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NASA NTRS2024

Exploration Systems Development Mission Directorate: Moon to Mars Architecture Definition Document

The National Aeronautics and Space Administration (NASA) explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery. Extending the reach of humanity through the human exploration of the Moon, Mars, and beyond is key to that mission. NASA’s Moon to Mars Strategy and Objectives document establishes long-term goals and objectives for crewed deep space exploration; however, satisfying NASA’s Moon to Mars Objectives requires an innovative approach to the definition, management, and execution of NASA’s Moon to Mars Architecture. An architecture offers a high-level unifying structure and defines a system. It provides rules, guidelines, and constraints that define a cohesive and coherent framework that identifies constituent parts, relationships, and connections and establishes how those parts fit and work together. This Architecture Definition Document (ADD) establishes the process for the decomposition of objectives empowers the agency’s success in achieving human exploration of the cosmos. NASA updates this document annually to reflect the maturation of the architecture and the progress NASA and partners make toward achieving exploration objectives. The ADD is not a manifest or requirements document. Instead, it serves as a tool for the programs, projects, and engineers who will implement and execute NASA’s bold ambitions for crewed exploration of deep space. As established in the Moon to Mars Strategy and Objectives, “Why” we explore encompasses three pillars: Science, Inspiration, and National Posture. Ensuring success in all three areas requires an architectural approach that incorporates innovation, collaboration, and partnerships that can be sustained across a multi-decadal effort. This second revision (Rev-B) of the ADD, developed to support NASA’s 2024 Architecture Concept Review (ACR), incorporates several key updates to support the continued evolution of the architecture. Since the last revision of the ADD, NASA has significantly improved the clarity of the objective decomposition, which distills exploration objectives into the characteristics and needs and use cases and functions needed to achieve them. The updated decomposition incorporates findings from internal studies and diverse stakeholder feedback. A model-based systems engineering approach ensures coherence and consistency, removing inconsistency and repetition. Revision B also incorporates advancements to NASA’s Mars architecture, including insight into initial capabilities, systems, and operations necessary to support the Humans to Mars segment. Updates to objective decomposition for Mars add significant detail to the ADD and hint at areas of forward work and future study. An appendix adds greater depth in the future decisions needed for Mars that will drive lunar needs. They are not the only decisions to be made, but they will have huge effects on subsequent decisions. NASA continues to introduce new exploration systems into the architecture. Two new elements — initial surface habitat and lunar surface cargo lander—successfully passed mission concept review in 2024 as a result of extensive analysis, concept refinement, and studies. These elements and their respective reference missions appear in this revision. NASA also continues to apply architecture processes to cross-agency efforts and coordination with external stakeholders by including definitions of architecture technology gaps — essential areas for engagement across and beyond the agency. The technology gaps appendix identifies areas that need attention and innovation to enable future exploration. In publishing this information, NASA communicates the technologies and capabilities that may benefit from partnership with industry, academia, other U.S. government agencies, and international space agencies. Ultimately, NASA established the Moon to Mars Architecture approach to communicate and facilitate humanity’s journey into the universe according to the principles and recurring tenets of NASA’s Moon to Mars Strategy and Objectives. The NASA architecture team thanks their many stakeholders, participants, and partners for their efforts to review and provide feedback. Their support has been critical to the success of this approach.

Elements↗

DOE OSTI2024

Importance of High Valence Element Nb in Ni-Rich Layered Cathodes for High-Voltage Lithium-Metal Batteries

Ni-rich layered cathode materials have attracted extensive attention due to their higher energy density and technological maturity in commercialization. As the nickel content is raised, especially surpassing 80%, the increased energy density comes with the tradeoff of diminished thermal stability and increased electrochemical structural instability of the cathode. Compared with Co, Al, B, and Ta, the introduction of high valence element Nb significantly improved the electrochemical cycling, delivering a capacity of 202 mAh/g, corresponding to a capacity retention of 92% after 200 cycles tested at 45 °C. Further, the ex situ differential scanning calorimetry and in situ isothermal microcalorimetry demonstrate that the Nb-modified cathode has the potential to enhance the safety of ultrahigh nickel (Ni) NMCs and displays remarkable resilience to extensive cycling by inhibiting high-temperature decomposition reactions and exhibiting a lower heat flow during electrochemical cycling.

