In this talk, I will present some results of a survey on the conception and the uses of a space System, the International Charter "Space and Major Disasters". Initiated in 1999 by the French and European space agencies (CNES and ESA) (and subsequently joined by a dozen other national space agencies), this innovative satellite system is designed to assist the "management" of impacts of major disasters, such as earthquakes, volcanic eruptions, floods, tsunamis, cyclones, fires, or oil spills. The space agencies and partner organizations (data providers, rapid mapping services) operate a constellation of Earth observation satellites (e.g. SPOT) immediately following a disaster; this body generates free of charge cartographic products based on satellite images (e.g. before-and-after maps used to depict the extent of the damage) that will be transmitted to authorized end users (civil protection agencies, NGO, etc.) for rescue operations. Since 1999, the Charter was activated during major disasters, like Katrina, the 2010 Haiti earthquake, the 2011 Japanese tsunami, and very recently during Hurricane Sandy. But these rapid cartographic satellite data based products are not the only outputs of the Charter. New functions were progressively tested (risk assessment and anticipation models, simulations of disasters, and geographic information systems), which demonstrates the plasticity and adaptability of the system. How is satellite information acquired and formatted? How is this collective activity distributed during an emergency operation? How is the "responsiveness" of this satellite system planned and organized? What kinds of mechanisms regulate the circulation and uses of these data? I will give some answers to these questions by combining a multiplicity of information (interviews, direct observations of activations, technical documentation, etc.). I will show how various dimensions (technical, organisational, socio-economic, and political) are articulated within the system. It will be argued that the Charter (among other examples) reveals a marginal but informative reconfiguration of the previously well-established jurisdiction of space activities and expertise, which is increasingly engaged in the fields of biosecurity and ecological engineering.