To satisfy the cooling demand from a particular space application, a closed-loop two-phase minichannel heat sink driven by a micro-gear pump was developed in this work. The cooling system was made of oxygen-free copper containing 14 parallel channels of the dimension of 0.8 mm (width) x 2 mm (depth) x 20 mm (length). The cooling performance of FC-72 and water was evaluated by the heat transfer coefficient and the pressure drop under different conditions. The analysis shows that both coolants can be used to achieve the design criteiron, that is, a maximum heat dissipation rate of 100 W/cm(2) while keeping the peak heating surface temperature below 90 degrees C. However for FC-72, the limitation is in the critical heat flux, which occurs easily under low-flow-rate conditions that deteriorates the performance of the cooling system. The comparion of boiling heat trnsfer coefficient shows that none of the compared correlations can predict both FC-72 and water data well, with the corrleation developed in 1996 by Tran, Wambsganss, and France achieving the best mean absolute error of similar to 45%.