Importance of geotechnical engineering on development and sustainability of lunar bases

Previous volumes of RAST (Recent Advances in Space Technologies) Proceedings presented important developments in various science and engineering disciplines combined in different aspects of space research. However, the very same proceedings have also revealed that the amount of research in some of the fundamental engineering disciplines such as civil engineering is quite limited. Ironically, many countries are planning to construct permanent lunar bases in future. Some of them such as United States and Japan declared this strategy explicitly, whereas some others such as Turkey have it implicitly in their space programs. This paper is written to emphasize the importance of geotechnical engineering, which is one of the several majors of civil engineering, on the development of lunar basis and lunar exploration. Shear strength of soils is briefly overviewed and strength characteristics of various lunar soil simulants are summarized, as shear strength is a key factor for most of the geotechnical analysis. Finally, the importance of simulant gradation on strength characteristics and the need for further research is mentioned with considerations of recent research on terrestrial silty sands.