Outer Space is an international common area, where exploration and use are recognized as the rights of all countries (Art.1, Outer Space Treaty (OST)). States bear international responsibility for their national activities, including those carried out by non-governmental entities with the requirement of “authorization and continuing supervision by the appropriate State” (Art.6, OST). Due to the operational nature of space activities, it is physically and legally unrealistic to separate them by some territorial criteria. Hence, it is natural for safety operations and other common domains of traffic, such as aviation or maritime, to pursue a certain level of unification of national control, although concrete measures for realizing the OST requirements are entrusted to each State. Thus, establishing an international regime for space traffic management is becoming a critical issue in contemporary space governance. From this point of view, the implementation of Art. 6 of the OST must be revisited as a precedent since it is the sole and explicit requirement of international law for States when controlling their space activities. Practically, national legislation for implementing this requirement is lumbering, even within major space powers. Thus, it is only in this decade that national regulations have rapidly begun to emerge. Based on the analysis of several practical cases, focusing particularly on non-governmental space activities, this paper aims to present the possibility and boundary of effective “authorization and continuing supervision by the appropriate State” to retain effective control, for the safety and sustainability of space activities.