Four-Legged Robots Prepare For Autonomous Mars Exploration

One day, space exploration might make use of astronauts living permanently offworld, as envisioned by the Artemis missions for the Moon, or by Elon Musk for Mars.

Still, even with human presence, a lot of the work needed in space will be done by robots, if nothing else, because they are a lot easier to replace than human astronauts and a lot less vulnerable to toxic air or vacuum, radiation, brutal temperatures, etc.

Ideally, most of the rovers and robots should be able to handle themselves for simple tasks, with humans on Earth or on-site only involved to help them solve specific problems or determine their daily missions.

As AI progresses quickly, including physical AI, a concept now championed by AI leader NVIDIA, this science-fiction vision might already be a reality.

For even more distant missions, like on Jupiter’s moons, the time lag in communication, up to 1 hour long, makes any direct control even more tricky, making any autonomous decision by the probes extra valuable.

“Rovers are designed for energy efficiency and safety, and to move slowly across hazardous terrain. As a result, exploration is typically limited to only a small portion of the landing site, with rovers typically traveling up to a few hundreds of meters per day, which makes it difficult to collect geologically diverse data.”

Another step will be giving space exploration robots more ability to move freely. After all, wheels and tracks might be more reliable, but it’s not like roads are waiting for them on the Moon and Mars.

As a result, most robotic exploration missions so far have focused on relatively flat, easily navigable regions. But these areas might also not be the most useful for future space colonization.

For example, lava tubes might make perfect pre-built shelters for future astronauts, but we never explored one properly, although AI-driven exploration of lava tubes is being planned. And most resources are likely to be found in deep craters (water) or mountainous regions (metals and other mineral deposits).

“On the Moon, many key resources are located in terrain that is difficult to access, including volatile- and titanium-rich pyroclastic deposits, REE-bearing KREEP basalts, and water ice within permanently shadowed regions near the South Pole. On Mars, water-ice exposures and metal-rich regolith have also been identified in high-latitude and highland regions, often within unstable slopes or fractured geological settings.”

So more advanced robots are needed, with quadrupedal “robodogs” a likely option, as this design is becoming increasingly popular on Earth as well.

This possibility is being tested by Swiss researchers at the ETH Zurich, the University of Zurich, the Neuchâtel Space Exploration Institute, the University of Basel, and the University of Bern.

They used a quadrupedal robot, they tested if it could handle semi-autonomous exploration and sample collection in a reconstructed space environment, and published their findings in Frontiers In Space Technologies¹, under the title “Semi-autonomous exploration of martian and lunar analogues with a legged robot using a Raman-equipped robotic arm and microscopic image”.

Recreating Mars On Earth

The researchers used the Marslabor facility at the University of Basel, which simulates planetary surface conditions using analogue rocks, regolith (planetary dust), and analogue lighting conditions to recreate an environment identical to Mars’ except for the gravity.

Marslabor encompasses an 80 m2 room featuring a 40 m2 test bed composed of Martian analogue materials. This included rocks with a strong potential for biosignature preservation, like gypsum or carbonate rock, which would be of major interest in a real Martian exploration looking to investigate past biological activity on the Red Planet.

Source: Frontiers In Space Technologies

In addition, rock types indicative of past flowing water, like siliciclastic carbonate rock and sulphur-bearing basalt, were also included.

A segment of the room was also recreating lunar conditions, with rock types that could be a useful source of oxides, titanium, aluminum, and silicon.

Four-Legged Explorers

Polyvalent Robot With Sensors

The robot used in this study was an ANYmal robot built by the Swiss company ANYbotics, specialized in industrial inspections in hazardous areas. To enable mapping and localization, ANYmal is equipped with a VLP-16 Puck LITE LiDAR by Velodyne, six RealSense D435 active stereo sensors by Intel for elevation mapping, and two FLIR Blackfly wide-angle cameras to provide RGB image streams.

Source: Frontiers In Space Technologies

The robot was equipped with a microscopic imager (MICRO) and a MIRA RTX Raman spectrometer produced by the Swiss company Metrohm. These sensors were installed on a robotic arm developed in-house by the ETH (Eidgenössische Technische Hochschule – Swiss Federal Institute of Technology).

It was remotely controlled by an operator using a graphical user interface (GUI) that shows a digital elevation map and camera images where commands and tasks are transmitted.

Source: Frontiers In Space Technologies

The MICRO imager’s goal is to capture close-up images of the rock samples’ texture, grain, and color, a crucial dataset to identify the type of rock and its composition. It incorporates a USB microscope, a ring of 48 RGB LEDs, a time-of-flight (ToF) sensor, and control electronics. A foam ring prevented stray light from entering when MICRO is in contact with a target.

The Raman spectrometer featured an infra-red excitation laser with a wavelength of 785 nm and a maximum power of 100 mW, with a range spanning from 400 to 2,300 cm with a resolution of 8–10 cm. The data complement the MICRO observation by revealing the chemical composition of the studied rocks.

Source: Frontiers In Space Technologies

Investigation with & Without Humans