Description: The formal description of the Space Instrumentation and Control systems (SICS) software (SW) verification purposes is given. The purposes of operative correcting verification (ОCV) of SW in flight are specified, and the theoretical-set description of functions in view of their criticality and ОCV purposes is offered. Scenarios and indicators for an estimation of SICS availability are proposed taking into account ОCV features. The brief description of SICS availability models for different ОCV scenarios is given. Concept of ОCV strategy and features of its formation are defined.
Keywords: space instrumentation and control system, software, on-line verification, correction of software