As lunar and planetary exploration grows over the next few decades, more humans, including scientists and engineers, will operate in increasingly remote and challenging locations with very limited infrastructure for real-time monitoring and emergency response. The paper reports on an exploratory study of potential technical options for a future Lunar surface emergency distress system. Key services include provision of critical safety alerts, incident reporting and localisation of user radio beacon devices for surface operations. The following results are presented:
Sample constellation design for lunar orbits, and corresponding analysis on positioning performance, coverage and availability. These analyses also consider obstruction and shadow effects due to the complex lunar terrain.

Lunar satellite link budget and margin for two-way communication with the proposed orbit, using practical assumptions on transmit and receive chain.

Communications waveform to support mixed services through an open standard for emergency message payloads and localisation of surface beacons.

The study shows the feasibility of Lunar Search and Rescue services, as well as potentially effective solutions for lunar search and rescue architectures. During this study, NASA’s Search and Rescue Mission Office served as a technical consultant regarding lunar distress message contents, lunar surface considerations, and insight into international frequency approvals as they evolved over the technical study. This paper details one of many potential approaches to the problem-set of lunar search and rescue communications as NASA and others look to expand exploration on the lunar surface.