Reconstruction of Rotational Motion of the Progress Spacecraft in the Mode of One-Axis Solar Orientation According to Solar Array Current Measurements

The uncontrolled rotational motion of the Progress M-24M and M-25M cargo spacecraft in the mode of one-axis solar orientation (the so-called “spin on the Sun”) has been reconstructed. The initial conditions of motion in this mode are the spinning of the spacecraft with an angular velocity of 2.2–2.4°/s around the normal to the sunward plane of the solar arrays. The duration of the mode is several orbits. The reconstruction was carried out using an integral statistical method based on telemetric values of the current taken from its solar arrays. As a result, the rotational motion of the spacecraft relative to the Earth–Sun direction is determined. A study of the spectrum of current oscillations during spinning was carried out, which explains the possibility of reconstruction based on such, at first sight, little informative data.