Preliminary analysis and simulation of a multi-stage pointing system for wireless power transmission

Major space agencies plan to establish permanent lunar bases by the 2030s, spearheaded by NASA’s Artemis program. NASA has identified the Moon’s South Pole as the ideal location for the future Base Camp, owing to its potential access to ice and continuous illumination. One of the significant challenges to be solved is power generation, as the peculiarities of the lunar environment make solar power unreliable as the sole power source, while alternatives such as nuclear power come with drawbacks of their own. The startup ORiS has proposed a novel solution to achieve continuous power delivery to the lunar soil: a constellation of satellites equipped with solar panels, that would accumulate energy along the orbit and transmit it to a receiver located on the surface with a high-power laser system. The transmission distance of about 1000 km requires controlling the mirror which deflects the laser beam with sub-microradian accuracy, a requirement far more stringent than what a typical satellite attitude control system (ACS) can achieve. In addition, the operation of the satellites’ onboard systems generates low-amplitude, broadband disturbances known as microvibrations, which cannot be compensated effectively by the ACS, driving the need for a dedicated pointing system. This work deals with the analysis of the pointing problem, from the formulation of the requirements up to the preliminary design and simulation of a potential laser beam steering system based on the state of the art of the field. The proposed solution is a multi-stage system, where the coarse stage performs pointing and a fine-steering mirror actively isolates the mirror from microvibrations while compensating the residual error of the previous stages. The addition of passive isolation to the coarse stage is shown to provide a degree of robustness and reduces the dynamic requirements of the fine stage. The mechanism was modelled in the Simscape Multibody environment and integrated with a model of the ACS to assess the overall pointing performance of the satellite under the effect of both environmental disturbances and on-board vibrations, demonstrating the system’s ability to meet the pointing requirements while leaving room for higher-fidelity models and further subsystem integration in future work.