Commercial space activities are now beginning in earnest by companies interested in mining asteroids and near earth objects for valuable minerals. Such private ventures open up new possibilities for space exploration, including scientific as well as economic pursuits, and lead the way for potential space manufacturing and future space colonization. Colonies and/or space manufacturing facilities will only be feasible if they rely minimally on material exports from Earth due to the high cost penalty of transportation through Earth's gravitational field. Bulk materials for space construction are likely to come from the Moon, near-Earth objects, or asteroids, which are known to be rich in mineral and metal content. Metals have favorable structural properties, and iron, which is the most abundant metallic element in our galaxy, makes it a likely candidate for space construction. Iron is known to exist in its metallic form in iron meteorites, and if it can be made into suitable powder, additive manufacturing (AM) methods would be able to use it for the direct digital manufacture of metallic components in space.
LLNL researchers have conceived and performed studies relevant to the development of AM powders synthesized from asteroidal or meteoritical sources and the use of the powder as the feed source for additive manufacturing systems deployed in space. The method includes the steps of locating an asteroid or meteorite, making contact with the asteroid or meteorite, harvesting material from the asteroid or meteorite, and processing material from the asteroid or meteorite to produce high quality powder capable of being used for defect-free AM processing. This powder can then be used for additive manufacturing feed stock in space, and completing the parts or products by the additive manufacturing in space.
Metallurgical thermochemical refining during the powder making method is required to produce high quality metal powder from asteroids or meteorites that is suitable for AM processes such as selected laser melting (SLM) powder bed, laser metal deposition (LMD) powder fed, electron beam additive manufacturing (EBAM) powder bed, and/or other 3D printing methods involving the melting and solidification of fine powders for the direct digital manufacture of components and structures.
High quality powder of the correct composition and size distribution is required for additive manufacturing processes involving laser and electron beam based AM systems in order to produce near fully dense AM components with minimal defects.
Refer to the research papers referenced below for further details on the LLNL studies.
- J. W. Elmer, C. L. Evans, J. J. Embree, G. F. Gallegos, and L. T. Summers, “Electron Beam Weldability of a Group IAB Iron Meteorite,” Science and Technology of Welding and Joining, V19(4), pp. 295-301, 2014. doi: 10.1179/1362171813Y.0000000188
- Nature Highlight, “Asteroids Prove Hard to Weld,” Nature 506 (13 February 2014) doi:10.1038/506135e
LLNL has filed U.S. Patent Application No. 15/358611 “Synthesis of Asteroidal or Meteoritical Powder for Additive Manufacture of High Fidelity Metallic Components in Space”.