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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Fatigue cracks were discovered in the STS-112 Liquid Hydrogen Feedline flowliners in 2002. This led to a development program aimed at providing nondestructive evaluation methods and techniques to verify the existence of these types of cracks in oval shaped slots cut into the ends of the feedlines above the bellows joints. These slots were used to improve flow dynamics and to facilitate cleaning in the bellow joint region. These types of fatigue cracks posed a possible metal debris ingestion threat for the Space Shuttle Main Engines, which attached to these particular joints. Results of this program produced three reliable inspection techniques utilizing the imaging of replisets with a Scanning Electron microscope, eddy current, and ultrasound. The program developed unique probes and fixtures and in the case of eddy current and ultrasound, provided qualification and certification of the particular techniques by various Design of Experiments and Probability of Detection studies utilizing multiple inspectors.
The Active Thermal Architecture (ATA) is an advanced sub-1U Active Thermal Control technology (ATC) for high power payload support in 6U CubeSat form factors and above. The design utilizes a two-stage, single-phase mechanically pumped fluid loop coupled through a two-axis flexible rotary fluid hinge, to reject thermal power to a deployable tracking radiator. A COTS Ricor K508N cryocooler forms the second stage and provides cryogenic cooling to a custom Kevlar detector mount through a TMT pyrolytic graphene thermal strap. Passive vibration isolation and damping technologies prevent the transfer of jitter to the satellite systems. The ATA design utilizes state-of-the-art 3D fabrication techniques such as Ultrasonic Additive Manufacturing (UAM) to directly embed the working fluid channels into the HX, radiator, and CubeSat chassis allowing for the miniaturization and simplification of the ATA system into an integrated thermal control solution. This paper will focus on the design and ground-based characterization and qualification of the ATA system and provide performance metrics for its use as a thermal support subsystem for advanced infrared electro-optical CubeSat payloads. The ATA project is funded through a NASA Small Satellite Technology Program (SSTP) and is a partnership between the Center for Space Engineering at Utah State University and the Jet Propulsions Laboratory. The ATA active thermal control system has been raised to a TRL of 6 and hopes to provide payload support to advanced missions such as the SABER-Lite and JPL CIRAS projects.
Northrop Grumman (NG) Tactical Space SystemsDivisionhas embarked on the development and qualification of a high throughput, low power Hall Thruster String (HTS) using hardware designed and built in-house.Following the success of Mission Extension Vehicles 1 and 2, NG is currently developing the next generation in its lineupof satellite servicing capabilities, the Mission Robotics Vehicle(MRV)and Mission Extension Pod (MEP).MEP’s mission profile imposes highly demanding requirements upon the electric propulsion system. When surveying the industry for available systems, NGwas unable to identify any mature Hall thrustersystems that could satisfy the performance and lifetime requirements for MEP. Eventually, it was decided to vertically integrate the EP development process, partneringwith NASA Glenn Research Center to leverage ongoing development at GRC of a high throughput, low power Hall thruster. The components of the HTS have successfully passed PDR and are currently in the engineering development and test phase. Based on performancecharacterization testingof the development hardware,NG’s low power Hall thruster, dubbed the NGHT-1X, promises to deliver state-of-the-art performanceand lifetime for a sub-kW Hall thruster, achieving total efficiencies of 50-55% over a wide range of throttle conditions. Results of a seriesof characterization tests including integrated systems testingwith the PPUare presented.Qualification methodology andthruster lifetime verification is also discussed. Environmental qualification of the HTS components is expected to completein mid-2023 with a first flight in mid-2024.
Following the successful implementation of full-field photogrammetry, more specifically three-dimensional Digital Image Correlation (3D-DIC), on the Mars 2020 Heat Shield Structural Failure Review assessment, 3D-DIC was selected as one of the primary measurement techniques for the Mars 2020 Rover wheel assembly qualification test at the NASA Jet Propulsion Laboratory (JPL). To validate the Rover wheel landing loads simulations, it was extremely important to have high confidence in the wheel models. Due to the large deformations and strains that the wheel would be subject to during landing, traditional instrumentation such as linear variable displacement transducers (LVDTs), electrical-resistance strain gages and string potentiometers, would not be sufficient on their own to provide all the necessary validation data. Therefore, the NASA Engineering and Safety Center (NESC) provided the 3D-DIC expertise and support to measure the high deformation and strain in the wheel flexures and qualify the overall structural response of the Mars 2020 rover wheel assembly. There were two key objectives for the photogrammetry technique: (1) monitor the wheel response in real-time, guarding against anomalous behavior and failure, and (2) provide test data for test-analysis correlation to validate and/or improve the high-fidelity computational model. The contents of this paper will focus on the challenges of applying 3D-DIC to the Mars 2020 Rover wheel assembly and how these challenges were overcome. Examples of test-analysis correlation during the stiffness characterization and structural qualification will be presented and discussed in detail. Experimental results were compared with the analysis and showed excellent agreement between the predicted behavior and helped validate the high-fidelity models.
