On the Problem of Determination of a Quasi-Stationary AES Orbit from Ground-Based Measurements

Microaccelerations onboard the Mir orbital station and their impact on the results of hydrodynamic experiments carried out under zero gravity are analyzed. The analysis makes use of the measurements data collected in September-October 1995 in experiments with the ALICE instrument. Microaccelerations were evaluated by means of two procedures: they were measured by the American accelerometer system SAMS (Space Acceleration Measurement System) and were calculated according to telemetric information concerning station orientation. The calculations enabled us to estimate the microacceleration quasi-static component and to compare it with the results of isolation of the low-frequency microacceleration component from the measurement data of the head B of SAMS. After some correction of the measurements data (elimination of the constant displacements, taking into account the orientation of head B sensitive axes with respect to the station construction frame of reference), results of both procedures agree sufficiently well. The methods for preprocessing the information on actual microaccelerations in order to exploit it in computational hydrodynamic problems are described. Also presented are examples of the mathematical simulation of thermoconcentration convection in a closed cavity with liquid, calculated using the data on actual microaccelerations. Feasibility of the onboard analysis of gravitational sensitivity of convective processes in real time is discussed.