Development of a High-Precision Pulsar-Based Lunar Coordinated1 Timekeeping Instrument (Pulsar-LTC)

We present the development of an innovative mission concept to establish a pulsar-based lunar time standard with microsecond precision, supporting the return of humans to the Moon in the next decade, enabling wide-field surveys, and facilitating a broad range of scientific investigations. This approach leverages millisecond pulsars (MSPs) rapidly rotating neutron stars that emit highly stable electromagnetic signals as natural celestial clocks, offering precision comparable to Earth-based atomic clocks, with a significantly lower cost and without the risk of communication loss with Earth. MSPs can serve as reliable, long-term timekeeping references due to their exceptional rotational stability over millions of years, which has been used as precision clocks to constrain Einstein’s theory of general relativity. In this paper, we present the design and analysis of a high-sensitivity instrument optimized for sub-microsecond precision timing, while maintaining a compact physical footprint. We conduct a comprehensive, end-to-end system-level analysis to explore design parameters for a deployable and space-efficient instrument capable of meeting precision timing requirements. Our simulations evaluate key performance metrics, including the field of view, sensitivity, compactness, spillover, noise levels, beamwidth, and overall timing accuracy as functions of feed design, system temperature, integration time, and pulsar characteristics. These initial studies serve as a proof of concept, demonstrating the feasibility of the proposed design and guiding further refinement. Our concept aims to enable high-precision timekeeping on the Moon, with potential applications in navigation, astronomy, and fundamental physics. It also lays the groundwork for a unified and accurate lunar time standard critical for sustained lunar operations, scientific exploration, and international coordination. Furthermore, this approach is scalable and adaptable for deployment at other locations across the solar system.