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At least 37 records · Page 2

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NASA NTRS2011

Full-Scaled Advanced Systems Testbed: Ensuring Success of Adaptive Control Research Through Project Lifecycle Risk Mitigation

The National Aeronautics and Space Administration's Dryden Flight Research Center completed flight testing of adaptive controls research on the Full-Scale Advance Systems Testbed (FAST) in January of 2011. The research addressed technical challenges involved with reducing risk in an increasingly complex and dynamic national airspace. Specific challenges lie with the development of validated, multidisciplinary, integrated aircraft control design tools and techniques to enable safe flight in the presence of adverse conditions such as structural damage, control surface failures, or aerodynamic upsets. The testbed is an F-18 aircraft serving as a full-scale vehicle to test and validate adaptive flight control research and lends a significant confidence to the development, maturation, and acceptance process of incorporating adaptive control laws into follow-on research and the operational environment. The experimental systems integrated into FAST were designed to allow for flexible yet safe flight test evaluation and validation of modern adaptive control technologies and revolve around two major hardware upgrades: the modification of Production Support Flight Control Computers (PSFCC) and integration of two, fourth-generation Airborne Research Test Systems (ARTS). Post-hardware integration verification and validation provided the foundation for safe flight test of Nonlinear Dynamic Inversion and Model Reference Aircraft Control adaptive control law experiments. To ensure success of flight in terms of cost, schedule, and test results, emphasis on risk management was incorporated into early stages of design and flight test planning and continued through the execution of each flight test mission. Specific consideration was made to incorporate safety features within the hardware and software to alleviate user demands as well as into test processes and training to reduce human factor impacts to safe and successful flight test. This paper describes the research configuration, experiment functionality, overall risk mitigation, flight test approach and results, and lessons learned of adaptive controls research of the Full-Scale Advanced Systems Testbed.

Pavlock, Kate M.↗

NASA NTRSDate not supplied

InVEST Urban Development: Incorporating Earth Observation Data into the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Urban Flood Risk Mitigation Model Python API

Urban flooding poses as one of the biggest issues for cities today, as its impacts are amplified by both climate change and urbanization. The Natural Capital Project’s Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Urban Flood Risk Mitigation (UFRM) model, which benefits from its simplicity and robustness, is commonly used in NASA DEVELOP projects for disaster mitigation, urban planning, and environmental justice issues. While InVEST UFRM model was able to produce the surface water runoff and retention map sufficient for the scopes of past projects, the model accuracy and spatial variability need improvement. Since the current InVEST UFRM model employs constant rainfall depth for all pixels in the area of interest (AOI), the model suffers from inaccurately estimating rainfall depth, runoff volume, and flood depth. Therefore, we adapted the model so that satellite-based precipitation raster datasets (i.e., Integrated Multi-satellitE Retrievals for Global Precipitation Measurement [GPM IMERG]) can be used instead of a single constant value. We simulated the flood events on August 21st and August 22nd, 2017 in Wyandotte County, Kansas using both our modified and the original InVEST UFRM model and then compared the results after incorporating the rainfall raster into the model. Areas with developed land on the land use map predicted moderate to high flood volume in the original volume regardless of the actual amount of precipitation. The modified model considered the rainfall depth’s spatial variation achieving less overestimation of flood runoff and volume at low-to-moderate rainfall area.

Son Do↗

NASA NTRS2023

InVEST Urban Development: Incorporating Earth Observation Data into the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Urban Flood Risk Mitigation Model Python API

Urban flooding poses as one of the biggest issues for cities today as its impacts are amplified by both climate change and urbanization. The Natural Capital Project’s Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Urban Flood Risk Mitigation (UFRM) model, which benefits from its simplicity and robustness, is commonly used in NASA DEVELOP projects for disaster mitigation, urban planning, and environmental justice issues. While the InVEST UFRM model was able to produce the surface water runoff and retention map sufficient for the scopes of past projects, the model’s accuracy and spatial variability need improvement. Since the current InVEST UFRM model employs constant rainfall depth for all pixels in the area of interest (AOI), the model suffers from inaccurately estimating rainfall depth, runoff volume, and flood depth. Therefore, we adapted the model so that satellite-based precipitation raster datasets (i.e., Integrated Multi-satellitE Retrievals for Global Precipitation Measurement [GPM IMERG]) can be used instead of a single constant value. We simulated the flood events on August 21st and August 22nd, 2017, in Wyandotte County, Kansas using both our modified and the original InVEST UFRM model and then compared the results after incorporating rainfall raster into the model. Areas with developed land on the land use map predicted moderate to high flood volume in the original volume regardless of the actual amount of precipitation. The modified model considered the rainfall depth’s spatial variation achieving less overestimation of flood runoff and volume at low-to-moderate rainfall area.

