It is proposed the approach to the analysis of SC's thermal condition in orbital flight, based on study of its signal characteristics and thermal optical portraits, which are gotten with various resolutions. The given approach consists of analysis and comparison of measurements in various bands of spectrum of radiation and reflection characteristics of investigated SC, with calculated and experimental data. The calculated estimations of SC's infra-red radiation were carried out for the occurrence on it the typical non-standard situation. In this paper it is proposed the criteria, which can be used during the fulfillment of distant analysis of SC's functional condition on the base of the data of observation of its signal optical characteristics. As the examples of non-standard situations there were considered the solar battery control malfunction, the locking of the heat-transport medium flow rate regulator, the break of the pump in thermal-control system, and the stall of the shield-vacuum heat insulation (SVHI) from the SC body (ref. 1).