Coatings for solar cells for space applications need to be both robust and high-performance. Especially for very high efficiency solar cells, reductions in overall reflectivity translate into improved performance. The coatings also have to withstand the extreme environments of space including thermal cycles and strong ultraviolet radiation. In this paper, broadband coatings are designed by a genetic algorithm to optimize for a particular response, and then fabricated by sputtering both individual layer and gradient-index mixtures of materials per the recipe. The fabricated coatings realized excellent broadband response at both normal and oblique incidence, on both silicon and glass substrates and showed minimal morphological and performance changes after extensive thermal cycling. This demonstrates the potential utility of these algorithmically-designed sputtered coatings for space power systems.