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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 55 records · Page 3

Mars Science Laboratory Rover System Thermal Test

On November 26, 2011, NASA launched a large (900 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars. The MSL rover is scheduled to land on Mars on August 5, 2012. Prior to launch, the Rover was successfully operated in simulated mission extreme environments during a 16-day long Rover System Thermal Test (STT). This paper describes the MSL Rover STT, test planning, test execution, test results, thermal model correlation and flight predictions. The rover was tested in the JPL 25-Foot Diameter Space Simulator Facility at the Jet Propulsion Laboratory (JPL). The Rover operated in simulated Cruise (vacuum) and Mars Surface environments (8 Torr nitrogen gas) with mission extreme hot and cold boundary conditions. A Xenon lamp solar simulator was used to impose simulated solar loads on the rover during a bounding hot case and during a simulated Mars diurnal test case. All thermal hardware was exercised and performed nominally. The Rover Heat Rejection System, a liquid-phase fluid loop used to transport heat in and out of the electronics boxes inside the rover chassis, performed better than predicted. Steady state and transient data were collected to allow correlation of analytical thermal models. These thermal models were subsequently used to predict rover thermal performance for the MSL Gale Crater landing site. Models predict that critical hardware temperatures will be maintained within allowable flight limits over the entire 669 Sol surface mission.

Novak, Keith S.↗

Gateway to the Future: Lessons Learned in Development of the Refueling Systems for NASA's First Lunar Space Station

Developed in collaboration with international and commercial partners, Gateway will be humanity’s first space station around the Moon as a vital component of NASA’s deep space exploration plans to the Moon, Mars and beyond. As part of it’s focus on developing a sustainable, long term lunar capability, both it’s Xenon based Solar Electric Propulsion System, as well as it’s bi-propellant Reaction Control System of the Gateway are designed to be on-orbit refuellable. Through design studies, numerical modeling, hardware development, and early testing, the system architecture has undergone significant changes to meet mission requirements and utilize evolving hardware capabilities between concept formulation and it’s successful completion of it’s Critical Design Review. This paper presents key lessons learned during this process, highlighting specific design elements and test results that contribute to a robust and adaptable refueling system for the Gateway.

Christopher Radke↗

Gateway to the Future: Lessons Learned in Development of the Refueling Systems for NASA's First Lunar Space Station

Developed in collaboration with international and commercial partners, Gateway will be humanity’s first crewed space station around the Moon as a vital component of NASA’s Artemis Program for exploration to the Moon, Mars and beyond. As part of it’s focus on developing a sustainable, long term lunar capability, both Xenon based Solar Electric Propulsion System, as well as bi-propellant Reaction Control System of Gateway are designed to be on-orbit refuelable. Through design studies, numerical modeling, hardware development, and substantial testing, the system architecture has undergone significant changes to meet mission requirements and utilize evolving hardware capabilities between concept formulation and the successful completion of its Critical Design Review. This paper presents key lessons learned during this process, highlighting specific design elements and test results that contribute to a robust and adaptable refueling system for the Gateway.

Christopher Radke↗

NASA's Evolutionary Xenon Thruster: The NEXT Ion Propulsion System for Solar System Exploration

This viewgraph presentation reviews NASA s Evolutionary Xenon Thruster (NEXT) Ion Propulsion system. The NEXT project is developing a solar electric ion propulsion system. The NEXT project is advancing the capability of ion propulsion to meet NASA robotic science mission needs. The NEXT system is planned to significantly improve performance over the state of the art electric propulsion systems, such as NASA Solar Electric Propulsion Technology Application Readiness (NSTAR). The status of NEXT development is reviewed, including information on the NEXT Thruster, the power processing unit, the propellant management system (PMS), the digital control interface unit, and the gimbal. Block diagrams NEXT system are presented. Also a review of the lessons learned from the Dawn and NSTAR systems is provided. In summary the NEXT project activities through 2007 have brought next-generation ion propulsion technology to a sufficient maturity level.

