Gravitational orientation mode of transport cargo spacecraft Progress MS-07 and MS-08

We reconstructed the uncontrolled attitude motion of the cargo spacecraft Progress MS-07 and Progress MS-08 in the mode of single-axis gravitational orientation (gravitational orientation of a rotated spacecraft). The orientation motions were realized in April and August 2018. The reconstruction was made using measurements of the spacecraft angular rate. The measurement data, collected in a time interval about 6 hours, 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. The results of reconstruction were checked by measurements of the electric current from the spacecraft solar batteries. The spacecraft orientated motions were rotation around its longitudinal axis with the angular rate $0.1\div0.2$ deg./s, the axes being oscillated near the local vertical.