Nonvolatile residue test methods
Light scattering nonvolatile residue spacecraft equipment cleanliness evaluation test methods
Vickers, D. N.↗
SEARCH · Engineering Papers
Results for “test and evaluation”
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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A portable X-band front-end test package for beam-waveguide antenna performance evaluation. Part 2: Tests on the antenna
Results are given for an X-band (8.45 GHz) test package for testing the new 34-m beam-waveguide antenna at Goldstone in an 'on-the-antenna' configuration. Included are X-band zenith noise temperature values and tipping-curve data obtained at the Cassegrain focal point F1 as well as at the pedestal room focal point F3. Subreflector Z-defocus test results for both F1 and F3 are also presented. The X-band test package operated well in all of the different test configurations and exceeded expected performance.
Otoshi, T. Y.↗
Advanced launch system. Advanced development oxidizer turbopump program
On May 19, 1989, Pratt & Whitney was awarded contract NAS8-37595 by the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville Alabama for an Advanced Development Program (ADP) to design, develop and demonstrate a highly reliable low cost, liquid oxygen turbopump for the Advanced Launch System (ALS). The ALS had an overall goal of reducing the cost of placing payloads in orbit by an order of magnitude. This goal would require a substantial reduction in life cycle costs, with emphasis on recurring costs, compared to current launch vehicles. Engine studies supporting these efforts were made for the Space Transportation Main Engine (STME). The emphasis on low cost required design simplification of components and subsystems such that the ground maintenance and test operations was minimized. The results of the Oxygen Turbopump ADP technology effort would provide data to be used in the STME. Initially the STME baseline was a gas generator cycle engine with a vacuum thrust level of 580,000 lbf. This was later increased to 650,000 lbf and the oxygen turbopump design approach was changed to reflect the new thrust level. It was intended that this ADP program be conducted in two phases. Phase 1, a basic phase, would encompass the preliminary design effort, and Phase II, an optional contract phase to cover design, fabrication and test evaluation of an oxygen turbopump at a component test facility at the NASA John C. Stennis Space Center in Mississippi. The basic phase included preliminary design and analysis, evaluation of low cost concepts, and evaluation of fabrication techniques. The option phase included design of the pump and support hardware, analysis of the final configuration to ensure design integrity, fabrication of hardware to demonstrate low cost, DVS Testing of hardware to verify the design, assembly of the turbopump and full scale turbopump testing. In December 1990, the intent of this ADP to support the design and development was changed. The design effort for the oxygen turbopump became part of the STME Phase B contract. The status of the pump design funded through this ADP was presented at the Preliminary Design Review (PDR) at the MSFC on October 24, 1990. Advancements in the design of the pump were subsequently continued under the Phase B Contract. The emphasis of this ADP became the demonstration of individual technologies that would have the greatest potential for reducing the recurring cost and increasing reliability. In October of 1992, overall program funding was reduced and work on this ADP was terminated.
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Immersive Technologies for Human-in-the-Loop Lunar Surface Simulations
NASA, the National Aeronautics and Space Administration, continually seeks innovative solutions to enhance its operations, particularly in the realms of testing, evaluation, and training for future missions. Immersive technologies, such as virtual, augmented, and mixed reality have proven to be powerful tools for realistic, interactive, and engaging environments. This paper explores how the Simulation and Graphics Branch at NASA’s Johnson Space Center (JSC) leverages immersive technology, modern commercial rendering engines, and physics-based systems simulations to develop human-in-the-loop systems for humanity’s return to the Moon through the Artemis program. When NASA returns to the Moon, astronauts will travel to the Moon’s South Pole where lighting conditions will cause a more complex operational environment. Human-in-the-loop testing plays a crucial role in NASA's mission planning, spacecraft and space systems development, and evaluation of operational scenarios. The development of immersive environments such as a lunar rover mockup at a video wall enables engineers and astronauts to simulate and experience mission scenarios, integrated spacecraft systems, and operational procedures in a relevant environment before deployment. By integrating realistic virtual environments, immersive technology allows for the visualization and interaction with virtual spacecraft models, mission landscapes, and complex operational tasks. This approach helps identify potential design flaws, operational challenges, and safety considerations. It also provides valuable insights for risk reduction and helps improve mission efficiency and effectiveness. With advanced motion tracking systems and custom virtual environments data can be gathered and evaluated to help NASA refine training protocols, develop specialized training procedures and optimize human-robotic interactions for future space missions. Furthermore, immersive technology offers opportunities for future training initiatives at NASA. The Virtual Reality Laboratory at JSC has pioneered training with Virtual Reality (VR) since the Hubble Space Telescope repair missions in the early 1990’s. Extended Reality (XR) simulations enable astronauts to rehearse complex spacewalks, spacecraft maneuvers, and extravehicular activities in a safe and controlled environment. By replicating the physical and cognitive challenges of space missions, immersive training experiences enhance astronauts' situational awareness, decision-making abilities, and adaptability to unexpected scenarios. Additionally, immersive technology facilitates collaborative training, allowing geographically dispersed crew and mission control personnel to engage in synchronized simulations, fostering teamwork and effective communication. The adoption of immersive technology in NASA's testing, evaluation, and future training programs has yielded significant benefits. By incorporating human-in-the-loop testing for studies involving Extra Vehicular Activities (EVA), surface mobility and landing systems, NASA can identify and mitigate risks, optimize operational procedures, and enhance mission success. Ultimately, immersive training experiences can empower astronauts to better navigate the complexities of space missions, ensuring their safety, productivity, and success in the dynamic and challenging environments they will experience at the Lunar South Pole.
