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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1960

Ranger Spacecraft

The thermal-control philosophy of the spacecraft currently under development by the Jet Propulsion Laboratory is design by passive means to maintain all components within the tolerances specified by cognizant engineers. Due to the complexity of the configurations, calculations are) of necessity, fairly generalized and final design is based upon tests in an environmental chamber. The Ranger series spacecraft is designed with a basic structure which is common to all models, with additional hardware to suit the individual mission. This basic structure of Rangers A-1 and A-2 is seen as the hexagonal instrument section, the erectable solar panels, the movable antenna, and the omniantenna. The Ranger A-1 and A-2 configuration is for engineering tests and space-exploration, with the scientific instrumentation isolation requirement dictating the spread-out design. The spacecraft stands 12 feet high, weighs 700 to 800 pounds, and has an internal power of 150 watts. Rangers A-3, A-4, and A-5 are designed to rough land a capsule on the moon. For these, a capsule and retrorocket replace the scientific instruments, occupying the space inside the tower structure. The spacecraft must survive many environments. Chronologically they are: 1) Folded configuration inside an aerodynamic shroud on the pad. 2) Thermal flux from shroud aerodynamically heated during boost phase. 3) Coasting up to 30 minutes attached to Agena stage after booster and shroud are separated. 4) Agena stage burning. 5) Coasting and tumbling after separation from Agena until it passes from earth's shadow. 6) Upon reaching sunlight, panels open and begin sun acquisition. 7) Antenna seeks earth after spacecraft locks onto sun. 8) Space phase- "steady state" with vehicle's vertical axis locked on sun, communicating with earth. The philosophy is to design for the sun-acquired mode, making allowances for the transient conditions.

Thostesen, T. O.↗
NASA NTRS2005

Large Liquid Rocket Testing: Strategies and Challenges

Rocket propulsion development is enabled by rigorous ground testing in order to mitigate the propulsion systems risks that are inherent in space flight. This is true for virtually all propulsive devices of a space vehicle including liquid and solid rocket propulsion, chemical and non-chemical propulsion, boost stage and in-space propulsion and so forth. In particular, large liquid rocket propulsion development and testing over the past five decades of human and robotic space flight has involved a combination of component-level testing and engine-level testing to first demonstrate that the propulsion devices were designed to meet the specified requirements for the Earth to Orbit launchers that they powered. This was followed by a vigorous test campaign to demonstrate the designed propulsion articles over the required operational envelope, and over robust margins, such that a sufficiently reliable propulsion system is delivered prior to first flight. It is possible that hundreds of tests, and on the order of a hundred thousand test seconds, are needed to achieve a high-reliability, flight-ready, liquid rocket engine system. This paper overviews aspects of earlier and recent experience of liquid rocket propulsion testing at NASA Stennis Space Center, where full scale flight engines and flight stages, as well as a significant amount of development testing has taken place in the past decade. The liquid rocket testing experience discussed includes testing of engine components (gas generators, preburners, thrust chambers, pumps, powerheads), as well as engine systems and complete stages. The number of tests, accumulated test seconds, and years of test stand occupancy needed to meet varying test objectives, will be selectively discussed and compared for the wide variety of ground test work that has been conducted at Stennis for subscale and full scale liquid rocket devices. Since rocket propulsion is a crucial long-lead element of any space system acquisition or development, the appropriate plan and strategy must be put in place at the outset of the development effort. A deferment of this test planning, or inattention to strategy, will compromise the ability of the development program to achieve its systems reliability requirements and/or its development milestones. It is important for the government leadership and support team, as well as the vehicle and propulsion development team, to give early consideration to this aspect of space propulsion and space transportation work.

