The breadcrumb trick of Hansel and Gretel inspires robotic exploration of caves on Mars and beyond

Engineers from the University of Arizona have developed a system that allows autonomous vehicles to scan underground habitats for astronauts

 

Searching for compounds where habitats can be built on Mars may soon become a real estate hit, and researchers at the University of Arizona are already engaged Looking for real estate that future astronauts could use it as habitats. Researchers at the university's College of Engineering have developed technology that will allow a troop of robots to explore subterranean environments on other worlds.

"Lava tubes and caves will be perfect habitats for astronauts because you don't need to build a structure; They will be protected from harmful cosmic radiation, and all that is needed is to make them pleasant places," he said Wolfgang Fink, professor of electrical and computer engineering at the University of Arizona.

Fink is the lead author of Article New in the journal Advances in Space Research, which specifies a communication network that will communicate between rovers, landers and even submarines using what is known as a topological network, and will allow the machines to work together as a team, independent of human instructions. According to Fink and his co-authors, the approach can help deal with one The great challenges of space technology of NASA and help overcome the limited ability of current technology to safely traverse environments on comets, asteroids, moons and planetary bodies. In a tribute to the children's fairy tale "Hansel and Gretel," the researchers named their patent-pending idea the "breadcrumb-style dynamic deployment communication network," or DDCN.

An inspiring legend for the future

"If you remember the book, you know how Hansel and Gretel dropped breadcrumbs to make sure they found their way back," said Fink, founder and director The laboratory for the study of visual and autonomous research systems at Caltech and the University of Arizona. "In our scenario, the 'breadcrumbs' are miniaturized sensors that the rovers deploy when traversing a cave or other underground environment."

Continuously monitoring their environment and maintaining an awareness of their position in space, the rovers continue on their own, connected to each other via a wireless data connection, and deploying communication nodes along the way. As soon as a rover senses that the signal is fading but still in range, it places a communication node, regardless of the actual distance traveled since it last placed the node.

"One of the new aspects is what we call opportunistic deployment - the idea that you deploy the 'breadcrumbs' when you need to and not according to a pre-planned schedule," Fink said.

All the while, no input from the motherboard is needed; Each subordinate rover would make that determination on its own, Fink added. The system can work in one of two ways: In one of them, the mother rover acts as a passive recipient, and collects data transmitted by the rovers performing the investigation. In another, the mother rover acts as an orchestrator, controlling the rovers' movements like a puppeteer.

Machines are taking over

The new idea fits with a paradigm The expandable tour invented by Fink and colleagues in the early 2000s. This idea envisions a team of robots operating at different levels of command - for example, a compass spacecraft controlling a blimp, which in turn controls one or more landers or rovers on the ground. Already, space missions, some involving researchers from the University of Arizona, have adopted this idea. For example, on Mars, this is how the Ingenuity robotic helicopter is commanded. An idea for another mission, which was ultimately not selected, proposed sending a balloon-carrying lander and a lake lander to investigate one of the hydrocarbon seas on Titan, one of Saturn's moons. The breadcrumb approach takes the idea one step further by providing a robust platform that allows robotic explorers to operate underground or even submerged in liquid environments. Such swarms of individual, autonomous robots could also aid in search and rescue efforts following natural disasters on Earth, Fink said.

Fink said the biggest challenge, aside from getting the rovers into the underground environment in the first place, is retrieving the data they record underground and bringing it back to the surface. The DDCN concept allows a crew of rovers to navigate even convoluted underground environments without losing contact with their parent rover on the surface. Equipped with a light detection and ranging system, or lidar, they could even map cave passages in all three dimensions, not like the drones seen exploring an alien spaceship in the movie "Prometheus".

"Once deployed, our sensors automatically create an undirected mesh network, which means each node updates itself about every node around it," said Fink, who first detailed the DDCN idea in a 2019 NASA proposal.

"They can pass between each other and compensate for dead spots and power outages of signals," he added Mark Treble, a co-author of the paper and a senior research scientist in Fink's lab. "Even if some of them die, there is still connectivity through the remaining nodes, so the mother rover never loses connection to the farthest node in the network."

A mission of no return

The robust network of communication nodes ensures that all data collected by the robotic explorers is returned to the mother rover, so there's no need to retrieve the robots after they've done their work, said Fink, who published the idea of ​​using groups of biodegradable mobile robotic surface probes back in 2014.

"They are meant to be biodegradable," he said. "Instead of wasting resources to get them into the cave and back it makes more sense to have them go as far as they can and leave them behind once they've completed their mission, run out of electrical power or succumbed to a hostile environment."

"The communication network approach presented in the new paper has the potential to herald a new era of planetary and astrobiological discoveries," he said. Dirk Schulze-McKoch, president of the German Astrobiological Society and author of numerous publications on extraterrestrial life. "This finally allows us to explore the lava tube caves of Mars and the subsurface oceans of the icy moons – places where extraterrestrial life might be present."

The proposed idea "contains magic", according to him Victor Baker, professor of hydrology and atmospheric sciences, geosciences and planetary sciences at the University of Arizona. "The most amazing discoveries in science occur when technological advances provide both access for the first time to a thing or place and the means to send what is thus discovered to creative minds seeking understanding," Baker said.

Explore hidden ocean worlds

In places that require underwater robots, the system can consist of a floating lander on a lake, as is the case on Titan, or sitting on the ice above an underground ocean as in Europe - and connected to the submarine, for example through a long cable. Here the communication nodes will act as amplifiers, boosting the signal at regular intervals to prevent it from degrading. More importantly, Fink pointed out, the nodes have the capabilities to collect data on their own - for example measuring pressure, salinity, temperature and other chemical and physical parameters - and send the data through the cable that connects back to the lander.

"Imagine you make it all the way to Europe, you melt your way through miles of ice, reach the subterranean ocean, where you find yourself surrounded by alien life, but you have no way to bring data back to the surface," he said. "This is the scenario we need to avoid."

Having developed the rovers and the communication technology, Fink's group is now working on building the actual mechanism by which the rovers will deploy the communication nodes. functioning", said Fink.

More of the topic in Hayadan:

• The first people on Mars will live in caves
• Good luck, and beware of the bears - on Carl Sagan, and human settlement on Mars and Venus
• Holes in Mars
• A guide for a traveler on Mars