FIBER OPTIC SENSORS ON THE MOON

The U.S.’s next lunar exploration program, publicly known as Artemis III, will happen by 2024, and be the first human lunar landing in over 50 years. Studying the interior structure and moonquakes of the Moon is an important scientific goal embedded in the original motivation of human’s lunar exploration. While conventional point seismic stations can be installed on the Moon either by an automated rover or by astronauts, the number of stations can be extremely limited to prohibitively high payload cost and operational risk, therefore the availability of lunar seismic data is intrinsically scarce. Optical Fiber based Distributed Acoustic Sensing (DAS) is rapidly evolving as a seismic observation tool. To understand the suitability of DAS for measuring lunar seismic activity, we constructed a large trough, almost 10 meters in length, and filled it with basalt dust which act as a lunar simulant. This experiment helps us to understand how the unique lunar regolith may affect the seismic coupling of the optical fiber, and how to design a system to maximize the coupling (e.g., depth of cable, cable type). We will briefly discuss optical fiber sensors which can be leveraged on the same fiber, and other practical concerns. LA-UR-22-27136