Rahman, Shamim A.↗
DOE OSTI2021

Microgrid's Role in Enhancing the Security and Flexibility of City Energy Systems

Smart cities depend on flexible and secure energy systems to ensure resilient power for critical infrastructure; however, recent weather-related events and cyberattacks have highlighted weaknesses in our energy systems, with the potential for widespread economic and security impacts. As stated by the Executive Office of the President, "the resilience of the US electric grid is a key part of the nation's defense against severe weather." To address the energy delivery security challenge, microgrids are rising as a viable solution that enhances the flexibility and resilience of the distribution grid and boosts the reliability of the local supply for the end-user. Traditionally, high capital investment has been a barrier to large-scale adoption of microgrid technology. Understanding the flexibility and resilience benefits of microgrids and accounting for the associated value streams can make the microgrid's proposition economically viable. In this chapter, microgrids' utility and their potential to serve as a flexible and resilient resource for the utility grid by providing capabilities such as peak shaving, demand response, and frequency regulation is presented. Moreover, other value streams, such as (1) their ability to island during a disaster and sustain critical loads which makes them a robust resilience solution for end-users, in the event of the utility grid outage and (2) microgrids also provide a flexible platform for integrating distributed energy resources in conjunction with storage and conventional generation technologies, strengthen microgrid's role in reducing the over-arching goal of emission reduction. Given the myriad of benefits associated with microgrids, we present strategies which can be employed for making microgrid itself resilient against physical and cyberthreats by employing hardware, software, and personnel training solutions to operate the microgrid before, during, and after a potential disaster. This chapter, thus, provides a holistic study of the microgrid as a resilience resource, for the utility grid, and a self-contained end-user for the end-user.

cyber-physical system↗
NASA NTRS1996

Low Temperature Performance of a Boost Converter with MPP and HTS Inductors

Low temperature performance of a 150 W, 50 kHz, 24/48 V boost PWM dc-to-dc converter is reported. The efficiency of the converter using a molypermalloy powder (MPP) core based inductor went up from 94% at room temperature (23 C) to 95.9% at liquid nitrogen temperature (-196 C). A BSCCO based high temperature superconducting (HTS) inductor with a transition temperature of approximately -158 C was compared to a MPP core based inductor in terms of the power converter performance at liquid nitrogen temperature. The use of the HTS inductor in the converter tested yielded no significant performance improvement over the same converter with the MPP inductor. The experimental results are discussed along with the HTS inductor characteristics.

Ray, Biswajit↗
NASA NTRS1961

Mission Capabilities of Ion Engines Using SNAP-8 Power Supplies

Mission performance capabilities of ion engines powered by the 30 kw and 60 kw SNAP-8 power supplies are compared for the following missions: a 24-hr equatorial satellite, a 100 n mi lunar satellite, a 500 n mi Mars satellite, a Mercury probe, and an out-of-the-ecliptic probe. The capabilities of arc- jet engines and chemical engines for the same missions are compared with those of the ion engines. The majority of the comparisons are for 8500-lb spacecraft which are boosted into a 300 n mi orbit by the Atlas-Centaur. Variations in initial orbit altitude, the use of actual launch dates rather than dates based on simplifying assumptions, and the combined use of chemical and electrical propulsion systems were also evaluated in terms of their effect on mission performance.

IONIC PROPULSION↗
NASA NTRS2005

Free Re-boost Electrodynamic Tether on the International Space Station

The International Space Station (ISS) currently experiences significant orbital drag that requires constant make up propulsion or the Station will quickly reenter the Earth's Atmosphere. The reboost propulsion is presently achieved through the firing of hydrazine rockets at the cost of considerable propellant mass. The problem will inevitably grow much worse as station components continue to be assembled, particularly when the full solar panel arrays are deployed. This paper discusses many long established themes on electrodynamic propulsion in the context of Exploration relevance, shows how to couple unique ISS electrical power system characteristics and suggests a way to tremendously impact ISS's sustainability. Besides allowing launch mass and volume presently reserved for reboost propellant to be reallocated for science experiments and other critically needed supplies, there are a series of technology hardware demonstrations steps that can be accomplished on ISS, which are helpful to NASA s Exploration mission. The suggested ElectroDynamic (ED) tether and flywheel approach is distinctive in its use of free energy currently unusable, yet presently available from the existing solar array panels on ISS. The ideas presented are intended to maximize the utility of Station and radically increase orbital safety.

