Low-Frequency Microaccelerations onboard the Foton-11 Satellite

On the accuracy of the interdiffusion measurements at low and moderate Rayleigh numbers. Some computational considerations

“…Nevertheless, due to the strong directionality dependence of the problem this convective contamination could be adequately minimized for even higher gravity levels constantly orienting the shear cell against the direction of the external disturbance. Table 2 Combination of complex deterministic translational vibrations extracted from the accelerometric data of the FOTON satellite [69][70][71][72][73][74]. C i (x, y) are scalar values without dimensions and the values of F i (x, y) are related to the orbital frequency of the abovementioned satellite (F 0 = 0.0405 or 0.205 for semiconductors or liquid metals respectively).…”

“…Obviously, this is not the real case, and to close the present considerations it is mandatory to evaluate the possible modifications generated by the simultaneous consideration of Table 2 [69][70][71][72][73][74], considering only the most active frequencies in the region around the maximum F = 0.5. In this way, the corresponding Rayleigh numbers can be derived from the data of Table 2 considering that, Raðx; yÞ ¼ Ra 1 ðx; yÞ þ Ra 2 ðx; yÞ ½ð1 þ sin 2pF 2 ðx; yÞtÞ sin 2pF 1 ðx; yÞt, with Ra i ðx; yÞ ¼ 0:05625C i ðx; yÞ; i ¼ 1; 2 in the melted semiconductor case or Ra iðx;yÞ ¼ 0:5625C iðx;yÞ ; i ¼ 1; 2 in the case of liquid metals.…”

Application of Fractal Analysis While Designing of Family of Spacecraft for Needs of Space Industry

“…The values of amplitudes (in successful and unsuccessful series) differed more than in 20 times. Later, during measurements of microaccelerations on the board of specialized technological spacecraft "FOTON-11" by French equipment BETA, the situation was similar [4]. Microaccelerometers, installed at different axes of bound coordinate system, showed data that differed more than 20 times.…”

“…Nevertheless, there were not any obvious causes for it. Sazonov et al [4] suppose that the software of BETA equipment was applied incorrectly. However, failure of some microaccelerometers is quite possible too.…”

Control of the apparent acceleration of a rigid body attached to a movable base by means of a two-degree-of-freedom gimbal

“…An analysis of the quasi static acceleration (see [8][9][10]) revealed that its magnitude and direction undergo significant changes with time, which are random because this acceleration is induced by random factors. Therefore, one cannot exclude the influence of the spatial evolution of the quasi static accelera tion vector on gravity sensitive processes using feedforward (calculated in advance) control of the mount rotation relative to the spacecraft.…”