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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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NASA NTRS2020

Cross-Cutting Computational Modeling Project: Exploration Medical Station Analysis

Astronauts will be away from Earth-based medical care for long periods during future exploration missions. Thus, it will be necessary for the astronauts to perform various medical tasks to monitor and maintain their health in the microgravity environment of space. Performance of these tasks will be constrained due to the limited volume available to perform the task, the absence of gravity and the limited resources and capabilities available in the medical work area. It is therefore necessary to evaluate exploration medical workstation designs for how well the designs will support crew performance of medical tasks. This evaluation featured two trained medical caregivers (99th percentile male, 26th percentile female) performing emergent care procedures (alone and in tandem) on a medical manikin. The procedures came from the The procedures came from the International Space Station Medical Checklist, and they are designed for spaceflight. The objectives of the evaluation included determining the operational volume required to perform the tasks, examining the effect of constraining the operational volume with partitions, determining candidate locations for foot restraints and equipment placements and determining the effect of single vs. dual caregiver on the operational volume.A marker-based motion capture system collected the motion data, which enabled computation of operational volumes and foot placement maps using custom Python code. Additional data collected included heart rate, time to perform the procedures, and feedback from the caregivers in the form of the NASA Task Load Index (TLX), the US Government System Usability Survey, and an open-ended questionnaire.

Christopher A Gallo↗
NASA NTRS1988

Space-based multifunctional end effector systems functional requirements and proposed designs

The end effector is an essential element of teleoperator and telerobot systems to be employed in space in the next decade. The report defines functional requirements for end effector systems to perform operations that are currently only feasible through Extra-Vehicular Activity (EVA). Specific tasks and functions that the end effectors must be capable of performing are delineated. Required capabilities for forces and torques, clearances, compliance, and sensing are described, using current EVA requirements as guidelines where feasible. The implications of these functional requirements on the elements of potential end effector systems are discussed. The systems issues that must be considered in the design of space-based manipulator systems are identified; including impacts on subsystems tightly coupled to the end effector, i.e., control station, information processing, manipulator arm, tool and equipment stowage. Possible end effector designs are divided into three categories: single degree-of-freedom end effectors, multiple degree of freedom end effectors, and anthropomorphic hands. Specific design alternatives are suggested and analyzed within the individual categories. Two evaluations are performed: the first considers how well the individual end effectors could substitute for EVA; the second compares how manipulator systems composed of the top performers from the first evaluation would improve the space shuttle Remote Manipulator System (RMS) capabilities. The analysis concludes that the anthropomorphic hand is best-suited for EVA tasks. A left- and right-handed anthropomorphic manipulator arm configuration is suggested as appropriate to be affixed to the RMS, but could also be used as part of the Smart Front End for the Orbital Maneuvering Vehicle (OMV). The technical feasibility of the anthropomorphic hand and its control are demonstrated. An evolutionary development approach is proposed and approximate scheduling provided for implementing the suggested manipulator systems in time for space stations operations in the early 1990s.

Mishkin, A. H.↗
NASA NTRS1992

Combustion of LOX with H2(sub g) under subcritical, critical, and supercritical conditions and experimental observation of dense spray and mixing of impinging jets

Progress made during the period of February 1 to October 15, 1992 is reported. The overall objective of Task 1 of the investigation is to achieve a better understanding of the combustion processes of liquid oxygen and gaseous hydrogen under subcritical, critical, and supercritical conditions. Specific objectives of the research program are: (1) to determine the evaporation- and burning-rate characteristics of LOX in hydrogen/helium environments under broad ranges of operating conditions; (2) to measure species concentration profile and surface temperature of LOX employing the gas chromatography and fine-wire thermocouples under non-reacting flow situations; (3) to perform a fugacity-based multicomponent thermodynamic phase equilibrium analysis for examining the high-pressure vapor-liquid equilibrium behavior at the liquid surface of LOX; (4) to formulate and solve a theoretical model for simulating the evaporation and combustion processes in a LOX/H2/He system; and (5) to validate the theoretical model with the measured experimental data. Task 2 of the investigation is described. Observation of a like-on-like injector element in the near-injector region performed in the previous phase of this project has identified the existence of a high Reynolds number regime in which the pre-impingement jets are fully turbulent and undergoing surface breakup. The new spray regime, which has not been observed by previous investigators, is characterized by the presence of many fine droplets and the disappearance of the well-defined liquid breakup wave pattern in the post-impingement region. It is speculated that a cavitating region may be present within the orifice so that it could induce strong turbulence, leading to an onset of atomization of the jets prior to impingement. To further investigate the dense spray behavior of the impinging jets in the high Reynolds number region, experiments were conducted using Plexiglas injector components for direct internal flow observation. The main objective is to determine under what conditions a cavitating region would form and whether or not the cavitation is reponsible for the development of the high Reynolds number spray regime. The procedure and major findings of the injector cavitation study are described.

