Energy Storage: Regenerative Fuel Cell Systems for Space Exploration 2011-01-2624

Future exploration missions, including human missions to the Moon and Mars, are expected to have increasingly demanding operational requirements. Generating electrical power, and also maintaining a specific thermal environment, are both critical capabilities for any mission. In the case of exploration, both a wide range of mission types (robotic, human, ISRU etc.) and a variety of environments exist: from interplanetary space, to the shadow of a lunar crater, to the attenuated and red-shifted lighting on the Martian surface, power requirements must be met. This objective could be met with different technologies. The choice is dictated by the operating conditions and the different types of mission. TAS-I is historically mainly involved in missions related to the space exploration with the presence of astronauts. A typical example is the exploration of the Moon with the installation on the Moon surface of a base inclusive of pressurized habitats and rovers. For this kind of application it has been identified as potential candidate the utilization of Regenerative Fuel Cell (RFC) System. The RFC is an electrochemical system that collects and stores solar energy during the day then releases that energy at night, thus making energy available all 24 hours. The process absorbs power from an external source (typically solar panels) and stores energy through the electrolysis process splitting water in Hydrogen and Oxygen. The energy is physically stored inside the reactant tanks, one for Hydrogen and one for Oxygen. When the energy is required the reactants are recombined inside a fuel cell, producing electric power, thermal power and water which is re-used during the next cycle. The research is being carried out by Thales Alenia Space Italy, in the framework of a regional program called STEPS. Thales Alenia Space has been supported in this activity by Politecnico di Torino and Hysytech.TAS-I with the associated team, has developed a 10 kW breadboard of a RFC System and in parallel a preliminary concept of a RFCS for a Pressurized Lunar Rover. The preliminary results on this subject are used to perform a reasoned comparison between this innovative technology w.r.t. Lithium Ion batteries technology.