Enhancing Lunar Exploration: Drilling, Sensing, and Sampling Systems for In-Situ Regolith Subsurface Analysis and for Sample Return

We report on the development of two promising analysis and sampling tools for use on the Moon that promise to enhance science return in upcoming lunar missions and which would inform the search for potentially valuable resources that would be worthwhile exploiting. Building on the success of ISRO's Chandrayaan missions, our efforts aim at 1) creating an advanced drilling instrument with an integrated sensing unit, referred to as the “Moon Sensing Drill" (MSD), and 2) a “Soil and Pebble Sampler” (SPS). The MSD partially builds on concepts already studied in Europe under an “instrumented drill" heading whereas the SPS is entirely new. We are realizing the systems in collaboration between D Y Patil International University in Pune, India, and European entities.

The MSD would be able to drill autonomously into lunar regolith and analyze the subsurface column in real-time, including detection of 3He, volatiles and key minerals. Moreover, temperature and thermal conductivity sensors would be part of the drill. The design is based primarily on a percussive drilling system, with the sensors incorporated inside the drill stem. The sensor data will be sent wirelesslessly to an electronics unit that integrates the information. This way, no rotary transmission of signal cables to and from sensors needs to be incorporated into the drill. Power transmission to the sensors is however via slip rings. The system can either be carried on a lunar rover or on lander Maximum drilling depth into the regolith is 20 cm. We are currently designing and building a demonstrator.

The Soil Pebble Sampler (SPS) is a versatile tool designed to allow the collection and analysis of soil / regolith and pebble samples. In particular, the SPS is the first ever concept for uncrewed missions for controlled sampling of both soil and pebbles in a single tool. This will be key to future sample return missions to the Moon, such as Chandrayaan-4 in the ISRO space program.

In the case of Drilling Mode, SPS employs a rotary drill equipped with radial blades and an external, thin-walled auger to drill into soil. With progressing depth, a longitudinal cavity (“tunnel") incorporated in the drill stem is filled with regolith. One of the SPS assemblies is the ball-end vibrating mechanism, which is able to shake particles loose from the drill and therefore keep debris from becoming lodged in the drill tip and the associated samples. Moreover, the vibrating mechanism is essential in shaking out the soil that would have been pressed into the sample tunnel.

A stable 3-jaw gripping structure is at the end of the ball-end vibrating mechanism and uses that mechanism's sideways motion capability to pick up a pebble.