Bonometti, Joseph A.↗
DOE OSTI2026

Advanced Semi-Supervised Learning with Uncertainty Estimation for Phase Identification in Distribution Systems

The integration of advanced metering infrastructure (AMI) into power distribution networks generates valuable data for tasks such as phase identification; however, the limited and unreliable availability of labeled data in the form of customer phase connectivity presents challenges. To address this issue, we propose a semi-supervised learning (SSL) framework that effectively leverages labeled and unlabeled data. Our approach incorporates self-training, label spreading, and Bayesian neural networks (BNNs) to enhance phase identification with AMI data. Our method uses an ensemble of multilayer perceptron classifiers in a self-training setup, iteratively adding high-confidence pseudo-labels to improve robustness. We also apply label spread to propagate labels based on data similarity, which enhances generalization across diverse distributions. In addition, we employ a BNNs with uncertainty estimation, boosting confidence in predictions and reducing phase identification errors. In our case study, we achieved approximately 98% +/- 0.08 accuracy with uncertainty using minimal and unreliable labeled data from a real U.S. utility, Duquesne Light Company. Our SSL approach, combined with uncertainty estimation, provides an efficient solution for phase identification in AMI data, ultimately improving the reliability of smart grid applications.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2026

Advanced Semi-Supervised Learning With Uncertainty Estimation for Phase Identification in Distribution Systems

The integration of advanced metering infrastructure (AMI) into power distribution networks generates valuable data for tasks such as phase identification; however, the limited and unreliable availability of labeled data in the form of customer phase connectivity presents challenges. To address this issue, we propose a semi-supervised learning (SSL) framework that effectively leverages labeled and unlabeled data. Our approach incorporates self-training, label spreading, and Bayesian neural networks (BNNs) to enhance phase identification with AMI data. Our method uses an ensemble of multilayer perceptron classifiers in a self-training setup, iteratively adding high-confidence pseudo-labels to improve robustness. We also apply label spread to propagate labels based on data similarity, which enhances generalization across diverse distributions. In addition, we employ a BNNs with uncertainty estimation, boosting confidence in predictions and reducing phase identification errors. In our case study, we achieved approximately 98% +/- 0.08 accuracy with uncertainty using minimal and unreliable labeled data from a real U.S. utility, Duquesne Light Company. Our SSL approach, combined with uncertainty estimation, provides an efficient solution for phase identification in AMI data, ultimately improving the reliability of smart grid applications.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1967

Lunar Orbiter II - Photographic Mission Summary

Lunar Orbiter II photography of landing sites, and spacecraft systems performance. The second of five Lunar Orbiter spacecraft was successfully launched from Launch Complex 13 at the Air Force Eastern Test Range by an Atlas-Agena launch vehicle at 23:21 GMT on November 6, 1966. Tracking data from the Cape Kennedy and Grand Bahama tracking stations were used to control and guide the launch vehicle during Atlas powered flight. The Agena spacecraft combination was maneuvered into a 100-nautical-mile-altitude Earth orbit by the preset on-board Agena computer. In addition, the Agena computer determined the maneuver 1 and engine-bum period required to inject the spacecraft on the cislunar trajectory 20 minutes after launch. Tracking data from the downrange stations and the Johannesburg, South Africa station were used to monitor the entire boost trajectory.

LUNAR ORBITER↗
NASA NTRS2000

Application of Radar Data to Remote Sensing and Geographical Information Systems

The field of synthetic aperture radar changed dramatically over the past decade with the operational introduction of advance radar techniques such as polarimetry and interferometry. Radar polarimetry became an operational research tool with the introduction of the NASA/JPL AIRSAR system in the early 1980's, and reached a climax with the two SIR-C/X-SAR flights on board the space shuttle Endeavour in April and October 1994. Radar interferometry received a tremendous boost when the airborne TOPSAR system was introduced in 1991 by NASA/JPL, and further when data from the European Space Agency ERS-1 radar satellite became routinely available in 1991. Several airborne interferometric SAR systems are either currently operational, or are about to be introduced. Radar interferometry is a technique that allows one to map the topography of an area automatically under all weather conditions, day or night. The real power of radar interferometry is that the images and digital elevation models are automatically geometrically resampled, and could be imported into GIS systems directly after suitable reformatting. When combined with polarimetry, a technique that uses polarization diversity to gather more information about the geophysical properties of the terrain, a very rich multi-layer data set is available to the remote sensing scientist. This talk will discuss the principles of radar interferometry and polarimetry with specific application to the automatic categorization of land cover. Examples will include images acquired with the NASA/JPL AIRSAR/TOPSAR system in Australia and elsewhere.