Kuo, Kenneth K.↗
NASA NTRS2004

Preliminary Analysis of ISS Maintenance History and Implications for Supportability of Future Missions

The International Space Station (ISS) enables the study of supportability issues associated with long-duration human spaceflight. The ISS is a large, complex spacecraft that must be maintained by its crew. In contrast to the Space Shuttle Orbiter vehicle, but similar to spacecraft that will be component elements of future missions beyond low-Earth orbit, ISS does not return to the ground for servicing and provisioning of spares is severely constrained by transportation limits. Although significant technical support is provided by ground personnel, all hands-on maintenance tasks are performed by the crew. It is expected that future missions to distant destinations will be further limited by lack of resupply opportunities and will, eventually, become largely independent of ground support. ISS provides an opportunity to begin learning lessons that will enable future missions to be successful. Data accumulated over the first several years of ISS operations have been analyzed to gain a better understanding of maintenance-related workload. This analysis addresses both preventive and corrective maintenance and includes all U.S segment core systems. Systems and tasks that are major contributors to workload are identified. As further experience accrues, lessons will be learned that will influence future system designs so that they require less maintenance and, when maintenance is required, it can be performed more efficiently. By heeding the lessons of ISS it will be possible to identify system designs that should be more robust and point towards advances in both technology and design that will offer the greatest return on investment.

Watson, Kevin J.↗
NASA NTRS2021

Advanced Multimodal Solutions for Information Presentation

High-workload, fast-paced, and degraded sensory environments are the likeliest candidates to benefit from multimodal information presentation. For example, during extra-vehicular activity (EVA) and telerobotic operations, the sensory restrictions associated with such a hostile environment provide a major challenge to maintaining the situation awareness (SA) required for safe operations. In particular, orientation, navigation, and collision avoidance are critical aspects of EVA tasks that need to be addressed to ensure the safety of the crew and the success of the mission. Multimodal displays hold promise to enhance situation awareness and task performance by utilizing different sensory modalities and maximizing their effectiveness based on appropriate interaction between modalities. Multimodal displays will also play an important role for long-duration information systems and will likely begin to be developed in the early phases of cislunar Gateway, and later lunar or Mars transit missions. Information systems are envisioned for LDEMs that require spacecraft with greater crew autonomy and increased dependence on computer-provided information needed to perform routine tasks, as well as time- and safety critical tasks. Such a system will require a single, common interface that is easy to learn and use and accesses key information from all relevant vehicle/habitat systems to enable task performance in both nominal and emergency conditions. Understanding of multimodal display technologies and their interactions will help to inform interface guidelines for LDEMs. The scope of the current report is an analysis of potential multimodal display technologies for long duration missions and, in particular, will focus on their potential role in EVA activities. The review will address multimodal (combined visual, auditory and/or tactile) displays investigated by the National Aeronautics and Space Administration (NASA), industry, and Department of Defense (DoD). It also considers the need for adaptive information systems to accommodate a variety of operational contexts such as crew status (e.g., fatigue, workload level) and task environment (e.g., EVA, habitat, rover, spacecraft). Current approaches to guidelines and best practices for combining modalities for the most effective information displays are also reviewed. Potential issues in developing interface guidelines for LDEMs are briefly considered.

multimodal displays↗
NASA NTRS2010

Spaceflight-Induced Cardiovascular Changes and Recovery During NASA's Functional Task Test

