Robotic drilling tests in simulated lunar regolith environment

A deep extraterrestrial drilling mission potentially adds a new level of complexity, and it is crucial to understand the associated challenges. To cope with China's Chang'E 5 mission to return subsurface regolith samples from the Moon, a series of laboratory tests were performed to validate the lunar robotic drilling from 2015 to 2018. The tests took place in a simulated thermal-vacuum regolith environment, a highly relevant lunar analog site. Force and temperature sensors were integrated into a 2-m class dry auger coring drill to assess the mechanical and thermophysical status of the sampling process. The operation of the entire testing system was automated, covering regolith penetration and data collection and storage. The science team used sensing data to characterize the subsurface geologic strata, assess the conditions of the drilling robot, and direct the sampling strategy. This experiment represents an essential first step in understanding the technology and operational requirements for lunar drilling and sampling mission. Many laboratory tests have helped guide the design and implementation of the highly successful lunar regolith-sampling task in the Chang'E 5 mission. This paper documents the experimental system design, highlighting some critical design criteria and design tradeoffs. It also discusses the results of laboratory testing and lists some of the key technological lessons learned.