Effective thermal management is a critical aspect of spacecraft design, ensuring operational safety and reliability of systems in the harsh and variable space environment. For long-duration missions, such as the Lunar Gateway, thermal regulation is especially vital to protect sensitive equipment and ensure crew comfort. Most cold-plate designs (such as the ones currently adopted on the Gateway as baseline), however, face significant limitations: they are not optimized concerning thermal efficiency, they are inhomogeneous in terms of materials and manufacturing, and contribute sensibly to the overall mass of the modules. The present thesis addresses these challenges by proposing an optimized cold-plate architecture designed taking into account the requirements of the International Habitat (I-HAB) module on the Lunar Gateway.