Edition. IKI RAN, 71 pages . The monograph develops the theory of planning the search for a space object on rough a priori information about the parameters of its orbit. The basis of the theory is the theoretical-multiple representation of the field of certainty of the current position of the desired object ,. formulation of the principle of equivalence of elements of the search plan for different moments of time (also in the theory-multiple interpretation) , athematic description of the phenomenon of degradation of the search plan in the process of its implementation. On the developed theoretical basis, a set of methods for optimal and suboptimal planning of the search for a space object for a variety of search situations is built. Planning the search for a space object on the basis of the above theory is most effective when using narrow-field (optical) and narrow-beam radar, laser) means of observation and with a weak useful signal from the desired object Keywords: space object, state vector, search plan, search theory, means of observation (sensor), observation, measurement, detection, efficiency.