Lunar Dust and Regolith
Lunar dust and regolith and its effect on robotic and human exploration systems
An understanding of the physical and chemical properties of extraterrestrial soils and surface rocks (regolith) is fundamental for future exploration missions, in particular for upcoming missions to the Moon. For example, the properties of lunar dust are poorly understood and fundamental questions still remain to be answered. What is the rate of dust deposition? What mechanisms exist for levitating and lofting dust in the lunar atmosphere? What are the physical, chemical and mineralogical properties of lunar dust and how do these properties vary around the globe? Understanding these properties is required in order to understand the effect of dust on equipment and the potential for nearby human activity (e.g., an extended lunar mission) to alter the dust environment. There is also evidence that lunar dust may have possible toxicological effects. The CLRN is looking to address these issues by characterizing the physical and chemical properties of lunar dust and regolith using a variety of microbeam analytical techniques (eg. scanning electron microscopy (SEM), LAM ICP MS, etc.).
The Apollo missions only returned small amounts of lunar regolith to the Earth. This presents a problem for engineers and scientists who need access to large quantities of lunar soils for studies involving in-situ resource extraction, drilling, excavation, construction, etc. For this reason, the investigation of methods to synthesize regolith simulants that mimic as closely as possible the properties of the real thing is currently a major issue for space exploration agencies throughout the world. CLRN members are currently participating in such studies.
CLRN researchers are also working to address the dynamics of ejected lunar dust. Our goal is to examine in detail the delivery of lunar dust from impacts of all sizes between the Moon and Earth. Numerical integration of the equations of motion, coupled with an ejection model and treatment of Lorentz forces is to be included. This will address the issue of ocean sediment He3 flux variations and if these could be due largely to lunar impacts alone. Furthermore, because the Moon is airless, material is easily ejected, but material on sub-orbital ballistic trajectories is also free to disperse across the surface. This results in secondary and possibly tertiary craters. Ongoing investigations include the effects of lunar impact flashes in terms of their ejecta. Although the impactors are relatively small, they could excavate a considerable amount of material that could form a short-lived dust plume as it disperses across the surface. This is of interest from a safety point of view in terms of the possibility of human lunar exploration.
A major part of the CLRN’s work includes the development of an instrument suite for a landed dust characterization mission, building upon Canadian expertise in Lidar systems (e.g., NASA Phoenix mission) and astromaterials. This mission will be directly complementary to the proposed orbital Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, currently in development by NASA. It is our hope that, through the NLSI, CLRN members will establish links with U.S. colleagues involved in the LADEE mission and so develop opportunities for Canadian involvement in a landed dust mission.