Semi-Autonomous Exploration of Martian and Lunar Analogues with a Legged Robot Using a Raman-Equipped Robotic Arm and Microscopic Imager.

Gabriela Ligeza^1,2*Philip Arm³Tomaso R.R. Bontognali^1,4Valentin T. Bickel⁵Hendrik Kolvenbach³Nikolaus Josef Kuhn¹Florian Kehl⁶

• ¹Department of Environmental Sciences, Physical Geography and Environmental Change Group, Universitat Basel, Basel, Switzerland
• ²European Space Research and Technology Centre, Noordwijk, Netherlands
• ³Robotic Systems Lab, Eidgenossische Technische Hochschule Zurich, Zürich, Switzerland
• ⁴Space Exploration Institute - Neuchatel, Neuchatel, Switzerland
• ⁵Center for Space and Habitability, Universitat Bern, Bern, Switzerland
• ⁶Space Science and Technology Group, Department of Earth and Planetary Science, Eidgenossische Technische Hochschule Zurich, Zürich, Switzerland

Future planetary exploration missions require advanced robotic capabilities to efficiently identify and characterize lithologies, rock textures, and mineralogies for astrobiological investigations and in-situ resource utilization (ISRU). Traditional single-target, human-supervised robot and instrument control methodologies are constrained by operational limitations, particularly on Mars, where long communication delays hinder real-time decision-making. This study explores an alternative semiautonomous, multi-target exploration strategy using a legged robotic system, which could enable faster, more efficient surface prospecting on the Moon and Mars. To assess this approach, we conducted Martian and lunar analogue missions using the legged robot ANYmal, equipped with a custom-built microscopic imager (MICRO) and a Raman spectrometer (MIRA XTR, Metrohm, Switzerland) mounted on a robotic arm. The primary objectives were to: (1) evaluate the feasibility of semi-autonomous, multi-target sampling, (2) compare it to conventional single-target, human-supervised exploration, and (3) assess the potential of MICRO and Raman spectroscopy in identifying lunar and Martian analogue samples. This study presents a successful demonstration of two distinct operational strategies, emphasizing the potential of multi-target robotic prospection for faster data acquisition in missions where real-time robot piloting is not possible, and the generation of scientifically valuable data for rock sample characterization. Furthermore, it highlights the effectiveness of robotic arm-mounted instruments, such as MICRO and the Raman spectrometer, in supporting astrobiological investigations and resource prospecting missions. The findings provide valuable insights for the development of semiautonomous, high-efficiency robotic exploration systems, contributing to the advancement of future Mars missions and planetary surface exploration.