In this project, Dr. Cao and team will be developing a miniaturized, low-power, ultra-stable fluxgate magnetometer system for prolonged, uninterrupted operation on the lunar surface. The system incorporates a low-power, magnetically-clean thermal solution to achieve a temperature stability of 0.2 degrees Celsius at two distinct set-point temperatures, one for the lunar day and the other for the lunar night, to minimize fluxgate sensor offset drifts. This instrument will facilitate high-precision monitoring of the lunar magnetic fields across different timescales, enabling survey of the lunar surface magnetic environment and low-frequency electromagnetic sounding of the lunar deep interior. These measurements will provide invaluable insights into the bulk water content of the lunar mantle, characteristics of the partial melt layer above the lunar core, and the physical properties of the iron core of the Moon; thus, placing critical constraints on the formation and evolution of the Earth-Moon system.