Solar-Powered Additive Manufacturing in Extraterrestrial Environments

Abstract

Kickstarting a space economy will require building communication relays, refueling depots, repair depots, habitats, and mining bases from in-situ resources in strategic locations between Earth, Moon, and Mars. Due to the high costs inherent in transporting resources from the Earth's surface to these locations, new methods of material extraction and construction are necessary. Paramount to these development requirements is the need for a low-cost and efficient means for construction of habitats and physical structures. Utilizing networks of small spacecraft and robots to perform the task will reduce cost, enable scalability, and robustness. The idea of 3D printing structures has risen to the forefront of construction methods for its ability to be sent in advance of the primary mission and build structures autonomously. Two distinct challenges are inherent in this concept: the 3D printer needs to be supplied material, and it must have the ability to generate a significant amount of energy to process the material into its final form. Refining this printing technology to be as energy and resource efficient as possible is of the utmost importance to future space missions. Once this is achieved, it will be economical to build lunar and planetary bases rooting in in-situ resource utilization. Reducing the necessary supply of material to the additive manufacturing process and the power consumption leads to a reduction in the size of these early missions. In an effort to confront these challenges, we are working to develop an additive manufacturing process based on the principles of the selective laser sintering (SLS) technique, whereby a heat source (a laser in the case of SLS) heats the material just below its liquefaction point before returning to a solid form. By replacing the laser in the SLS process with a large Fresnel lens, we aim to focus enough sunlight to be able to sinter the material and create solid shapes. In this way, the system fully relies on renewable solar energy for its operation. In this paper, we propose development of solar additive manufacturing printers for melting and use of sand for construction. The paper will analyze the conceptualization, design, and prototype construction of the solar 3D printer. Current simulations are being done in support of the printer to determine best operating parameters and performance. Lesson learned from the simulations and prototype development will be used to develop a miniature scale printer for extended experiments. © 2021 ASCE.