Simulation Modeling Virtual Reality Immersive Tech↗
Towards an Open, Distributed Software Architecture for UxS Operations
To address the growing need to evaluate, test, and certify an ever expanding ecosystem of UxS platforms in preparation of cultural integration, NASA Langley Research Center's Autonomy Incubator (AI) has taken on the challenge of developing a software framework in which UxS platforms developed by third parties can be integrated into a single system which provides evaluation and testing, mission planning and operation, and out-of-the-box autonomy and data fusion capabilities. This software framework, named AEON (Autonomous Entity Operations Network), has two main goals. The first goal is the development of a cross-platform, extensible, onboard software system that provides autonomy at the mission execution and course-planning level, a highly configurable data fusion framework sensitive to the platform's available sensor hardware, and plug-and-play compatibility with a wide array of computer systems, sensors, software, and controls hardware. The second goal is the development of a ground control system that acts as a test-bed for integration of the proposed heterogeneous fleet, and allows for complex mission planning, tracking, and debugging capabilities. The ground control system should also be highly extensible and allow plug-and-play interoperability with third party software systems. In order to achieve these goals, this paper proposes an open, distributed software architecture which utilizes at its core the Data Distribution Service (DDS) standards, established by the Object Management Group (OMG), for inter-process communication and data flow. The design decisions proposed herein leverage the advantages of existing robotics software architectures and the DDS standards to develop software that is scalable, high-performance, fault tolerant, modular, and readily interoperable with external platforms and software.
Cross, Charles D.↗
REGULATORY TESTING AND POSTTEST ANALYSIS OF THE DPP-3 TYPE B SHIPPING CONTAINER FOR NCT AND HAC TESTS
The safe transportation of radioactive material using appropriately designed and certified transportation packages is important to protect the public and environment. Therefore, a comprehensive and rigorous system of packaging requirements are required. The purpose of this test protocol is to determine the effects of drop testing on package performance in a Type B shipping package (DPP-3). Required physical tests for the DPP-3 package include normal conditions of transport and hypothetical accident conditions test requirements. The preparation, regulatory testing, and post-test evaluation of a Type B shipping package tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements will be presented. Six packages were tested and the responses when subjected to the HAC sequence of free drop, puncture, and thermal tests according to 10 CFR 71.73 were measured. The posttest helium leak test showed a leak rate less than 1 × 10-7 He-cc/sec which means that the containment boundary was maintained after the regulatory testing, therefore maintaining a leak tight environment. To determine the amount of change in the package performance measurements, statistical analyses were conducted using SPSS version 26. The null hypothesis of the testing was that there would not be a change in the measurements from pre to post-testing large enough to find statistical significance. Therefore, a finding of statistical significance indicated too much variability in the package design and was deemed an unfavorable finding. A repeated measures t-test was used to analyze the drum lids and CV torques. A one-way ANOVA was used to analyze height and diameter packages. Results of the repeated measures t-test indicated that all six containment vessel lid torques were statistically significant. However only three out of the six drum lid torques were statistically significant. Therefore, design of the lids caused more variability than necessary when subjected to the following drop tests: 1.) horizontal and cold; 2.) vertical lid down; and 3.) corner with lid up. Results of the one-way ANOVA analysis on height indicated that four out of the six CTUs were statistically significant. Thus, design of the CTUs caused more variability then necessary when subjected to the following drop tests: 1.) horizontal hot; 2.) horizontal cold; 3.) corner lid up; and 4.) corner lid down. Results of the one-way ANOVA analysis on diameter indicated that all six CTUs were statistically significant. Thus, design of the CTUs caused more variability then necessary when subjected to all of the tests. The DPP-3 design has been shown to be an acceptable design for the transport of radioactive materials. However, results of the statistical analysis reveal a possible improvement in package and test design to reduce variability in package performance measurement before and after testing.
