This thesis investigated if Fused Filament Fabrication (FFF), a 3D printing technique, could be used in a simulated on-orbit environment. A modified FFF printer was exposed to a vacuum environment and fabricated a variety of components from polycarbonate filament. The printer and its subsystems were evaluated for functionality in the vacuum environment. The fabricated components were analyzed for dimensional accuracy and subjected to mechanical testing. It was found that the FFF process can be carried out in a vacuum environment with minimal modifications to the printer. The dimensions and mass of components fabricated in vacuum were found to be practically indistinguishable from those fabricated in a normal atmosphere although statistical differences were sometimes present. Polycarbonate components fabricated in a vacuum environment were found to have an ultimate tensile strength 10% higher and a compressive yield strength 5% higher than equivalent components fabricated in atmosphere.