Lunar Exploration Advanced by Coordinated Robotics: Swiss Team Prepares for Upcoming Missions

Credit for the initial test: ETH Zurich / Takahiro Miki

Unexploited mineral resources are present on the Moon, and agencies like the European Space Agency (ESA) are making preparations to investigate these untapped assets more closely on our nearest celestial body.

A consortium of scientists from ETH Zurich in Switzerland is planning an advanced approach to lunar surveying by not merely sending an individual rover but by deploying a well-organized group of both ground-based and aerial devices to collaborate in the exploration.

The scientific team has outfitted three types of a legged robot, known as ANYmal, which was developed within ETH. These robots are equipped with a comprehensive set of analytical and measuring tools that qualify them as potential tools for future extraterrestrial investigations. These robots have undergone rigorous testing on different types of terrain in Switzerland, as well as at the European Space Resources Innovation Centre (ESRIC) in Luxembourg. Here, they secured victory in a Europe-wide competition focused on lunar exploration robotics, in collaboration with German counterparts.

The challenge required the identification and detection of minerals in a test environment designed to mimic the Moon’s surface. A recently published paper in the journal Science Robotics outlines their methodologies for probing unknown landscapes using a collaborative robotic team.

Risk Mitigation Strategies

Philip Arm, a doctoral candidate working under ETH Professor Marco Hutter, elaborated on the benefits of deploying multiple robots. “Operating several robots concurrently allows for the assignment of specialized functions and their simultaneous execution. Furthermore, a multi-robot system can offset the incapacitation of a single unit through its built-in redundancies,” Arm stated. This redundancy signifies that crucial measuring instruments are distributed across multiple robots, thereby achieving a balanced trade-off between redundancy and specialization.

Credit: University of Zurich / Central IT – MELS

To address this issue, the team from ETH Zurich in conjunction with the Universities of Basel, Bern, and Zurich, designated two of the legged robots as specialists. One was engineered to excel at terrain mapping and geological classification, employing a laser scanner and various cameras, some of which could perform spectral analysis. The second specialist robot was designed to accurately identify rock samples through the use of a Raman spectrometer and a microscopy camera.

The third robot acted as a generalist, capable of both tasks but with reduced precision. This configuration ensures mission continuity in the event of a malfunction of any individual robot, according to Arm.

The Importance of Versatility

During the ESRIC and ESA Space Resources Challenge, the panel expressed specific admiration for the team’s intentional incorporation of redundancy to protect against possible system failures. As a reward, the Swiss scientists, in collaboration with their colleagues from the FZI Research Center for Information Technology in Karlsruhe, were granted a one-year research contract to continue the technological development. This will include the integration of wheeled robots, drawing upon the experience of FZI researchers with such configurations.

“Legged robots like our ANYmal are particularly adept at navigating rocky and steep landscapes, such as descending into craters,” pointed out Hendrik Kolvenbach, a senior scientist in Professor Hutter’s group. Wheeled robots might be less capable in challenging terrains but can move swiftly on flatter grounds. For any future mission, the amalgamation of different modes of locomotion, possibly including flying robots, would be advantageous.

The researchers are also aiming to enhance the robots’ autonomy. Currently, all data collected is sent to a central control center where human operators assign tasks. Going forward, the robots will be designed for semi-autonomous operation, enabling them to allocate specific tasks among themselves, albeit with the option for human oversight and intervention.

Reference: “Scientific exploration of challenging planetary analog environments with a team of legged robots” by Philip Arm, Gabriel Waibel, Jan Preisig, Turcan Tuna, Ruyi Zhou, Valentin Bickel, Gabriela Ligeza, Takahiro Miki, Florian Kehl, Hendrik Kolvenbach, and Marco Hutter, published on 12 July 2023, in Science Robotics.
DOI: 10.1126/scirobotics.ade9548

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More about Lunar Exploration Robotics

• ETH Zurich Robotics Research
• European Space Agency (ESA)
• European Space Resources Innovation Centre (ESRIC)
• Science Robotics Journal
• FZI Research Center for Information Technology
• University of Basel
• University of Bern
• University of Zurich
• DOI Link to the Published Paper