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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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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Space transfer concepts and analysis for exploration missions. Implementation plan and element description document (draft final). Volume 6: Lunar systems

NASA's two Office of Space Flight (Code M) Space Transfer Vehicle (STV) contractors supported development of Space Exploration Initiative (SEI) lunar transportation concepts. This work treated lunar SEI missions as the far end of a more near-term STV program, most of whose missions were satellite delivery and servicing requirements derived from Civil Needs Data Base (CNDB) projections. Space Transfer Concepts and Analysis for Exploration Missions (STCAEM) began to address the complete design of a lunar transportation system. The following challenges were addressed: (1) the geometry of aerobraking; (2) accommodation of mixed payloads; (3) cryogenic propellant transfer in Low Lunar Orbit (LLO); (4) fully re-usable design; and (5) growth capability. The leveled requirements, derived requirements, and assumptions applied to the lunar transportation system design are discussed. The mission operations section includes data on mission analysis studies and performance parametrics as well as the operating modes and performance evaluations which include the STCAEM recommendations. Element descriptions for the lunar transportation family included are a listing of the lunar transfer vehicle/lunar excursion vehicle (LTV/LEV) components; trade studies and mass analyses of the transfer and excursion modules; advanced crew recovery vehicle (ACRV) (modified crew recovery vehicle (MCRV)) modifications required to fulfill lunar operations; the aerobrake shape and L/D to be used; and some costing methods and results. Commonality and evolution issues are also discussed.

Source record↗
NASA NTRS1994

Investigating and implementing enhancements to the simulation of short-term collision hazards

A software tool, the Relative Collision Matrix (RCM), has been developed to provide a quick-look representation of the shortterm collision hazard to space systems from a fragmentation event in Earth orbit. The software performs multiple fragmentation simulations of space objects to quantify the probability of collision for a satellite or a constellation of satellites nearby. Previously, the results were displayed in a color matrix format which showed the relative hazard of each constellation. The RCM can be used for scientific research and operational assessments even though it was designed for test and evaluation applications. Because of its successful use as an analytical tool, the capabilities of RCM are being extended by enhancing the orbital hazard analysis routines, developing ballistic trajectory hazard analysis routines, and expanding the breakup modeling. Improvements are also being made to the RCM's usability and presentation quality by developing a graphical user interface and by providing graphical animated and nonanimated output.

Huth, Jeffrey S.↗
NASA NTRSDate not supplied

Thermal-Fluid Analysis of a Liquid-Cooled Battery Module for Electrified Aircraft

The development of safe, energy-dense batteries is critical to advancing hybrid electric and fully electrified aircraft propulsion. Achieving this capability requires a thermal management system that can maintain battery performance and safety under demanding operational conditions. The objective of this project is to support the maturation of next-generation lithium-ion batteries for electrified aircraft by conducting performance testing on integrated battery modules, specifically a 2-cell series configuration module housed within an aluminum enclosure. Designed to operate at a nominal 7.2 V with discharge rates up to 2.5C, the module will eventually be used to power an electric motor and DC-DC converter, generating substantial thermal loads that must be effectively managed to increase the usable energy and power density of electrified aircraft. To address these thermal challenges, this study presents the development and thermal-fluid analysis of a liquid-cooled thermal management system. While the full aircraft architecture utilizes an eight-string configuration, the present work evaluates a representative single-string water coolant loop to characterize baseline performance. The active cooling loop circulates water through a reservoir, pump, the battery module, and a variable area flow meter. Key performance metrics including component-level temperatures, mass flow rates, and pressure drops are quantified across the loop. Across discharge rates ranging from 0.5C to 2.5C, the active thermal loop consistently and effectively removed heat from the module, validating the design approach and confirming readiness for further development. The validated thermal performance indicates a path toward scalable battery modules that could enable energy and power dense systems for hybrid electric aircraft.

Electrified Aircraft↗
NASA NTRS2004

An Empirical Evaluation of Automated Theorem Provers in Software Certification

We describe a system for the automated certification of safety properties of NASA software. The system uses Hoare-style program verification technology to generate proof obligations which are then processed by an automated first-order theorem prover (ATP). We discuss the unique requirements this application places on the ATPs, focusing on automation, proof checking, and usability. For full automation, however, the obligations must be aggressively preprocessed and simplified, and we demonstrate how the individual simplification stages, which are implemented by rewriting, influence the ability of the ATPs to solve the proof tasks. Our results are based on 13 certification experiments that lead to more than 25,000 proof tasks which have each been attempted by Vampire, Spass, e-setheo, and Otter. The proofs found by Otter have been proof-checked by IVY.

