While rovers have made incredible discoveries, their wheels can hold them back, and erratic terrain can mean damage. There is no replacing something like Perseverance, but sometimes rovers could use a leg up, and they could get that from a small swarm of four-legged robots.

They look like giant metal insects, but the trio of ANYmal robots customized by researchers at ETH Zurich was tested in environments as close to the harsh lunar and Martian terrain as possible. Robots capable of walking could assist future rovers and mitigate the risk of damage from sharp edges or loss of traction in loose regolith. Not only do the ANYmals’ legs help them literally step over obstacles, but these bots work most efficiently as a team. They are each specialized for particular functions but still flexible enough to cover for each other—if one glitches, the others can take over its tasks.

“Our technology can enable robots to investigate scientifically transformative targets on the Moon and Mars that are unreachable at present using wheeled rover systems,” the research team said in a study recently published in Science Robotics.

Three of a kind

The ETH Zurich team designed each of its three semi-autonomous bots so they would be able to work both independently and together. They were specialized enough for particular tasks but also similar enough to replace each other if one went down. Because they could not operate autonomously, some involvement with human scientists and operators was necessary.

Every robot had a LiDAR (light detection and ranging) sensor. Beyond the LiDAR and legs, however, each model had some differences. The Scout model’s main objective was to survey its surroundings using RGB cameras. This robot also used another imager to map regions and objects of interest using filters that let through different areas of the light spectrum. During the demonstration, the Scout transmitted its images to a team of planetary scientists and operators who decided which areas were the most viable for exploring.

The Scientist model had the advantage of an arm featuring a MIRA (Metrohm Instant Raman Analyzer) and a MICRO (microscopic imager). The MIRA was able to identify chemicals in materials found on the surface of the demonstration area based on how they scattered light, while the MICRO on its wrist imaged them up close. The Hybrid was somewhere in between, helping out the Scout and the Scientist with measurements of scientific targets such as boulders and craters.

The dream team of the future

What made this squad succeed was redundancy. Although each robot had distinct features, all three shared some hardware and software capabilities. The possibility of failure influenced the design of the robots. If one encountered trouble, redundant features would make either of the remaining two able to back it up while still using their specialized features to complete their own tasks.

The robots proved themselves on one testing ground similar to the surface of the Moon and two much like the surface of Mars, all part of the ESA/ESRIC Space Resources Challenge (SRC) in Alzette, Luxembourg. Notably, the three bots explored an analog for the lunar south pole, where Artemis 3 astronauts will eventually land.

It may be dangerous for astronauts to venture to certain areas, so robots could be needed to explore perilous territory. This is why the bots were challenged with everything from craters, boulders, and loose regolith to beds of hardened lava known as mares.

On what was as close to lunar ground as you can get on Earth, the robots investigated the objects of most scientific interest and sent data back for further (human) analysis. They went through similar challenges at the other lunar analog site and the quarry that was a Martian analog site and had previously been used to test the ExoMars rover.

The researchers want to continue giving these bots upgrades, such as complete autonomy, so they can operate and reallocate tasks on their own. “A higher level of autonomy will additionally improve the system’s scalability to applications with even more challenging communication, such as Mars exploration,” they also said in the study.

Legged robots could join rovers and airborne spacecraft in the future, stepping into treacherous regions rovers cannot access and making exploration more efficient. Teamwork really could make the proverbial dream work in space.

Science Robotics, 2023.  DOI: 10.1126/scirobotics.ade9548 (About DOIs).

Elizabeth Rayne is a creature who writes. Her work has appeared on SYFY WIRE, Space.com, Live Science, Grunge, Den of Geek, and Forbidden Futures. When not writing, she is either shapeshifting, drawing, or cosplaying as a character nobody has ever heard of. Follow her on Twitter @quothravenrayne.

https://arstechnica.com/?p=1955825