Martinez, Oscar↗
REGULATORY TESTING AND 3D SCANNING METHODOLOGY OF THE DPP-1 TYPE SHIPPING CONTAINER FOR NCT AND HAC TESTS
The safe transportation of radioactive material using appropriately designed and certified transportation packages is important to protect the public and environment. In the United States of America all transportation of radioactive material is regulated by the Department of Transportation (DOT) along with input by the Nuclear Regulatory Commission (NRC). All packages that contain radioactive material requires that it be transported and regulated by the requirements set by the DOT Class 7 hazardous material transportation. Federal regulations place strict administrative controls on the transport of radioactive materials. The two main goals for transporting radioactive materials are 1. Safety should be the primarily focused on the package because it is the first line of defense. 2. Package integrity should be directly related to the degree of the hazard of the radioactive material contents. The two-part goal ensures that the right package is used. Type B packages are designed to transport radioactive materials with the highest level of radioactivity. Examples of material transported in Type B packagings include spent nuclear fuel, high-level radioactive waste, and high concentrations of other radioactive materials. The purpose of this test protocol is to determine the effects of drop and thermal testing on package performance in a Type B shipping package (DPP-1). Required physical tests for the DPP-1 package include free drop, crush, puncture, penetration, compression, vibration, water spray, water immersion, and thermal. The preparation, regulatory testing, and post-test evaluation of a Type B shipping package tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements will be presented. Six packages were tested and the responses when subjected to the HAC sequence of free drop, puncture, and thermal tests according to 10 CFR 71.73(c)(1), (c)(2), (c)(3) and (c)(4) were measured. The Free Drop, Crush and Puncture tests were performed at the NTRC in Knoxville, TN, and the Thermal tests were performed Southwest Research Institute in San Antonio, TX. The test units were subjected to a pre-operational leak testing before the NCT and HAC tests and a post-operational leak test and a helium leak test once regulatory testing was complete. Finally, all test units were scanned with a handheld blue light scanner to capture a 3D CAD geometry of the test units in the deformed shape. The handheld scanner provided the most effective and reliable way to acquire accurate 3D measurements of the test unit. The scanned geometry was sectioned in areas with deformation and the cross-section profile was measured to determine accurate and repeatable results of the deformed shape of the test units.
Martinez, Oscar↗
Performance of two load-limiting subfloor concepts in full-scale general aviation airplane crash tests
Three six-place, low wing, twin-engine general aviation airplane test specimens were crash tested at the langley Impact Dynamics research Facility under controlled free-flight conditions. One structurally unmodified airplane was the baseline airplane specimen for the test series. The other airplanes were structurally modified to incorporate load-limiting (energy-absorbing) subfloor concepts into the structure for full scale crash test evaluation and comparison to the unmodified airplane test results. Typically, the lowest floor accelerations and anthropomorphic dummy occupant responses, and the least seat crushing of standard and load-limiting seats, occurred in the modified load-limiting subfloor airplanes wherein the greatest structural crushing of the subfloor took place. The better performing of the two load-limiting subfloor concepts reduced the peak airplane floor accelerations at the pilot and four seat/occupant locations to -25 to -30 g's as compared to approximately -50 to -55 g's acceleration magnitude for the unmodified airplane structure.
Carden, H. D.↗
Materials for advanced turbine engines. Project 2: Rene 150 directionally solidified superalloy turbine blades, volume 2
The results of the engine testing of Rene 150 Stage 1 high pressure turbine blades in CF6-50 core and fan engines are presented. The core engine test was conducted for 233 hours with a variety of test cycles, and the fan engine test was conducted for 1000 C cycles. Post-test analysis of the core engine test data confirmed the suitability of the Rene 150 HPT blade for fan engine testing. Post-test evaluation and analysis of the fan engine test blades included visual and dimensional inspection as well as metallographic examination of selected blades. The Rene 150 HPT blade met the target goal of this project by demonstrating increased metal temperature capability; however, the post-test analysis revealed several areas that would have to be addressed in designing a long-life Rene 150 CF6-50 HPT blade.
