The paper deals with an analysis of the results of theoretical and experimental research on an evaporating system for cryogenic support as supplied to long length thermostatting channels of high-temperature superconducting (HTS) cables and hybrid power transmission lines as well as thermal control systems for cryogenic components in aircraft fuel tanks during long-term spaceflights. Experimental evidence for nitrogen and hydrogen are presented here. The importance of such research for practical application in developing modern cryostatting systems has been highlighted. The design of an experimental hybrid power transmission line for studying thermostatting of superconducting power cables has been considered in the paper. The transmission line contains three sections with different types of thermal insulation and current leads providing high current supply to superconducting threads with minimum external heat inflow. The unique experimental data on heat inflows from the outer surface of the transmission line in different sections has been obtained by the authors. It is shown that it may be possible to compensate fully for external heat inflow to a cryogenic line as well as to lower the temperature of a cryogenic coolant in the section with an evaporating system for cryogenic support. In order to determine the possible length of the cryostatting work field of a long length superconducting cable, estimates of using liquid nitrogen and liquid hydrogen as a working fluid for various mass flow rates of the coolant feed have been made via the mathematical model describing physical processes in a thermostatting channel using an evaporating system for cryogenic support. Calculation data on changes in the length of the long length temperature cryostat, pressure and cooling capacity of the evaporating cryostat system has been obtained. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.