Open Atmosphere In Situ Processing of Termal Control Thin Films for Spacecraft

Combustion chemical vapor deposition (CCVD), which was invented by the principal investigator, is the only open atmosphere CVD technique for ceramics and metals. The CCVD method has been shown to inexpensively and quickly apply dense, adherent, epitaxial thin films in a continuous manner. This technology can be used for the production of thermal control coatings onto spacecraft even after assemblage. The CCVD method is low cost, high quality and versatile. It does not require a reaction chamber or furnace, yet the thin films produced are comparable in quality to CVD films, and allows a deposition zone to be moved over a large area. The deposition apparatus is lightweight and easier to manipulate than thermal spray devices. The thin film multilayering capability of CCVD processing, which is not line-of-sight limited, is need to bring desired thin film heterostructure coatings to in situ applications. We have produced CVD quality films of numerous materials using CCVD in the open atmosphere without a furnace or reaction chamber. In this project, thin films of thermal control coatings for spacecraft will be grown onto flat substrates and curved surfaces in the open atmosphere using CCVD. The composition, morphology, microstructure, and absorbance and emittance properties of the films will be determined as a function of deposition conditions. A series of run studies will be performed to optimize the process. This research will demonstrate the ability of CCVD to inexpensively deposit thermal control coatings for spacecraft with solar absorbance of less than 0.10 and thermal emittance of greater than 0.90.