Urban flooding↗

NASA NTRS2008

Supporting Technology at GRC to Mitigate Risk as Stirling Power Conversion Transitions to Flight

Stirling power conversion technology has been reaching more advanced levels of maturity during its development for space power applications. The current effort is in support of the Advanced Stirling Radioisotope Generator (ASRG), which is being developed by the U.S. Department of Energy (DOE), Lockheed Martin Space Systems Company (LMSSC), Sunpower Inc., and the NASA Glenn Research Center (GRC). This generator would use two high-efficiency Advanced Stirling Convertors (ASCs) to convert thermal energy from a radioisotope heat source into electricity. Of paramount importance is the reliability of the power system and as a part of this, the Stirling power convertors. GRC has established a supporting technology effort with tasks in the areas of reliability, convertor testing, high-temperature materials, structures, advanced analysis, organics, and permanent magnets. The project utilizes the matrix system at GRC to make use of resident experts in each of the aforementioned fields. Each task is intended to reduce risk and enhance reliability of the convertor as this technology transitions toward flight status. This paper will provide an overview of each task, outline the recent efforts and accomplishments, and show how they mitigate risk and impact the reliability of the ASC s and ultimately, the ASRG.

Schreiber, Jeffrey G.↗

NASA NTRS2009

Supporting Technology at GRC to Mitigate Risk as Stirling Power Conversion Transitions to Flight

Schreiber, Jeffrey G.↗

NASA NTRSDate not supplied

Milwaukee Urban Development: Assessing the Drivers of Urban Flood Vulnerability in Milwaukee using the Integrated Valuation of Ecosystem Services and Tradeoffs Urban Flood Risk Mitigation Model (InVEST)

Milwaukee County has experienced an increase in flooding due to climate change and urbanization. The frequency and severity of flooding vary spatially due to differences in land cover, surface permeability, and infrastructure. Marginalized communities tend to experience disproportionately high flooding and damage due to infrastructural inequalities and limited access to resources. To quantify these differences, we used the Natural Capital Project’s Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Urban Flood Risk Mitigation Model to calculate and create maps of runoff retention, nominal flood depth, and economic damage to buildings in Milwaukee. Our model inputs included land cover, surface permeability, and rainfall. To inform our precipitation inputs, we used NASA’s Integrated Multi-satellite Retrievals for Global Precipitation Measurement (GPM IMERG) and National Weather Service (NWS) data. We assessed the relationship between flood risk and social and environmental spatial data including redlining, racial demographics, greenspace, and community resilience. The data demonstrate that flood risk is higher in historically redlined neighborhoods, majority Hispanic and Black census block groups, areas that lack parks and trees, and areas of low community resilience as measured by the Census Bureau’s Community Resilience Estimates (CRE). These findings will support our partners, Groundwork Milwaukee and Groundwork USA, in their efforts to promote the equitable distribution of resources and support environmental health in urban spaces. The end products of this project provide our partners with tools to assess urban flooding vulnerability, guide future intervention projects, quantify the effects of environmental injustice, and improve stakeholder access to data.

Madeleine Tango↗

NASA NTRS2016

Trajectory Design to Mitigate Risk on the Transiting Exoplanet Survey Satellite (TESS) Mission

The Transiting Exoplanet Survey Satellite (TESS) will employ a highly eccentric Earth orbit, in 2:1 lunar resonance, reached with a lunar flyby preceded by 3.5 phasing loops. The TESS mission has limited propellant and several orbit constraints. Based on analysis and simulation, we have designed the phasing loops to reduce delta-V and to mitigate risk due to maneuver execution errors. We have automated the trajectory design process and use distributed processing to generate and to optimize nominal trajectories, check constraint satisfaction, and finally model the effects of maneuver errors to identify trajectories that best meet the mission requirements.

design↗

NASA NTRS2016

Trajectory Design Enhancements to Mitigate Risk for the Transiting Exoplanet Survey Satellite (TESS)

The Transiting Exoplanet Survey Satellite (TESS) will employ a highly eccentric Earth orbit, in 2:1 lunar resonance, which will be reached with a lunar flyby preceded by 3.5 phasing loops. The TESS mission has limited propellant and several constraints on the science orbit and on the phasing loops. Based on analysis and simulation, we have designed the phasing loops to reduce delta-V (DV) and to mitigate risk due to maneuver execution errors. We have automated the trajectory design process and use distributed processing to generate and optimal nominal trajectories; to check constraint satisfaction; and finally to model the effects of maneuver errors to identify trajectories that best meet the mission requirements.

