A luminescence-based instrument to explore the history and nature of the lunar surface.

Abstract:

Thermoluminescence (TL) properties of lunar samples have been the subject of scientific research since the return of the first Apollo samples. Operating a rover equipped with a TL instrument provides a method for in-situ evaluations of the thermal and radiation environment history of the lunar surface and subsurface, as well as providing geological information such as the maturity of the regolith, and the taxonomy of the surface soil and rocks. Information on the nature of the rocks and boulders would be helpful for surface operations and radiation shielding. For in-situ resource utilization (ISRU), thermoluminescence measurements contribute towards understanding the surface material in terms of construction requirements and thermal history relevant to volatile (e.g. ³He and water) retention. As such, in-situ TL measurements are relevant for science investigations, human exploration, as well as ISRU.

With the support from NASA’s ANGSA program, we currently refine the physical parameters governing the TL process for lunar regolith through a series of laboratory studies investigating the thermoluminescence properties of pristine Apollo 17 samples that haven been in cold storage since their return to Earth. Our work is the evolution of TL studies on Apollo samples done in the 1970’s, and as such is a unique 50-year experiment to better understand the kinetics of the TL process of lunar samples. With an improved understanding of the TL process, we discuss how heating a few grains of lunar regolith to ~773 K within 90 seconds, as well recording the light emitted during that heating, facilitates a number of fundamental science investigations that also relate to human exploration and ISRU as part of the Artemis program. All of the principal components of this TL instrument are equivalents of parts used for instruments on past and current space flight missions, such as NASA’s Curiosity rover. The TL instrument proposed by us to accomplish this work (in-situ and sample triage) would be low-mass (<1 kg), small-size (~0.009 m³), and require low power (~35 W at peak).