vanZyl, Jakob J.↗
DOE OSTI2023

Highly transparent silanized cellulose aerogels for boosting energy efficiency of glazing in buildings

Abstract To maintain comfortable indoor conditions, buildings consume ~40% of the energy generated globally. In terms of passively isolating building interiors from cold or hot outdoors, windows and skylights are the least-efficient parts of the building envelope because achieving simultaneously high transparency and thermal insulation of glazing remains a challenge. Here we describe highly transparent aerogels fabricated from cellulose, an Earth-abundant biopolymer, by utilizing approaches such as colloidal self assembly and procedures compatible with roll-to-roll processing. The aerogels have visible-range light transmission of 97–99% (better than glass), haze of ~1% and thermal conductivity lower than that of still air. These lightweight materials can be used as panes inside multi-pane insulating glass units and to retrofit existing windows. We demonstrate how aerogels boost energy efficiency and may enable advanced technical solutions for insulating glass units, skylights, daylighting and facade glazing, potentially increasing the role of glazing in building envelopes.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2025

High-performance windows improve thermal survivability of occupants during cold snaps

Exposure to low indoor air temperature is a major contributor to temperature-related mortality during extreme cold events, especially when power outages disrupt operation of space heating systems. This study explores the impact of high-performance windows on the thermal resilience of residential buildings during extreme cold weather and grid power outages, as well as their long-term benefits through energy efficiency and reduced risk of property damage. Building performance simulations were conducted for reference residential buildings in three construction vintages and two major U.S. cities located in cold climate zones, considering two types of extreme cold events: short and severe, and long and milder. Our research found that even houses compliant with current energy codes struggle to maintain safe indoor temperatures for more than a few hours during power outages, necessitating rapid evacuations. High-performance windows can extend the thermal survivability time by up to 3.8 days within a 7-day cold snap and significantly reduce risk of bursting frozen water pipes, depending on the building’s insulation and infiltration level, cold event severity, and occupant vulnerability. This extended thermal safety time is crucial in scenarios where reduced mobility complicates emergency responses in senior housing. In addition to boosting thermal resilience, upgrading older homes with high-performance windows can reduce heating energy consumption by over 18% and cooling energy by 15%. Our findings highlight the need to incorporate thermal resilience assessments into new designs or major retrofits, including the use of typical and extreme weather scenarios and advanced technologies like high-performance windows.

Krelling, Amanda F↗
DOE OSTI2021

A machine learning aided interpretable model for rupture strength prediction in Fe-based martensitic and austenitic alloys

Abstract The class of 9–12% Cr ferritic-martensitic alloys (FMA) and austenitic stainless steels have received considerable attention due to their numerous applications in high temperature power generation industries. To design high strength steels with prolonged service life requires a thorough understanding of the long-term properties, e.g., creep rupture strength, rupture life, etc., as a function of the chemical composition and processing parameters that govern the microstructural characteristics. In this article, the creep rupture strength of both 9–12% Cr FMA and austenitic stainless steel has been parameterized using curated experimental datasets with a gradient boosting machine. The trained model has been cross validated against unseen test data and achieved high predictive performance in terms of correlation coefficient ( $$R^{2} > 0.98 $$ R 2 > 0.98 for 9–12% Cr FMA and $$R^{2} > 0.95 $$ R 2 > 0.95 for austenitic stainless steel) thus bypassing the need for additional comprehensive tensile test campaigns or physical theoretical calculations. Furthermore, the feature importance has been computed using the Shapley value analysis to understand the complex interplay of different features.