25 ENERGY STORAGE↗

DOE OSTI2024

Structural and chemical evolutions of a magnesium vanadium oxide cathode under electrochemical cycling in magnesium batteries

The design of cathode materials that remain chemically and structurally stable during repetitive ion insertion and extraction poses a significant challenge in developing multivalent batteries. The cycling stability of traditional metal oxide-based cathode is challenged by sluggish diffusion of multivalent cations and parasitic reactivity at interfacial regimes, including the cathode electrolyte interphase layer (CEI). Understanding the reactions at the cathode-electrolyte interface, particularly those induced by non-stoichiometric surface layers, is a crucial design parameter for both cathode materials and electrolytes. Here, in this study, we employed multimodal analysis, including in situ and ex situ X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS) to examine the surface reactions and subsequent structural and chemical evolutions of the CEI on high voltage magnesium vanadium oxide (MgV 2 O 4 ) spinel cathode during the Mg 2+ insertion/extraction processes. The results revealed that the presence of non-stoichiometric surface layers in the magnesium vanadium oxide cathode drive the decomposition of bis(trifluoromethanesulfonyl)imide (TFSI - ) anion, leading to the formation of the CEI layer. The CEI layer could inhibit the Mg 2+ ion transfer processes. Accompanying this reactivity-driven degradation, the magnesium vanadium oxide cathode undergoes pulverization, forming clusters of nanosized particles. This process likely improves cycling ability by creating new intercalation sites and shortening the diffusion pathway for the Mg 2+ cations. This study demonstrates that controlling surface stoichiometry and engineering morphological properties are critical design parameters for high performance cathodes for multivalent batteries.

25 ENERGY STORAGE↗

DOE OSTI2025

Gas-phase synthesis of naphthalene through an unconventional thermal alkyne–alkene [2 + 2] cycloaddition mechanism

Exotic cycloaddition entrance channels were discovered for the bimolecular gas-phase reactions of the phenylethynyl radical (C 6 H 5 CC, X 2 A 1 ) with ethylene-d 4 (C 2 D 4 ) and propylene (C 3 H 6 ) as explored under single-collision conditions utilizing the crossed molecular beams technique combined with electronic structure and statistical calculations. Connecting the concepts of barrierless entrance channels, excited states, and facile non-photochemically activated cycloadditions, the reaction pathway features an unconventional thermal [2 + 2] cycloaddition forming a four-membered ring collision complex followed by multiple isomerizations prior to unimolecular decomposition via atomic hydrogen loss to (un)substituted naphthalenes—naphthalene-d 4 (C 10 H 4 D 4 ) and 1-/2-methylnaphthalene (C 11 H 10 ). The small energy gap between the singly-occupied a 1 highest occupied molecular orbital (HOMO) with a σ-character and the underlying doubly-occupied b 1 molecular orbital with a π-character allows a facile promotion of an electron. This in turn enables a versatile low-temperature reactivity of phenylethynyl, where the end-on and side-on barrierless approaches of ethylene are due to its interaction with the σ and π orbitals, respectively, thus suggesting this mechanism as a possible method for tuning substituents in polycyclic aromatic hydrocarbon (PAH) formation and highlighting its versatility as a probe of fundamental carbon chemistry via counterintuitive cycloaddition reactions under single-collision conditions.

Goettl, Shane J. [University of Hawaii at Manoa, H↗

DOE OSTI2025

Space-Time Finite Element Tensor Network Approach for the Time-Dependent Convection–Diffusion–Reaction Equation with Variable Coefficients

