L. Wang, R. Mosher, P. Duett
Mississippi State University,
United States
Keywords: additive manufacturing, in-situ resource utilization, microgravity, computer vision, autonomy, convolutional neural network
Summary:
For the extension of manned missions to a place outside the earth’s atmosphere (e.g., the Moon and Mars), in-situ resource utilization (ISRU) has been the utmost priority. Additive manufacturing (AM) in space is an important area because capacities for sending equipment and materials into space are very limited and costly. Manufacturing in space refers to processes and techniques with which products are produced outside the Earth’s atmosphere. The working material in this situation would be the regolith. For deep space missions, there should be many in-space activities such as manufacturing and assembly of large structures, repair, and services. Current maintenance logistics are not very effective for deep space missions. AM has the potential to significantly reduce maintenance logistics mass requirements and enable the use of recycled materials and ISRU for more dramatic reductions in mass requirements. NASA has worked on the AM of food in space to serve the purpose in long manned missions to Mars or even the moon where normal food storage and carrying is a big problem. The physical conditions in space are drastically different from those on Earth. This includes factors such as microgravity, infinitesimal pressure, radiation, rapid changes in temperature, intense thermal fluctuations, etc. There are substantial challenges in in-space AM due to the extreme and harsh conditions. Although there are various AM methods on Earth, only a few can be realized in space. For example, the processes of direct energy deposition (DED) with wire are considered suitable for AM in space. Computer vision could be a feasible method to evaluate AM parts and detect failures. The convolutional neural network (CNN)-based quality assessment (QA) method for AM can potentially enhance the automatic operation of an in-space AM system with minimal human intervention. The AM system has the potential to reduce material waste and lower the cost of resupplying materials in space by enabling an automatic closed control loop for the printing process with the QA system. It is vital to fully automate and test the printing software to reduce the risk of mission failures due to autonomy. In-space AM has the potential to help serve long manned missions to the Moon and Mars. This presentation discusses the trends and state of the art of AM in space and highlights challenges and future work.