The paper presents a collection of magnetic field measurements performed by early Soviet magnetic satellite missions Kosmos-49 (1964) and Kosmos-321 (1970). These data were used as initial data for analysis of the structure of the Earth’s magnetic field sources and for compilation of a series of its analytical models. The most notable model that employed Kosmos-49 data was the first generation of the International Geomagnetic Reference Field for epoch 1965.0.