Scalable and Sustainable Microwave Power Beaming to Mobile Lunar Surface Assets

Abstract

Lunar missions are hindered by the challenges of maintaining continuous operation, especially during the 14-day lunar night, when solar power sources may be unavailable, causing significant mission delays and limiting efficiency. Frequent returns to charging stations supplied by fixed lunar surface power plants further disrupt workflows and restrict the operational range of lunar vehicles. To address these issues and enhance lunar mission performance, a continuous, secure, and shareable power source is essential. While nuclear power and larger battery systems are viable options for continuous lunar energy supply, they pose challenges such as safety risks, complex deployment, and limited scalability. This thesis focuses on exploring microwave-beamed power systems as a flexible and scalable solution for sustained lunar operations. Ideally, the power source would enable 24/7 operations without requiring vehicles to return to base stations, allowing for unrestricted navigation across the lunar surface, including in permanently shadowed regions (PSR). In addition, it would support the construction of critical infrastructure, accelerating the development of the lunar economy. This thesis aims to support sustained lunar exploration and infrastructure development by exploring the design space for microwave-beamed power systems under three different demand use cases of increasing scale, loosely corresponding to the three phases of the Artemis program: Local (Shackleton Crater), Regional (navigation between equatorial regions and South Pole), and Global (entire lunar surface). A case study focused on the YUTU-2 lunar rover investigates alternative architectures for each use case, comparing power beaming from tall towers vs. satellites. Evaluation reveals that the most effective solution for the Local use case is a tower-based approach featuring a single 100m tower, >10,000 solar modules, and using 1 GHz operating frequency, at a cost of $3.4M/W. For the Regional use case, a satellite-based solution is preferred, utilizing 6-7 satellites per plane, 210,000 solar modules, and a frequency range of 1.0 GHz, at a cost of $1.7M/W - $1.8M/W. The Global use case also favors a satellite-based approach, employing 6 satellites per plane across 5 polar planes, with varying numbers of solar modules and utilizing a frequency of 1 GHz, at a cost of $0.8M/W. The trade studies showed that larger receiver antenna areas and lower frequencies improve performance and cost-effectiveness. Furthermore, larger microwave-beamed power systems leverage economies of scale, lowering the cost per watt by an average of $1M/W when scaling from the Regional to the Global power system, with potential for further reductions through future expansions.