The Tethered Satellite System (TSS) is a Space Shuttle payload that was flown on July 31, 1992. Though anomalies prevented full deployment, the duration of the mission was approximately as planned, so it was possible to assess system thermal performance. The deployer, which supports the satellite and controls tether movement, has a thermal design that includes multilayer insulation, heaters, and the Spacelab Freon Loop. The Deployer Thermal Subsystem met all requirements, and there were no anomalies during the flight. This paper summarizes the TSS deployer thermal design and compares pre- and post-flight thermal analyses. It also describes simplified personal-computer thermal models of the TSS-1 and presents analysis results for the as-flown timeline.