The study of molecular physics using ultracold gases has provided a unique probe into the fundamental properties of nature and offers new tools for quantum technologies. In this article we outline how ultracold molecular physics in a space environment opens opportunities for (a) exploring ultra-low energy regimes of molecular physics with high efficiency, (b) providing a toolbox of capabilities for fundamental physics, and (c) enabling new classes of matter-wave interferometers with applications in precision measurement for fundamental and many-body physics.