2023 Volume 1 Article ID: 6
In recent years, planetary exploration has received increasing interest from both the research community and the private sector, with ambitious missions being planned to target the Moon, Mars, and beyond. In the scope of the Artemis Project, multiple space agencies and industry partners are working together to safely send humans back to the Moon, intending to eventually create sustainable on-site settlements. Lunar caves are good candidates for long-term habitats thanks to their almost constant temperature and protection from space radiation. These caves are accessible mainly through skylights that are hypothesized to have been created by the collapse of cave ceilings, making the terrain at the bottom of the skylight particularly rough, with a mix of large debris and finer regolith. Exploring these entrances represents a significant challenge for current robotic platforms due to the roughness of their environment and the limited solar exposure at the bottom of the skylight. This study investigates a disruptive solution to safely transport large payloads together with robotic units, referred to as Base Units (BUs), from the skylight's rim to the bottom of the cave by leveraging the innovative concept of Robotic Exoskeletons (REs). In this work, a lunar cave with approximated dimensions for the skylight of 100m in diameter and 100m deep is considered as a representative test environment. BUs are approximated as compliant spheres of 20cm in diameter and a mass of 400g. This paper explores the design and evaluation of a fully passive Multi-Unit RE weighing less than 10kg and able to transport 6 BUs and a payload in a free-fall scenario from the skylight’s rim to the bottom of the cave. The energy of the free-fall is reused to propel 3 of the BUs further into the cave to act as scouting units, while the 3 others will remain at the point of impact to unpack the delivered payload. Our current non-space-ready design relies on flexible carbon fiber blades and shockabsorbing honeycomb structures. Our tests show promising qualitative results in terms of energy dissipation and BUs propulsion.
