Lunar regolith is known to be surprisingly stiff compared to terrestrial soils because of its angular grain shape, very small grain size, and high relative density. One of the ways to reduce the excavation force and energy is to loosen the soil prior to excavation. In experiments using JSC-1A lunar regolith simulant at three different compaction levels, ripping of the simulant was followed by pushing a wide blade though it. The energy required to move the ripper and the wide blade was measured and analyzed to determine how the excavation energy is affected by the density of simulant, as well as the number and position of tines on the ripper. It was found that ripping increases the efficiency of excavation of lunar regolith denser than 60% relative density. The optimal spacing of tines in this simulant is about 25mm (1.0inch), which agrees with the condition that the failure zones formed by neighboring tines just touch each other.
- Failure Zone,
- Grain Shapes,
- Lunar Regolith,
- Optimal Spacing,
- Relative Density,
- Small Grain Size,
- Terrestrial Soils,
- Aerospace Engineering,
- Compaction,
- Lunar Surface Analysis,
- Excavation,
- Excavation,
- Lunar soil,
- Soil ripping
Available at: http://works.bepress.com/leslie-gertsch/17/