Automated Additive Construction (AAC) for Earth and Space Using In Situ Resources

Using automated additive construction (AAC), low-fidelity large-scale compressive structures can be produced out of a wide variety of materials found in the environment. Compression-intensive structures need not utilize materials that have tight specifications for internal force management, meaning that the production of the building materials do not require costly methods for their preparation. Where a certain degree of surface roughness can be tolerated, lower-fidelity numerical control of deposited materials can provide a low-cost means for automating building processes, which can be utilized in remote or extreme environments on Earth or in space. For space missions where every kilogram of mass must be lifted out of Earth’s gravity well, the promise of using in situ materials for the construction of outposts, facilities, and installations could prove to be enabling if significant reduction of payload mass can be achieved. In a 2015 workshop sponsored by the Keck Institute for Space Studies, on the topic of three dimensional (3D) additive construction for space using in situ resources, was conducted with additive construction experts from around the globe in attendance. The workshop explored disparate efforts, methods, and technologies and established a proposed framework for the field of additive construction using in situ resources. This paper defines the field of automated additive construction using in situ resources, describes the state-of-the-art for various methods, establishes a vision for future efforts, identifies gaps in current technologies, explores investment opportunities, and proposes potential technology demonstration missions for terrestrial, International Space Station (ISS), lunar, deep space zero-gravity, and Mars environments.