Microgravity-induced physiological changes could impair a crewmember s performance upon return to a gravity environment. The Functional Task Test (FTT) is designed to correlate these physiological changes to performance in mission-critical tasks. The Recovery from Fall/Stand Test (RFST) simulates one such task, measuring the ability to recover from a prone position and the cardiovascular response to orthostasis. The purpose of this study was to evaluate spaceflight-induced cardiovascular changes during the FTT. METHODS: Five astronauts participated in the FTT before 10-15 day missions, on landing day (R+0), and one (R+1), six (R+6) and thirty (R+30) days after landing. The RFST consisted of a 2-minute prone rest followed by a 3-minute stand during which heart rate (HR, Holter) and continuous blood pressure (BP, Finometer) were measured. Spectral heart rate variability (HRV) was calculated during the RFST to approximate autonomic function. Statistical analysis was performed with two-factor repeated measures ANOVA. RESULTS: During RFST, HR was higher on R+0 than preflight (p<0.004). This increase in HR persisted on R+1 and R+6 during the stand portion of RFST (p<0.026). BP was well-regulated on all test days. Parasympathetic activity was diminished on R+0 (p=0.035). Sympathovagal balance tended to be affected by spaceflight (main effect, p=0.072), appearing to be slightly elevated during postflight RFST except on R+30. Additionally, analysis of HR during the functional tasks yielded a higher HR on R+0 than preflight during 8 of 11 tasks analyzed, where all tasks had HR return to preflight values by R+30 (p<0.05). CONCLUSION: Spaceflight causes an increase in HR, decrease in parasympathetic activity, and increase in sympathovagal balance, which we confirmed during RFST. These spaceflight-induced changes seen in the RFST, along with the increased postflight HR in most functional tasks, can be used to assess functional performance after short-duration spaceflight.

Arzeno, N. M.↗
DOE OSTI2025

MiniMOD

SAND2025-03854O MiniMod is a user-friendly software tool designed to assess the performance of high-performance computing (HPC) systems. Researchers can use the program to test communication methods and computational tasks to understand how different setups can affect application efficiency. This software is particularly useful for optimizing network performance in scientific research, simulations, and data analysis. MiniMod‘s flexible design allows users to make informed decisions about their computing environments, which can enhance productivity and results in real-world applications. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Dosanjh, Matthew [Sandia National Lab. (SNL-CA), L↗
NASA NTRS1973

Spacecraft systems analysis project

The research in spacecraft analysis is reported. The Skylab task is reviewed along with the ASTP, and the shuttle tasks. The current status, progress, problems, and the work to be performed are described.

Source record↗
NASA NTRS1983

A comparison of rating scale, secondary-task, physiological, and primary-task workload estimation techniques in a simulated flight task emphasizing communications load

Sixteen potential metrics of pilot mental workload were investigated regarding their sensitivity to communication load and their intrusion on primary-task performance. A moving-base flight simulator was used to present three cross-country flights. The flights varied only in the difficulty of the communications requirements. Rating scale measures were obtained immediately postflight; all others were taken over a 7-min segment of the flight task. The results indicated that both the Modified Cooper-Harper Scale and the workload Multi-descriptor Scale were sensitive to changes in communications load. The secondary-task measure of time estimation and the physiological measure of pupil diameter were also sensitive. As expected, those primary-task measures that were direct measures of communicative performance were also sensitive to load, whereas aicraft control primary-task measures were not, attesting to the task specificity of such measures. Finally, the intrusion analysis revealed no differential interference between workload measures.

Casali, J. G.↗
NASA NTRS1984

Communications-imposed pilot workload - A comparison of sixteen estimation techniques

Sixteen potential metrics of mental workload were investigated in regard to their relative sensitivity to communications load and their differential intrusion on primary task performance. A moving-base flight simulator was used to present three cross-country flights to each of 30 subject pilots, each flight varying only in the difficulty of the inherent communications requirements. With the exception of the rating scale measures, which were obtained immediately post-flight, all measures were taken over a seven minute segment of the flight task. The results indicated that both the Modified Cooper-Harper and the workload Multi-descriptor rating scales were reliably sensitive to changes in communications load. Also, the secondary task measure of time estimation and the physiological measure of pupil diameter yielded sensitivity. As expected, those primary task measures which were direct measures of communicative performance were also sensitive to load, while aircraft control primary task measures were not, attesting to the task-specificity of such measures. Finally, the intrusion analysis revealed no differential interference between workload measures.

Casali, J. G.↗
NASA NTRS1988

Integrated avionics reliability

The integrated avionics reliability task is an effort to build credible reliability and/or performability models for multisensor integrated navigation and flight control. The research was initiated by the reliability analysis of a multisensor navigation system consisting of the Global Positioning System (GPS), the Long Range Navigation system (Loran C), and an inertial measurement unit (IMU). Markov reliability models were developed based on system failure rates and mission time.

