This Small Business Innovation Research Phase I project will demonstrate a vapor compressor driven hybrid two-phase loop technology. The hybrid two-phase loop technology incorporates an advanced evaporator design that is capable of passive separation of liquid and vapor phases at high heat flux conditions. Combining the hybrid two-phase loop technology with a vapor compressor increases the technology's operating range. The integral phase separation feature in the evaporator greatly improves the vapor compressor performance and reliability by preventing two-phase flows in the compressor. The proposed technology is particularly suited for the lunar surface systems where the cooling system size, mass, reliability and operation under widely varying environmental conditions are critically important.