This article provides an overview of the main technical solutions of the Spektr-R observatory (RadioAstron) and the scientific results obtained during its operation at the orbit in 2011—2019. We also briefly described the general characteristics and scientific tasks of the space observatory "Millimetron" ("Spectrum-M"). This observatory is a further development of the "Spectrum-R" project in the sub-millimeter wavelength range and is planned for launch in early 2030s years. The lead scientific organization in both projects is P.N. Lebedev Physical Institute.