A chondrule formation experiment aboard the ISS: Experimental set-up and test experiments

Abstract The formation of chondrules in the solar nebula is still an enigmatic process. In order to reconstruct this process, we performed a chondrule formation experiment aboard the International Space Station (ISS), called EXCISS. The purpose of the EXCISS experiment is to acquire new insights in chondrule formation by “nebular lightnings”. During the experiment forsterite (Mg 2 SiO4) particles were repeatedly exposed to arc discharges under long-term micro-gravity conditions. The purpose of this paper is to describe the experimental set-up and establish and benchmark approaches for the analysis of the samples once they are returned from the ISS. We produced aggregates of fused Mg 2 SiO4 particles in our Earth-based experiment which we studied by SEM and X-ray microtomography. The results of our preliminary Earth-based experiments indicate that the chosen experimental parameters will likely lead to melting of Mg 2 SiO4 particles and the formation of aggregates. The results from the first experiments aboard the ISS revealed that the EXCISS experiment is fully operational.