The International Space Station (ISS) utilizes two large rotating mechanisms, the solar alpha rotary joints (SARJs), as part of the solar arrays' alignment system for more efficient power generation. Each SARJ is a 10.3m circumference, nitrided 15-5PH steel race ring of triangular cross-section, with 12 sets of trundle bearing assemblies transferring load across the rolling joint. The SARJ mechanism rotates continuously and slowly - once every orbit, or every 90 minutes. In 2007, the starboard SARJ suffered a lubrication failure, resulting in severe damage (spalling) to one of the race ring surfaces. Extensive effort was conducted to prevent the port SARJ from suffering the same failure, and fortunately that effort was ultimately successful in also recovering the functionality of the starboard SARJ. The M&P engineering function was key in determining the cause of failure and the means for mechanism recovery. From a M&P lessons-learned perspective, observations are made concerning the original SARJ design parameters (boundary conditions), the perceived need for nitriding the race ring, the test conditions employed during qualification, the environmental controls used for the hardware preflight, and the lubrication robustness necessary for complex kinematic mechanisms expecting high-reliability and long-life.
NASA is continuing to invest in advancing Hall thruster technologies for implementation in commercial and government missions. There have been several recent iodine Hall propulsion system development activities performed by the team of the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and Busek Co. Inc. In particular, the work focused on qualification of the 200 W Busek BHT-200-I and the continued development of the 600 W BHT-600-I Hall thruster propulsion systems. This paper presents an overview of these development activities and also reports on the results of short duration tests that were performed on the engineering model BHT-200-I and the development model BHT-600-I Hall thrusters.
This document contains instructions for the assembly and checkout of the Melt Evaporate Drain (MEDE) project 5-Zone Furnace system that is required for demonstration of sodium removal from a Fermi-1 reactor blanket element.
The Oak Ridge National Laboratory (ORNL) has developed and tested a novel system architecture for acquiring high fidelity high-speed data. The approach uses a consumer grade audio recording device that is normally associated with “garage band” recording of music. ORNL has coupled this low-cost data acquisition hardware with computing technology running open-source software. The main advantage of this approach is per-channel cost; an instrument grade data acquisition system typically costs between $800 to $2000 per channel compared to less than $50 per channel for these consumer grade components. Three systems, each featuring four channels, have been deployed for acquiring data from geophones and the electrical supply system that supports the High Flux Isotope Reactor (HFIR) and the Radiochemical Engineering Development Center (REDC) at ORNL. Each channel samples at 96 kHz at 24-bit resolution. The deployed systems operate continuously 24/7 and produce about 4 terabytes of data per month per system. This paper provides a technical overview of this approach, its implementation, and some preliminary results from qualification testing. This work was conducted in support of the Multi-Informatics for Nuclear Operations Scenarios (MINOS).Keywords: Data acquisition Measurement Informatics
Description of the engineering support activities which were required to ensure fulfillment of objectives specified for the Apollo 17 SEP (Surface Electrical Properties) Experiment. Attention is given to procedural steps involving verification of hardware acceptability to the astronauts, computer simulation of the experiment hardware, field trials, receiver antenna pattern measurements, and the qualification test program.
Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite at lower temperatures in an oxygen-enriched environment than in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Many metals burn violently in an oxygen-enriched environment when ignited. Lubricants, tapes, gaskets, fuels, and solvents can increase the possibility of ignition in oxygen systems. However, these hazards do not preclude the use of oxygen. Oxygen may be safely used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. These ignition and combustion hazards necessitate a proper oxygen hazards analysis before introducing a material or component into oxygen service. The objective of this test plan is to describe the White Sands Test Facility oxygen hazards analysis to be performed on components and systems before oxygen is introduced and is recommended before implementing the oxygen component qualification procedure. The plan describes the NASA Johnson Space Center White Sands Test Facility method consistent with the ASTM documents for analyzing the hazards of components and systems exposed to an oxygen-enriched environment. The oxygen hazards analysis is a useful tool for oxygen-system designers, system engineers, and facility managers. Problem areas can be pinpointed before oxygen is introduced into the system, preventing damage to hardware and possible injury or loss of life.
