To accomplish the dream of continuous presence on the Moon, humanity has to face many challenges. A major one is to provide continuous electrical power to all the necessary installations on the surface during the long lunar nights or in the dark polar craters. This study explores the design and optimization of one solution to this problem: space-based solar power (SBSP). The SBSP system consists of one or more solar power satellites, generating power and transmitting it remotely to a receiver on the surface.

Two system concepts are investigated: a constellation of satellites in lunar elliptical frozen orbits and a single satellite in the L1 Lagrange point. Both concepts are designed to deliver at least 100 kW of continuous power to the lunar surface through laser power transmission. The study combines sizing of the spacecraft, the ground element, propagation of the final trajectory and a detailed model of the transmission efficiency to find an optimal design for both concepts. The space elements make use of concentrated photovoltaics, an active fluid loop and a high-power laser, while the ground elements are build out of modular elements of either stretched lens arrays or heat pipe cooled laser power converters.

Selected subsystems of the lunar orbit constellation have been designed in more detail, resulting in a 7 satellite constellation of 2247 kg per satellite a 816 kg modular ground element. Both the Lagrange point and lunar orbit architectures outperform alternative power systems (nuclear & microwave-based SBSP) in terms of launch costs by almost an order of magnitude on average.