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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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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Enabling Architecture Trades and Design Exploration for Nuclear Electric Propulsion

Recent renewed interest in Nuclear Electric Propulsion (NEP) at NASA has driven the need for design space exploration and analysis of alternative architectures to evaluate performance and feasibility of NEP concepts. It has been over a decade since NASA last invested in Nuclear Electric Propulsion development efforts, and the landscape has shifted in both mission objectives and technology readiness levels. This also means that many of the engineering analyses and design frameworks tailored to NEP date back to the Jupiter Icy Moons Orbiter (JIMO) days of the early 2000s. Thus, a need was identified for updating and modernizing the modeling and simulation toolsets for NEP. This paper will detail the development efforts in the Marshall Space Flight Center’s Advanced Concepts Office, with a particular focus on the development of the NEP stage of the NEP-Chem vehicle. The paper will cover the various models used, and their current development status, as well as provide an overview of the integrated vehicle model and plans for further development.

Nuclear↗
NASA NTRSDate not supplied

ENABLING ARCHITECTURE TRADES AND DESIGN EXPLORATION FOR NUCLEAR ELECTRIC PROPULSION

Recent renewed interest in Nuclear Electric Propulsion (NEP) at NASA has driven the need for design space exploration and analysis of alternative architectures to evaluate performance and feasibility of NEP concepts. It has been over a decade since NASA last invested in Nuclear Electric Propulsion development efforts, and the landscape has shifted in both mission objectives and technology readiness levels. This also means that many of the engineering analyses and design frameworks tailored to NEP date back to the Jupiter Icy Moons Orbiter (JIMO) days of the early 2000s. Thus, a need was identified for updating and modernizing the modeling and simulation toolsets for NEP. This paper will detail the development efforts in the Marshall Space Flight Center’s Advanced Concepts Office, with a particular focus on the development of the NEP stage of the NEP-Chem vehicle. The paper will cover the various models used, and their current development status, as well as provide an overview of the integrated vehicle model and plans for further development.

Nuclear↗
NASA NTRS1983

Model error estimation for distributed systems described by elliptic equations

A function space approach is used to develop a theory for estimation of the errors inherent in an elliptic partial differential equation model for a distributed parameter system. By establishing knowledge of the inevitable deficiencies in the model, the error estimates provide a foundation for updating the model. The function space solution leads to a specification of a method for computation of the model error estimates and development of model error analysis techniques for comparison between actual and estimated errors. The paper summarizes the model error estimation approach as well as an application arising in the area of modeling for static shape determination of large flexible systems.

Rodriguez, G.↗
NASA NTRS1994

Modelling of Surfaces. Part 1: Monatomic Metallic Surfaces Using Equivalent Crystal Theory

We present a detailed description of equivalent crystal theory focusing on its application to the study of surface structure. While the emphasis is in the structure of the algorithm and its computational aspects, we also present a comprehensive discussion on the calculation of surface energies of metallic systems with equivalent crystal theory and other approaches. Our results are compared to experiment and other semiempirical as well as first-principles calculations for a variety of fcc and bcc metals.

Bozzolo, Guillermo↗
NASA NTRSDate not supplied

Sensitivity Analysis of Heat Rejection and Propellant Management Technologies for Nuclear Thermal Propulsion Architectures

Cryogenic fluid management (CFM) technologies are very important for enabling a wider range of missions to utilize space nuclear propulsion (SNP) concepts such as nuclear thermal propulsion (NTP). Technologies for thermal and cryogenic propellant management allow for vehicles to take full advantage of the higher efficiency NTP systems for longer duration human interplanetary and deep space robotic missions. Currently, the CFM Portfolio Project at NASA’s Marshall Space Flight Center (MSFC) is developing thermal and propellant management technologies needed for SNP. When developing these technologies, it is important to understand the sensitivities of key performance parameters (KPPs) at the system and overall mission level due to the ways the technologies interact with each other, other subsystems, and influence the overall vehicle. The Advanced Concepts Office (ACO) at NASA-MSFC was tasked with building an integrated system model of a human Mars NTP mission to evaluate the impacts and sensitivities of CFM technologies on the overall vehicle and mission. This paper will cover the buildup of the model and highlight major sensitivities and breakpoints encountered, as well as future work in improving the existing models and sensitivities being evaluated.

