Shock Hazard Prevention through Self-Healing Insulative Coating on SSA Metallic Bearings

The space suit assembly (SSA) contains metallic bearings at the wrist, neck, and waist, which are exposed to space environment, and pose a potential shock hazard. Current methods to mitigate the hazard are short-term, and there is a need for an insulative and durable coating on the metallic components. In Phase I, working with a supplier of space suits to NASA, we demonstrated proof-of-concept of a novel Self-Healing Coating (SHC) system which is highly insulative and is capable of healing surface damages at ambient conditions. The three-layered self-healing coating was applied on flat panels of stainless steel, titanium and aluminum. In addition to self-healing, the ability of the coating to resist impact damage was demonstrated. Building upon the successful Phase I demonstration, the focus of the Phase II effort will be to further test and optimize the SHC system and implement on a prototype metallic bearing. The Phase II objectives include: (i) ensuring that the self-healing coating system can be used in space environment; (ii) determining the least coating thickness that will provide both self-healing and electrical resistance; (iii) developing a suitable process for depositing the coating on components of different geometries; and (iv) developing a property and performance data set that best predicts useful life of the coating. Successful development will culminate in applying the SHC system on a prototype component and performing the needed qualification testing. We anticipate achieving a TRL of 6 by the end of the Phase II program. The work plan includes preparing coating solutions and coating flat test panels; conducting performance tests and optimizing coating thickness using coated plates; qualifying the SHC system for use in a space environment; developing a property and performance data set that best predicts useful life of the coating; applying SHC system to a prototype hardware; and evaluating performance of coating on prototype hardware.