this step has been made by the new generation germanium substrate gaas cells developed by researchers at cise -lsb- center for data , studies , and experimentation -rsb- in milan -lrb- an enel -lsb- national electric power company -rsb- research company -rsb- and successfully tested for 11 months on the eureca -lsb- european retrievable carrier -rsb- platform in space from which they have now returned for further laboratory tests .