Engineering Readiness of Lunar-Orbit Laser Power Beaming Technology Maturity and Qualification Roadmap

Laser power beaming from lunar orbit to surface users can enable survival through lunar night, support permanently shadowed regions (PSRs), and reduce the mass of surface energy storage for distributed or duty-cycled loads. The physics and mission-level performance trades (orbits, geometries, and delivered-energy maps) are treated in detail in [1]; this paper is a companion engineering assessment focused on implementation realism and technology maturity. We decompose the system into Critical Technology Elements (CTEs), summarize the demonstrated state-of-the-art (ground and on-orbit) with quantitative figures of merit, assign Technology Readiness Levels (TRLs) using standard definitions, and specify a verification matrix and development gates required to close from laboratory/adjacent-flight heritage to a flight-qualified lunar-orbit service. To maintain an auditable engineering basis, we provide transparent mass/power/thermal closures for three reference space segments (Deff = 2 m, Ptx = 10 kW; Deff = 5 m, Ptx = 30 kW; Deff = 10 m, Ptx = 100 kW), including solar-array area, radiator area, and rough dry mass using explicit specific-power and areal-density assumptions. The assessment identifies the principal maturity gaps for space-based phased-array lasers as: (1) diffraction-limited, kW-class optical channels with multi-year life in radiation/contamination environments; (2) high-bandwidth phase metrology and control that sustains ∼ 100 nm optical-path stability across multi-meter apertures under spacecraft disturbances; and (3) integrated pointing/acquisition/tracking (PAT) delivering sub-µrad jitter when coupled to large deployables. For the surface segment, the dominant gaps are the packaging of high-efficiency laser power converters (LPCs) and thermal/dust mitigation that preserves ηsurf under lunar exposure.