In this paper, we present a new space-time Galerkin-like method, where we treat the discretization of spatial and temporal domains simultaneously. This method utilizes a mixed formulation of the tensor-train (TT) and quantized tensor-train (QTT) (please see Section Tensor-Train Decomposition), designed for the finite element discretization (Q1-FEM) of the time-dependent convection–diffusion–reaction (CDR) equation. We reformulate the assembly process of the finite element discretized CDR to enhance its compatibility with tensor operations and introduce a low-rank tensor structure for the finite element operators. Recognizing the banded structure inherent in the finite element framework’s discrete operators, we further exploit the QTT format of the CDR to achieve greater speed and compression. Additionally, we present a comprehensive approach for integrating variable coefficients of CDR into the global discrete operators within the TT/QTT framework. The effectiveness of the proposed method, in terms of memory efficiency and computational complexity, is demonstrated through a series of numerical experiments, including a semi-linear example.

convection–diffusion–reaction equation↗

NASA NTRS1974

Decomposition-aggregation stability analysis of the spinning Skylab

Stability of an 11-th order linear model of the spinning Skylab is determined by the decomposition-aggregation method based upon the comparison principle and vector Liapunov functions. To reduce the inherent conservativeness of the method an optimization problem is formulated and resolved producing the optimum comparison system. The system provides the best estimate of the stability region of the important structural parameter - asymmetry in the boom settings.

Cuk, S. M.↗

NASA NTRS1984

Laser-assisted solar cell metallization processing

Laser assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high efficiency solar cells are investigated. The tasks comprising these investigations are summarized. Metal deposition experiments are carried out utilizing laser assisted pyrolysis of a variety of metal bearing polymer films and metalloorganic inks spun onto silicon substrates. Laser decomposition of spun on silver neodecanoate ink yields very promising results. Solar cell comb metallization patterns are written using this technique.

Dutta, S.↗

NASA NTRS1986

Survey of the status of finite element methods for partial differential equations

The finite element methods (FEM) have proved to be a powerful technique for the solution of boundary value problems associated with partial differential equations of either elliptic, parabolic, or hyperbolic type. They also have a good potential for utilization on parallel computers particularly in relation to the concept of domain decomposition. This report is intended as an introduction to the FEM for the nonspecialist. It contains a survey which is totally nonexhaustive, and it also contains as an illustration, a report on some new results concerning two specific applications, namely a free boundary fluid-structure interaction problem and the Euler equations for inviscid flows.

Temam, Roger↗

NASA NTRS1992

Implementation of non-hierarchic decomposition for multidisciplinary system optimization

Modular prototype software has been designed to implement the method of non-hierarchic decomposition for optimization of coupled, multidisciplinary systems. The modules are intended to be run concurrently on separate processors and to automate all aspects of the method except for the objective function and subspace analysis subroutines, which are inherently problem-dependent. Minimal analysis of problem structure is required, since the software is designed to handle arbitrary system coupling with full generality. The basic feasibility of the approach has been confirmed using six example problems, with varying degrees of lateral coupling among the subspace constraints and dependent variables. Results are given for two of the test problems.

Eason, Ernest D.↗

NASA NTRS1997

Kinetics and Thermochemistry of Reversible Adduct Formation in the Reaction of Cl((sup 2)P(sub J)) with CS2

Reversible adduct formation in the reaction of Cl((sup 2)P(sub J)) with CS2 has been observed over the temperature range 193-258 K by use of time-resolved resonance fluorescence spectroscopy to follow the decay of pulsed-laser-generated Cl((sup 2)P(sub J)) into equilbrium with CS2Cl. Rate coefficients for CS2Cl formation and decomposition have been determined as a function of temperature and pressure; hence, the equilbrium constant has been determined as a function of temperature. A second-law analysis of the temperature dependence of Kp and heat capacity corrections calculated with use of an assumed CS2Cl structure yields the following thermodynamic parameters for the association reaction: Delta-H(sub 298) = -10.5 +/- 0.5 kcal/mol, Delta-H(sub 0) = -9.5 +/- 0.7 kcal/mol, Delta-S(sub 298) = -26.8 +/- 2.4 cal/mol.deg., and Delta-H(sub f,298)(CS2Cl) = 46.4 +/- 0.6 kcal/mol. The resonance fluorescence detection scheme has been adapted to allow detection of Cl((sup 2)P(sub J)) in the presence of large concentrations of O2, thus allowing the CS2Cl + Cl + O2 reaction to be investigated. We find that the rate coefficient for CS2Cl + O2 reaction via all channels that do not generate Cl((sup 2)P(sub J)) is less than 2.5 x 10(exp-16) cu cm/(molecule.s) at 293 K and 300-Torr total pressure and that the total rate coefficient is less than 2 x 10 (exp -15) cu cm/(molecule.s) at 230 K and 30-Torr total pressure. Evidence for reversible adduct formation in the reaction of Cl((sup 2)P(sub J)) with COS was sought but not observed, even at temperatures as low as 194 K.

