Small satellites for benchmark measurements of aerosol transport parameters

Small satellites are of high interest for benchmark measurements of aerosol/dust particle transport properties that are widely used in science and technology. Among the motion phenomena are thermophoresis, photo-, diffusio-, gravito-photo phoresis, chemojet and many other types of particle motion driven by physicochemical transformation and accommodation peculiarities on the particle-gas interface. There is a strong need in high quality experimental data with vivid interest to expand the scope for non-isometric particles, agglomerates, dense clouds.

Microgravity is the most favorable condition to get accurate results. Particularly, microgravity suppresses particle sedimentation, gravity driven convection; it facilitates precise measurements for big particles and/or in rarefied gases. Current technologies provide at least ten times increase of the accuracy, i.e. better than 10^-4 with respect to particle velocity in free-molecular regime, making reference measurements in microgravity for most wide range of precisely known Knudsen number, thermal conductivity ratio and accommodation properties. Contrary to the current practice, fitting parameters may and should be excluded from interpreting the data.

Such program should envisage accumulation of relatively big amount of data obtained within a uniform approach. It is of clear educational interest and may be supported/executed by university groups.

ESA PRODEX program, the Belgian Federal Science Policy Office is greatly acknowledged.