satellite↗

NASA NTRS2006

Satellite Breakup Risk Mitigation

Many satellite breakups occur as a result of an explosion of stored energy on-board spacecraft or rocket-bodies. These breakups generate a cloud of tens or possibly hundreds of thousands of debris fragments which may pose a transient elevated threat to spaceflight crews and vehicles. Satellite breakups pose a unique threat because the majority of the debris fragments are too small to be tracked from the ground. The United States Human Spaceflight Program is currently implementing a risk mitigation strategy that includes modeling breakup events, establishing action thresholds, and prescribing corresponding mitigation actions in response to satellite breakups.

Leleux, Darrin P.↗

NASA NTRSDate not supplied

Establishing the Assurance Efficacy of Automated Risk Mitigation Strategies

Verification and validation of increasingly autonomous aviation systems is a major challenge. Traditional techniques for the assurance of high-confidence, safety-critical systems are not equipped to handle the complexity, uncertainty, and lack of predictability inherent in non-deterministic systems. Techniques such as run time monitoring, formal methods, and testing and simulation have been applied to some effect, but it is difficult to properly assess the success of such measures. The authors propose the concept of Assurance Efficacy to address this gap. Assurance Efficacy is seen as a parameter, criteria, or perspective by which to evaluate, identify and explore safety risk mitigation strategies and operational assurance architectures. Validation of the utility of this concept through flight testing is a first step in determining its potential role in assessing the overall safety of complex, increasingly autonomous systems that cannot be fully assured in the design phase.

system safety↗

NASA NTRS2003

Biotechnology System Facility: Risk Mitigation on Mir

NASA is working with its international partners to develop space vehicles and facilities that will give researchers the opportunity to conduct scientific investigations in space. As part of this activity, NASA's Biotechnology Cell Science Program (BCSP) at the Johnson Space Center (JSC) is developing a world-class biotechnology laboratory facility for the International Space Station (ISS). This report describes the BCSP, including the role of the BTS. We identify the purpose and objectives of the BTS and a detailed description of BTS facility design and operational concept, BTS facility and experiment-specific hardware, and scientific investigations conducted in the facility. We identify the objectives, methods, and results of risk mitigation investigations of the effects of microgravity and cosmic radiation on the BTS data acquisition and control system. These results may apply to many other space experiments that use commercial, terrestrial-based data acquisition technology. Another focal point is a description of the end-to-end process of integrating and operating biotechnology experiments on a variety of space vehicles. The identification of lessons learned that can be applied to future biotechnology experiments is an overall theme of the report. We include a brief summary of the science results, but this is not the focus of the report. The report provides some discussion on the successful 130-day tissue engineering experiment performed in BTS on Mir and describes a seminal gene array investigation that identified a set of unique genes that are activated in space.

Gonda, Steve R., III↗

NASA NTRS2013

NASA Technology Evaluation for Environmental Risk Mitigation Remediation Technology Collaboration Development

NASA is committed to finding solutions to agency cleanup problems that are better, cheaper, and more effective than the status quo. Unfortunately, some potential solutions involve innovative technologies for which NASA remediation managers may not have a high level of understanding or confidence. Since 2004, NASA's Stennis Space Center (SSC) in Mississippi has been pumping groundwater contaminated with trichloroethylene (TCE) and other halogenated volatile organic compounds (HVOC) from their cleanup location designated "Area G" through extraction wells to an aboveground treatment system. Over time, however, the effectiveness of this treatment strategy has diminished and an alternative approach is needed. In 2012, professionals from NASA's Principal Center for Technology Evaluation for Environmental Risk Mitigation (TEERM) introduced SSC managers to an innovative technology for enhancing the performance of SSC's existing pump and treat system. The technology, generally referred to as in situ chemical oxidation (ISCO), involves slowly and continuously injecting a strong but safe chemical oxidant into the groundwater. Treatment is enhanced by a "surfactant-type effect" which causes residual contamination from saturated soil to be released into the dissolved-phase where it can be readily oxidized. Any dissolved-phase contamination that was not oxidized can be collected by the extraction well network and treated aboveground. SSC was not familiar with the technology so to increase their confidence, TEERM identified a contractor who was willing to demonstrate their product and process at a significantly reduced price. An initial, small-scale demonstration of ISCO began at sse in March 2012 and completed in August 2012. This successful demonstration was followed by three larger-scale ISCO demonstrations between August and December 2012. The contractor's innovative Continuous Injection System (CIS) incorporated "green" and sustainable technologies and practices. A slow injection rate was maintained autonomously by the CIS, eliminating the need for multiple mobilizations of personnel and powered equipment. The CIS was calibrated to deliver only as much reagent as the formation would accept without "short circuiting", minimizing material waste. Public utility water pressure was used to mix, dilute, and inject the reagent. NASA personnel were trained to operate and maintain the system and remote monitoring and injection control capabilities were developed, further reducing the need for contractor mobilizations to the site. An integrated solar photovoltaic panel was used to power the control valves and web monitoring telemetry. SSC provided hydrogen peroxide for the process using their existing supplier for the aboveground pump and treat systems. The only consumable required from the contractor was their proprietary activator to catalyze SSC's peroxide.

