Laser-induced plasma spectroscopy for in-situ chemical analysis for lander missions to icy moons

Kurzfassung

Several future space missions to planets, moon and asteroids in solar system consider the landers equipped with laser-induced plasma (breakdown) spectroscopy (LIBS) instruments in the scientific payload. This technique provides quantitatively the microscopic in-situ abundances of all major and many trace elements of surfaces of solar system bodies. Since excitation and evolution of the plasma depend on the properties of the investigated material and on environmental conditions, the capability of this spectroscopic method to operate at different pressures, atmospheres as well as for materials with different absorbance must be studied for each individual space mission. We focus on two major parameters affecting laser-induced plasma spectroscopy for exploration of icy moons: transparent icy materials as well as thin atmospheres. We demonstrate the spectroscopy capability for analysis of different frozen salt solutions as well as operation at ultra-high vacuum (below 1 mPa). In both cases we derive the laser power density necessary for creation of a plasma with brightness required for analysing the chemical composition.