Extending Arc Heater Operating Pressure Range for Improved Reentry Simulation

Arc-heated facilities play an important role in discriminating between materials, validating designs, and gathering data for the validation and tuning of material models used in the design of hypersonic reentry vehicle flight tests. Information gathered from experiments in arc heaters is critical in reducing risk to flight programs and ensuring range safety. In addition, ground testing can aid in the down-select of heat-shield materials, allowing flight-testing resources to be used for only the most viable materials. Finally, the carefully controlled conditions afforded by ground testing allow instrumentation and data collection that are not possible in flight testing. In this paper, the methodology used in planning and executing a reentry material ground-test program is discussed with an emphasis placed on arc-heater testing and the use of results from such testing in support of follow-on flight-tests. Plans for the expansion of high-pressure arc-heater capabilities to provide conditions even closer to flight, and thereby to expose material features currently seen only in flight tests, are then presented. Progress on the technology development needed for fielding such a capability is then discussed, and the results from recent AEDC heater runs at elevated pressures are presented. It is demonstrated that large-scale heater operation well in excess of the current operating range is possible with proper design changes, and would provide a powerful capability in support of material model development and flight testing. Technical challenges that still remain are then discussed.