Denney, Ewen↗
NASA NTRS1994

Knowledge-based critiquing of graphical user interfaces with CHIMES

CHIMES is a critiquing tool that automates the process of checking graphical user interface (GUI) designs for compliance with human factors design guidelines and toolkit style guides. The current prototype identifies instances of non-compliance and presents problem statements, advice, and tips to the GUI designer. Changes requested by the designer are made automatically, and the revised GUI is re-evaluated. A case study conducted at NASA-Goddard showed that CHIMES has the potential for dramatically reducing the time formerly spent in hands-on consistency checking. Capabilities recently added to CHIMES include exception handling and rule building. CHIMES is intended for use prior to usability testing as a means, for example, of catching and correcting syntactic inconsistencies in a larger user interface.

Jiang, Jianping↗
NASA NTRS2017

Wearable Biosensor Monitor to Support Autonomous Crew Health and Readiness to Perform

For future human exploration missions, NASA needs a health monitoring system composed of hardware that is compact, fully interoperable with an integrated data management system, and requires minimal consumables. Such a system will be achieved through the integration of small, easy to use biomedical sensors that will have the ability to measure, store and transmit physiological parameters during operational and ambulatory activity. Since 2012, the Canadian Space Agency (CSA) has been active in funding the development of wearable biomonitoring sensors. The Astroskin is the first prototype and consists of a shirt-based garment and headband with embedded sensors, and associated software and technology that measure vital signs, sleep quality and activity level of the wearer. NASA and CSA have been collaborating since 2014 to test and validate this system in a lab environment at Ames Research Center and more recently in the Human Exploration Research Analog (HERA) located at Johnson Spaceflight Center. Specific objectives of the HERA study were: 1) to assess the performance of the Astroskin biosensor system for long-term health monitoring (24-hours) capabilities and during exercise as a measure of crew fitness; 2) to obtain crew feedback on comfort and usability of the Astroskin system; 3) to demonstrate performance of Bluetooth communication during real-time transmission and for verification of data in this environment; and 4) to obtain baseline data for further development of algorithms and tools that facilitate decision support for diagnosing and monitoring of a sick or injured crewmember. HERA Campaign 3 included four missions (each 30-days in duration) with four crewmembers assigned to each mission. A total of 9 men and 7 women participated in the Astroskin evaluation that included continuous physiological monitoring (24-hours) on mission days MD-11, MD1 (high workload), MD15 (low workload), MD19, MD29, and MD+7. Mission days 19 and 29 also included 30 minutes of sub-maximal exercise on a cycle ergometer. Following each 24-hour monitoring session crew physiological data were downloaded to laptops and each crewmember completed a 28 question survey on their experiences with the Astroskin hardware and software. This presentation will focus on lessons learned from the HERA missions. Specifically it will address Astroskin system performance in terms of data loss and data quality (no comparison to lab standard devices), wireless communication with the onboard mobile device, crew usability and comfort, and future development of a next generation biomonitoring system.

crew fitness↗
NASA NTRS1971

Reflectance and transmittance characteristics of several selected green and blue-green unialgae.

Obtained reflectance properties of green and blue-green unialgae are evaluated for determining the feasibility of using selected wavelengths in differentiating between green and blue-green algae. The attempt is made to establish selected wavelengths and ratios that would delineate relative concentrations of the algal suspensions. The results should prove helpful in the selection of spectral bands usable in conjunction with multispectrum scanners for qualitative and quantitative studies of algae in bodies of water.

Gramms, L. C.↗
NASA NTRS1984

Status of high temperature adhesives

The status of high temperature organic adhesives is reviewed. These materials are defined by having usable adhesive properties at temperatures ranging from 232 C (after hundreds of hours at 232 C) to 538 C (after a few minutes at 538 C). The search for high temperature adhesives began in the 1960s, primarily under government funding. Since then, many high temperature polymers have undergone evaluation as adhesives. In spite of this effort, only a few are commercially available because of an elusive market and an unfavorable combination of price, processability and performance. The principal adhesives to be discussed will be addition and condensation polyimides, polyquinoxalines, polybenzimidazoles, and addition, condensation, and cross-linked polyphenylquinoxalines. The synthesis, processability, adhesive performance, and availabiity of these materials are addressed.

