LunarLeaper - Exploring Lunar Lava Tubes

 

LunarLeaper is a robotic mission concept aimed at advancing our understanding of the Moon’s subsurface structure and geological evolution through the exploration of volcanic pits—steep-walled collapse features on the lunar surface. Orbital observations indicate that some of these pits may provide access to extensive subsurface lava tube systems. However, such interpretations are limited by spatial resolution and viewing geometry, and only an in-situ surface mission can unambiguously confirm and characterize the relationship between pits and underlying caves. We propose the use of a legged robotic platform to deploy geophysical instrumentation to the rim of a lunar pit on the near side of the Moon. From this vantage point, the mission will confirm the presence of a lava tube, constrain its geometry, and employ imaging and spectrometric measurements to reconstruct the volcanic history of the pit and its surrounding terrain.

The baseline payload for LunarLeaper consists of a camera system, a ground-penetrating radar, a gravimeter, and a spectrometer. We report the current status of payload accommodation on the robotic platform:

• The camera requirements for the mission can be met by an COTS camera system previously used as engineering cameras for ESA spacecraft, such as BepiColombo.
• We have developed a compact, PCB-based antenna system for the ground-penetrating radar that can be fully integrated beneath the robot body.
• Forward modelling of the expected gravimetric signal, combined with a preliminary noise budget that accounts for instrument tilt, shows that the sensitivity of the HERA-heritage gravimeter exceeds mission requirements by approximately an order of magnitude.
• Measurements with the Fabry-Perot spectrometer have been demonstrated against several mineralogical compositions.
• A preliminary concept of operations demonstrates that payload operation and data acquisition are compatible with overall mission constraints, specifically the mission duration of less than one lunar day.

Together, these results demonstrate that the combined geophysical and imaging payload suite can be accommodated on a small robotic platform, as currently being developed by the Robotic Systems Lab at ETH Zürich.