GEOTECHNICAL ANALYSIS OF MARTIAN SOIL SIMULANT JSC MARS-1

We tested Martian soil simulant JSC MARS-1 for geotechnical properties including California Bearing Ratio (CBR), optimal water content for compaction, and unconfined compressive strength. Both NASA and Mars One are planning to send manned missions to Mars in the coming decades. Mars One plans to leave humans on Mars indefinitely with the prospect of expansion. This necessitates an understanding of soil characteristics for construction of static structures as well as stability of transported habitats. The JSC MARS-1 soil is classified as non-plastic silt by the Unified Soil Classification System. The California Bearing Ratio (ASTM D1883-14) test reveals penetrative resistance of soil as well as the suitability for use in roads, runways, and landing pad construction including base, subbase, and subgrade. The CBR test at optimal water content gave a result of 5.6%. At a dry condition the CBR test gave a result of 8.4%. Unconfined compressive strength (ASTM D2166-85) testing reveals the strain behavior of soil resulting from compressive stress and allows identification of yield strength and ultimate strength of soil for supporting a structural load. Near optimal water content, the ultimate strength of JSC MARS-1 is 3000 psf. Ultimate strength of dry JSC MARS-1 is 2300 psf. Water will be a valuable commodity on Mars. Understanding the effects of reduced water and gravity on soil behavior is an important part of Mars mission planning. Adaptation of testing methods may be required for use on Mars.