Experiments with attitude motion of spacecraft Progress

We reconstructed the uncontrolled attitude motion of the spacecraft Progress M-15M and Progress M-17M during experiments carried out in the mode of single-axis solar orientation. At the beginning of the oriented motion, the spacecraft rotated around the normal to solar batteries with angular rate 2.2 deg./s and the normal was directed to the Sun. The oriented motion lasted for a few orbit revolutions. The reconstruction was made using measurements of the spacecraft angular rate and the electric current from their solar batteries. The measurement data, collected in a time interval about a few tens minutes, were processed simultaneously by statistical methods and integration of the spacecraft attitude motion equations. The estimations of the mathematical model parameters and initial conditions of the attitude motion were obtained as a result of such processing. We investigated two variants of the orientation mode realized in the flight of Progress M-17M when the spacecraft was rotates around different but near axes. The experiments were made for preparation to the experiments with convection sensor DACON-M.