Alikiotis, Dimitri↗
NASA NTRS1993

Data analysis tasks: BATSE

Miscellaneous tasks related to the operation of, and analysis of data from, the Burst and Transient Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) were performed. The results are summarized and relevant references are included.

Paciesas, William S.↗
NASA NTRS1995

Client/server study

The goal of this project is to find cost-effective and efficient strategies/solutions to integrate existing databases, manage network, and improve productivity of users in a move towards client/server and Integrated Desktop Environment (IDE) at NASA LeRC. The project consisted of two tasks as follows: (1) Data collection, and (2) Database Development/Integration. Under task 1, survey questionnaires and a database were developed. Also, an investigation on commercially available tools for automated data-collection and net-management was performed. As requirements evolved, the main focus has been task 2 which involved the following subtasks: (1) Data gathering/analysis of database user requirements, (2) Database analysis and design, making recommendations for modification of existing data structures into relational database or proposing a common interface to access heterogeneous databases(INFOMAN system, CCNS equipment list, CCNS software list, USERMAN, and other databases), (3) Establishment of a client/server test bed at Central State University (CSU), (4) Investigation of multi-database integration technologies/ products for IDE at NASA LeRC, and (5) Development of prototypes using CASE tools (Object/View) for representative scenarios accessing multi-databases and tables in a client/server environment. Both CSU and NASA LeRC have benefited from this project. CSU team investigated and prototyped cost-effective/practical solutions to facilitate NASA LeRC move to a more productive environment. CSU students utilized new products and gained skills that could be a great resource for future needs of NASA.

Dezhgosha, Kamyar↗
NASA NTRS2002

A Response Surface Methodology for Bi-Level Integrated System Synthesis (BLISS)

The report describes a new method for optimization of engineering systems such as aerospace vehicles whose design must harmonize a number of subsystems and various physical phenomena, each represented by a separate computer code, e.g., aerodynamics, structures, propulsion, performance, etc. To represent the system internal couplings, the codes receive output from other codes as part of their inputs. The system analysis and optimization task is decomposed into subtasks that can be executed concurrently, each subtask conducted using local state and design variables and holding constant a set of the system-level design variables. The subtasks results are stored in form of the Response Surfaces (RS) fitted in the space of the system-level variables to be used as the subtask surrogates in a system-level optimization whose purpose is to optimize the system objective(s) and to reconcile the system internal couplings. By virtue of decomposition and execution concurrency, the method enables a broad workfront in organization of an engineering project involving a number of specialty groups that might be geographically dispersed, and it exploits the contemporary computing technology of massively concurrent and distributed processing. The report includes a demonstration test case of supersonic business jet design.

Altus, Troy David↗
NASA NTRS2001

NASA Technical Management Report (533Q)

The objective of this task is analytical support of the NASA Satellite Laser Ranging (SLR) program in the areas of SLR data analysis, software development, assessment of SLR station performance, development of improved models for atmospheric propagation and interpretation of station calibration techniques, and science coordination and analysis functions for the NASA led Central Bureau of the International Laser Ranging Service (ILRS). The contractor shall in each year of the five year contract: (1) Provide software development and analysis support to the NASA SLR program and the ILRS. Attend and make analysis reports at the monthly meetings of the Central Bureau of the ILRS covering data received during the previous period. Provide support to the Analysis Working Group of the ILRS including special tiger teams that are established to handle unique analysis problems. Support the updating of the SLR Bibliography contained on the ILRS web site; (2) Perform special assessments of SLR station performance from available data to determine unique biases and technical problems at the station; (3) Develop improvements to models of atmospheric propagation and for handling pre- and post-pass calibration data provided by global network stations; (4) Provide review presentation of overall ILRS network data results at one major scientific meeting per year; (5) Contribute to and support the publication of NASA SLR and ILRS reports highlighting the results of SLR analysis activity.

Klosko, S. M.↗
NASA NTRS2012

Exploratory Climate Data Visualization and Analysis Using DV3D and UVCDAT

Earth system scientists are being inundated by an explosion of data generated by ever-increasing resolution in both global models and remote sensors. Advanced tools for accessing, analyzing, and visualizing very large and complex climate data are required to maintain rapid progress in Earth system research. To meet this need, NASA, in collaboration with the Ultra-scale Visualization Climate Data Analysis Tools (UVCOAT) consortium, is developing exploratory climate data analysis and visualization tools which provide data analysis capabilities for the Earth System Grid (ESG). This paper describes DV3D, a UV-COAT package that enables exploratory analysis of climate simulation and observation datasets. OV3D provides user-friendly interfaces for visualization and analysis of climate data at a level appropriate for scientists. It features workflow inte rfaces, interactive 40 data exploration, hyperwall and stereo visualization, automated provenance generation, and parallel task execution. DV30's integration with CDAT's climate data management system (COMS) and other climate data analysis tools provides a wide range of high performance climate data analysis operations. DV3D expands the scientists' toolbox by incorporating a suite of rich new exploratory visualization and analysis methods for addressing the complexity of climate datasets.

