MELiSSA (Micro-Ecological Life Support System Alternative) is a multidisciplinary research project managed by the European Space Agency (ESA) and funded by the Belspo Prodex programme. It started in 1989 and now involves approximately 10 teams throughout Europe and Canada. The aim of this ambitious project is to offer solutions to the issues of food and waste disposal of astronauts during long space missions. From this perspective, the solution prescribed in the MELiSSA project is an artificial microbial ecosystem which, through five interconnected bioreactors, will reproduce the major degradation pathways found in the biosphere. This set of bioreactors contains different bacteria within five compartments in order to produce oxygen, purified water and biomass with plant nutrition. The UMONS Research Institute for Biosciences contributes significantly to this project by providing its internationally recognised expertise in the identification and quantification of proteins in order to better understand the physiological changes of bacteria in space.