text: EXPOSE has several objectives, specific to each experiments, but all linked to the astrobiology domain. Their collective objective is to better understand the nature and evolution of organic matter present in extraterrestrial environments and their potential implications in astrobiology. These experiments mostly study molecules of cometary interest in order to understand the results of the Rosetta mission, the chemistry of Titan (Cassini–Huygens mission), or the organic chemistry of the Martian environment (Mars Science Laboratory and ExoMars project).