Cooperative robotic exploration of a planetary skylight surface and lava cave

Exploration of lava caves on the surface of planetary bodies near Earth is of high importance for scientific research and space exploration. The natural shielding that these caves offer against radiation and small meteorites makes them well suited for preserving exobiological signatures and protecting human-made facilities. The use of a robot team arises as the safest and most cost-efficient way to explore extraterrestrial lava caves because they are difficult to access. Although the approach has been demonstrated in similar scenarios on Earth, its adaptation to space conditions needs further research. Here, we define a lava cave exploration mission concept, including four mission phases that are performed by a heterogeneous team of three robots equipped with the required hardware and software. This mission concept was validated in a relevant scenario, a lava cave on Lanzarote island (Spain), where the team of robots was able to build a three-dimensional model of the surrounding area and skylight, introducing a scout rover through rappelling and exploring the inner part of the cave. The results obtained demonstrate the proposed mission concept's feasibility, including three next-generation planetary exploration rovers that were coordinated to obtain meaningful information about the lava cave's external and internal morphology.