Robert J. Hetterich↗
NASA NTRSDate not supplied

Sensitivity Analysis of Heat Rejection and Propellant Management Technologies for Nuclear Thermal Propulsion Architectures

Cryogenic fluid management (CFM) technologies are very important for enabling a wider range of missions to utilize space nuclear propulsion (SNP) concepts such as nuclear thermal propulsion (NTP). Technologies for thermal and cryogenic propellant management allow for vehicles to take full advantage of the higher efficiency NTP systems for longer duration human interplanetary and deep space robotic missions. Currently, the CFM Portfolio Project at NASA’s Marshall Space Flight Center (MSFC) is developing thermal and propellant management technologies needed for SNP. When developing these technologies, it is important to understand the sensitivities of key performance parameters (KPPs) at the system and overall mission level due to the ways the technologies interact with each other, other subsystems, and influence the overall vehicle. The Advanced Concepts Office (ACO) at NASA-MSFC was tasked with building an integrated system model of a human Mars NTP mission to evaluate the impacts and sensitivities of CFM technologies on the overall vehicle and mission. This paper will cover the buildup of the model and highlight major sensitivities and breakpoints encountered, as well as future work in improving the existing models and sensitivities being evaluated.

Robert J Hetterich↗
NASA NTRS1982

Lithium-thionyl chloride battery safety

Primary lithium cells which use LiAlCl4/SOCl2 electrolyte exhibit high energy density and long life. Currently these cells pose a safety problem since they have been found to vent or explode. This paper summarizes experiments to resolve the safety problem of Li-SOCl2 cells by thermal modeling and identification of possibly hazardous intermediates formed during discharge of these cells. A thermal model and mechanism for the reduction of SOCl2 are presented, as well as a discussion of their application to Li-SOCl2 cell safety.

Carter, B.↗
NASA NTRS2000

A New Coherent Radar for Ice Sounding in Greenland

This paper will discuss a new multifrequency dual channel coherent radar depth sounder for sounding ice. This sounder is unique since it is a fully coherent chirp radar design to operate at low (1500') as well as high altitudes (30,000').

radar↗
NASA NTRS2006

Certification Testing Approach for Propulsion System Design

The Certification of Propulsion Systems is costly and complex, involving development and qualification testing. The desire of the certification process is to assure all requirements can be demonstrated to be compliant. The purpose of this paper is to address the technical design concerns of certifying a propulsion system for flight. Presented are Pressurization, Tankage, Feed System and Combustion Instability concerns. Propulsion System Engineers are challenged with the dilemma for testing new systems to specific levels to reduce risk yet maintain budgetary targets. A methodical approach is presented to define the types of test suitable to address the technical issues for qualifying systems for retiring the risk levels. Experience of the lessons learned from supporting the Shuttle Program for Main Propulsion and On Orbit Propulsions Systems as well as previous collaborations on design concerns for certifying propulsion systems are utilized to address design concerns and verification approaches.

Rodriguez, Henry↗
NASA NTRSDate not supplied

Delta Method Application for the Correlation of IR Detector Thermal Parasitic Loads with Statistically Accurate Results

