolf Emil Kalman was an American mathematician of Hungarian descent. The Budapest-born scientist fled WW2 with his family in 1943 and immigrated to the U.S. He lived a long life dedicated to research mathematics until he passed away in 2016, leaving a rich legacy of applied mathematics in signal processing, control systems, and navigation. Kalman earned his B.Sc degree in electrical engineering from the Massachusetts Institute of Technology (MIT) and subsequently attended postgraduate studies at Columbia University, where he received his doctoral degree and wrote his thesis “Analysis and Synthesis of Linear Systems Operating on Randomly Sampled Data” in 1958. After a short research experience at IBM's research laboratory in Poughkeepsie, New York, Kalman took a position at the Research Institute for Advanced Studies in Baltimore, Maryland, where he produced some of his most significant work. In 1964, he left Baltimore to work as a professor of engineering mechanics, electrical engineering, and mathematical system theory at Stanford University. He spent his later academic years at the University of Florida, Gainesville, where he held positions as a graduate research professor in the departments of mathematics, electrical engineering, and industrial and systems engineering. Simultaneously, he was appointed the director of the Center for Mathematical System Theory and took yet another professorship at the Eidgenössische Technische Hochschule in Zürich. Rudolf Kalman has received many of the highest prizes and awards obtainable for academic work in electrical engineering, including the IEEE Medal of Honor in 1974, the IEEE Centennial Medal in 1984, the Inamori foundation’s Kyoto Prize in Advanced Technology in 1985, the Richard E. Bellman Control Heritage Award in 1997, and the National Academy of Engineering’s Charles Stark Draper Prize in 2008. In 2009 he received the National Medal of Science from President Obama. He has been elected to the American National Academy of Engineering, the National Academy of Sciences of the United States, and the American Academy of Arts and Sciences. Internationally, he has also been a member of the science academies in Hungary, France, and the former USSR. The American Mathematical Society awarded Kalman the Steele Prize for his contributions to three papers on the modern theory and practice of control systems: “A new approach to linear filtering and prediction problems” (1960) “New results in linear filtering and prediction theory” (1961) “Mathematical description of linear dynamical systems” (1963) He co-authored the last one with Richard S. Bucy. Hence, the Kalman recursive algorithm filters were once called Kalman-Bucy filters. The paper was initially met with skepticism. However, the NASA Ames Research Center in Mountain View later used the Kalman filter to estimate navigation for the Apollo spacecraft and make the moon landing mission a success.