This paper presents the thermal control system of the Advanced Spaceborne Thermal Emission and Reflection Radiometer ( ASTER ) as a successor to the paper previously introduced. ASTER is a dominant payload of the EOS-AM1 spacecraft which is to be launched in June 1998. ASTER consists of three radiometers, a Master Power Supply ( MPS ), and a Common Signal Processor ( CSP ). The radiometers are the Visible and Near Infrared Radiometer ( VNIR ), the Short Wave Infrared Radiometer ( SWIR ) and the Thermal Infrared Radiometer ( TIR ). Each of these subsystems has an independent thermal control configuration.Tests were conducted in order to validate the thermal design of each subsystem using the engineering models. The models were placed in the space simulating vacuum chamber and they were soaked in various thermal conditions by activating the heaters and chillers of the chamber. Test results were compared with analytical results obtained by thermal mathematical methods. It was proven that test results were identical with the analytical results of the thermal design. Each subsystem meets entirely all the specifications, inducing the appropriateness to enter into the manufacturing phase of protoflight models.