This publication presents a science activity and instructional information on the mechanics of granular materials, interparticle friction and geometric interlocking between particles which is a fundamental concept in many fields like in the study of earthquakes. This document describes the Mechanics of Granular Materials (MGM) experiments which are conducted under the microgravity of orbit to test sand columns. This information can be applied to engineering, agriculture and other industries to improve the Earth's foundation. These concepts are discussed in terms of the National Science Education Standards. Student activity worksheets, such as the "Laboratory Direct Shear Test Data Sheet," are provided. A brief glossary and list of related Internet resources are also included. (Contains 12 figures.) (YDS)