Abstract <p>The paper considers various options for implementing the orbital orientation mode of a spacecraft intended for conducting experiments in microgravity conditions over long time intervals. The system of gyroscopic controls (gyrosystem) is used as the actuators of the angular motion control system. The gyrosystem control laws proposed in the paper allow not only to provide a given orientation of the spacecraft, but also to limit the accumulation of the gyrosystem’s own angular momentum, which significantly increases the duration of time intervals of unperturbed motion of the spacecraft. The efficiency of the considered control laws in the presence of external destabilizing disturbing moments acting on the spacecraft is confirmed by the results of numerical modeling of the equations of motion. The main orientation mode of the spacecraft investigated in the paper is its orbital orientation using gyrodamping. For this mode, an assessment of the level of quasi-static microaccelerations occurring on board the spacecraft is carried out, and the results of their spectral analysis are shown.</p>