Engineers develop robots to house-hunt and scout real estate in space

Dropping miniaturized sensors like breadcrumbs

The scientists named their patent-pending concept the "Breadcrumb-Style Dynamically Deployed Communication Network" paradigm or DDCN, based on the fairy tale 'Hansel and Gretel'. According to Fink, DDCN could help resolve one of NASA's Space Technology Grand Challenges by helping overcome the limited ability of current technology to safely traverse environments on comets, asteroids, moons, and planetary bodies.

"If you remember the book, you know how Hansel and Gretel dropped breadcrumbs to make sure they'd find their way back. In our scenario, the 'breadcrumbs' are miniaturized sensors that piggyback on the rovers, which deploy the sensors as they traverse a cave or other subsurface environment," explained Fink.

The rovers are connected via a wireless data connection and deploy communication nodes. They're also continuously monitoring their environment. When a rover sense that signal is fading, but still within range, it drops a communication node, regardless of the distance it has covered after placing the last node.

The robotic explorers are free once their job has been done

The rovers need no hand-holding from their mother, said Fink. Each subordinate rover will make it on its own. The DDCN concept allows a team of rovers to navigate even complex underground environments without ever losing contact with their "mother rover" on the surface.

All data collected by the robotic explorers will return to the mother rover on the surface. As a result, retrieving the robots is not required once their job is completed.

"Instead of wasting resources to get them into the cave and back out, it makes more sense to have them go as far as they possibly can and leave them behind once they have fulfilled their mission, run out of power, or succumbed to a hostile environment," said Fink.

"The communication network approach introduced in this new paper has the potential to herald a new age of planetary and astrobiological discoveries," said Dirk Schulze-Makuch, president of the German Astrobiological Society and author of many publications on extraterrestrial life. "It finally allows us to explore Martian lava tube caves and the subsurface oceans of the icy moons – places where extraterrestrial life might be present."

Study Abstract:

We introduce a dynamically deployed communication network (DDCN) paradigm using mesh topology to support a distributed robotic multi-agent approach for the autonomous exploration of subsurface environments, i.e., caves, lava tube caves, lakes, and oceans, etc. The DDCN, comprising wireless communication beacons autonomously deployed via a rover or submersible in a Hansel & Gretel-inspired breadcrumb style, allows for the longest and most robust communication link between subterranean robotic agent(s) within, e.g., a lave tube cave or a subsurface ocean, and associated surface-borne robotic agent(s). Moreover, we briefly touch on the development of a robotic testbed and wired/wireless communication beacons in support of such astrobiological surface/subsurface exploration scenarios. Candidate lava tube caves have been identified on the Moon and Mars, raising possibilities for planetary exploration, astrobiology, habitat construction for future astronauts, and potential mining operations. Subterranean caverns, and in particular relatively deep lava tube caves, provide a possible refuge for life under otherwise challenging planetary surface conditions, and, as such, are of prime astrobiological relevance. Lava tube caves or other subsurface environments may also be suitable habitats for astronauts and subsequent human settlement but are yet to be explored in part due to difficulties ensuring continued communication with a robotic probe inside these environments. Moreover, the existence of subsurface oceans on ocean worlds, such as Europa, Enceladus, and Titan, has been backed by varying levels of evidence since the 1980s, though there has been no confirmation, i.e., direct observation, thus far. Such environments are also shielded from radiation and, in combination with the hypothesized presence of water, are additional candidate environments for finding extant or fossilized life. The DDCN paradigm introduced herein directly addresses NASA’s Space Technology Grand Challenges – “All Access Mobility” by enabling the most unconstrained exploration of subsurface environments through a dynamic communication network which ensures transmission of data from and possibly commands to the subsurface robotic probe.