Space Environmental Effects on AM Parts on MISSE-9/10

The Materials on International Space Station Experiment (MISSE) experiments have made a continuous presence on the ISS and allowed for testing of performance and durability of materials exposed to the Low Earth Orbit (LEO) space environment. Additive Manufacturing (AM) has been included on several MISSE flights, and many companies (Redwire and Stratasys) and NASA centers wanted to test various AM material samples. The goal of the MISSE-9/10 missions was to fly promising metal and polymer AM material samples (dogbones) that could have future manufacturing capabilities in space and conduct post-flight analysis of these materials via mechanical and optical properties. On these flights, MISSE-9 contained three Inconel and 12 polymer samples and MISSE-10 included three Inconel and 16 polymer samples. Before flying to the ISS, all the samples underwent thermal vacuum bakeout (at 60°C for 24 hours and 10^-6 torr). After bakeout, control and flight experiments were weighed, and optical properties were taken. Optical properties such as solar absorptance and infrared emittance were taken on the control samples and the flight samples (preflight and postflight). To understand more about the mechanical properties of the AM samples, tensile testing was conducted on the samples to determine the yield and ultimate tensile strength and strain of the dogbone samples against the ground control. From both optical and mechanical results, it was found that the space environmental effects did play a factor into reflectance and strength data on most of the samples (especially with Ultem 1010 and Polycarbonate). With postflight analysis completed, NASA engineers can use this data to better characterize how UV radiation and thermal cycling affect their material properties on spacecraft and other related work.