Romeo, James↗

NASA NTRS2004

Case Study of Risk Mitigation Based on Hardware/Software Integration (HSI) Testing for the International Space Station (ISS) Node 2 Module

Within the pressurized elements of the International Space Station (ISS), requirements exist to ensure a safe, habitable environment for the crew. In order to provide this environment, thermal control components work in conjunction with software controls to provide heat rejection for subsystem avionics equipment, for the environmental control system and for experiment payloads. It is essential to ISS operations, mission success and crew safety that necessary testing incorporates the extreme conditions to ensure proper performance. This paper provides a general description and methodology applied to thermal related Hardware/Software Integration (HSI) tests for the ISS Node 2 module. A detailed test plan was developed and implemented with two objectives: the first was for risk mitigation of the thermal control algorithms and software qualification, and the second was for data collection which will substantiate thermalhydraulic models of the Internal Active Thermal Control System (IATCS). Analytical models are utilized to determine on-orbit performance for conditions and scenarios where the simulation of actual on-orbit system performance is limited by test configuration constraints. Node 2 IATCS HSI activities were performed at the Alenia Spazio facility in Torino, Italy with participation from the National Aeronautics and Space Administration (NASA), Alenia Spazio, Jacobs Engineering Sverdrup (JE Sverdrup) and Boeing.

Holt, James Mike↗

NASA NTRSDate not supplied

Decision Aid for Conjunction Risk Mitigation by Differential Drag

The NASA Conjunction Assessment Risk Analysis (CARA) team has conducted are view of the historical record of high-risk conjunctions involving CARA-protected missions and evaluated whether (and how much) differential drag can provide effective mitigation. From this analysis, CARA has identified a rule of thumb: missions with perigees below 560 km capable of tripling their drag area for 72 hours(or a larger scale factor for a lesser amount of time) can reliably use differential drag to remediate high-risk events.

mission design↗

NASA NTRS1993

Mission design considerations for nuclear risk mitigation

Strategies for the mitigation of the nuclear risk associated with two specific mission operations are discussed. These operations are the safe return of nuclear thermal propulsion reactors to earth orbit and the disposal of lunar/Mars spacecraft reactors.

Stancati, Mike↗

NASA NTRS2011

Ensuring Success of Adaptive Control Research Through Project Lifecycle Risk Mitigation

Lessons Learne: 1. Design-out unnecessary risk to prevent excessive mitigation management during flight. 2. Consider iterative checkouts to confirm or improve human factor characteristics. 3. Consider the total flight test profile to uncover unanticipated human-algorithm interactions. 4. Consider test card cadence as a metric to assess test readiness. 5. Full-scale flight test is critical to development, maturation, and acceptance of adaptive control laws for operational use.

Pavlock, Kate M.↗

NASA NTRS2023

Extravehicular Activity on the Lunar Surface: Mapping Mitigation Risk Consequence for Crew Needing Assistance or Rescue

The lunar environment offers unique challenges for human health and safety over the course of performing Extravehicular Activities (EVAs) during early Artemis missions. Driver medical conditions leading to an injured EVA crewmember needing assistance or rescue were analyzed and correlated to established, defined consequence categories. Catastrophic Drivers were identified, and three mitigation strategies were analyzed to determine if there was a potential change in consequence with their application. Risk consequence across the mitigations were compared with each other and the original risk without mitigations. Mitigations were further evaluated in a broader context with prospective preventions to understand the design and risk trade space associated with an early Artemis EVA.

Risk↗

NASA NTRS2023

Extravehicular Activity on the Lunar Surface: Mapping Mitigation Risk Consequence for Crew Needing Assistance or Rescue

Risk↗