Aerospace Instrument-Making Annotation << Back Decisional Rule Providing the Required Probability of Selecting the Most Dangerous Space Object from the Multiple Observed by a Near-Earth Space Monitoring Space Car Klyuchkin А.K Introduction: a large number of artifi cial space objects have accumulated in nearearth space. They pose a threat to spacecraft. To detect the most dangerous objects, it is planned to use specialized spacecraft equipped with optical-electronic means. The problem arose of choosing the most dangerous object from the multitude of heterogeneous selective features observed from the results of measurements that characterize them. Purpose: form a complex dimensionless indicator, depending on the quantity and quality of measurement information about the observed space objects, and the decisive rule for choosing the most dangerous object that provides the maximum probability of making the right decision. Results: a method is proposed for selecting the most dangerous space object with limited volumes of measurement information about physically inhomogeneous selective features of space objects located in the area observed by a specialized spacecraft. In this case, measurement data on individual selective features of space objects may be absent. The proposed decision rule for the selection of the most dangerous space object takes into account not only errors, but also the number of measurements of the selective characteristics of each object. The effi ciency of the method has been demonstrated on an up-to-date example. Practical relevance: the simplicity of the determination of complex indicators characterizing space objects that are in the observation area of a specialized spacecraft, and the decisive rule for choosing the most dangerous object makes it possible to solve this problem on board a specialized spacecraft in real time. Keywords: Most dangerous space object, selective signs, specialized spacecraft, observation, complex indicator. DOI: 10.25791/aviakosmos.12.2023.1379 Pp. 29-38.