Results for “process development” — Page 68

NASA NTRSDate not supplied

CFS Test Framework

NASA's Core Flight System (cFS) provides a generic flight software framework architecture for developing flight software. As the cFS framework has gained popularity over the years within the flight software community, supporting software tools have been developed to assist in the design, development, testing and verification of flight software. The cFS Test Framework (CTF) is a recently developed cFS tool with capabilities to develop and run automated test and verification scripts against flight software targets. The CTF tool parses and executes JSON-based test scripts containing test instructions, while logging and reporting the results. CTF utilizes a plugin-based architecture to allow developers to extend CTF with new test instructions, external interfaces, and custom functionality. To interface with flight software, CTF parses a set of CCSDS message definition files to create the necessary command and telemetry structures for use during the test run. Additionally, CTF also supports interfacing with multiple cFS instances, allowing a test script to verify requirements that involve multiple flight software targets. Lastly, CTF provides support for executing test scripts against FSW running on remote or embedded hardware. This allows CTF to execute the same test scripts across different target configurations throughout the development process. In this presentation, we will introduce the cFS Test Framework (CTF) architecture, discuss the history of cFS testing frameworks, and present the features and capabilities currently provided by CTF. Lastly, we will show a demo of the CTF tool being used to execute test scripts against flight software.

cfs↗

NASA NTRSDate not supplied

Verification and Validation of Elastodynamic Simulation Software for Aerospace Research

Physics-based simulation of nondestructive evaluation (NDE) inspection can help to advance the inspectability and reliability of mechanical systems. However, NDE simulations applicable to non-idealized mechanical components often require large compute domains and long run times. This has prompted development of custom NDE simulation software tailored to high performance computing (HPC) hardware. Verification and validation (V&V) is an integral part of developing this software to ensure implementations are robust and applicable to inspection problems, producing tools and simulations suitable for computational NDE research. This presentation addresses factors common to V&V of several elastodynamic simulation codes applicable to ultrasonic NDE. Examples are drawn from in-house simulation software at NASA Langley Research Center, ranging from ensuring reliability in a 1D heterogeneous media wave equation solver to the V&V needs of 3D cluster-parallel elastodynamic software. Factors specific to a research environment are addressed, where individual simulation results can be as relevant as the software product itself. Distinct facets of V&V are discussed including testing to establish software reliability, employing systematic approaches for consistency with fundamental conservation laws, establishing the numerical stability of algorithms, and demonstrating concurrence with empirical data. This talk also addresses V&V practices for small groups of researchers. This includes establishing resources (e.g. time and personnel) for V&V during project planning to mitigate and control the risk of setbacks. Similarly, we identify ways for individual researchers to use V&V during simulation software development itself to both speed up the development process and reduce incurred technical debt.

NDE↗

NASA NTRS2021

Potential impact of aerosols on convective clouds revealed by Himawari-8 observations over different terrain types in eastern China

Convective clouds are common and play a major role in Earth's water cycle and energy balance; they may even develop into storms and cause severe rainfall events. To understand the convective cloud development process, this study investigates the impact of aerosols on convective clouds by considering the influence of both topography and diurnal variation in radiation. By combining texture analysis, clustering, and thresholding methods, we identify all convective clouds in two warm seasons (May–September, 2016/17) in eastern China based on Himawari-8 Level 1 data. Having large diurnally resolved cloud data together with surface meteorological and environmental measurements, we investigate convective cloud properties and their variation, stratified by elevation and diurnal change. We then analyze the potential impact of aerosol on convective clouds under different meteorological conditions and topographies. In general, convective clouds tend to occur preferentially under polluted conditions in the morning, which reverses in the afternoon. Convective cloud fraction first increases then decreases with aerosol loading, which may contribute to this phenomenon. Topography and diurnal meteorological variations may affect the strength of aerosol microphysical and radiative effects. Updraft is always stronger along the windward slopes of mountains and plateaus, especially in northern China. The prevailing southerly wind near the foothills of mountains and plateaus is likely to contribute to this windward strengthening of updraft and to bring more pollutant into the mountains, thereby strengthening the microphysical effect, invigorating convective clouds. By comparison, over plain, aerosols decrease surface heating and suppress convection by blocking solar radiation reaching the surface.

clouds↗

NASA NTRSDate not supplied

Adaptive Stress Testing of Collision Avoidance Systems for Small UASs with Deep Reinforcement Learning

