TPSAS-NF1676L-11913-DND
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Engineering topics
Publications and source records attributed to Jennifer Inman.
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In this presentation, we introduce phase-change tunable filters (PCTFs), which are capable of actively tunable spectral filtering as well as continuous tuning (hyperspectral) across multiple IR wavebands (1–10 μm); several orders-of-magnitude faster switching speeds (GHz–MHz) than the state-of-the-art, and narrowband filtering (~50 nm passband). This technology subsystem is based on the unique electro-optics of non-volatile, phase-change materials (PCMs) such as GeSbTe and SbS. PCMs exhibit a large, reversible refractive index shift through applied energetic pulses. By integrating PCMs with established optical filter designs—whose optical properties are strongly dependent on the constituent materials’ refractive indices—we can rapidly and reversibly tune the PCTFs center wavelength (passband).
NASA’s Space Launch System (SLS) and Orion Crew Module have been studied in wind tunnels using the planar laser-induced fluorescence (PLIF) technique for flow visualization and quantitative thermometry and in flight using high-resolution imagery and quantitative infrared surface heating measurements. This paper reviews both types of measurements. OCIS codes: (120.1740) Combustion diagnostics; (300.2530) Fluorescence, laser-induced; (110.3080) Infrared imaging.
Meet SCIFLI, NASA’s diehard team of space geeks who chase spacecraft in a quest to capture data on the cutting edge of our collective aerothermodynamic understanding.
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Measurements made during actual flight on a spacecraft represent the holy grail in supporting cutting edge research and providing critical vehicle health information during exposure to the harsh environments of launch and reentry. Remote optical imaging data obtained by the Scientifically Calibrated In-Flight Imagery (SCIFLI) team at NASA Langley Research Center (LaRC) is currently being used by NASA’s Artemis and Commercial Crew Programs to ensure the safety of astronauts. This emerging capability had its genesis during the Space Shuttle Program. A look toward the future will showcase the use of high-altitude long-endurance uncrewed aircraft coupled with novel sensors to support civilian and national flight-testing interests more effectively.
SCIFLI, The Scientifically Calibrated In-Flight Imagery (https://scifli.larc.nasa.gov/), team at NASA Langley Research Center specializes in the collection of multispectral data for space vehicles during Ascent and Entry, Descent, and Landing (EDL) observations. Multispectral datasets are invaluable across the NASA Agency and to commercial stakeholders for evaluating the performance of launch and re-entry space vehicles and ensuring the safety of the scientific research community. The launch of Artemis 1 marked the initiation of NASA returning to lunar exploration. SCIFLI’s Airborne Multispectral Imager (SAMI) was deployed by the SCIFLI team to scientifically document the historic event and provide the NASA research community with aerial footage of the event in wavelength channels ranging from the ultraviolet (UV) to the visible (VIS) to mid-wave infrared (MWIR). SAMI was designed to spectrally image unique aerothermal phenomena during the Artemis 1 launch. The use of these datasets captured in-flight during the launch will provide insight to research organizations across the Agency; aiding in validation efforts for simulations and modeling that contributed to the kickoff of the Agency’s resurgence to lunar exploration. This presentation will focus on the imagery captured on SAMI by the WB-57 team on November 16th, 2022, during the observation. Imaging objectives were identified and considered beforehand to determine the configuration of the SAMI instrument for the imaging mission. SCIFLI and Opto-Knowledge Systems, Inc. (OKSI) performed a thorough review of the datasets collected to identify and characterize aerothermal phenomena occurring during the observation. Additional post-processing was completed to provide quantitatively calibrated temperature images of the rocket during the observation. Some of the candidates were not optimal for quantitative temperature extraction due to common degradation factors, but after various image enhancements they proved useful for qualitatively characterizing different phenomena during the observation.
In 2003 a mobile planar laser-induced fluorescence (PLIF) system was constructed at NASA Langley Research Center to visualize and quantify high speed flow fields containing fluorescent species such as nitric oxide (NO). Thereafter, a series of test entries utilizing NO PLIF were conducted in the NASA Langley Research Center’s 31 Inch Mach 10 air wind tunnel, which is a hypersonic blowdown wind tunnel located in Hampton, Virginia. This paper briefly reviews laser-based measurements previously performed in hypersonic blowdown wind tunnel facilities and then details NO PLIF measurement campaigns performed at this facility in the 20 years to date. Measurements were performed to develop 2D and 3D visualization capabilities and quantitatively measure velocity and temperature. Applications described herein include historical models (e.g., Apollo, X-33 and X-43), flight vehicles under development at the time (e.g., Mars Science Lab (MSL), Orion, and LOFTID), as well as fundamental research (e.g., flat plates with and without discrete roughness).