Lava Tube Exploration with LunarLeaper

Lunar pits, some interpreted as collapse features into underlying lava tubes, expose otherwise inaccessible stratigraphy and may provide entry points to subsurface voids that preserve records of lunar volcanism and offer potential sites for future human exploration. The paper synthesizes the current state of knowledge on these features, covering their morphological characteristics, classification, proposed formation mechanisms, mechanical stability, and detection from orbit.

It then reviews the open science questions that pit and pit-wall investigation is uniquely placed to address, spanning the volcanic stratigraphy of the lunar maria, the structure and lateral variability of the regolith, and the dimensions and accessibility of subsurface conduits.

To evaluate how these questions can be tackled in situ, the authors assess the feasibility and expected performance of geophysical and remote-sensing investigations for subsurface voids and surface exposures, focusing mainly on gravity measurements, ground-penetrating radar, high-resolution imaging, and spectroscopy.

Building on that assessment, they present LunarLeaper: a small legged robot mission concept that combines a gravimeter, ground-penetrating radar, a high-resolution imager, a spectrometer, and leg-based geomechanical experiments to deliver the first in situ investigation of a mare pit. The concept targets the Marius Hills Pit and its associated rille, with a mobility architecture optimized for the rugged terrain encountered at pit edges and funnel slopes.