Mathematical processing of results of experiment “Dynamics-M” carried out onboard the spacecraft Foton M-3

We consider the space experiment on determining quasi-steady accelerations onboard an artificial Earth satellite by the video images of freely moving objects. The experiment was carried out in the spacecraft Foton M-3. A few pellets moved in the cubic box, which was fixed on the spacecraft body and had two transparent adjacent walls. The digital TV camera shot their movement. The camera was placed opposite to a transparent wall; the mirror was placed angle-wise to another transparent wall. This optical system was able to receive images of the pellets from two points of view in a frame. Shooting of pellet movements was made in time intervals of 96 seconds. Pauses between those intervals equaled 96 seconds too. Special processing of each frame allowed to determine coordinates of the pellet centers in the camera coordinate system. We processed sequences of frames, obtained in an interval of continuous shooting, in the following way. Using the least squares method, we constructed parabolas that approximated time dependence of pellet coordinates. The coefficients of time squares equaled a half of corresponding components of acceleration. Processing showed that the described method of determining quasi-steady acceleration appeared quite sensitive and exact.