This paper describes results of the thermal-hydraulic performance experiment system (THYPES) of the two-phase flow loop thermal control system using the test rocket which can maintain a gravity level of 10-4G for about six minutes. Feasibility study of this system had been conducted for loading into a experiment module of test rocket TR-IA No. 3. In 1991, engineering model of the experiment system was designed and manufactured in order to investigate its function, performance, and endurance against launching conditions. In 1992, flight model of the experiment system was designed and manufactured. The following tests were conducted so as to ensure the capability and compatibility of THYPES; functional test, performance test, environmental test, and interface tests between the experiment system and rocket avionics section. The experiment was performed on September 17, 1993 and the results are evolved.