The thin film solar cells (TFSC, a new development of the German company Solarion GmbH) are a scientific payload of the COMPASS2-satellite.

Their purpose is to increase the available solar-cell-area of the satellite, in order to generate more electrical power for the on-board systems. As the name already indicates, the TFSC are composed of a thin semiconductor layer and a polyimide substrate, which makes them very flexible. For this reason, they can be stored within the leading module of our satellite – with minimum space requirements and protected from external influences. To maintain their shape in orbit, two bistable booms by the German company Cobra Bandstahl GmbH stabilize them.

Once deployed, the TFSC will have a total span of two meters and increase the overall solar cell area of the satellite by 594 cm² (which corresponds to an enhancement by roughly 73%). This makes them an important factor regarding the overall power-budget of the satellite. To determine the level of that impact, different voltage and current states will be measured, to generate a U/I-diagram. Additionally, the TFSC are equipped with temperature sensors to determine the level of their efficiency.