The Linear Etalon Imaging Spectral Array (LEISA) is a cryogenic IR detector that is passively cooled below 110K. LEISA is part of the L’Ralph instrument, which is going on the Lucy mission, with planned flyby’s of the Trojan asteroids around 5.5 AU. One of the primary thermal challenges is to successfully quantify each significant parasitic heat flow value with statistical certainty.Simulation of flight-like thermal environments and correlation of thermal models is an important part of this challenge, which can be critical for thermally sensitive systems such as cryogenic detectors that are passively cooled. It is common practice during TVAC to achieve several thermal balance points and then to correlate several design variables in order to achieve the closest match to all balance points tested. This approach lends itself to high levels of uncertainty in the correlated values due to the cumulative effect of absolute temperature uncertainty and differences between the sensors used for the measurement. Accuracy can be improved with the use of more accurate sensors, by calibrating all sensors with respect to each other, and by using Zero-Q methodologies, all of which add cost and complexity to the test.The Delta Method uses the difference in temperature caused by the changes in the boundary conditions to calculate heat flows and/or thermal resistances across temperature differentials. This eliminates the problem of high uncertainties with absolute temperature measurements, and yields statistically accurate results down to the sensor resolution of 1mK at < 100K, by taking the sensor’s calibration errors out of the equation. During testing, this method relies on parametric variations around an initial balance point, by varying the boundary conditions of the different parasitic heat sources. The Delta Method, as well as its application on the LEISA thermal test, will be discussed in detail.

Daniel G. Bae↗
DOE OSTI2025

Active light-controlled frontal ring-opening metathesis polymerization

Frontal ring-opening metathesis polymerization (FROMP) is a promising energy-efficient approach to fabricate polymeric materials. Recent advances have demonstrated FROMP for diverse applications, including additive manufacturing, composites, and foams. However, the characteristic properties of the front are currently controlled primarily by varying the resin composition or the environmental conditions. In this work we present an approach to control FROMP of dicyclopentadiene (DCPD) using photochemical methods. A photobase generator is used to inhibit FROMP of DCPD with UV light while a photosensitizer and co-initiator are used to accelerate FROMP with blue light, enabling orthogonal active photocontrol of front velocity. In addition, photoinhibition-enabled lithographic patterning of frontal polymerizations is demonstrated. Frontal polymerizations are spatially controlled, redirected, and even split into diverging fronts. This work establishes a foundation for advanced control of frontal polymerizations, enabling innovation in traditional and additive manufacturing, as well as emerging processes like morphogenic manufacturing.

Polymer synthesis↗
NASA NTRS2020

KELT-25 b and KELT-26 b: A Hot Jupiter and a Substellar Companion Transiting Young A Stars Observed by TESS

We present the discoveries of KELT-25 b (TIC 65412605, TOI-626.01) and KELT-26 b (TIC 160708862, TOI-1337.01), two transiting companions orbiting relatively bright, early A stars. The transit signals were initially detected by the KELT survey and subsequently confirmed by Transiting Exoplanet Survey Satellite (TESS) photometry. KELT-25 b is on a 4.40 day orbit around the V=9.66 star CD-24 5016(=-+T8280eff180440K,Må=-+2.180.110.12Me), while KELT-26 b is on a 3.34 day orbit around the V=9.95 star HD 134004 (Teff=-+8640240500K,Må=-+1.930.160.14Me), which is likely an Am star. We have confirmed the substellar nature of both companions through detailed characterization of each system using ground-based and TESS photometry, radial velocity measurements, Doppler tomography, and high-resolution imaging. For KELT-25, we determine a companion radius of RP=-+1.640.0430.039RJ and a 3σupper limit on the companion’s mass of64MJ. For KELT-26 b, we infer a planetary mass and radius of MP=-+1.410.510.43MJ and RP=-+1.940.0580.060RJ. From Doppler tomographic observations, we find KELT-26 b to reside in a highly misaligned orbit. This conclusion is weakly corroborated by a subtle asymmetry in the transit light curve from the TESS data. KELT-25 b appears to be in a well-aligned, prograde orbit, and the system is likely a member of the cluster Theia 449.