Maxwell, Thomas↗
NASA NTRS2014

Using Tests Designed to Measure Individual Sensorimotor Subsystem Perfomance to Predict Locomotor Adaptability

Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the readapation phase following a return to a gravitational environment. These alterations may lead to disruption in the ability to perform mission critical functions during and after these gravitational transitions. Astronauts show significant inter-subject variation in adaptive capability following gravitational transitions. The way each individual's brain synthesizes the available visual, vestibular and somatosensory information is likely the basis for much of the variation. Identifying the presence of biases in each person's use of information available from these sensorimotor subsystems and relating it to their ability to adapt to a novel locomotor task will allow us to customize a training program designed to enhance sensorimotor adaptability. Eight tests are being used to measure sensorimotor subsystem performance. Three of these use measures of body sway to characterize balance during varying sensorimotor challenges. The effect of vision is assessed by repeating conditions with eyes open and eyes closed. Standing on foam, or on a support surface that pitches to maintain a constant ankle angle provide somatosensory challenges. Information from the vestibular system is isolated when vision is removed and the support surface is compromised, and it is challenged when the tasks are done while the head is in motion. The integration and dominance of visual information is assessed in three additional tests. The Rod & Frame Test measures the degree to which a subject's perception of the visual vertical is affected by the orientation of a tilted frame in the periphery. Locomotor visual dependence is determined by assessing how much an oscillating virtual visual world affects a treadmill-walking subject. In the third of the visual manipulation tests, subjects walk an obstacle course while wearing up-down reversing prisms. The two remaining tests include direct measures of knee and ankle proprioception and a functional movement assessment that screens for movement restrictions and asymmetries. To assess each subject's locomotor adaptability subjects walk for twenty minutes on a treadmill that oscillates laterally at 0.3 Hz. Throughout the test metabolic cost provides a measure of exertion and step frequency provides a measure of stability. Additionally, at four points during the perturbation period, reaction time tests are used to probe changes in the amount of mental effort being used to perform the task. As with the adaptive capability observed in astronauts during gravitational transitions, our data shows significant variability between subjects. To aid in the analysis of the results, custom software tools have been developed to enhance in the visualization of the large number of output variables. Preliminary analyses of the data collected to date do not show a strong relationship between adaptability and any single predictor variable. Analysis continues to identify a multifactorial predictor outcome "signature" that do inform us of locomotor adaptability.

Peters, B. T.↗
NASA NTRS2024

Machine Learning for the Prediction of Local Asteroid Damages

Risk assessment studies of local asteroid hazards traditionally simulate the physics of meteors with engineering models tailored to analyze tens-of-millions of scenarios. However, these simplified approaches still need to solve time-dependent ODEs to model the entry process and the resulting ground damage. With a computational cost of O(0.01 CPU.s) per scenario, simulating these large numbers of potential entry conditions in risk assessment studies can take several days on local computers. To improve computational efficiency, we propose in this paper an orthogonal approach based on machine learning models to predict the size of damaged areas given a list of entry parameters. We train 5 machine learning methods and compare the predictions to the outputs of the PAIR model, first only with primitive entry condition variables, and then with more advanced features. We find that complex models like neural networks are well-suited to estimate blast hazards, while simpler linear models can accurately assess thermal damage. For both types of hazards, the radii of damaged areas can be predicted with around 10% average errors and a coefficient of determination (R2) of 0.99. The CPU time is decreased by a factor O(10 3 ) compared to the PAIR model, which enables the simulation of millions of scenarios in minutes, on a local computer. We then use the same machine learning approaches for a classification task where the models are trained to predict if an asteroid will produce a given level of damage. Results show that complex models like the gradient boosting classifier and the neural network can perform this task with 98% accuracy. Beyond surrogate models, we finally incorporate the machine learning algorithms to the state-of-the-art Shapley sensitivity analysis and present a ranking of the entry parameters based on their contributions to ground damages.

SMD↗