| With the establishment of a lunar base, or the landing of a robotic rover on the Moon, excavation of the lunar soil will be integral to the mission's success. Many researchers have addressed the problem of lunar excavation, but most of the work to date has been conjecture based on a simple extrapolation of terrestrial excavation techniques to the lunar environment. In order to understand the process of physically removing an in situ soil mass with a tool, the excavation process is analyzed for its determinants. Through arrangement of these determinants, various excavating implements and techniques can be compared by virtue of their overall efficiency.; In this arrangement of the parameters of excavation, it is found that force is derived from constant parameters. With this, it is determined that the force required for a tool to fail the lunar soil is the first step in determining its overall efficiency. Thus, it is the first parameter investigated in this research process.; With the lunar soil being a vital national resource, various lunar soil simulants have been developed. Researchers then conduct experiments upon this lunar soil simulant. In this research, the index properties of the lunar soil simulant (JSC-1) are assessed and compared to that of the lunar soil.; An apparatus that can draw tools of various configurations through the compacted JSC-1 lunar soil simulant is developed. It has the capability of variable tool speed, and measures the horizontal force required to fail the lunar soil simulant over time. Flat blades of various scale ratios are affixed to this apparatus and drawn through the lunar soil simulant while measuring force and time. Upon the conclusion of each test, the mode of soil failure and the dimensions of the ensuing rupture surfaces are recorded.; Similitude analysis is then employed to develop predictive equations from the empirical results of the geometrically similar tools. After this, a theoretical model is developed that accepts the properties ofthe soil, tool, and the interaction between the soil and tool. From this, it predicts the horizontal force, and the dimensions of the rupture surfaces. This model is then verified against the measured results. |