Hergenrother, P. M.↗
NASA NTRS1988

Investigation of radar backscattering from second-year sea ice

The scattering properties of second-year ice were studied in an experiment at Mould Bay in April 1983. Radar backscattering measurements were made at frequencies of 5.2, 9.6, 13.6, and 16.6 GHz for vertical polarization, horizontal polarization and cross polarizations, with incidence angles ranging from 15 to 70 deg. The results indicate that the second-year ice scattering characteristics were different from first-year ice and also different from multiyear ice. The fading properties of radar signals were studied and compared with experimental data. The influence of snow cover on sea ice can be evaluated by accounting for the increase in the number of independent samples from snow volume with respect to that for bare ice surface. A technique for calculating the snow depth was established by this principle and a reasonable agreement has been observed. It appears that this is a usable way to measure depth in snow or other snow-like media using radar.

Lei, Guang-Tsai↗
NASA NTRS2014

Use of an OSSE to Evaluate Background Error Covariances Estimated by the 'NMC Method'

The NMC method has proven utility for prescribing approximate background-error covariances required by variational data assimilation systems. Here, untunedNMCmethod estimates are compared with explicitly determined error covariances produced within an OSSE context by exploiting availability of the true simulated states. Such a comparison provides insights into what kind of rescaling is required to render the NMC method estimates usable. It is shown that rescaling of variances and directional correlation lengths depends greatly on both pressure and latitude. In particular, some scaling coefficients appropriate in the Tropics are the reciprocal of those in the Extratropics. Also, the degree of dynamic balance is grossly overestimated by the NMC method. These results agree with previous examinations of the NMC method which used ensembles as an alternative for estimating background-error statistics.

Data Assimilation↗
NASA NTRS1983

Propulsion and fluid management - Station keeping will eat energy on a new scale

An attempt is made to identify technologies that could be brought to a state of minimal development risk in the near term, yet offer the potential for evolutionary growth consistent with future space station propulsion requirements. Prospective auxiliary propulsion propellants will be usable by other systems, thereby offering resupply benefits and a benign rather than corrosive or toxic handling environment. NASA programs are currently underway to develop the storage and supply methods for cryogenic liquids in orbit. The recovery of unused propellants from the Space Shuttle Orbiter and External Tank are being evaluated in order to define Shuttle modifications and performance penalties. Fluid management subsystem requirements and characteristics cannot, however, be fully defined until a firm mission scenario has been established and other space station subsystems are more clearly defined.

Petrash, D. A.↗
NASA NTRS1973

Liquid metal magnetohydrodynamics (LMMHD) technology transfer feasibility study. Volume 1: Summary

The potential application of liquid metal magnetohydrodynamics (LMMHD) to central station utility power generation through the period to 1990 is examined. Included are: (1) a description of LMMHD and a review of its development status, (2) LMMHD preliminary design for application to central station utility power generation, (3) evaluation of LMMHD in comparison with conventional and other advanced power generation systems and (4) a technology development plan. One of the major conclusions found is that the most economic and technically feasible application of LMMHD is a topping cycle to a steam plant, taking advantage of high temperatures available but not usable by the steam cycle.

Phen, R. L.↗
NASA NTRS1991

Lunar anorthosites, their equilibrium melts and the bulk moon

The present study uses plagioclase compositions and partition coefficients for several elements to estimate melts from which lunar anorthosites formed and the partition liquids from which these melts were derived. The Fe and Mg contents of the plagioclases are examined for their potential use as predictors of Fe and Mg in associated melts. Usable trace elements are employed with selected partition coefficients to predict the equilibrium melts for lunar anorthosites, and melts for anorthosites are used in various models to calculate the composition of the initial melt from which the lunar mantle and eventually the anorthosites evolved. The initial melts are compared with bulk moon compositions to evaluate the nature of the melting that could have produced the anorthosites. All the models indicate that extensive melting of all or nearly all of the lunar mantle is required to produce a lunar crust that constitutes 13-15 percent of the moon's volume.

Phinney, W. C.↗
NASA NTRS1992

Multifrequency passive microwave observations of soil moisture in an arid rangeland environment

A cooperative experiment was conducted by teams from the U.S. and U.S.S.R. to evaluate passive microwave instruments and algorithms used to estimate surface soil moisture. Experiments were conducted as part of an interdisciplinary experiment in an arid rangeland watershed located in the southwest United States. Soviet microwave radiometers operating at wavelengths of 2.25, 21 and 27 cm were flown on a U.S. aircraft. Radio frequency interference limited usable data to the 2.25 and 21 cm systems. Data have been calibrated and compared to ground observations of soil moisture. These analyses showed that the 21 cm system could produce reliable and useful soil moisture information and that the 2.25 cm system was of no value for soil moisture estimation in this experiment.

