GoSolAr – A Gossamer Solar Array Concept for High Power Spacecraft Applications using flexible Photovoltaics

In recent years the German Aerospace Center (DLR) developed Gossamer deployment systems in different projects. DLR recently focused on the development of new deployable photovoltaic (PV) technologies that are suitable for generating 10's of kW per array as power requirements of spacecraft are getting more and more demanding. Possible space applications that may also require high power supply are missions using electric propulsion like interplanetary missions, placing of geostationary (GEO) satellites in their orbit or even more future oriented as space tugs or lightweight power generation on extraterrestrial infrastructures. The paper gives an overview about a feasibility study for a flexible solar array based on new thin-film photovoltaics. It is expected that the combination of new thin-film PV technologies, e.g. Copper Indium Gallium Selenide (CIGS) cells, together with Gossamer deployment technologies, could significantly increase the power availability for spacecraft. Based on a requirement analysis system concepts were evaluated. A focus is on the potential of CIGS PV combined with a two-dimensional deployment of the array and DLR's coilable Carbon Fiber Reinforced Plastic (CFRP) booms. Therefore, a concept based on crossed booms with a foldable PV membrane is considered as baseline for further developments. The array consists of rectangular PV generators that are interconnected by flexible Printed Circuit Board (PCB) harness. By a double folding technique these generators are laid on top of each other in such that the membrane can be extracted from its stowing box during the deployment in a controlled manner. Considering constantly increasing efficiencies of the CIGS PV combined with Gossamer structures, there is clear potential of reaching a very high specific power value exceeding that of conventional PV systems. Furthermore, the CIGS PV appears to be more radiation resistant and has already reached more than 20% efficiency in laboratories. Such efficiencies are expected to be achieved in the near future in a standard manufacturing process. DLR's research has the goal to develop a Gossamer Solar Array (GoSolAr) in order to investigate and exploit the described potential.