Deboer, G. J.↗
Physical and chemical test results of electrostatic safe flooring materials
This test program was initiated because a need existed at the Kennedy Space Center (KSC) to have this information readily available to the engineer who must make the choice of which electrostatic safe floor to use in a specific application. The information, however, should be of value throughout both the government and private industry in the selection of a floor covering material. Included are the test results of 18 floor covering materials which by test evaluation at KSC are considered electrostatically safe. Tests were done and/or the data compiled in the following areas: electrostatics, flammability, hypergolic compatibility, outgassing, floor type, material thickness, and available colors. Each section contains the test method used to gather the data and the test results.
Gompf, R. H.↗
Integral Airframe Structures (IAS): Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs
The Integral Airframe Structures (IAS) program investigated the feasibility of using "integrally stiffened" construction for commercial transport fuselage structure. The objective of the program was to demonstrate structural performance and weight equal to current "built-up" structure with lower manufacturing cost. Testing evaluated mechanical properties, structural details, joint performance, repair, static compression, and two-bay crack residual strength panels. Alloys evaluated included 7050-T7451 plate, 7050-T74511 extrusion, 6013-T6511x extrusion, and 7475-T7351 plate. Structural performance was evaluated with a large 7475-T7351 pressure test that included the arrest of a two-bay longitudinal crack, and a measure of residual strength for a two-bay crack centered on a broken frame. Analysis predictions for the two-bay longitudinal crack panel correlated well with the test results. Analysis activity conducted by the IAS team strongly indicates that current analysis tools predict integral structural behavior as accurately as built-up structure. The cost study results indicated that, compared to built-up fabrication methods, high-speed machining structure from aluminum plate would yield a recurring cost savings of 61%. Part count dropped from 78 individual parts on a baseline panel to just 7 parts for machined IAS structure.
Munroe, J.↗
20 Meter Solar Sail Analysis and Correlation
This paper describes finite element analyses and correlation studies to predict deformations and vibration modes/frequencies of a 20-meter solar sail system developed by ATK Space Systems. Under the programmatic leadership of NASA Marshall Space Flight Center's In-Space Propulsion activity, the 20-meter solar sail program objectives were to verify the design, to assess structural responses of the sail system, to implement lessons learned from a previous 10-meter quadrant system analysis and test program, and to mature solar sail technology to a technology readiness level (TRL) of 5. For this 20 meter sail system, static and ground vibration tests were conducted in NASA Glenn Research Center's 100 meter diameter vacuum chamber at Plum Brook station. Prior to testing, a preliminary analysis was performed to evaluate test conditions and to determine sensor and actuator locations. After testing was completed, an analysis of each test configuration was performed. Post-test model refinements included updated properties to account for the mass of sensors, wiring, and other components used for testing. This paper describes the development of finite element models (FEM) for sail membranes and masts in each of four quadrants at both the component and system levels, as well as an optimization procedure for the static test/analyses correlation.
Taleghani, B. K.↗
Reliability of COTS MEMS accelerometer under shock and thermomechanical cycling
A comparison of the data from microaccelerometers of the same type and between several types will be presented. Self-test output signals and X-ray evaluation test data after completion of 182 thermal cycles will also be presented.
MEMS thermal cycling microaccelerometers↗
A Method of Compliance for Achieving Target Collision Risk in UTM Operations
This work proposes a method of compliance to ensure that the collision risks among small unmanned aircraft systems meet the target level of safety. This method presents what is needed for a strategic conflict detection service to achieve the target level of safety when conflict between operational intents are not permitted in nominal situations. A volume-based collision risk model is first developed to calculate the UA-to-UA collision risk given any two operational intent volumes. With this collision risk model, a test strategy is then proposed to assess if a strategic conflict detection service can reduce the collision risk and meet the target level of safety. The method also specifies operational data that are required to be collected to verify if requirements on conformance are being met. Additionally, two new requirements are identified and proposed by this method beyond the current standard for strategic conflict detection. In the sensitivity analysis, three main factors contributing to the collision risk are investigated. The analysis shows that buffers should be considered in a strategic conflict detection service when deconflicting operational intents. The results also reveal that the selection of test cases plays an important role in evaluating the strategic conflict detection service, and they should be representative and sufficiently complex in evaluation tests.
