The National Aeronautics and Space Administration (NASA) Space Station Freedom (SSF) will use Flow-Through Radiators (FTRs) to reject waste heat that is collected from the on-board Heat Acquisition Devices (HADs). The waste heat is sent to the FTRs via the Pump Module Assembly (PMA) subsystem of the External Active Thermal Control System (EATCS). Two developmental FTR panels were integrated with the EATCS Ground Test Article (GTA). The integrated components were investigated under a thermal/vacuum environment in Thermal/Vacuum Chamber A at NASA/JSC during June, 1992.A detailed SINDA/FLUINT FTR model was developed to predict the steady-state thermal/hydraulic performance of the FTRs. A simplified SINDA/FLUINT FTR model was also developed for use in the GTA integrated model. Schematics and plots comparing the test data and model results are presented for both steady-state and transient conditions.