The Institute of Space Systems of the University of Stuttgart (IRS), the Institute of Technical Thermodynamics (ITT) of the German Aerospace Centre (DLR) and the Fraunhofer-Institute for Interfacial Engineering and Biotechnology (IGB) work together in a project on advanced LSS research and development. The IRS will investigate the integration of a photobioreactor (PBR) for algae cultivation as biological component and a reversible proton exchange membrane fuel cell (PEFC) as physico-chemical component into an LSS. Algae in the PBR absorb the carbon dioxide exhaled by the crew and produce biomass (food) and oxygen under light influence. The oxygen can be directed either into the crew cabin or into the fuel cell for generating electricity. Vice versa the electrolysis process splits water (from the PBR or the fuel cell process) into oxygen and hydrogen used as energy storage or propellant. Main task at IRS is a feasibility study on the mentioned technologies, considering the capability of media and product regeneration as well as the ability of integration of the components into a system. Synergies, mass reduction, dissimilar redundancy, and safety enhancement must be taken into account in order to specify integration problems and filtration costs. The IGB supports this study by its expertise in PBR operation, algae cultivation, and algae species selection. The ITT investigates the coupling of the PBR with three different fuel cell types: namely PEFC, SOFC (Solid Oxide Fuel Cell), and AFC (Alkaline Fuel Cell) under electrochemical performance aspects. The influence of PBR products on performance and lifetime of the different fuel cells is of high interest. The potential of potable water and electrical power supply is considered.