To enhance NASA systems, Spire proposes a novel technique for growing a graded nanocrystalline ZrON/ZrO2 protective coating with superior heat tolerance on relevant in-space substrates. The proposed coating technology will adhere to and protect engine components such as injectors, combustion chambers, nozzles, and nozzle extenders. Conventional high temperature coatings applied by chemical vapor deposition inadequately adhere, and often spall. The proposed coating will distribute stress induced by thermal cycling and improve adhesion, resulting in an improved and longer lasting coating. The high temperature phase of ZrO2 is produced by controlling nucleation, grain growth, and grain size via the unique features of our deposition technique. The increased surface energy of the nanograins results in the formation of a dense cubic phase of zirconia, which is stable at very high temperature. Phase I will develop a base-line process for applying highly adherent, thermally-resistant cubic ZrO2 layers on in-space propulsion substrates with a functionally graded ZrON metalloceramic transition layer at the metal interface. The deposition guidelines for nanocrystalline ZrON/ZrO2 coating will be perfected to each unique substrate in Phase II. In addition, a number of metallic components will be coated and delivered to NASA to be evaluated for in-space propulsion use.