<p>As space missions grow increasingly complex, the demand for highly reliable and efficient mechanical systems has underscored the critical role of tribology in aerospace engineering. Tribology, encompassing friction, wear, and lubrication, must be reimagined for space environments characterized by high vacuum, radiation, extreme temperatures, and abrasive extraterrestrial dust. Unlike terrestrial systems, space mechanisms suffer from cold welding, lubricant evaporation, and radiation-induced material degradation, which can compromise mission success. This review highlights significant advancements in space tribology, including the development of solid–liquid composite coatings, self-lubricating nanocomposites, and boundary lubrication strategies tailored for vacuum conditions. It also emphasizes the rising integration of 2D materials, ionic liquids, and nano-lubricants to improve frictional performance under high thermal and radiation loads. Notably, the document identifies a research gap in long-term, adaptive tribological systems capable of in situ lubricant replenishment and wear debris management in deep-space missions. Many traditional lubricants fail under cryogenic and vacuum environments, necessitating further development of multifunctional, environmentally adaptive coatings and materials. This review also presents historical mission failures, such as those involving the Hubble Space Telescope and Galileo spacecraft, to underscore the consequences of inadequate tribological planning. Case studies demonstrate how modern tribological innovations such as graphene-enhanced composites and diamond-like carbon (DLC) coatings have significantly extended the operational lifespan of spacecraft mechanisms. The novelty of this work lies in its comprehensive synthesis of emerging materials and strategies, addressing not only performance in current missions but also laying a foundation for future sustainable, autonomous, and long-duration space exploration systems.</p>