FEMME: a precursor experiment for the evaluation of bioregenerative life support systems

In long term manned space missions, oxygen, water and food supplies are a c ritical issue. Bioregenerative systems, and among them those relying on mic robial processes, represent one of the most promising alternatives. Studies of these systems from the engineering point of view, requires the developm ent of mathematical models and their validation with small scale experiment al systems (breadboards, pilot plants, etc.). Usually, these studies do not take into account the effects of space environment (i.e. reduced gravity o r microgravity, radiation, direct sunlight, temperature, etc...). Despite s everal scientific experiments, intending to qualify such effects, only few quantitative results are available. In this paper, the possibility of an au tonomous off-board experiment, named the First Extraterrestrial Man Made Ec osystem, is investigated. The experiment is based on a very simplified ecos ystem consisting in a photoautotrophic compartment and a heterotrophic one, linked by their gas phase. According to its biological concept, this exper iment should provide data on microbial growth kinetics in space, and the ef fects of radiation and gravity. It has been conceived as an entirely automa tic device. Its design involves several technological concepts such as ther mal control, the use of direct sunlight and radiation shielding. This work is done under the framework of ESA biological life support systems research program. The aim of this document is to provide a preliminary concept of t he experiment. (C) 2000 Elsevier Science Ltd. All rights reserved.