The next-generation Airborne Collision Avoidance System for smaller UASs (ACAS sXu) is currently being developed and tested by the Federal Aviation Administration (FAA) to provide detect-and-avoid capability for small unmanned aircraft operating beyond line-of-sight. Due to the complexity and safety-critical nature of the system, safety validation is important not only for the certification of the final system, but also for informing changes during the iterative development process. In this paper, we analyze a prototype of ACAS sXu in simulated aircraft encounters to discover scenarios of small near mid-air collisions (sNMACs), an important safety event in which two aircraft come closer than 50 feet horizontally and 15 feet vertically. Due to the size and complexity of the system as well as rarity of sNMAC events, traditional methods such as Monte Carlo testing often require informed setup and targeting to elicit failures. However, such a dependence on domain knowledge can be incompatible with the independent verification and validation (IV&V) process, the aim of which is to discover unforeseen issues. To address these challenges, we apply an accelerated validation method called adaptive stress testing (AST) to find the most likely sNMAC scenarios without reliance on system introspection. AST uses reinforcement learning to adapt the search towards the most promising areas of the search space as it progresses. We use a state-of-the-art deep reinforcement learning algorithm, proximate policy optimization, to more efficiently search the large and continuous state space. We find that this approach significantly improves the performance of AST compared to a prior approach based on Monte Carlo tree search. We perform experiments using AST to find sNMAC events under various encounter configurations, varying parameters pertaining to dynamics and coordination. Our experiments show AST to be very effective at finding sNMAC scenarios. We summarize our findings, presenting high-level categories of discovered sNMACs and specific examples of encounters in each category.

aircraft collision avoidance↗

NASA NTRSDate not supplied

Risk-Based Methodology for the Determination of Hall Thruster Performance Specifications

This work adapts manufacturing and metrology industry standards to create a risk-based approach for the determination of electric propulsion performance specifications. The developed process is applied to 208 total thrust measurements acquired using three different NASA Hall Effect Rocket with Magnet Shielding (HERMeS) Technology Demonstration Unit (TDU) 12.5-kW Hall thrusters in three different test facilities in order to generate thrust specifications at the 300 V/6.25 kW, 400 V/8.33 kW, 500 V/10.42 kW, and 600 V/12.5 kW operating conditions. These thrust specifications are used to perform a set of sample acceptance tests to illustrate the importance of adding additional conservatism using a parameter known of the Test Accuracy Ratio in order to control the risk to the thruster producer and consumer from false rejection and acceptance of thruster units.

HERMeS↗

NASA NTRSDate not supplied

Risk-based Methodology for the Determination of Hall Thruster Performance Specifications

This work adapts manufacturing and metrology industry standards to create a risk-based approach for the determination of electric propulsion performance specifications. The developed process is applied to 208 total thrust measurements acquired using three different NASA Hall Effect Rocket with Magnet Shielding (HERMeS) Technology Demonstration Unit (TDU) 12.5-kW Hall thrusters in three different test facilities in order to generate thrust specifications at the 300 V/6.25 kW, 400 V/8.33 kW, 500 V/10.42 kW, and 600 V/12.5 kW operating conditions. These thrust specifications are used to perform a set of sample acceptance tests to illustrate the importance of adding additional conservatism using a parameter known of the Test Accuracy Ratio in order to control the risk to the thruster producer and consumer from false rejection and acceptance of thruster units.

HERMeS↗

NASA NTRS2021

Potential impact of aerosols on convective clouds revealed by Himawari-8 observations over different terrain types in Eastern China

Convective clouds are common and play a major role in Earth’s water cycle and energy balance; they may even develop into storms and cause severe rainfall events. To understand the convective cloud development process, this study investigates the impact of aerosols on convective clouds by considering the influence of both topography and diurnal variation of radiation. By combining texture analysis, clustering and thresholding methods, we identify all convective clouds in two warm seasons (May-September, 2016-2017) in eastern China based on Himawari-8 Level 1 data. Having a large diurnally resolved cloud data together with surface meteorological and environmental measurements, we investigate convective cloud properties and their variation, stratified by elevation and diurnal change. We then analyze the potential impact of aerosol on convective clouds under different meteorological conditions and topographies. In general, convective clouds tend to occur preferentially under polluted conditions in the morning, which reverses in the afternoon. Convective cloud fraction first increases then decreases with aerosol loading, which may contribute to this phenomenon. Topography and diurnal meteorological variations may affect the strength of aerosol microphysical and radiative effects. Updraft is always stronger along the windward slopes of mountains and plateaus, especially in northern China. The prevailing southerly wind near the foothills of mountains and plateaus is likely to contribute to this windward strengthening of updraft and to bring more pollutant into the mountains, thereby strengthening the microphysical effect, invigorating convective clouds. By comparison, over plain, aerosols decrease surface heating and suppresses convection by blocking solar radiation reaching the surface.