Pencil, Eric J.↗

Xenon Isotopic Analysis of Individual Intermediate Particles From the OSIRIS-REx Sample of Asteroid Bennu

The OSIRIS-REx mission sampled material from the B-type asteroid Bennu and delivered the sample to Earth on 24 September 2023. Here we present initial xenon isotopic analysis of individual intermediate particles of Bennu material collected by the OSIRIS-REx mission. Noble gases are key tracers of Solar System evolution. Xenon is particularly useful among the noble gases because its nine isotopes allow multiple contributing sources to be unambiguously identified. The sun, asteroids (as measured in meteorites), and comets (measured in the coma of comet 67P) have distinct xenon isotopic signatures reflecting different mixtures of nucleosynthetic components. In addition, 129 I, 238 U, and 244 Pu decay with different half-lives, producing characteristic xenon signatures. Exposure of samples containing light rare earth elements and barium to cosmic rays produces xenon from spallation and secondary neutron capture reaction. Noble gas analyses help address several of the driving hypotheses of the mission [9]. Particle-by-particle analysis can elucidate the diversity of material present and reveal distinct noble gas compositions, including the potential to detect presolar or cometary noble gas signatures on a small scale. The isotopic signature provides a fingerprint that can be used to constrain the sources of volatiles in planetary reservoirs and combined with other information (e.g. mineralogy and petrology of the material analyses) contributes to our understanding of the initial constituents, formation, and history of Bennu and its parent asteroid.

S A Crowther↗

A first roadmap for kryptology

Studies of the complex variations of the isotopic composition of xenon in the solar system have been christened 'xenology'. In the title of the present investigation, the word 'kryptology' is employed to indicate the primary objective of the reported studies. This objective is related to the prediction of the isotopic composition of krypton which comes from a number of specific locations of a supernova in association with the isotopic compositions of xenon from these locations. Krypton is a logical candidate for testing the stellar theory on geochemical grounds, taking into account also the point of view of nucleosynthesis, because the isotopes of xenon and krypton are formed by the same thermonuclear processes in stars. The data and arguments presented in the investigation show that the treatment by Heymann and Dziczkaniec (1979), although not wrong, is too simplistic, because it has ignored the possibility of holdup and arrest in Xe network.

Heymann, D.↗

The influence of ambient light spectrum (LED, INC, CFL, Xenon…) on the efficiency of perovskite indoor photovoltaic solar cells for Internet of Things (IoT) applications

This record provides a numerical investigation of a MAGeI₃-based perovskite solar cell with the structure FTO/TiO₂/MAGeI₃/Spiro-OMeTAD, evaluated for both outdoor and indoor light-harvesting applications using the SCAPS-1D simulator. Device performance is analyzed under AM 1.5G sunlight and several artificial light sources, including LED, incandescent, compact fluorescent lamp (CFL), flashlight, and xenon illumination. The study reports initial and optimized power conversion efficiencies and examines the influence of absorber layer thickness and bandgap on device performance under different lighting conditions. The results highlight the potential of MAGeI₃-based perovskite solar cells for indoor energy harvesting and low-power Internet of Things (IoT) applications.

14 SOLAR ENERGY↗

Thermal laboratory report

Uniformity filtering, spectral filtering, and spectral matching using krypton and xenon lamps in solar simulation techniques development

SPECTRAL ANALYSIS↗

Mechanical and SEM analysis of artificial comet nucleus samples

Since 1987 experiments dealing with comet nucleus phenomena have been carried out in the DFVLR space simulation chambers. The main objective of these experiments is a better understanding of thermal behavior, surface phenomena and especially the gas dust interaction. As a function of different sample compositions and exposure to solar irradiation (xenon-bulbs) crusts of different hardness and thickness were measured. The measuring device consists of a motor driven pressure foot (5 mm diameter), which is pressed into the sample. The applied compressive force is electronically monitored. The microstructure of the crust and dust residuals is investigated by scanning electron microscopy (SEM) techniques. Stress-depth profiles of an unirradiated and an irradiated model comet are given.

Thiel, K.↗

Altering Flashlamp Output for Realistic Solar Simulation

Commercial glass optical filter corrects spectrum of xenon flashtubes used to test photovoltaic solar cells. Filter withstands thousands of flashes without perceptible alteration of passband characteristics. With filter, calibration errors reduced to less than 1 percent.

