Spacebok during early tests ESA

By  Chris Young

Though wheeled robots are more stable, legged robots can reach areas that a rolling rover couldn’t.

Every roving robot that has landed on Mars up to the latest Perseverance rover, which touched down in February, has one thing in common — every single one of them has wheels.

SpaceBok, built by a team of scientists from ETH Zurich in Switzerland and the Max Planck Institute in Germany, is a small quadrupedal robot named after the springbok antelope, a report from Wired explains.

The robot was originally designed to leap and bound on the surface of the Moon in the same way astronauts did during the Apollo landings — Springboks are also known to “pronk” or leap into the air, though the exact reason is not known.

The team tested different gaits, as well as small hoof-like feet and flat, round feet with cleats for more stability. 

As much of the research on Mars revolves around craters — Mars Perseverance landed on the Jezero crater due to the belief that it may have once been a habitable river valley — the team behind SpaceBok trained their robot on a large tilted sandbox full of rocks to simulate Mars.

SpaceBok is advancing space exploration robotics

Though wheeled robots are more stable, and have therefore been favored for off-world exploration, legged robots have the potential to reach areas that a rolling rover could not. 

The first machine to perform a controlled flight on Mars, NASA’s Ingenuity helicopter, does have great potential for surveying the land, but a quadrupedal robot would, in theory, allow for detailed exploration of rocky terrain and martian cave systems.

In their paper, the SpaceBok team showed that their machine is able to efficiently climb a simulated Martian incline without falling over, which would be disastrous for a mission that will have cost billions of dollars.

The researchers wrote that their findings present new avenues for “safe and energy-efficient global path-planning strategies for accessing steep topography on Mars.”

It was found that both the smaller feet and the round snowshoe-like feet both allowed SpaceBok to keep a stable footing on a 25-degree incline. 

With new innovations in robotics coming at full pace — such as proprioceptive feedback for walking down a set of stairs — more tricks will undoubtedly be added to SpaceBok’s arsenal over the coming years. 

Though SpaceBok itself is a research platform for advancing space exploration robotics, an iteration on this model may well be launched to Mars in the coming years.