In a clean room at NASA's Jet Propulsion Laboratory in Southern California in March 2024, engineers and technicians prepare the agency's Farside Seismic Suite (FSS) for testing.

The cube-shaped payload contains two instruments that will gather NASA's first seismic data from the Moon in nearly 50 years and take the first-ever seismic measurements from the Moon's far side. FSS will operate continuously for at least 4½ months, working through the long, cold lunar nights.

Here, engineers move FSS onto a fixture that will allow them to tilt the payload, simulating the pull of lunar gravity in the direction at which one of the instrument's two seismometers is sensitive to motion. (The Moon's gravity is about one-sixth of Earth's.) Called an ambient tilt test, this activity allows engineers to check the seismometers' performance.

The two seismometers are packaged together with a large battery, a computer, and electronics inside a cube structure that's surrounded by several layers of insulation and suspended within an outer protective cube, which is in turn covered with a shiny insulating blanket. The suite's single solar panel can be seen right of center.

Surrounding the instrument are (from left): Nik Schwarz, Vik Singh, Joanna Farias, and Bert Turney.

A division of Caltech in Pasadena, California, JPL manages, designed, assembled, and tested Farside Seismic Suite. The French space agency, CNES (Centre National d'Études Spatiales), and IPGP (Institut de Physique du Globe de Paris) provided the suite's Very Broadband seismometer with support from Université Paris Cité and the CNRS (Centre National de la Recherche Scientifique). Imperial College, London and the University of Oxford collaborated to provide the Short Period sensor, managed by Kinemetrics in Pasadena. The University of Michigan provided the flight computer, power electronics, and associated software.

A selection of NASA's PRISM (Payloads and Research Investigations on the Surface of the Moon), FSS is funded by the Exploration Science Strategy and Integration Office within the agency's Science Mission Directorate. The Planetary Missions Program Office at NASA's Marshall Space Flight Center provides program management. FSS will land on the Moon as part of an upcoming lunar delivery under NASA's CLPS (Commercial Lunar Payload Services) initiative.