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    • By NASA
      Download PDF: Statistical Analysis Using Random Forest Algorithm Provides Key Insights into Parachute Energy Modulator System

      Energy modulators (EM), also known as energy absorbers, are safety-critical components that are used to control shocks and impulses in a load path. EMs are textile devices typically manufactured out of nylon, Kevlar® and other materials, and control loads by breaking rows of stitches that bind a strong base webbing together as shown in Figure 1. A familiar EM application is a fall-protection harness used by workers to prevent injury from shock loads when the harness arrests a fall. EMs are also widely used in parachute systems to control shock loads experienced during the various stages of parachute system deployment.
      Random forest is an innovative algorithm for data classification used in statistics and machine learning. It is an easy to use and highly flexible ensemble learning method. The random forest algorithm is capable of modeling both categorical and continuous data and can handle large datasets, making it applicable in many situations. It also makes it easy to evaluate the relative importance of variables and maintains accuracy even when a dataset has missing values.
      Random forests model the relationship between a response variable and a set of predictor or independent variables by creating a collection of decision trees. Each decision tree is built from a random sample of the data. The individual trees are then combined through methods such as averaging or voting to determine the final prediction (Figure 2). A decision tree is a non-parametric supervised learning algorithm that partitions the data using a series of branching binary decisions. Decision trees inherently identify key features of the data and provide a ranking of the contribution of each feature based on when it becomes relevant. This capability can be used to determine the relative importance of the input variables (Figure 3). Decision trees are useful for exploring relationships but can have poor accuracy unless they are combined into random forests or other tree-based models.
      The performance of a random forest can be evaluated using out-of-bag error and cross-validation techniques. Random forests often use random sampling with replacement from the original dataset to create each decision tree. This is also known as bootstrap sampling and forms a bootstrap forest. The data included in the bootstrap sample are referred to as in-the-bag, while the data not selected are out-of-bag. Since the out-of-bag data were not used to generate the decision tree, they can be used as an internal measure of the accuracy of the model. Cross-validation can be used to assess how well the results of a random forest model will generalize to an independent dataset. In this approach, the data are split into a training dataset used to generate the decision trees and build the model and a validation dataset used to evaluate the model’s performance. Evaluating the model on the independent validation dataset provides an estimate of how accurately the model will perform in practice and helps avoid problems such as overfitting or sampling bias. A good model performs well on
      both the training data and the validation data.
      The complex nature of the EM system made it difficult for the team to identify how various parameters influenced EM behavior. A bootstrap forest analysis was applied to the test dataset and was able to identify five key variables associated with higher probability of damage and/or anomalous behavior. The identified key variables provided a basis for further testing and redesign of the EM system. These results also provided essential insight to the investigation and aided in development of flight rationale for future use cases.
      For information, contact Dr. Sara R. Wilson. sara.r.wilson@nasa.gov
      View the full article
    • By NASA
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      The Airspace Operations and Safety Program (AOSP) enables safe, sustainable, and efficient aviation transportation operations to benefit the flying public and ensure the global competitiveness of the U.S. aviation industry. We are transforming the future of aviation into a digital, federated, and service-oriented architecture that fosters the growth of safe airspace for all users.
      By partnering with FAA, academia, safety experts, operators, manufacturers, municipalities, and other government agencies, we facilitate the integration of new aviation technologies, ensure airspace access for new entrants, and champion the success of increasingly autonomous operations. At AOSP, safety is at the heart of everything we do. We stand firm in our unwavering commitment to the safe integration of these vehicles.
       AOSP Approach:
      Efficient, Sustainable Aviation Operations Seamless Integration of Heterogeneous and Emergent Aviation Prognostic In-Time Aviation Safety Management System of Future Operations System Level Autonomy for Aviation Operations, Vehicle Command and Control Systems, and Safety Meet the diversity, density, and complexity challenges of future aviation AOSP Projects
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      Facebook logo @NASA@NASAaero@NASA_es @NASA@NASAaero@NASA_es Instagram logo @NASA@NASAaero@NASA_es Linkedin logo @NASA Explore More
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      Last Updated Dec 17, 2024 EditorLillian GipsonContactJim Bankejim.banke@nasa.gov Related Terms
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    • By European Space Agency
      A multi-orbit constellation of about 300 satellites that will deliver resilient, secure and fast communications for EU governments, European companies and citizens will be put in orbit after two contracts were confirmed today in Brussels.
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    • By NASA
      Teams with NASA’s Exploration Ground Systems Program lift the agency’s SLS (Space Launch System) core stage for the Artemis II mission from horizonal to vertical inside the transfer aisle at the Vehicle Assembly building at NASA’s Kennedy Space Center in Florida on Tuesday, Dec. 10, 2024. The one-of-a kind lifting beam is designed to move the core stage from the transfer aisle to High Bay 2 where it will remain while teams stack the two solid rocket boosters for the SLS core stage. NASA/Adeline Morgan NASA’s SLS (Space Launch System) Moon rocket core stage is vertical in High Bay 2 on Tuesday, Dec. 10, 2024, inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida.
      The core stage arrived on July 23 to NASA Kennedy, where it remained horizontal inside the facility’s transfer aisle. With the move to High Bay 2, technicians with NASA and Boeing now have 360-degree access to the core stage both internally and externally. The move also frees up more space in the transfer aisle to allow technicians to continue transporting and integrating two solid rocket boosters onto mobile launcher 1 in High Bay 3 for the Artemis II mission. Boeing and their sub-contractor Futuramic refurbished High Bay 2 to increase efficiencies while processing core stages for Artemis II and beyond.
