The Langley Research Center (LaRC or NASA Langley), located in Hampton, Virginia, United States, is the oldest of NASA's field centers. It directly borders Langley Air Force Base and the Back River on the Chesapeake Bay. LaRC has focused primarily on aeronautical research, but has also tested space hardware such as the Apollo Lunar Module. In addition, a number of the earliest high-profile space missions were planned and designed on-site, and Langley was considered a potential site for NASA's Manned Spacecraft Center prior to the eventual selection of Houston, Texas.Established in 1917 by the National Advisory Committee for Aeronautics (NACA), the research center devotes two-thirds of its programs to aeronautics and the rest to space. LaRC researchers use more than 40 wind tunnels to study and improve aircraft and spacecraft safety, performance, and efficiency. Between 1958 and 1963, when NASA (the successor agency to NACA) started Project Mercury, LaRC served as the main office of the Space Task Group.In September 2019, after previously serving as associate director and deputy director, Clayton P. Turner was appointed director of NASA Langley.
Overshooting storms are convective systems with updrafts that penetrate through the tropopause into the overlying stratosphere. These storms can rapidly transport a wide variety of chemical species and aerosols from the boundary layer and free troposphere directly to the stratosphere. The central plains of the U.S. and the Sierra Madre Occidental of Mexico are two of the global hotspots for overshooting convection. While the existence of these storms has been known for several decades, the amount of tropospheric air, including water vapor, trace gases, and aerosols, transported across the tropopause is poorly understood, as is their impact on the dynamics, chemistry, and radiative balance of the stratosphere. Climate models suggest that as Earth’s climate continues to warm, overshooting convection over the U.S. may increase, potentially causing changes to stratospheric composition and transport. To address these scientific questions, the NASA ER-2 high-altitude research aircraft flew 31 missions during the summers of 2021 and 2022 to make observations of the outflow from overshooting storms in the stratosphere over North America and the eastern Pacific Ocean as part of the Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) project. The ER-2 carried a payload of 12 instruments to measure meteorological parameters, water and its isotopologues, trace gases, and aerosol properties. Ozone, water vapor, and aerosol sondes were also launched on balloons during the field deployments. This paper describes the science goals of the DCOTSS project, the aircraft measurement strategy, the data produced by the project, and highlights of science results to date.
Accurate surface temperature prediction is critical for ensuring quality control and process optimization in automated fiber placement (AFP). While traditional heat transfer modeling approaches rely on finite element analysis (FEA) and numerical methods, they often struggle to generalize across different tool geometries and heating mechanisms because they are typically tailored to specific conditions and require substantial reformulation when conditions change. This study introduces a data-driven modeling approach to predict applied surface temperature during AFP layup. A polynomial regression model was developed using experimental data collected from infrared (IR) and pulsed light (PL) heating systems across various processing parameters, including heater power, layup speed, distance-to-surface, and p-angle (AFP end-effector head tilt relative to the nip-point). A 10fold cross-validation demonstrated strong predictive accuracy, yielding coefficient of determination, R2, values of 0.914 and 0.916 for the IR and PL models, respectively. A manufacturing case study further demonstrated the ability of the model to predict temperature variations across flat and complex tool surfaces, while flux knockdown experiments were used to quantify temperature distribution effects. Experimental validation using thermocouple measurements confirmed the accuracy of the model in predicting surface temperature, with a mean percent error of 3.01%, highlighting the model's potential for real-time AFP process monitoring. While the model effectively captures key thermal behaviors, future work will focus on incorporating two- and three-dimensional thermal effects, integrating physics-based modeling, and expanding validation to laser-assisted AFP heating. This research advances machine learning-driven heat transfer modeling in AFP, paving the way for intelligent composite manufacturing.
Biomass burning is a major global source of atmospheric ammonia (NH3), significantly influencing air quality, aerosol formation, and nitrogen cycling. Nitrogen isotope composition (delta 15N) of NH3 has been proposed as a powerful tool for source apportionment, yet values for several emission sources remain poorly constrained. This study presents the first field-based delta 15N of total reduced inorganic nitrogen (NH x = NH3 + pNH4) measurements from fresh and aged biomass-burning plumes, collected during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign in the western United States during summer 2019. The NH x concentrations were strongly correlated with carbon monoxide (CO) and fine particulate matter (PM2.5), reflecting elevated emissions during smoldering conditions. The delta 15N(NH x ) ranged from -9.1 parts per thousand to 2.1 parts per thousand (x +/- sigma: -3.3 +/- 2.9 parts per thousand; n = 16). Using a Keeling plot approach, we derived a representative biomass-burning delta 15N(NH3) value of -4.7 +/- 1.3 parts per thousand, that integrates measurements across the sampled biomass burning events, while also accounting for background NH x influences. This field-based isotopic signature is clearly distinct from agricultural and vehicular sources and substantially lower than the +12 parts per thousand value commonly assumed for biomass burning in delta 15N-based source apportionment studies. Overall, this work improves our ability to track NH3 emissions using novel isotopic constraints. Field-based nitrogen isotope measurements of ammonia emissions from biomass burning reveal distinct isotopic signatures, enabling improved source apportionment and nitrogen cycling insights.
High-altitude, multi-spectral, aerial imagery is scarce and expensive to acquire, yet it is necessary for algorithmic advances and application of machine learning models to high-impact problems such as wildfire detection. We introduce a human-annotated dataset from the NASA Autonomous Modular Sensor (AMS) using 12-channel, medium to high altitude (3 - 50 km) aerial wildfire images similar to those used in current US wildfire missions. Our dataset combines spectral data from 12 different channels, including infrared (IR), short-wave IR (SWIR), and thermal. We take imagery from 20 wildfire missions and randomly sample small patches to generate over 4000 images with high variability, including occlusions by smoke/clouds, easily-confused false positives, and nighttime imagery. We demonstrate results from a deep-learning model to automate the human-intensive process of fire perimeter determination. We train two deep neural networks, one for image classification and the other for pixel-level segmentation. The networks are combined into a unique real-time segmentation model to efficiently localize active wildfire on an incoming image feed. Our model achieves 96
This paper presents a history of the assumptions that led to backshell radiative heating being ignored for Earth entry prior to 2015. The errors in these assumptions are identified, which are the result of limitations in both the theory and relevant measurements available during the Apollo era. The process of including this new heating component within a few months of its discovery to the design of the Orion capsule for Artemis-1 is discussed, which required efficient simulation techniques developed at NASA over the past 20 years. Artemis-1 flight measurements indicate that this nearly missed radiative heating component was the dominant heating mechanism over a large section of the Orion backshell. This confirms the importance of identifying and including this backshell radiative heating component for the Orion backshell design, which will be used for future crewed Artemis flights.
