The discussion of Space Traffic Management (STM) has rapidly emerged over the past couple of years but policy decisions or concrete actions are yet to be ignited to date. From the beginning of discussions of the Draft International Code of Conduct for Space Activities (ICOC), a combination of a top-down approach engaging the political commitments of States and a bottom-up approach of technically affordable solutions have become essential for realizing sustainable space activities at a global level. These approaches are the logical conclusion of the need to establish common standards and safety regulations across the entirety of operations in outer space. However, after experiencing the multiple disappointments of topdown approaches, some began as bottom-up approaches but ended up as top-down, including the Draft Best Practice Guidelines for the Long-Term Sustainability of Space Activities at Committee on the Peaceful Uses of the Outer Space (COPUOS), ICOC, and the Report of the Group of Governmental Experts for Transparency and Confidence-Building Measures in Space Activities; therefore, methods of engaging actors must be carefully designed. At this point, considering from the actors’ incentives, a bottom-up approach among civil operators towards global STM rule-making for safe space operations should be promoted. This paper will describe the main reason why the operators have to be the main players at this stage, based on the reluctance of States to regulate traffic in outer space. States are unlikely to regulate other traffic areas, apart from their incentive to maintain the order of the area, as they do not have sovereignty over any part of the area. Civil operators, on the other hand, will become liable for damages due to on-orbit accidents in the near future. The current evaluation standard of fault liability for on-orbit damage will change in the near future, due to the accumulation of cases involving the practical standards of operations. In these circumstances, those operators who do not conform to the stipulated standards will be deemed liable for damages. Therefore, at this stage, operators have incentives to take an important role in the de facto rulemaking process by producing practical standards and guidelines. This process will help secure the future of space activities while forming standards of fault liability affordably.