Reconstruction of the spacecraft Monitor-E attitude motion by measurements of the current from solar arrays

The spacecraft Monitor-E was out of control owing to off-optimum situation and there was not telemetry data about its attitude motion. The problem arose to reconstruct that motion by the accessible indirect information, i. e. the data of the electric current generated by solar arrays of the spacecraft. We describe the statistical technique that solved this problem. According to the technique, the measurements of the current, collected on a time interval about a few tens minutes, were processed simultaneously by means of the least squares method and integration of the spacecraft attitude motion equations. The estimations of the mathematical model parameters and initial conditions of an attitude motion were obtained as a result of such processing. We quote the results of processing of 12 segments of data, which allowed to reconstruct the spacecraft real attitude motion.