The operating regimes and basic control principles of SNPS ‘‘Topaz’’

The basic operating regimes of space nuclear power system (SNPS) ‘‘Topaz’’ are considered. These regimes include: prelaunch preparation and launch into working orbit, SNPS start‐up to obtain desired electric power, nominal regime, SNPS shutdown. The main requirements for SNPS at different regimes are given, and the control algorithms providing these requirements are described. The control algorithms were chosen on the basis of theoretical studies and ground power tests of the SNPS prototypes. ‘‘Topaz’’ successful ground and flight tests allow to conclude that for SNPS of this type control algorithm providing required thermal state of cesium vapor supply system and excluding any possibility of discharge processes in current conducting elements is the most expedient at the start‐up regime. At the nominal regime required electric power should be provided by maintenance of reactor current and fast‐acting voltage regulator utilization. The limitation of the outlet coolant temperature should be foreseen also.