The Phase I project will develop a suite of diagnostic sensors using Direct Write technology to measure temperature, surface recession depth, and heat flux of an ablative thermal protection system (TPS) in real time, which can be integrated to support TPS evaluation and in-situ diagnostics during planetary entry. Standalone heat flux sensors and those fabricated by direct deposition will be developed and demonstrated for integration within TPS materials for use in extreme re-entry conditions. The intent is to use the sensors for real time heat flux measurements to validate new materials and systems, as well as for flight structures where space and accessibility are limited. Methods for incorporating thermocouples, heat flux and recession sensors using Direct Write technology will be developed to provide accurate sensing capabilities. Notably, recession tolerant heat flux sensors will be designed and fabricated to demonstrate feasibility of this new heat flux sensor technology and subsequent instrumentation capability for TPS.