Nicovich, J. M.↗

NASA NTRSDate not supplied

Use of Spectral Analysis of Singular Values as a Test Metric for IMMAT Trials

One of many challenges in the implementation of multiple exciter testing is establishing a reasonable set of test metrics to measure the quality of testing. This is especially true in the application of Impedance Matched Multi-Axis Testing; in that it is possible to have very large spectral density matrices that serve as reference criteria. While there exist plotting schemes to view a spectral density matrix, it is often necessary to break the overlay of reference and test results into subsections of the matrices to get sufficient resolution to interpret the data. In addition, as one attempts to control multiple locations on a structure, implementation of classical single degree-of freedom test tolerances across all channels and associated cross spectra is simply not feasible. Hence it is challenging to evaluate overall test quality. The use of spectral views of the dominant singular values from the singular value decomposition of the spectral density matrices and metrics based upon them is proposed for establishing a set of compact metrics for evaluating test quality. A laboratory experiment will be included to demonstrate this proposed technique.

Impedance Matched Multi-Axis Testing↗

NASA NTRSDate not supplied

Use of Spectral Analysis of Singular Values as a Test Metric for Impedance Matched Multi-Axis Test Trials

Vibration Testing↗

NASA NTRS1984

Input-output description of linear systems with multiple time-scales

It is pointed out that the study of systems evolving at multiple time-scales is simplified by studying reduced-order models of these systems valid at specific time-scales. The present investigation is concerned with an extension of results on the time-scale decomposition of autonomous systems to that of input-output systems. The results are employed to study conditions under which positive realness of a transfer function is preserved under singular perturbation. Attention is given to the perturbation theory for linear operators, the multiple time-scale structure of autonomous linear systems, the input-output description of two time-scale linear systems, the positive realness of two time-scale systems, and multiple time-scale linear systems.

Madriz, R. S.↗

NASA NTRS1987

Experiences with the Lanczos method on a parallel computer

A parallel computer implementation of the Lanczos method for the free-vibration analysis of structures is considered, and results for two example problems show substantial time-reduction over the sequential solutions. The major Lanczos calculation tasks are subdivided into subtasks, and parallelism is introduced at the subtask level. A speedup of 7.8 on eight processors was obtained for the decomposition step of the problem involving a 60-m three-longeron space mast, and a speedup of 14.6 on 16 processors was obtained for the decomposition step of the problem involving a blade-stiffened graphite-epoxy panel.

Bostic, Susan W.↗

NASA NTRS1993

The multicomponent structure of bulges

The morphology of disk galaxies is usually described by two major components, the centrally concentrated spheroidal component, called the bulge, and an oblate disk. The ratio of there contribution to the total luminosity - the bulge-to-disk ratio - is one of the parameters characterizing the Hubble sequence. Following de Vaucouleurs (1948), for most galaxies the radial distribution of the outer spheroid is fairly well described by the r exp 1/4 law I(r)=I(sub 0) exp(-(alpha)r), whereas the radial luminosity distribution of the disk follows an exponential law: I(r)=I(sub 0) exp(-alpha(r exp 1/4)) (Freeman 1970), with r the radial distance from the center. I(sub 0) and alpha are characteristic constants for each individual galaxy. Parameters for the structural properties of these components give important constraints for models of the formation and evolution of galaxies. Therefore we have tried to decompose disk and bulge components from high S/N CCD observations of a sample of edge-on disk galaxies. A common procedure for the decomposition is to model one component in a region where it dominates and subtract it from the combined light distribution. This technique was successfully carried out e.g. by van der Kruit & Earl (1981, 1982) and Wakamatsu & Hamabe (1984, 1989). Here we present two more examples of bulge-dominated edge-on SO galaxies, namely ESO 506-G33 and NGC 7123, which show an additional small and concentrated central component besides disk and 'bulge'.

