The goal of our NLSI team has been to advance our scientific understanding of the Moon’s poles and to fill in strategic knowledge gaps that facilitate the robotic and human exploration of these areas. There is substantial overlap across tasks, each providing information to the others to facilitate a deeper, more thorough understanding of the questions posed.
We have conducted studies designed to elucidate the geological histories, nature and origin of the polar deposits. Additionally we have investigated a possible exploration architecture that extends human reach beyond low Earth orbit by creating a permanent space transportation system with reusable and refuelable vehicles.
We have characterized the polar illumination at a scale useful for planning future lander missions. We also discovered that permanent shadow can exist at latitudes as low as 58°.
We have analysed lunar volatiles data and conducted modelling to support interpretation of those data. We have simulated the evolution of an ice layer and compared the model results as they would be observed in neutrons, FUV, radar, and in situ.
We have conducted laboratory and modelling experiments to better characterize the nature and evolution of H2O, hydroxyl, and other volatiles. We analyse lunar analog materials to determine the thermal stability of both molecular water and hydroxyl on the surface.
We have determined that self-secondary cratering on the continuous ejecta is a significant factor during an impact event. Since the lunar chronology is tied to the crater frequencies of the Copernicus and Tycho ejecta blankets, if those frequencies do not represent the impact flux, the chronology will be incorrect.
We have developed discrete element models of excavation and mobility problems on the Moon. We compare physical testing of wheel digging, static and percussive excavation, penetration, and geotechnical tri-axial strength tests on lunar simulants with the model results.
Ground-Penetrating Radar (GPR) data can help constrain models of the evolution of the lunar surface, predict the nature of subsurface properties, and aid interpretation of orbital SAR data. By comparing GPR data with known local stratigraphy has shown that GPR can be used to probe the subsurface and help constrain the physical properties of near surface materials.
We have conducted a reexamination of the hydrogen abundance sensitivity limits of orbital neutron data. A wet-over-dry, two-layer stratigraphy has been modeled for the first time using neutron transport codes.
We have examined the potential for a long-term full-disk Earth observing instrument on the Moon that would characterize the remotely detectable physical and biological signatures of the Earth as a function of time. A lunar polar vantage point is unique, making it possible to track Earth's ever-changing photometric, spectral and polarimetric signatures in a manner analogous to future observations of terrestrial planets orbiting other stars. Part of this effort included analysis of full-Earth data collected by the LCROSS spacecraft.
During our four-year effort we have made significant progress on the topics described here. We will present a review of these advances at the meeting. “Luna Incognita” has truly become “Luna Cognita”