Two-phase active thermal control systems for spacecrafts

The lower mass flow rate for a two-phase system compared with that of a single-phase system results in benefits in terms of reduced pumping power, system size and weight. The design and testing of two-phase fluid thermal loops for future large spacecraft has been conducted at NASA Johnson Space Center since 1982. This report presents a review and summary of the two-phase thermal system test results of Grumman Thermal Bus System, Lockheed Ground Test Unit and Boeing/Sundstrand Ground Test Article (GTA) Space Station prototypes, which were tested from 1987 to 1993. The thermal-hydraulic performances of the two-phase thermal buses are briefly described and comparison of three bus test results is made. The advantages of the selected thermal bus (GTA) are described.