Karl Alexandrovich Gilzin (1910–1977) was a Soviet aeronautical engineer and science popularizer. After graduating from the Moscow Aviation Institute (MAI) in 1936 and obtaining a candidate's degree in technical sciences (1949), he devoted his career to popularizing rocketry and astronautics. He authored numerous books on jet and rocket propulsion and co-edited the collective anthology Polyot na Lunu (Trudrezervizdat, 1955), a pioneering near-future science fiction work imagining a Soviet lunar mission fifteen years ahead. His popular science writing, circulated in millions of copies, played a significant role in shaping Soviet space culture in the postwar period.