36 MATERIALS SCIENCE↗
NASA NTRS2000

Assessment of MCRM Boost Assist from Orbit for Deep Space Missions

Report provides results of analysis for the beamed energy driven MHD Chemical Rocket Motor (MCRM) for application to boost from orbit to escape for deep space and interplanetary missions. Parametric analyses were performed in the mission to determine operating regime for which the MCRM provides significant propulsion performance enhancement. Analysis of the MHD accelerator was performed numerical computational methods to determine design and operational features necessary to achieve Isp on the order of 2,000 to 3,000 seconds. Algorithms were developed to scale weights for the accelerator and power supply. Significant improvement in propulsion system performance can be achieved with the beamed energy driven MCRM. The limiting factor on achievable vehicle acceleration is the specific power of the rectenna.

Source record↗
DOE OSTI2025

Harnessing Machine Learning to Predict MoS 2 Solid Lubricant Performance

Physical vapor deposited (PVD) molybdenum disulfide (MoS 2 ) solid lubricant coatings are an exemplar material system for machine learning methods due to small changes in process variables often causing large variations in microstructure and mechanical/tribological properties. Here, in this work, a gradient boosted regression tree machine learning method is applied to an existing experimental data set containing process, microstructure, and property information to create deeper insights into the process-structure–property relationships for molybdenum disulfide (MoS 2 ) solid lubricant coatings. The optimized and cross-validated models show good predictive capabilities for density, reduced modulus, hardness, wear rate, and initial coefficients of friction. The contribution of individual deposition variables (i.e., argon pressure, deposition power, target conditioning) on coating properties is highlighted through feature importance. The process-property relationships established herein show linear and non-linear relationships and highlight the influence of uncontrolled deposition variables (i.e., target conditioning) on the tribological performance.

MoS2↗
NASA NTRS1989

Laser-boosted lightcraft technology demonstrator

The ultimate goal for this NASA/USRA-sponsored 'Apollo Lightcraft Project' is to develop a revolutionary manned launch vehicle technology that can potentially reduce payload transport costs by a factor of 1000 below the space shuttle orbiter. The Rensellaer design team proposes to utilize advanced, highly energetic, beamed-energy sources (laser, microwave) and innovative combined-cycle (airbreathing/rocket) engines to accomplish this goal. This year's effort, the detailed description and performance analysis of an unmanned 1.4-m Lightcraft Technology Demonstrator (LTD) drone, is presented. The novel launch system employs a 100-MW-class ground-based laser to transmit power directly to an advanced combined-cycle engine that propels the 120-kg LTD to orbit, with a mass ratio of two. The single-stage-to-orbit (SSTO) LTD machine then becomes an autonomous sensor satellite that can deliver precise, high-quality information typical of today's large orbital platforms. The dominant motivation behind this study is to provide an example of how laser propulsion and its low launch costs can induce a comparable order-of-magnitude reduction in sensor satellite packaging costs. The issue is simply one of production technology for future, survivable SSTO aerospace vehicles that intimately share both laser propulsion engine and satellite functional hardware. A mass production cost goal of 10(exp 3)/kg for the LTD vehicle is probably realizable.

Antonison, M.↗
DOE OSTI2024

An Experimental Investigation of Sintered Particle Effect on Heat Transfer Performance in an “Annular Flow” Evaporation Tube

Wicking structures have been widely used within passive heat transfer devices with high heat fluxes, such as heat pipes, to enhance their thermal performance. While wicking structures promote capillary pumping of the working fluid and thin film evaporation, they can result in capillary evaporation and further enhance the evaporation heat transfer. In this study, a 0.5 mm thick layer of 105 µm sintered copper particles was added to the inner wall of a copper tube, aiming to form an “annular flow” and enhance the heat transfer characteristics by taking advantage of thin film and capillary evaporation. Acetone was chosen as the working fluid, and the performance of an evaporation tube was tested for power inputs of 10, 30, 50, and 70 W. For each power input, trials were run at inclination angles varying from -90 deg to 90 deg to investigate the capillary effects. The temperature measurements showed that the temperature distribution along the evaporation tube is always downward sloping, meaning the temperature at the fluid inlet is larger than the outlet. In conclusion, results show that an “annular flow” formed by a thin layer of sintered particles can promote thin film and capillary evaporation and, therefore, boost the evaporation heat transfer coefficient.

42 ENGINEERING↗