The DLR is currently exploring the feasibility of an on-board ship detection system, prospectively installed on Earth observation satellites. The applications are manifold: illegal activities like piracy, unauthorized fishery, refugee shipment, illegal cleaning and ocean dumping are daily occurrences. Furthermore, such a system can support live saving by detecting dangerous situations like sinking ships and facilitate fast reaction in case of oil spills or other sea pollution. The key value for all these applications is the topicality of information. By now, near-realtime services offered by data processing centers on ground can provide information in the range of 15 minutes measured from on-ground data reception. Obviously, the bottleneck in this process is the time delay occurring between data acquisition and reception on ground. To react as fast as possible, product data like position, velocity, heading and condition of maritime objects are of interest, while high-quality image data in full spatial and spectral resolution is not obligatory in the first instance. The on-board system introduced hereafter is intended to provide the mentioned product data in real-time and independent of a direct contact to a ground station. The aim is to completely overcome the usual delay emanating from the process of data acquisition, on-board storing and downlink. Furthermore, the product data can be received on any smart device on ground independent of its locality.