Uncontrolled Attitude Motion of the Orbital Station Mir in 1999.
Abstract:
The techniques are described for determining uncontrolled attitude motion of the orbital station Mir by means of processing on board measurements of the Earth magnetic field strength and telemetry information about the station orientation parameters and angular rates. The measurement data of the same type, collected on a time interval about a few hours, are processed simultaneously by means of the least squares methods and integration the station attitude motion equations. The estimations of the mathematical model parameters and initial conditions of an attitude motion are obtained as a result of such processing.
The techniques allowed to determine the real station attitude motion in September - December 1999. The motion is divided on two segments. In the first segment (September 7 - 24), the station rotated around its axis of the minimal moment of inertia, which made small oscillation near the normal to the orbital plane. Such mode of the station attitude motion was used for the first time in the Russian practice. In the second segment (September 24 - December 7), the station was in the mode of biaxial rotation at first and then, after some weeks, it passed to the single axis rotation around the normal to the orbital plane but around the axis of the maximal moment of inertia.