Collision Risk↗
A Method of Compliance for Achieving Target Collision Risk in UTM Operations
This work proposes a method of compliance to ensure that the collision risks among small unmanned aircraft systems meet the target level of safety. This method presents what is needed for a strategic conflict detection service to achieve the target level of safety when conflict between operational intents are not permitted in nominal situations. A volume-based collision risk model is first developed to calculate the UA-to-UA collision risk given any two operational intent volumes. With this collision risk model, a test strategy is then proposed to assess if a strategic conflict detection service can reduce the collision risk and meet the target level of safety. The method also specifies operational data that are required to be collected to verify if requirements on conformance are being met. Additionally, two new requirements are identified and proposed by this method beyond the current standard for strategic conflict detection. In the sensitivity analysis, three main factors contributing to the collision risk are investigated. The analysis shows that buffers should be considered in a strategic conflict detection service when deconflicting operational intents. The results also reveal that the selection of test cases plays an important role in evaluating the strategic conflict detection service, and they should be representative and sufficiently complex in evaluation tests.
UTM, Method of Compliance, collision risk↗
A Method of Compliance for Achieving Target Collision Risk in UTM Operations
This work proposes a method of compliance to ensure that the collision risks among small unmanned aircraft systems meet the target level of safety. This method presents what is needed for a strategic conflict detection service to achieve the target level of safety when conflict between operational intents are not permitted in nominal situations. A volume-based collision risk model is first developed to calculate the UA-to-UA collision risk given any two operational intent volumes. With this collision risk model, a test strategy is then proposed to assess if a strategic conflict detection service can reduce the collision risk and meet the target level of safety. The method also specifies operational data that are required to be collected to verify if requirements on conformance are being met. Additionally, two new requirements are identified and proposed by this method beyond the current standard for strategic conflict detection. In the sensitivity analysis, three main factors contributing to the collision risk are investigated. The analysis shows that buffers should be considered in a strategic conflict detection service when deconflicting operational intents. The results also reveal that the selection of test cases plays an important role in evaluating the strategic conflict detection service, and they should be representative and sufficiently complex in evaluation tests.
UTM↗
In Flight Evaluation of Active Inceptor Force-Feel Characteristics and Handling Qualities
The effect of inceptor feel-system characteristics on piloted handling qualities has been a research topic of interest for many years. Most of the research efforts have focused on advanced fly-by-wire fixed-wing aircraft with only a few studies investigating the effects on rotorcraft. Consequently, only limited guidance is available on how cyclic force-feel characteristics should be set to obtain optimal handling qualities for rotorcraft. To study this effect, the U.S. Army Aeroflightdynamics Directorate working with the DLR Institute of Flight Systems in Germany under Task X of the U.S. German Memorandum of Understanding have been conducting flight test evaluations. In the U.S., five experimental test pilots have completed evaluations of two Mission Task Elements (MTEs) from ADS-33E-PRF and two command/response types for a matrix of center-stick cyclic force-feel characteristics at Moffett Field. In Germany, three experimental test Pilots have conducted initial evaluations of the two MTEs with two command/response types for a parallel matrix of side-stick cyclic force-feel characteristics at WTD-61 in Manching. The resulting data set is used to correlate the effect of changes in natural frequency and damping ratio of the cyclic inceptor on the piloted handling qualities. Existing criteria in ADS-33E and a proposed Handling Qualities Sensitivity Function that includes the effects of the cyclic force-feel characteristics are also evaluated against the data set and discussed.
Lusardi, Jeff A.↗
Accelerated development and flight evaluation of active controls concepts for subsonic transport aircraft
The flight test of an active load alleviation/extended span for the L-1011 wide-body transport aircraft, and piloted simulation work leading to use of active stability augmentation with a small tail and aft center of gravity are reported. The extended span showed the expected cruise drag reduction of 3%. The small tail is expected to reduce cruise drag by another 3%, and eventual use of more aft center of gravity with active stability augmentation will provide further fuel savings. The active load alleviation functions included maneuver load control (MLC) and elastic mode suppression (EMS), using symmetric motions of the outboard ailerons to reduce wing bending loads in maneuvers or long-term up- or down-drafts (MLC), and to damp wing bending motions in turbulence (EMS). A gust load alleviation function using the active horizontal tail to provide airplane pitch damping in turbulence was found unnecessary. The piloted simulation tests evaluated criteria for augmentation-on and augmentation-off flying qualities. of a simple pitch control law was verified at neutral static margin. The simulation tasks established the basis for follow-on construction and flight testing of a small tail with active stability augmentation.
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