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The use of bounding scenarios is a common practice that greatly simplifies the design and qualification of structures. However, this approach implicitly assumes that the quantities of interest increase monotonically with the input to the structure, which is not necessarily true for nonlinear structures. This paper surveys the literature for observations of nonmonotonic behavior of nonlinear systems and finds such observations in both the earthquake engineering and applied mechanics literature. Numerical simulations of a single degree-of-freedom mass-spring system with an elastic–plastic spring subjected to a triangular base acceleration pulse are then presented, and it is shown that the relative acceleration of this system scales nonmonotonically with the input magnitude in some cases. The equation of motion for this system is solved symbolically and an approximate expression for the relative acceleration is developed, which qualitatively agrees with the nonmonotonic behavior seen in the numerical results. The nonmonotonicity is investigated and found to be a result of dynamics excited by the discontinuous derivative of the base acceleration pulse, the magnitude of which scales nonmonotonically with the input magnitude due to the fact that the first yield of the spring occurs earlier as the input magnitude is increased. The relevance of this finding within the context of defining bounding scenarios is discussed, and it is recommended that modeling be used to perform a survey of the full range of possible inputs prior to defining bounding scenarios.
The Certification of Propulsion Systems is costly and complex, involving development and qualification testing. The desire of the certification process is to assure all requirements can be demonstrated to be compliant. The purpose of this paper is to address the technical design concerns of certifying a propulsion system for flight. Presented are Pressurization, Tankage, Feed System and Combustion Instability concerns. Propulsion System Engineers are challenged with the dilemma for testing new systems to specific levels to reduce risk yet maintain budgetary targets. A methodical approach is presented to define the types of test suitable to address the technical issues for qualifying systems for retiring the risk levels. Experience of the lessons learned from supporting the Shuttle Program for Main Propulsion and On Orbit Propulsions Systems as well as previous collaborations on design concerns for certifying propulsion systems are utilized to address design concerns and verification approaches.
The Advanced Sensors and Instrumentation (ASI) program facilitates the development of new sensors for both conventional and advanced reactors. Advanced reactor concepts utilize coolants other than light water, such as molten salts, liquid sodium, and high-temperature helium. Qualification of sensors developed for these advanced reactors is complicated by the relatively small number of facilities available that can provide relevant testing conditions (e.g., temperature, flow, and coolant chemistry). This report identifies sensors that were developed under the ASI program and may be tested in one available testbed: the Mechanisms Engineering Test Loop (METL) at Argonne National Laboratory (ANL), a non-nuclear liquid sodium flow facility.
The proceedings of a workshop sponsored by the Confederation of European Aerospace Societies (CEAS), the American Institute of Aeronautics and Astronautics (AIAA), the National Aeronautics and Space Administration (NASA), Washington, D.C., and the Institute for Computer Applications in Science and Engineering (ICASE), Hampton, Virginia, and held in Williamsburg, Virginia June 22-25, 1999 represent a collection of the latest advances in aeroelasticity and structural dynamics from the world community. Research in the areas of unsteady aerodynamics and aeroelasticity, structural modeling and optimization, active control and adaptive structures, landing dynamics, certification and qualification, and validation testing are highlighted in the collection of papers. The wide range of results will lead to advances in the prediction and control of the structural response of aircraft and spacecraft.
The limits and conditions under which an infrared thermographic nondestructive evaluation can be utilized to assess the quality of aerospace hardware is demonstrated in this research effort. The primary focus of this work is on applying thermography to the inspection of advanced composite structures such as would be found in the International Space Station Instrumentation Racks, Space Shuttle Cargo Bay Doors, Bantam RP-1 tank or RSRM Nose Cone. Here, the detection of delamination, disbond, inclusion and porosity type defects are of primary interest. In addition to composites, an extensive research effort has been initiated to determine how well a thermographic evaluation can detect leaks and disbonds in pressurized metallic systems "i.e. the Space Shuttle Main Engine Nozzles". In either case, research into developing practical inspection procedures was conducted and thermographic inspections were performed on a myriad of test samples, subscale demonstration articles and "simulated" flight hardware. All test samples were fabricated as close to their respective structural counterparts as possible except with intentional defects for NDE qualification. As an added benefit of this effort to create simulated defects, methods were devised for defect fabrication that may be useful in future NDE qualification ventures.