This NASA SBIR Phase II project will produce a flight suitable test bench based on a modular spray-cooled assembly that considers NASA power and mass budgets and can be scaled to cool multiple heat sources producing high heat fluxes under gravity and microgravity conditions. Thermal management solutions for certain NASA applications like laser diodes are not all that suitable with a need for a better solution. PELS in a NASA SBIR Phase I project developed a modular assembly based on spray cooling under phase change achieving heat fluxes approaching 100 W/cm2 per evaporator using FluorinertTM
(FC-72) as the cooling liquid. This was possible because of PELS novel fluid removal approach. This Phase II project builds upon the improvements in spray cooling performance by bringing improvements in the packaging to achieve volume and weight gains at the system level so spray cooling can become the standard thermal management solution. The terminal objectives of this SBIR Phase II project are (a) To optimize the design of the modular spray-cooled assembly demonstrated in the SBIR Phase I project, and (b) To extend this design to cool multiple heat sources subjected to heat fluxes approaching 200 W/cm2 under microgravity conditions.