Dettmar, Ralf-Juergen↗

NASA NTRS2011

Multifluid Simulations of the Global Solar Wind Including Pickup Ions and Turbulence Modeling

I will describe a three-dimensional magnetohydrodynamic model of the solar wind that takes into account turbulent heating of the wind by velocity and magnetic fluctuations as well as a variety of effects produced by interstellar pickup protons. The interstellar pickup protons are treated in the model as one fluid and the protons and electrons are treated together as a second fluid. The model equations include a Reynolds decomposition of the plasma velocity and magnetic field into mean and fluctuating quantities, as well as energy transfer from interstellar pickup protons to solar wind protons that results in the deceleration of the solar wind. The model is used to simulate the global steady-state structure of the solar wind in the region from 0.3 to 100 AU. The simulation assumes that the background magnetic field on the Sun is either a dipole (aligned or tilted with respect to the solar rotation axis) or one that is deduced from solar magnetograms.

Goldstein, Melvyn L.↗

NASA NTRS2011

Magnetofluid Simulations of the Global Solar Wind Including Pickup Ions and Turbulence Modeling

I will describe a three-dimensional magnetohydrodynamic model of the solar wind that takes into account turbulent heating of the wind by velocity and magnetic fluctuations as well as a variety of effects produced by interstellar pickup protons. In this report, the interstellar pickup protons are treated as one fluid and the protons and electrons are treated together as a second fluid. The model equations include a Reynolds decomposition of the plasma velocity and magnetic field into mean and fluctuating quantities, as well as energy transfer from interstellar pickup protons to solar wind protons that results in the deceleration of the solar wind. The model is used to simulate the global steady-state structure of the solar wind in the region from 0.3 to 100 AU. Where possible, the model is compared with Voyager data. Initial results from generalization to a three-fluid model is described elsewhere in this session.

Goldstein, Melvyn L.↗

DOE OSTI2025

Fabrication, oxidation, and combustion of nanoscale magnesium diboride and tetraboride

The difficult ignition of boron decreases the combustion efficiency of boron-loaded, fuel-rich propellants. One approach to solving this problem involves the use of magnesium diboride (MgB2), which ignites easier than boron. Magnesium tetraboride (MgB4) offers greater energy density owing to its higher boron content. However, the effect of B/Mg ratio on the ignition and combustion is unknown. Additionally, while nanoscale MgB₂ particles and quasi-2D structures were recently recognized as promising energetic additives, the oxidation and combustion properties of nanoscale MgB₄ have not been explored. The objectives of the present work included synthesis, purification, and high-energy ball milling of MgB2 and MgB4 powders as well as investigation of their thermal decomposition, oxidation, and combustion. The MgB2 and MgB4 powders were fabricated by combustion synthesis in the chemical oven mode and by heating Mg/B mixtures in a tube furnace. The latter method was superior in the synthesis of MgB4. Oxide impurities in the synthesized powders were removed by acid leaching. Nanoscale powders were obtained by high-energy ball milling. Thermal decomposition and oxidation of the obtained MgB₂ and MgB₄ powders were investigated by conducting non-isothermal thermogravimetric analysis (TGA) at temperatures up to 1550 °C in argon and oxygen flows. Combustion of B, MgB₂, and MgB₄ powders with oxygen at atmospheric pressure was studied in a windowed chamber using laser ignition and high-speed video recording. The TGA has shown multi-step decomposition of both magnesium borides in an argon environment. The maximum oxidation rate of MgB4 in oxygen was observed at a much lower temperature than in the case of MgB2. In the combustion experiments, both magnesium borides burned much faster than submicron boron. Ball milling of the borides further increased their burning rates. It has been concluded that nanoscale magnesium tetraboride is a promising ingredient for fuel-rich propellants owing to its high energy density, efficient oxidation, and rapid combustion.

Molina, Andre [The University of Texas at El Paso]↗