Аннотация:The development of the multi-purpose spectrometer of electrons with energies ~0.1...10 MeV, protons with energies ~2...160 MeV and α-particles with ener- gies of several MeV for installation in CubeSat format is presented. The main element of the spectrometer is a telescope assembly, including semiconductor (silicon) detectors with different thickness, which are placed coaxially one under the other. To measure the pitch-angle distribution and omnidirectional fluxes, several telescopes with differently directed axes can be used. Direct measure- ment of omnidirectional particle fluxes can be realized using spacecraft rotation. The axis of rotation should be perpendicular to the Equatorial plane. An active orientation system of the spacecraft is not critical for mission success, but the availability to point exact directions with accuracy not less than 5° can signifi- cantly expand scientific mission objectives. The main operational mode is when all detectors are switched-on and operate continuously. Instrument switching be- tween operational modes is carried out by commands from the ground station or by the internal scheduler of the control unit. To optimize the payload energy consumption, several energy-saving modes to be implemented (different sam- pling rates from full-speed operating up to partial switching-off).