Exoplanet astronomy↗
DOE OSTI2024

Use of Modeling and Experiments to Assess the Effect of Minor Alloying Additions on Alumina Scale Formation during High-Temperature Oxidation

During the last decades, new generations of Ni-based superalloys have emerged with judiciously controlled chemistries. These alloys heavily rely on the addition of refractory elements to enhance their mechanical properties at elevated temperatures; however, a clear interpretation of the influence of these minor-element additions on the alloy's high-temperature oxidation behavior is still not well understood, particularly from the standpoint of predicting the transition from internal to external alumina formation. In this context, the present investigation describes a systematic study that addresses the intrinsic effects that minor element additions of Nb, Ta, and Re have on the oxidation behavior of alumina-scale forming γ-Ni alloys. By combining a novel simulation approach with high-temperature oxidation experiments, the present study evidences the generally positive effect associated with 2 at. % addition of Ta and Re as well as the detrimental consequences of Nb additions on the 1100 °C oxidation of (in at. %) Ni-6Al-(0,4,6,8)Cr alloys.

Rodriguez, Rafael↗
DOE OSTI2025

Surface Protection and Catalytic CH Alumination

This dataset supports a publication, "Surface Protected Organozirconium Catalyzes C–H Alumination of Saturated Hydrocarbons", and describes the surface-organozirconium catalyzed exchange of ethyl group in AlEt3 for dodecyl or methyl from dodecane or methane. The research describes the benefits of capping remaining surface OH with SiMe3 for improving yields and turnovers. The dataset includes characterization of the precatalyst using solid-state nuclear magnetic resonance spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), as well as gas chromatography and solution NMR of reaction products.

Catalysis and mechanisms of reactions↗
NASA NTRS2020

The Next Generation of L Band Radiometry: User’s Requirements and Technical Solutions

After almost 10 years in operation (SMOS- Aquarius - SMAP) the very high potential of L band radiometry is clearly demonstrated. Several applications are already operational (assimilation at ECMWF, for hurricanes, for sea ice etc.) so it is crucial to maintain such measurements. To do so while satisfying the current missions specifications is also of prime importance. Degrading spatial resolution is thus a significant step back which will impact science and applications). These missions are now getting older and the goal of the study presented in this paper is to assess which planned mission could fulfill the requirements to ensure data continuity. For this purpose, an extensive users’ requirements study was performed in 2018-2019 assessing what would be required in the near future as well as when L band radiometry was absolutely necessary to satisfy the requirements. From the gathered results a cluster analysis was performed and the only.

Yann H Kerr↗
NASA NTRSDate not supplied

Timed Collections in the NASA Cosmic Dust Aircraft Collected Particle Collection Including Previous Collectors

The NASA Cosmic Dust Collections includes a collection of interplanetary particles gathered using high-altitude aircraft (the Aircraft Collected Particle collection, or ACP). These particles include cosmic-origin particles as well as particles of terrestrial origin such as volcanic ash, solid rocket motor effluent, and terrestrial dust. The cosmic-origin dust comes from two principal sources - material originating from the diffuse interplanetary background which are uncoupled from the orbits of larger bodies, and cometary-origin particles which are dynamically coupled with the orbits of their parent bodies to form dust streams. These dust stream particles generate short-lived, annual meteor showers and are important because, if they can be identified as originating from a given dust stream, they can be studied in the laboratory as samples of a specific comet. Collecting these particles requires dedicated ACP flights which are timed to coincide with a specific meteor shower. These “timed collections” hold the promise of providing samples from a suite of comets including those never visited by spacecraft [1-3]. This abstract describes a recent (Dec 2020) timed collection attempt, lists previous timed collections with collected particles available for request from the NASA Cosmic Dust Collections, as well as listing ACP collectors which were collected when no meteor showers were active for potential use as control samples.

cosmic dust↗
DOE OSTI2024

Where are the Data? Automating a Workflow for Carbon Storage Data Gap Analyses

This presentation demonstrates a spatial analysis workflow to assess data availability for the many components of geologic carbon storage technical viability. The workflow relies upon a knowledge-data framework that links the different components of GCS technical viability to the data types needed for evaluation. Using this contextual information, a combination of data science methods (e.g., natural language processing) and spatial analyses are applied to identify areas where sufficient data exists for a given component. The results are aggregated into maps illustrating data density and spatial gaps across all technical viability factors and data categories, as well as the individual component and category level for a more nuanced understanding. Presented at the FECM NETL Carbon Management Program Review Meeting 2024.

Creason, Christopher↗