The story of Hansel and Gretel inspired researchers to explore and map Martian caves from millions of miles away. Cosmic radiation on Mars means future missions there will face tough surface conditions, but the planet’s subterranean caves could provide shelter for human explorers. To build anything inside the caves, we need a map of them first. To do this, researchers have developed robotic “breadcrumb droppers” that explore and map the caves using a mesh topology network. The mother robot is connected to a fleet of smaller rovers that explore and map the caves independently. When they stray too far, they drop a signal boosting node to keep in touch with the mother robot, so they can constantly send their data back home. This wireless connection eliminates the need for the robots to return for data drop off, essentially doubling their range. This means we get better and more complete cave maps, so even space researchers can learn something from fairy tales.