Tianmeng Chen↗

NASA NTRSDate not supplied

Bion-M2

Bion-M2, scheduled to launch in April 2023, continues the 30+ year collaboration between the Institute of Biomedical Problems of the Russian Academy of Sciences (IBMP RAS) and the National Aeronautics and Space Administration (NASA). Bion-M2 is the second biosatellite in the Bion-M series and its goal is to investigate how the space environment affects living organisms, with emphasis on physiological changes in rodents, gravitational biology using a wide variety of specimens, and radiation biology. The Bion-M2 biosatellite will complete a 30-day low earth orbit (LEO) flight to study the combined effects of microgravity and ionizing radiation (IR) on multiple organisms, where the payload may be exposed to IR at 20-30 times thedose rate seen on the International Space Station. Following return, nine U.S. collaborators selected through the NASA Space Biology Research Announcement will conduct post-flight rodent experiments using male C57BL/6 mice. The post-flight experiments will investigate the effects of the space environment on bone and skeletal muscle health, cardiac function, reproductive system function, neurovascular systems, protein composition in plasma, and thermoregulation in the mice. Currently, the Bion-M2 mission is in the development phase of theproject lifecycle. The mission objectives, constraints, requirements, and timeline have been defined in the project plan and contracts. Technology for the mission is under development and science procedures will be finalized by FY22. The aim of this presentation is to highlight the importance of the Bion-M2 mission and provide insight into the mission development process, including an overview of the project plan and the tissue sharing plan that will be utilized during the post-flight dissection procedures.

Bion-M2↗

NASA NTRSDate not supplied

Origami-based Composite Space Structures

The main objective of my internship was working on developing a new type of deployable composite for space structures and new method of deployment via use of origami, composites, UV curing resins, and shape memory polymers. My role in the project was to collect an initial literature survey on the subject including origami, the history of deployable space structures, previous issues and problems faced in the field, previous and current research being done on the structural aspect as well as the materials aspect of the subject. I presented this information to our team, where we discussed and determined our research focus and project design specs. We have been making or will make decisions on the project’s purpose, material, origami type, manufacturing method, and testing methods. I am now in charge of the protype design as we enter the design stage of our research. I am using PTC Creo software to design the structural aspects of the first protype so that we can begin small scale testing. I will perform data analysis in order to review the results with our team, so we can make the next design decisions regarding changes or iterations of the design. We hope to renew this project in the next fiscal year in order to increase the TRL of the project so that it can eventually be used in multiple functions in space such as the construction of lunar habitats. In just my brief time with NASA, I have gained so much personally and professionally. I developed my ability to search through and narrow down information when doing research. In the weekly meetings I practiced presenting information to my peers and superiors, and, just as importantly, discussing and adapting to what we were learning. I acquired experience in using technology to my advantage including remote work, new software like PTC Creo, NASA archives, and connecting with others beyond my team to gain help. I enjoyed the immense resource of knowledge that my mentors had to offer, and that they gave me a large amount of responsibility in this research. I truly felt like I was contributing to something bigger than myself and understood how directly I was involved in NASA’s work. This internship has further cemented my love for space and desire to continue in the field. I have a better understanding of the research and development process and am now considering joining a research lab with my university next year.

Composite↗

NASA NTRSDate not supplied

Assessing the Needs for Space Reactor Standards

A U.S. governmental interagency space reactor standards working group (SWG) was convened to address the limited availability of voluntary consensus standards currently in place specifically for space nuclear reactor design and safety. The SWG focused on reviewing existing standards, assessing agency needs, specifying gaps that could be addressed by new standards, and prioritizing those gaps through consensus group deliberations. The SWG identified a series of findings and recommendations relative to the development of space reactor standards, including moving three specific high-priority gap items to be pursued through a consensus standards development process: Safety and Risk Analysis Methods for Space Reactors, Testing Requirements for Space Reactors, including Facility Requirements, and Safe Operating Practices for Space Reactors.

Andrew Klein↗

NASA NTRSDate not supplied

STMD-GCD Reactive Additive Manufacturing for Fourth Industrial Revolution Exploration Systems (RAMFIRE)

Elementum 3D, in partnership with NASA-MSFC under an ACO, seeks to help further increase launch performance and reduce launch and mission cost by advancing novel additively manufactured (AM) aluminum materials for large-scale complex rocket components and launch vehicle structures. The proposed outcome of this ACO is to advance large-scale directed energy deposition (DED) of highstrength aluminum alloys through process development, characterization, and testing.

