Development of methods of conducting microgravity experiments in free flight of Progress M-20M logistics vehicle

The paper discusses experiments designed to select uncontrollable rotation modes of Progress spacecraft for conducting microgravity studies. 1t provides results of determining uncontrollable rotation of Progress M-20M logistics vehicle in the mode of gravity orientation of the rotating spacecraft, which provides a fairly low level of residual microaccelerations. The studies were conducted for three variants of satellite rotational motion in the given mode of one-axis gravitational orientation: with angular rate w = 0,1 °/s about the longitudinal axis of the logistic vehicle, with angular rate w = 0,15 °/s about the longitudinal axis of the logistic vehicle, and angular rate w = 0,2 °/s about the longitudinal axis of the logistic vehicle. As a result of processing telemetry data on angular rates and solar array currents, initial motion conditions and parameters of the math model that was used were evaluated. It was shown that the implemented variants of the gravitation orientation mode provide stable angular motion of the logistics vehicle, sufficient electrical energy input and residual microaccelerations, that are acceptable for conducting microgravity studies. Development of gravitation orientation modes was carried out within the framework of preparations for conducting experiments with convection sensor DAKON onboard Progress spacecraft.