TOWARD IN-SPACE ADDITIVE MANUFACTURING OF THERMOSETS WITH EMBEDDED FIBERS CURRENT IN-SPACE ADDITIVE MANUFACTURING (ISAM) RELIES ON FUSED DEPOSITION MODELING (FDM) OF THERMOPLASTICS SUCH AS ACRYLONITRILE BUTADIENE STYRENE (ABS) WHICH HAVE LIMITED MECHANICAL PERFORMANCE (E.G. THERMAL STABILITY UP TO ~100 C [1]). TO OVERCOME THE OPERATING TEMPERATURE LIMITS OF CURRENTLY EMPLOYED THERMOPLASTIC MATERIALS PROPOSED HERE IS EXTRUDED PRINTING OF THERMOSET MATERIALS WITH EMBEDDED FIBERS. THIS WORK WILL FURTHER DEVELOP ISAM THROUGH THE EXTRUDED PRINTING OF THERMAL-CURING HIGH-PERFORMANCE POLYMERS IN LOW GRAVITY WHICH WOULD ENABLE FUNCTIONAL TOOLS AND ACTUATORS MADE OF HARD EPOXIES AND SOFT ELASTOMERS. THE TARGET OUTCOME IS AN EXPERIMENTAL AND THEORETICAL PLATFORM WITH AN ADDITIVE MANUFACTURING (AM)-BASED MACHINE ON EARTH AND ACCOMPANYING NUMERICAL SIMULATIONS WHICH WILL THEN BE CAPABLE OF PREDICTING PERFORMANCE IN LOW OR HIGH-GRAVITY ENVIRONMENTS. ONCE CREATED THIS PLATFORM WILL ENABLE THE DESIGN AND FABRICATION OF NEW MACHINES FOR ISAM WITH HIGH-PERFORMANCE THERMOSETS WITH EMBEDDED FIBERS. IN THE FUTURE WE ENVISION THIS WORK IN DESIGN AND PREDICTIVE MODELING WILL BE USEFUL FOR AM AND DEPOSITION OF NEW MATERIALS BEYOND THERMAL-CURING THERMOSETS WITH EMBEDDED FIBERS SUCH AS RECYCLED FEEDSTOCK CONCRETE HIGH-TEMPERATURE THERMOPLASTICS AND EVEN REGOLITH BECAUSE WE WILL BE ABLE TO ENTER NEW MATERIAL PROPERTIES INTO OUR MULTI-PHYSICS-BASED SIMULATIONS. THE RESULTING TECHNOLOGY WILL PROVIDE NEW MATERIALS FOR ISAM AND GO FURTHER IN PROVIDING MARKETABLE CAPABILITIES OF TEST AND SIMULATION TO COMPANIES WORKING TO EVALUATE THE FEASIBILITY OF PRINTING OR DEPOSITING ADVANCED MATERIALS THAT SPREAD AND CURE ON SURFACES. ADDITIONALLY THIS TECHNOLOGY WILL SERVE AS A TEST SYSTEM FOR THE EMBEDDING OF COMPOSITE FIBERS WITHIN AN ADDITIVELY MANUFACTURED THERMOSET MATRIX. THE TESTING OF FIBER WETTING WITHIN THESE AM THERMOSET MATRICES IS CRITICAL TO THE MATERIAL AND APPLICATION DEVELOPMENTS OF CAM. A STUDY OF THE COMMERCIAL MARKET SHOWS THAT THERE ARE NO AM-BASED TECHNIQUES SUITABLE FOR PRINTING THERMAL-CURING THERMOSETS WITH EMBEDDED FIBERS AND POSSESSING HIGH-PERFORMANCE PROPERTIES AND THERE IS LIKEWISE VERY LITTLE ACADEMIC RESEARCH WHICH IS INDICATIVE OF THE TECHNICAL HURDLES WE WILL OVERCOME BY TAKING ADVANTAGE OF LOW GRAVITY (SEE NEXT SECTION). TO CREATE NEW TECHNOLOGIES FOR ISAM AND CAM WITH THERMAL-CURING THERMOSETS WITH EMBEDDED FIBERS AND MOVE IT TOWARD COMMERCIAL FEASIBILITY WE WILL PURSUE THE FOLLOWING TECHNICAL TASKS/OBJECTIVES: (I) MODIFY EXISTING 3D PRINTERS AT MSFC FOR THE EXTRUSION OF THERMOSETS; (II) BUILD ANALYTICAL MODEL TO PREDICT THE BEHAVIOR OF EXTRUSION AND THERMAL CURING OF VISCOUS MATERIALS; (III) EXTRUDE DROPLETS PUDDLES AND LINEAR BEADS OF THERMAL-CURING THERMOSETS ON HEATED SURFACES AT BOTH 0DEG AND MULTI DEG ANGLES.; (IV) COMPARE EXTRUDED FEATURES TO SIMULATED PREDICTIONS; (V) USE CALIBRATED MODELS TO PREDICT PERFORMANCE IN VARIED-GRAVITY ENVIRONMENTS AND (VI) EMBED COMPOSITE FIBERS INTO EXTRUDED THERMOSETS USING THE MODIFIED 3D PRINTER. AN ADDITIONAL NON-TECHNICAL ADJECTIVE WILL INCLUDE LEVERAGING INTERNAL AND EXTERNAL RELATIONSHIPS TO BUILD STRONG COLLABORATING EFFORTS FOR FUTURE EXTERNAL FUNDING OPPORTUNITIES. THIS PROJECT WILL COMBINE NASAS EXTENSIVE EXPERIENCE WITH MECHANICAL DESIGN OPTIMIZATION ISAM AND SMALL-SCALE AM IN ES21 WITH NEW UNIVERSITY-BASED EXPERTISE IN PROCESSING OF THERMOSETS HIGH-GRAVITY SPREADING OF LIQUID COATINGS AND MODELING. THE INNOVATION COMES FROM REALIZING THAT LOW-GRAVITY ENVIRONMENTS WILL AID ISAM OF THERMAL-CURING THERMOSETS BY (I) LIMITING THE LATERAL SPREAD OF EXTRUDED DROPLETS AND (II) REDUCING THE LOSS OF HEAT SURROUNDING AN EXTRUDED DROPLET WITH A LACK OF BUOYANCY-DRIVEN CONVECTION.