ABSTRACT: The benefits of using nonterrestrial sources of bulk material and fuel for future missions have been well established. Accessing these resources from other bodies (planets, moons, asteroids or comets) in space requires the excavation and handling of materials before they can be processed into useful products. For bases or operations on planetary surfaces, site preparation will also require the excavation and handling of local material. Mining and excavation processes and equipment need to be defined early for accomplishing the required site preparation and resource recovery.
Material properties, for the purposes of this discussion, are considered the physical properties or characteristics of the regolith and/or rock which will affect its excavatability of a material. These properties will determine the cutting forces for a given penetration, and the energy required to remove a given volume of material. Thus for any excavation system, the required reaction mass (or force) and power can be defined in terms of instantaneous production rates (production requirements/utilization).
This paper discusses the current state of knowledge on in situ lunar materials properties, how these properties will affect excavation for mining and construction, and identifies additional tests or missions required for optimum system definition.
INTRODUCTION From early tool making to modern industrialization, society has depended upon a base of resource discovery, development, and utilization. A similar fundamental base will be required in the exploration, colonization, and development of space. The basic Human quest for knowledge will assure the progression of the move to space, and the science and engineering community needs to be ready. The benefits of using nonterrestrial sources of bulk materials and fuel for future missions have been well established. Accessing these resources from other bodies (planets, moons, asteroids or comets) in space requires the excavation and handling of materials before they can be processed into useful products. For bases or operations on planetary surfaces, site preparation will also require the excavation and handling of local material. Clearly, the properties of the in situ material, as well as local environmental conditions, will control the design and capabilities of an excavating system.
BACKGROUNDRequirements Certain requirements can be identified for any facilities in space, although this report is primarily concerned with operations on the lunar surface. Shelter is required for all systems or inhabitants operating in the nonterrestrial environment. Protection is needed from radiation, particle impacts, temperature variations, and atmospheric extremes. This shelter can be imported, provided with local materials, or constructed on site. Generally, structures are required both for shelter and to support the functioning and purpose of the facility. These structures, in turn, need foundations or support on local material. For manned operations, or special atmospheric requirements, life support needs such as gasses, liquids, and food sources must be considered. Fuel (energy source) will be required for facility power needs and propulsion systems. Transportation requirements, and specifically materials handling at the local level, have to be considered. Finally, waste handling/recycling is a necessity in an environment where one cannot afford to throw anything away.