Mueller, R. L.↗

On-Orbit Xenon Refueling Loading Times and Transient Analysis

The Power and Propulsion Element (PPE) of the Lunar Orbital Platform-Gateway will demonstrate the first on-orbit refueling of xenon propellant for a solar electric propulsion system. An analysis was performed in Microsoft Excel to determine what factors influence the overall refueling time of a single 2,000-kilogram capacity xenon propellant tank, as well as provide estimates for overall refueling duration. Due to the high heat of compression of xenon, the propellant tank could exceed its maximum allowable temperature during refueling if the xenon flow rate and temperature are unregulated. In order to prevent overheating, a logic based "bang-bang" operation was used for refueling, shutting off the mass feed when the tank reached a maximum temperature. Heat is removed from the tank via radiation to the surrounding spacecraft bus. The analysis shows that optimizing key parameters such as mass flow rate into the tank, residual propellant in the tank during the onset of refueling, and tank diameter significantly reduces the overall refueling duration. Optimization is not straightforward, however, as the loading time does not trend monotonically with the parameters. Overall, the most significant impact on loading duration comes from altering the residual propellant in the tank. Increasing the mass of residual propellant from 2 percent to 20 percent reduces the overall refueling duration by 56 percent. Future work based on this analysis includes creation of a SINDA/FLUINT model and building a ground-based xenon refueling system emulator.

Xenon↗

Iodine-Xenon Dating: Sensitive Chronometer for Reprocessing in the Primitive Solar System

The I-Xe chronometer is based upon decay of I-129 to Xe-129 in the early Solar System. Recent comparison of I-Xe system in individual mineral separates from twelve different meteorites with independent Pb-Pb data has demonstrated that I-Xe clock is a reliable sensitive chronometer when applied to a single mineral system. Since most iodine hosts are secondary minerals, the I-Xe clock generally records post-formational processing, providing the information on early meteorite evolution. Absolute I-Xe ages can be found by normalization using the measured I-Xe and Pb-Pb ages of Acapulco phosphate (4.557 plus or minus 0.002 Ga). Absolute ages for the I-Xe internal standards Shallow water and Bjurbole, 4.566 plus or minus 0.002 Ga and 4.565 plus or minus 0.003 Ga, respectively, provide absolute I-Xe ages for all other samples. The I-Xe age of bulk meteorite is meaningful and interpretable only when the carrier of primordial iodine is a major mineral phase (e. g., enstatite chondrites). Using the "monomineral" approach, separated phases from the Richardton H5 chondrite provide a case history of post-formational alteration in this object. This work applies the I-Xe chronometer to determine the times of reprocessing of selected minerals in single meteorite types. A preliminary account of this work was recently reported. Additional information is contained in the original extended abstract.

Pravdivtseva, O. V.↗

Modeling ARRM Xenon Tank Pressurization Using 1D Thermodynamic and Heat Transfer Equations

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Xenon storage↗

Modeling Xenon Tank Pressurization using One-Dimensional Thermodynamic and Heat Transfer Equations

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Thermodynamic tank modeling↗

Compilation of a Solar Mirror Materials Database and an Analysis of Natural and Accelerated Mirror Exposure and Degradation

The National Renewable Energy Laboratory (NREL) has been conducting exposure experiments on solar reflectors for over four decades. Thousands of mirror samples from over one hundred suppliers have been exposed to and monitored in a range of relevant environments. These test conditions include outdoor test settings and several controlled laboratory environments. These samples have been rigorously individually characterized using a series of reflectance measurements, visual inspections, and in some cases, in-depth composition analysis to identify degradation modes, reflectance losses, and other mirror properties integral to understanding the solar reflector's life cycle. Here, this paper compiles the decades of measurement data into a concise statistical analysis. It includes exposure and degradation data for numerous reflector types, including secondary-surface reflector permutations of polymer and glass superstrates with silver and aluminum reflectors as well as front-surface reflectors. The results herein are intended to analyze environmental stressors and degradation trends among various historical and state-of-the-art solar reflectors. It may be used to support solar reflector design, effective testing methodology, and inform manufacturing decisions moving forward. Presented are the results of the compiled database and an initial analysis for degradation rate modeling using full-spectrum and wavelength-dependent approaches. The database is a growing resource hosted on a live, publicly accessible website. In conjunction with the analysis presented here, it provides a valuable resource to the solar reflector manufacturing and testing industry.

14 SOLAR ENERGY↗