Nuclear Thermal Rocket Engine Instrumentation Addressing Environmental Limitations on Temperature Measurements

The development of nuclear thermal rockets has received renewed interest in recent years due to the benefits that can attained from this method of propulsion. Currently, instrumentation work is focused on the evaluation of current and near-term technology for implementation within a nuclear thermal rocket engine. One aspect of this evaluation is focused on the various instrumentation requirements of the system regarding necessary measurement parameters and environmental conditions for survivability. Historical nuclear rocket programs that have been conducted in the United States provide the basis for this information and indicates a critical need for high temperature measurement technology that can survive extreme environmental conditions. Through a survey of the current state-of-the-art of temperature measurement technology indicates that are still several gaps between high technology readiness level instruments and their potential application in a nuclear rocket. Due to the need for in-situ re-calibration, Johnson noise thermometry provides the best path forward but requires an extreme temperature resistance temperature detector for operation. Currently, there is no such instrument available for use and requires investigation into the feasibility of such an instrument to be used within a Johnson noise thermometry system. The current work provides a conceptual design for a high temperature resistance temperature detector, an evaluation of the design, and experimental plans.