Inherent features of Laser Induced Breakdown Spectroscopy (L IBS), such as fast in-situ determination of the rich elemental composition of materials, high late ral resolution and depth profiling, have been cons idered for the development of mini aturized LIBS instruments for the next planetary missions to Mars 1 , Europa 2 and the Earth’s moon 3 . Due to the strict mass limitations, the laser for plasma excitation will pr ovide not more than a few mJ per a few ns radiation pulses. Remote LIBS analysis implie s that preparation of rock materials is not possible and that changing local atmospheric and radiation conditions have to be taken into account. For the interpretation of planetary LIBS data it is therefore mandatory to study in detail the experimental conditions whic h may occur on a planetary surface.