HIT-SAT has been designed and developed in order to examine functions of the bus system. It was successfully launched by M-V rocket #7 on 23rd September 2006. The volume and weight of HIT-SAT are about 12[cm^3] and 2.7[kg], respectively. HIT-SAT has a flame-panel structure that consists of 6 panels, 4 columns and 2 shelves made of the aluminum alloy that has a high conductivity. The passive thermal control is adopted. Thermal analysis was conducted using Thermal Desktop/SINDA/FLUINT before launch. However, the result of thermal analysis is quite different from on-orbit thermal data of HIT-SAT. So the thermal analytical model is reviewed. It has been concluded that the main cause is the difference between the assumed attitude of HIT-SAT before launch and the actual attitude of HIT-SAT on the or-bit.
