The Thermionic System Evaluation Test (TSET) facility, part of the TOPAZ International Program, in Albuquerque is currently testing Russian TOPAZ II space power systems (Wold 1993). The TOPAZ International Program has received six TOPAZ II Space Nuclear Power Reactors. Two of these reactors (Eh‐43 and Eh‐44) are considered ‘‘flight quality.’’ A considerable transfer of technology has occurred during the preparations for acceptance testing of the Eh‐43 and Eh‐44 TOPAZ II reactors. Eh‐43 and Eh‐44 are new systems that require the coolant loop and gas cavities to be filled and have not undergone any testing. In comparison to the tests performed on the V‐71 and Ya‐21u systems, the future operations with the flight units Eh‐43 and Eh‐44 will require expansion of the Baikal Test Stand’s capabilities. © 1995American Institute of Physics