Analysis of specimens from phase I of the 3D printing in Zero G technology demonstration mission

Purpose - Human space exploration to date has been limited to low Earth orbit and the moon. The International Space Station (ISS) provides a unique opportunity for researchers to prove out the technologies that will enable humans to safely live and work in space for longer periods and venture farther into the solar system. The ability to manufacture parts in-space rather than launch them from earth represents a fundamental shift in the current risk and logistics paradigm for human space exploration. The purpose of this mission is to prove out the fused deposition modeling (FDM) process in the microgravity environment, evaluate microgravity effects on the materials manufactured, and provide the first demonstration of on-demand manufacturing for space exploration. Design/methodology/approach - In 2014, NASA, in cooperation with Made in Space, Inc., launched a 3D printer to the ISS with the goal of evaluating the effect of microgravity on the fused deposition modeling (FDM) process and prove out the technology for use on long duration, long endurance missions where it could leveraged to reduce logistics requirements and enhance crew safety by enabling a rapid response capability. This paper presents the results of testing of the first phase of prints from the technology demonstration mission, where 21 parts where printed on orbit and compared against analogous specimens produced using the printer prior to its launch to ISS. Findings - Mechanical properties, dimensional variations, structural differences and chemical composition for ground and flight specimens are reported. Hypotheses to explain differences observed in ground and flight prints are also developed. Phase II print operations, which took place in June and July of 2016, and ground-based studies using a printer identical to the hardware on ISS, will serve to answer remaining questions about the phase I data set. Based on Phase I analyses, operating the FDM process in microgravity has no substantive effect on the material produced. Practical implications - Demonstrates that there is no discernable, engineering significant effect on operation of FDM in microgravity. Implication is that material characterization activities for this application can be ground-based. Originality/value - Summary of results of testing of parts from the first operation of 3D printing in a microgravity environment.