Lunar Problems in Soil Engineering

In the relatively near future unmanned, and perhaps manned spacecraft will make soft landings on the moon, and ultimately on some of the other planets. Because our knowledge of the intimate small-scale properties of the lunar surface is almost nonexistent, it is desireable to devise surface models and materials in line with current information for the purpose of designing test experiments and forecasting possible future problem areas. This paper considers briefly the state of knowledge of the lunar surface from an engineering viewpoint and outlines a variety of plausible soil or rock profiles to shallow depths. The engineering properties of the soil and rock materials are defined arbitrarily in terms of an idealized mechanical behavior. An attempt is made to establish ranges of material behavior in terms of quantitative properties, and the classes of soil engineering problems that might arise with respect to operations on the lunar surface are examined. Finally, consideration is given to suitable simple experiments that may be conducted from spacecraft on the surface for the purpose of measuring the quantitative properties.