Shared time across the Moon

New Moon missions are being planned everyday but technical and political challenges are abound. One key question plagues these endeavours: what time is it on the Moon? Satellites - like computer systems on Earth - are typically managed centrally. Their tasking, including manoeuvres and Earth Observation activities, is reliant on all the network’s satellites being time synchronised, meaning that their internal clocks all show the same time. Currently, most satellites rely on the existing network of GPS satellites flying overhead for their time synchronisation, with the GPS satellites acting as central servers whose time data is broadcasted down to satellites in lower orbits. This centralisation leaves satellite systems vulnerable to single points of failure, with errors occurring close to the system’s core having the potential to cascade and cause system-wide failures. A centralised system cannot be implemented on the Moon; excluding its inherent vulnerabilities, there are no Moon GPS networks, and the costs and politics thereof are highly challenging. A novel solution is proposed: Moon-Sync, a decentralised resilient time synchronisation framework! The Moon-Sync framework enables efficient time synchronisation to be reached in lunar systems without the need for an external terrestrial reference source or a central authority. This dynamic approach also allows satellite systems to cope with unknown disruptors without knowledge of the network topology. Moon-Sync represents the next step in the decentralisation of space systems, making them more autonomous, resilient, and cooperative.