Lunar Landing and Launching Pad Design Considerations Using ISRU Materials

Launching and landing pads (LLPs) will be essential elements to serve a future lunar base. There is widespread acceptance that these structures will be manufactured from in situ materials. Structural materials made from these indigenous materials are expected to be brittle. Thus, they will exhibit the typical diverse behaviors and inherent variabilities in properties that are common in indigenous construction materials. Hard-won lessons on how to design reliable structures from brittle materials on the Earth need to be leveraged. It should be noted that earlier examples of these applications resulted in massive structures. It was not until Portland cements, other cementitious materials, chemical admixtures, steel, and more recently carbon fiber-based elements became available, and in general, composites were better understood, that more elegant and slender structures were realized. In this research, we adapt and apply well-established methodologies used for slab-on-grade construction toward the development of a design framework for lunar LLPs. The structural considerations in designing such a slab are discussed in detail starting from first principles and unknown initial dimensions to illustrate their impact on the design. This approach is necessary given the low state of entropy of the knowledge with respect to performance and actual material properties in such extreme environments. It is demonstrated through an illustrative example in which we design an LLP using the best available information and properties for sintered lunar regolith. Additional information that will need to be obtained or verified through in situ testing is also defined. The example design is intended to service spacecraft of up to 50 tons. The dimensions used for the loads represent spacecraft being developed at the present time for transporting cargo and supplies to the surface of the Moon. The application of a wealth of fundamental knowledge, practical experience, and technologies will be essential for the design and construction of resilient and sustainable infrastructure on the Moon and other similarly challenging environments. The paper concludes with a discussion of the path forward to design and realize such construction on the Moon.