RAMFIRE↗

NASA NTRSDate not supplied

Realizing a Spacesuit Compatible Augmented Reality System to Meet the Work Needs of Future Human Spaceflight Exploration

In this paper, we identify the broad range of challenges associated with creating an augmented reality for future spaceflight missions. The challenges were framed within a sociotechnical framework to explore how an imagined augmented reality system might one day help crew cope with future exploration mission demands. Key challenges include an augmented reality system cannot simply be designed to help a single suited astronaut and must enable the broader mission team. There exists a host of optical, compute, and control technical challenges that must be simultaneously addressed while the work domain itself is in development. There exist limited methods to help cope with the envisioned world problem; however, we emphasize a few strategies to articulate work design assumptions and host this detail in a transparent fashion. Finally, we note the broader organizational constraints that shape the creation of such novel technology for spaceflight. By addressing these broad range of challenges directly, early in the design and development process, key trade-offs can be considered and fundamental concerns within the community can be addressed to yield desired mission outcomes.

Matthew J. Miller↗

NASA NTRS2022

Ask SME - Close-Up With a NASA Subject Matter Expert

Overview of plant growth for space exploration presented by Jacob Torres from Kennedy Space Center. Developing processes and instrumentation that will allow for all year around plant growth.

Jacob J Torres↗

NASA NTRSDate not supplied

SERVIR: Cross-Comparison of Carbon Emission Estimates Based on Variable Land Use Land Cover Changes within SERVIR Focus Regions

Deforestation in the tropics contributes approximately one-fifth of the annual global greenhouse gas (GHG) emissions. In an effort to reduce GHG emissions, SERVIR - a joint USAID and NASA initiative - is currently implementing the SERVIR CArbon Pilot (S-CAP) activity. By developing a comprehensive CO2 tracking system in Google Earth Engine based on both remotely sensed data and in situ observations, S-CAP aims to build capacity within the SERVIR regional hubs to improve decision making and local monitoring efforts surrounding GHG emissions. The S-CAP estimations are being completed throughout 11 pilot countries within the SERVIR regions of Asia, Africa, and the Americas to integrate partner contributions and local input into the development process. These emission estimate calculations use country-level REDD+ FREL reported values, global remotely sensed data (e.g. Global Forest Watch) and regional datasets and are completed using the IPCC Guidelines for National Greenhouse Gas Inventories. From the S-CAP activity thus far, country CO2 estimations had varied differences, ranging from 56% to 197% between their lowest and highest estimates. The results from this study show that CO2 emission estimates can differ greatly depending on the land cover data sets used as well as the biomass values, and how a comprehensive database is essential in understanding the full range of impacts that land cover change has in these regions. Using this ensemble approach, SERVIR hubs can better select the most appropriate datasets available for estimating emissions.

Carbon Emission↗

NASA NTRSDate not supplied

Core Stage TVC Systems Engineering Challenges in Reusing Heritage Hardware

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Two actuators are used to move each engine in two planes perpendicular to one another (i.e., pitch and yaw). The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Core Auxiliary Power Unit (CAPU) is derived from the Orbiter Auxiliary Power Unit (APU). The Orbiter and Solid Rocket Booster APU turbines are powered by hot gas produced by catalyzed hydrazine decomposition. On the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. While direct reuse or slight modification of existing hardware may seem to be a triple-win for a program in cost, schedule, and technical risk mitigation, those benefits can only be realized when its degree of application in a new system is carefully and thoughtfully managed. The heritage hardware reuse should be prescribed within the heritage design capability and reuse environments must lie within the envelope of heritage qualification testing. Despite the significant test and flight experience of the Shuttle heritage hardware components, successful integration with the newly designed CS TVC components and incorporation into the stage design proved to be a challenge which required re-qualification of the heritage hardware as well as thorough integrated testing to support flight certification. Examples of the challenges that were overcome include: re-qualifying heritage hardware to survive new shock and vibration environments, certifying performance of extensively modified heritage hardware, regenerating design insight due to lack of available heritage vendor data, showing compliance to modern structural design standards, translation of heritage requirements for analog avionics to modern digital avionics, and interfacing heritage mechanical hardware with newly designed avionics. This paper is the second installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. This paper will discuss several engineering challenges encountered during the development process for SLS CS TVC and how they were successfully overcome to reach flight readiness.

