General Concept of Thermal Vacuum Tests of Space-Appliance Elements at Helium Temperatures.

Three main types of cryothermal vacuum units for testing spacecraft products at liquid-helium temperature are considered. Methods for heat removal from test objects depending on their geometric and thermophysical properties are presented. The designs of the different thermal vacuum chambers are discussed considering the thermophysical processes occurring in them. The operating efficiency of the thermal vacuum chambers and their advantages and disadvantages are estimated based on an analysis of heat-transfer processes. [ABSTRACT FROM AUTHOR]