EXPOSE

EXPOSE is a multi-user facility mounted outside the International Space Station (ISS) dedicated to astrobiology. EXPOSE was developed by the European Space Agency (ESA) for long-term spaceflights and was designed to allow exposure of chemical and biological samples to outer space while recording data during exposure. The results will contribute to our understanding of photobiological processes in simulated radiation climates of planets (e.g. early Earth, early and present Mars, and the role of the ozone layer in protecting the biosphere from harmful UV-B radiation), as well as studies of the probabilities and limitations for life to be distributed beyond its planet of origin. EXPOSE data support long-term in situ studies of microbes in artificial meteorites, as well as of microbial communities from special ecological niches. Some EXPOSE experiments investigated to what extent particular terrestrial organisms are able to cope with extraterrestrial environmental conditions. Others tested how organic molecules react when subjected for a prolonged period of time to unfiltered solar light. 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). With the experiments onboard of the EXPOSE facilities, various aspects of astrobiology were investigated that could not be sufficiently approached by use of laboratory facilities on ground. The chemical set of experiments is designed to reach a better understanding of the role of interstellar, cometary and planetary chemistry in the origin of life.