      During Apollo, technicians stacked the Saturn V rocket in High Bay 2. During the Space Shuttle Program, the high bay was used for external tank checkout and storage and as a contingency storage area for the shuttle. The Artemis II test flight will be NASA’s first mission with crew under the Artemis campaign, sending NASA astronauts Victor Glover, Christina Koch, and Reid Wiseman, as well as CSA (Canadian Space Agency) astronaut Jeremy Hansen, on a 10-day journey around the Moon and back.
      Image credit: NASA/Adeline Morgan
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    • By NASA
      4 min read
      Expanded AI Model with Global Data Enhances Earth Science Applications 
      On June 22, 2013, the Operational Land Imager (OLI) on Landsat 8 captured this false-color image of the East Peak fire burning in southern Colorado near Trinidad. Burned areas appear dark red, while actively burning areas look orange. Dark green areas are forests; light green areas are grasslands. Data from Landsat 8 were used to train the Prithvi artificial intelligence model, which can help detect burn scars. NASA Earth Observatory NASA, IBM, and Forschungszentrum Jülich have released an expanded version of the open-source Prithvi Geospatial artificial intelligence (AI) foundation model to support a broader range of geographical applications. Now, with the inclusion of global data, the foundation model can support tracking changes in land use, monitoring disasters, and predicting crop yields worldwide. 
      The Prithvi Geospatial foundation model, first released in August 2023 by NASA and IBM, is pre-trained on NASA’s Harmonized Landsat and Sentinel-2 (HLS) dataset and learns by filling in masked information. The model is available on Hugging Face, a data science platform where machine learning developers openly build, train, deploy, and share models. Because NASA releases data, products, and research in the open, businesses and commercial entities can take these models and transform them into marketable products and services that generate economic value. 
      “We’re excited about the downstream applications that are made possible with the addition of global HLS data to the Prithvi Geospatial foundation model. We’ve embedded NASA’s scientific expertise directly into these foundation models, enabling them to quickly translate petabytes of data into actionable insights,” said Kevin Murphy, NASA chief science data officer. “It’s like having a powerful assistant that leverages NASA’s knowledge to help make faster, more informed decisions, leading to economic and societal benefits.”
      AI foundation models are pre-trained on large datasets with self-supervised learning techniques, providing flexible base models that can be fine-tuned for domain-specific downstream tasks.
      Crop classification prediction generated by NASA and IBM’s open-source Prithvi Geospatial artificial intelligence model. Focusing on diverse land use and ecosystems, researchers selected HLS satellite images that represented various landscapes while avoiding lower-quality data caused by clouds or gaps. Urban areas were emphasized to ensure better coverage, and strict quality controls were applied to create a large, well-balanced dataset. The final dataset is significantly larger than previous versions, offering improved global representation and reliability for environmental analysis. These methods created a robust and representative dataset, ideal for reliable model training and analysis. 
      The Prithvi Geospatial foundation model has already proven valuable in several applications, including post-disaster flood mapping and detecting burn scars caused by fires.
      One application, the Multi-Temporal Cloud Gap Imputation, leverages the foundation model to reconstruct the gaps in satellite imagery caused by cloud cover, enabling a clearer view of Earth’s surface over time. This approach supports a variety of applications, including environmental monitoring and agricultural planning.  
      Another application, Multi-Temporal Crop Segmentation, uses satellite imagery to classify and map different crop types and land cover across the United States. By analyzing time-sequenced data and layering U.S. Department of Agriculture’s Crop Data, Prithvi Geospatial can accurately identify crop patterns, which in turn could improve agricultural monitoring and resource management on a large scale. 
      The flood mapping dataset can classify flood water and permanent water across diverse biomes and ecosystems, supporting flood management by training models to detect surface water. 
      Wildfire scar mapping combines satellite imagery with wildfire data to capture detailed views of wildfire scars shortly after fires occurred. This approach provides valuable data for training models to map fire-affected areas, aiding in wildfire management and recovery efforts.
      Burn scar mapping generated by NASA and IBM’s open-source Prithvi Geospatial artificial intelligence model. This model has also been tested with additional downstream applications including estimation of gross primary productivity, above ground biomass estimation, landslide detection, and burn intensity estimations. 
      “The updates to this Prithvi Geospatial model have been driven by valuable feedback from users of the initial version,” said Rahul Ramachandran, AI foundation model for science lead and senior data science strategist at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “This enhanced model has also undergone rigorous testing across a broader range of downstream use cases, ensuring improved versatility and performance, resulting in a version of the model that will empower diverse environmental monitoring applications, delivering significant societal benefits.”
      The Prithvi Geospatial Foundation Model was developed as part of an initiative of NASA’s Office of the Chief Science Data Officer to unlock the value of NASA’s vast collection of science data using AI. NASA’s Interagency Implementation and Advanced Concepts Team (IMPACT), based at Marshall, IBM Research, and the Jülich Supercomputing Centre, Forschungszentrum, Jülich, designed the foundation model on the supercomputer Jülich Wizard for European Leadership Science (JUWELS), operated by Jülich Supercomputing Centre. This collaboration was facilitated by IEEE Geoscience and Remote Sensing Society.  
      For more information about NASA’s strategy of developing foundation models for science, visit https://science.nasa.gov/artificial-intelligence-science.
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      Last Updated Dec 04, 2024 Related Terms
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