Next-generation Laser-induced Fluorescence Diagnostic Systems for NASA Arc Jet Facilities

The spectroscopic diagnostic technique of two-photon laser-induced fluorescence (2PLIF) of atomic species has been applied to measurements of flow properties in the NASA Ames Aerodynamic Heating Facility (AHF) arc jet since the mid-1990s. Current NASA program goals have placed renewed emphasis on flow stream thermochemistry characterization as part of efforts to develop and validate human-rated thermal protection materials and systems for the Orion crew exploration vehicle. New laser diagnostic laboratories at two other NASA arc jet facilities at Ames and the Johnson Space Center have been developed to support expanded testing and analysis of human-rated thermal protection materials. The new laboratories have benefited from previous experience with the Ames AHF arc jet laser laboratory, leading to new approaches to optical and mechanical systems design, software development, and systems integration. The new laboratories are highly automated and capable of quality measurements with minimal impact on facility operations. This paper documents the new system design for the Ames Interaction Heating Facility arc jet.