Mars rovers could explore caves like Hansel and Gretel: study

While cities on Earth are locked in a perpetual struggle to solve housing shortages, the market on Mars is already heating up.

Engineers at the University of Arizona have developed a system they believe could allow autonomous vehicles to spot astronaut habitats in caves and other subterranean features. It’s been a long time since humans considered caves their home, but researchers say the Red Planet’s subterranean features will provide some of the best shelter options when humans finally arrive on Mars.

“Lava tubes and caves would make perfect habitats for astronauts because you don’t have to build a structure,” said Wolfgang Fink, associate professor of electrical and computer engineering at the University of Arizona, in a Press release. “You’re shielded from harmful cosmic radiation, so all you have to do is make it look nice and comfortable.”

Fink and his co-authors detailed how the system works in a peer-reviewed study published in the scientific journal Advances in space research February 11. Their approach involves a communication network that would link different types of moving vehicles through a “mesh topology network”.

These independent rovers would be deployed by a larger “mother” rover and move on and under the Martian surface on their own, constantly monitoring their surroundings and remaining aware of their position in space. They would also stay in touch with each other via a wireless data connection.

To avoid traveling outside of comms range and getting lost, the rovers would deploy comms nodes along the way, much like Hansel and Gretel leave a trail of breadcrumbs in the classic German fairy tale.

In a nod to the legendary siblings, the team named their patent-pending system the “Breadcrumb-Style Dynamically Deployed Communication Network” paradigm, or DDCN.

“In our scenario, ‘breadcrumbs’ are miniaturized sensors that overlay the rovers, which deploy the sensors as they pass through a cave or other subterranean environment,” Fink said.

Once a rover detects that the signal is fading but remains within range, it drops a communication node, regardless of how far it has traveled since it placed the last node.

“One of the new things is what we call opportunistic deployment — the idea that you deploy the ‘breadcrumb’ when you have to and not on a pre-planned schedule,” Fink said.

Fink and his co-authors say their new approach could help address one of NASA’s great space technology challenges by providing the technology needed to safely traverse the environments on comets, asteroids, moons, and planetary bodies. NASA’s Grand Challenges are an open call for innovative solutions that solve critical space-related problems, such as the need for mobility systems that allow humans and robots to explore on, above, or under any destination surface.

The DDCN concept can work in two ways. In one mode, a mother rover passively receives data transmitted by rovers as they explore Martian caves and lava tubes. In the other, the mother rover plays the role of orchestrator, telling the rovers where to go.

Both modes should allow a team of rovers to navigate subterranean environments without ever losing contact with their “mother rover” above ground. Equipped with a light detection and ranging system, also called lidar, the rovers could even map cave passages in three dimensions.

The paper attracted attention in the field of solar system exploration, drawing praise from Dirk Schulze-Makuch, president of the German Astrobiological Society.

“The communication network approach introduced in this new paper has the potential to herald a new era of planetary and astrobiological discovery,” Schulze-Makuch said in a press release.

“It finally allows us to explore Martian lava tube caves and the subterranean oceans of icy moons – places where extraterrestrial life could be present.”