The use of the infrared camera as a temperature transducer in wind tunnel applications is convenient and widespread. Nevertheless, the infrared data are available in the form of 2D images while the observed surfaces are often not planar and the reconstruction of temperature maps over them is a critical task. In this work, after recalling the principles of IR thermography, a methodology to rebuild temperature maps on the surfaces of 3D object is proposed. In particular, an optical calibration is applied to the IR camera by means of a novel target plate with control points. The proposed procedure takes also into account the directional emissivity by estimating the viewing angle. All the needed steps are described and analyzed. The advan- tages given by the proposed method are shown with an experiment in a hypersonic wind tunnel

Aims. Micrometeoroids (cosmic dust with size between a few μm and ∼1 mm) dominate the annual extraterrestrial mass flux to the Earth. We investigate the range of physical processes occurring when micrometeoroids traverse the atmosphere. We compute the time (and altitude) dependent mass loss, energy balance, and dynamics to identify which processes determine their survival for a range of entry conditions. Methods. We develop a general numerical model for the micrometeoroid-atmosphere interaction. The equations of motion, energy, and mass balance are simultaneously solved for different entry conditions (e.g. initial radii, incident speeds and angles). Several different physical processes are taken into account in the equation of energy and in the mass balance, in order to understand their relative roles and evolution during the micrometeoroid-atmosphere interaction. In particular, to analyze the micrometeoroid thermal history we include in the energy balance: collisions with atmospheric particles, micrometeoroid radiation emission, evaporation, melting, sputtering and kinetic energy of the ablated mass. Results. Low entry velocities and grazing incidence angles favor micrometeoroid survival. Among those that survive, our model distinguishes (1) micrometeoroids who reach the melting temperature and for which melting is the most effective mass loss mechanism, and (2) micrometeoroids for which ablation due to evaporation causes most of the the mass loss. Melting is the most effective cooling mechanism. Sputtering-induced mass loss is negligible.

The SMART-1 flight data provided an excellent opportunity for extending validation of plume prediction codes to actual flight conditions. This paper will present the results obtained for the numerical simulation of the SMART-1 plasma plume using the PICPluS particle in cell code, which had been previously validated using ground experiment data. This activity can be considered as the first important step in the direction of a full in-flight validation for the code models and algorithms. A description of the implemented physical models is provided, followed by simulation results of experimental data from Alta's tests and from the literature. Finally, the results of the code application to the SMART-1 mission are presented, focusing on the simulation of retarding potential analyzer measurement, spacecraft floating potential, and interaction of the plasma field with the satellite (in particular the solar array). The results show that, although the possibility of dangerous interaction between the electric propulsion system and the spacecraft is very limited, a number of complex phenomena arise due to the use of the electric propulsion system in orbit. For example, the interaction between the plume and the solar array orientation leads to complex patterns for the spacecraft floating potential. Eventually, full three-dimensional simulation is therefore needed to accurately model this kind of phenomena with a realistic description of the involved geometries. Nomenclature e = electron charge, C k = Boltzman constant, J=K I = current, A n = number density, m 3 P = probability, -r = position vector, m T = temperature, K Vd = discharge potential, V ", "0 = dielectric constant, F=m = charge density, C=m 3 , ' = electric scalar potential, V

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