Design of inflatable lunar structure

NASA and other space agencies are now looking to create a lunar settlement for the continued exploration of Moon and beyond. The most challenging aspect of a lunar settlement is its construction, and the weight and size of building materials brought from Earth. In-Situ Resource Utilization (ISRU) and inflatable structures are considered to be the most preferred way for the fabrication of a lunar settlement because they minimize weight and size. The use and performance of inflatables and flexible structures in space applications have been increased in the recent past due to the technological advancements in materials technology. So, we propose the concept of two-tier semi-rigid inflatable structure where the base is built with the help of autonomous robots using ISRU, and the main inflatable structure is manufactured on Earth and inflated on the lunar surface. Also, magnesium is proposed as the base material as it is the most abundantly available structural-strength material in lunar environment, and it is relatively easy to machine. A hemispherical inflatable structure placed on top of a cylindrical base with regolith shielding around the structure is considered as a possible lunar design as well as the test prototype. A static analysis is first conducted on the proposed design using ANSYS, and the stress values are order-of-magnitude verified with simple calculations that prove the possibility of the material and model. Also, an order-of-magnitude analysis is conducted on meteoroid impact loads where we estimate the maximum size of meteoroid that our structure can sustain. As future work, we suggest the framework known as Performance Based Engineering. We had spent some time attempting to use this framework for a simplified lunar structural analysis. However, large data gaps precluded significant progress. But we include it as one of our future research topics.M.S.Includes bibliographical referencesby Dheeraj Kumar Kaj