Thrust Vector Control↗

NASA NTRSDate not supplied

Space Launch System: Core Stage Thrust Vector Control Systems Engineering Challenges in Reusing Heritage Hardware

The Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Two actuators are used to move each engine in two planes perpendicular to one another (i.e., pitch and yaw). The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Core Auxiliary Power Unit (CAPU) is derived from the Orbiter Auxiliary Power Unit (APU). The Orbiter and Solid Rocket Booster APU turbines are powered by hot gas produced by catalyzed hydrazine decomposition. On the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. While direct reuse or slight modification of existing hardware may seem to be a triple-win for a program in cost, schedule, and technical risk mitigation, those benefits can only be realized when its degree of application in a new system is carefully and thoughtfully managed. The heritage hardware reuse should be prescribed within the heritage design capability and reuse environments must lie within the envelope of heritage qualification testing. Despite the significant test and flight experience of the Shuttle heritage hardware components, successful integration with the newly designed CS TVC components and incorporation into the stage design proved to be a challenge which required re-qualification of the heritage hardware as well as thorough integrated testing to support flight certification. Examples of the challenges that were overcome include: re-qualifying heritage hardware to survive new shock and vibration environments, certifying performance of extensively modified heritage hardware, regenerating design insight due to lack of available heritage vendor data, showing compliance to modern structural design standards, translation of heritage requirements for analog avionics to modern digital avionics, and interfacing heritage mechanical hardware with newly designed avionics. This paper is the second installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. This paper will discuss several engineering challenges encountered during the development process for SLS CS TVC and how they were successfully overcome to reach flight readiness.

Thrust Vector Control↗

NASA NTRSDate not supplied

Analysis of the Artemis I Orion Spacecraft Power System Performance

NASA successfully completed an uncrewed test flight of the Orion spacecraft during the 26-day Artemis I mission in November and December 2022. The Artemis I mission profile included several potentially stressing features for Orion electrical power system (EPS) performance, including eclipse duration, multiple propulsive or navigational maneuvers which constrained positioning of the solar array wings (SAWs), and the proximity and phasing of various events together. All of these features vary significantly with Earth-sun-moon geometry, providing a unique challenge for predicting EPS performance before an exact launch date is known. This presentation will provide a brief mission overview, discuss the different computer models with varying levels of fidelity used to analyze Orion EPS performance, as well as the screening process developed to incorporate EPS performance as a consideration for launch epoch selection. Final preflight model predictions of EPS performance will be compared to in-flight telemetry measurements, and several EPS anomalies observed will be briefly discussed.

Orion↗

NASA NTRS2022

Making or Breaking a Rover: System Engineering Parameters On-Board the Mars 2020 Perseverance Rover

On February 18, 2021, Perseverance, NASA’s Jet Propulsion Laboratory’s (JPL’s) Mars 2020 Rover, successfully landed on Mars with all systems nominal, despite the risk surrounding the over 200,000 internal flight parameters that had to be properly configured. The Perseverance team defines these parameters as software variables that are configurable, commandable and retrievable from Earth. In 2015, the Mars 2020 project leaders focused on improving systems engineering of parameters based on their experiences from parameter management on previous Mars rovers (Curiosity, Opportunity, Spirit, and Pathfinder) and parameter failures of past missions, such as the mission-ending parameter of the Mars Climate Orbiter. The new rigorous development process allowed for efficient certification and effective implementation of the parameters, allowing the rover to approach and land on the red planet (the most challenging phase of the mission) with zero parameter issues. Although successful, the Perseverance team learned many lessons for how to better manage parameters for the continued surface operations of the Mars 2020 mission and future missions. This paper will discuss eight parameter-management topics for the Perseverance Mission. The first is parameter definition: how we define parameters on our mission, where they are physically located on the vehicle, and why we have so many of them. The second topic is the updated parameter flight software module from Curiosity, including details on the 99% reduction in parameter commands, new bulk configuration capabilities, and improved parameter traceability. The third topic is parameter selection for different mission phases; this includes improving and tweaking our preferred parameter settings until they become certification candidates and managing parameter configurations based on test venue throughout the mission life cycle. The fourth topic is our flight certification process; this includes certification of flight values for four different epochs in the mission: Launch, Entry Decent and Landing (EDL) - 6days, Landing + 5 Sols (Martian Days, still on Cruise Flight Software), and once are on Surface Flight Software (FSW). The fifth topic covers in-flight command implementation, along with details on testing, validation, and verification of those commands. In the sixth section, we will explain our use of open-source management tools, including how we used GitHub for version control and management approvals. The seventh topic will describe the ground tools used in operations, including capabilities of the in-house built tool called Parasol. The eighth and final topic will dig into lessons learned for improving parameter management in the future of this mission and others.

Roth, Brian↗