Jackson, T. J.↗
NASA NTRS1991

International manned lunar base - Beginning the 21st century in space

An evaluation is made of requirements for, and advantages in, the creation of a manned lunar base whose functions emphasize astronomical investigations. These astronomical studies would be able to capitalize on the lunar environment's ultrahigh vacuum, highly stable surface, dark and cold sky, low-G, absence of wind, isolation from terrestrial 'noise', locally usable ceramic raw materials, and large radiotelescope dish-supporting hemispherical craters. Large telescope structures would be nearly free of the gravity and wind loads that complicate their design on earth.

Smith, Harlan J.↗
NASA NTRS1999

Numerical Investigation of the ARMSEF Arc-Jet

The NASA/JSC 10 MW Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) is used for the development and evaluation of thermal protection systems for manned reentry vehicles. In an effort at better understanding the flow characteristics of an arc-jet wind tunnel and hence the correlation between simulation and actual flight conditions, preliminary numerical analyses have been made. Difficulties in defining inlet boundary conditions to the plenum chamber, where there is very little usable experimental data, are discussed. Two different boundary conditions for the plenum, a straight profile and parabolic profile, are employed to describe the conditions in this very important flow defining region. Comparisons are made to experimental data with the results showing that some type of parabolic or step profile is needed to adequately resolve the strong core flow that is present in the nozzle and plume region. Recommendations are made regarding future efforts in analyzing this challenging flow field.

Cox, Carey F.↗
NASA NTRS1978

A study of commuter airplane design optimization

The usability of the general aviation synthesis program (GASP) was enhanced by the development of separate computer subroutines which can be added as a package to this assembly of computerized design methods or used as a separate subroutine program to compute the dynamic longitudinal, lateral-directional stability characteristics for a given airplane. Currently available analysis methods were evaluated to ascertain those most appropriate for the design functions which the GASP computerized design program performs. Methods for providing proper constraint and/or analysis functions for GASP were developed as well as the appropriate subroutines.

Keppel, B. V.↗
NASA NTRS2016

Risk of Performance Decrement and Crew Illness Due to an Inadequate Food System

NASA is preparing for long duration manned missions beyond low-Earth orbit that will be challenged in several ways, including long-term exposure to the space environment, impacts to crew physiological and psychological health, limited resources, and no resupply. The food system is one of the most significant daily factors that can be altered to improve human health, and performance during space exploration. Therefore, the paramount importance of determining the methods, technologies, and requirements to provide a safe, nutritious, and acceptable food system that promotes crew health and performance cannot be underestimated. The processed and prepackaged food system is the main source of nutrition to the crew, therefore significant losses in nutrition, either through degradation of nutrients during processing and storage or inadequate food intake due to low acceptability, variety, or usability, may significantly compromise the crew's health and performance. Shelf life studies indicate that key nutrients and quality factors in many space foods degrade to concerning levels within three years, suggesting that food system will not meet the nutrition and acceptability requirements of a long duration mission beyond low-Earth orbit. Likewise, mass and volume evaluations indicate that the current food system is a significant resource burden. Alternative provisioning strategies, such as inclusion of bioregenerative foods, are challenged with resource requirements, and food safety and scarcity concerns. Ensuring provisioning of an adequate food system relies not only upon determining technologies, and requirements for nutrition, quality, and safety, but upon establishing a food system that will support nutritional adequacy, even with individual crew preference and self-selection. In short, the space food system is challenged to maintain safety, nutrition, and acceptability for all phases of an exploration mission within resource constraints. This document presents the evidence for the Risk of Performance Decrement and Crew Illness Due to an Inadequate Food System and the gaps in relation to exploration, as identified by the NASA Human Research Program (HRP). The research reviewed here indicates strategies to establish methods, technologies, and requirements that increase food stability, support adequate nutrition, quality, and variety, enable supplementation with grow-pick-and-eat salad crops, ensure safety, and reduce resource use. Obtaining the evidence to establish an adequate food system is essential, as the resources allocated to the food system may be defined based on the data relating nutritional stability and food quality requirements to crew performance and health.

Douglas, Grace L.↗