The present invention relates to a device for storing and restoring electrical energy comprising a chamber in which water electrolysis means, a fuel cell, and monitoringcontrol means for monitoring the operation of said device in the fuel cell mode or the electrolyzer mode are arranged. In one embodiment, an integrated circuit has at least three cooperating frequency domains with variable operating frequencies. The hub satellite, using the aggregator payload, aggregates at least two data flows received from the at least two client satellites over an inter-satellite link, by the inter-satellite communications payload, into a data stream that is downlinked to the ground station, using the downlink communications payload, over a space-to-ground link.