Abstract DGP2026-69

South Pole Seismic Station (SPSS): An Artemis IV active and passive seismic experiment getting ready for the Moon via LUNA

Brigitte Knapmeyer-Endrun (1), Mark Panning (2), Ceri Nunn (2), Philippe Lognonné (3), Takeshi Tsuji (4), Shinsuke Abe (5), James Cutler (6), Marco Delbo (7), Mélanie Drilleau (3), Raphael Garcia (8), Taichi Kawamura (3), Olga Podgornova (9), Satoshi Tanaka (10), Chrysoula Avdellidou (11), Éric Beucler (12), Karan Jani (13), David Mimoun (8)

(1) Microgravity User Support Center, DLR Köln, Germany, (2) Jet Propulsion Laboratory, California Institute of Technology, USA, (3) Université Paris Cité-Institut de Physique du Globe, France, (4) University of Tokyo, Japan, (5) Nihon University, Japan, (6) University of Michigan, USA, (7) Observatoire de la Côte d’Azur, France, (8) ISAE Supaero, France, (9) SLB, Houston, USA, (10) ISAS, JAXA, Japan, (11) University of Leicester, UK, (12) Nantes Unversité, France, (13) Vanderbilt University, USA

The South Pole Seismic Station (SPSS), led by JPL and recently selected by NASA as deployed instrument for Artemis IV, will be the 4th seismometer placed in the southern hemisphere of the Moon, following ChangE’7 (2026), FSS (2028) and LEMS on Artemis III (2027-2028). As it will be equipped with a spare unit of the state-of-the-art Very Broad Band (VBB) InSight Mars seismometer provided by CNES and IPGP, it will probe the south polar region of the Moon with unprecedented sensitivity and spectral range. In addition, SPSS will be equipped with three vertical component geophones, provided by SLB USA, which will complement the VBBZ recordings and enable an active seismic survey performed by the astronauts with a compact Portable Active Seismic Source (PASS), provided by JAXA and the University of Tokyo. The instrument will be deployed by the astronauts for ideal seismic coupling and leveling, minimizing tilt and sun-related noise. SPSS will continue operating as a long-term seismic station after the astronauts leave.

SPSS has the following four major science objectives: 1. Determine lunar interior structure to better understand the geologic processes that affect planetary bodies; 2. Understand the current lunar bombardment rate; 3. Monitor real-time environment affecting operations for astronauts and potential for future stable astrophysical and physics observatories; and 4. Determine near-surface and regolith properties to address active surface processes and polar volatiles.

Objectives 1 and 2 will be completed by a worldwide network of infra-red telescopes. Telescopic observations will allow to time and locate impacts occurring on the near side of the Moon, which will give a direct access to the absolute travel times of P and S waves when recorded on the SPSS seismometer. Impact observation can thus complement the PASS active seismic experiment with several naturally provided explosive-source seismic profiles, enabling seismic imaging of the lunar subsurface and crust at singular resolution.

SPSS will utilize LUNA, the DLR-ESA Moon analog facility in Cologne, to test both the interaction between individual components, like the influence of the structure housing the sensors on the PASS signals recorded by the geophones, as well as the operational and deployment concept at a high level of fidelity. A prototype of PASS was already used in a regolith environment for the first time during an independent LUNA campaign in October 2025.