Quasi-steady Accelerations Onboard FOTON M-3 Spacecraft

The paper presents the results of the full reconstruction of the attitude motion of the spacecraft Foton M-3 during its uncontrolled flight in September 14 — 24, 2007. The motion was reconstructed in the form of solutions of appropriate spacecraft motion equations. We found the solutions by processing onboard measurements of the Earth magnetic field strength. The measurement data were accumulated continually during the whole flight but the processing procedure dealt with data segments, which had length about a few hours. The measurement data on each such segment were processed simultaneously by means of the least squares method and integration of the spacecraft motion equations. This approach gives us the solution that provided the best approximation of measurement data. We adopted the solution as a motion reconstruction in the considered time segment. Then we certain calculated functions along this solution, which allow to calculate quasi-steady accelerations at any point of the spacecraft body. We check our description by comparing the functions found in overlapping data segments.