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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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The environmental control systems and system requirements of the Apollo command service module and the lunar module are described. The overall performance of both systems during the Apollo program is discussed. Other topics covered include: dust control, EVA provisions, Apollo 13 emergency, component redundancy, modular construction, and subatmospheric design.
A numerical method is outlined for solving the equation which describes the solar modulation of cosmic rays in models where interplanetary conditions can vary with heliocentric latitude. As an illustration of the use of this method, it is shown how variations in the modulation with latitude could produce the small radial gradients in the intensity that were observed from the Pioneers 10 and 11 spacecraft.
The capability of the 25 kW power module to conduct representative missions which include Earth, solar, and stellar observation as well as zero-gravity experiments was assessed. Mission accommodations and related technical characteristics of the various operating modes are summarized. The minimum power module provides a substantial mission support on sortie flights. The addition of an attitude sensor is required for free-flying pointing missions.
Design, fabrication and test of the Block IV residential load module are reported. Design changes from the proposed module design through three iterations to the discontinuance of testing are outlined.
Velocity-modulation spectroscopy is an established technique for performing laser absorption spectroscopy of molecular ions in a discharge. However, such experiments are often plagued by a coherent background signal arising from emission from the discharge or from electronic pickup. Fluctuations in the background can obscure the desired signal. A simple technique using amplitude modulation of the laser and two lock-in amplifiers in series to detect the signal is demonstrated. The background and background fluctuations are thereby eliminated, facilitating the detection of molecular ions.
This report documents the final reliability prediction performed on the Earth Observing System/Advanced Microwave Sounding Unit-A (EOS/AMSU-A). The A1 Module contains Channels 3 through 15, and is referred to herein as 'EOS/AMSU-A1'. The A2 Module contains Channels 1 and 2, and is referred herein as 'EOS/AMSU-A2'. The 'specified' figures were obtained from Aerojet Reports 8897-1 and 9116-1. The predicted reliability figure for the EOS/AMSU-A1 meets the specified value and provides a Mean Time Between Failures (MTBF) of 74,390 hours. The predicted reliability figure for the EOS/AMSU-A2 meets the specified value and provides a MTBF of 193,110 hours.
The Quench Module Insert (QMI) and the Diffusion Module Insert (DMI) are microgravity furnaces under development at Marshall Space Flight Center. The furnaces are being developed for the first Materials Science Research Rack (MSRR-1) of the Materials Science Research Facility (MSRF), one of the first International Space Station (ISS) scientific payloads. QMI is a Bridgman furnace with quench capability for studying interface behavior during directional solidification of metallic and alloy materials. DMI will be a Bridgman-Stockbarger furnace to study diffusion processes in semiconductors. The design for each insert, both QMI and DMI, is driven by specific science, operations and safety requirements, as well as by constraints arising from resource limitations, such as volume, mass and power. Preliminary QMI analysis and testing indicates that the design meets these requirements.
We present the design for a phase-modulated Opto-Electronic Oscillator (OEO) that incorporates asymmetric Mach- Zehnder (AMZ) interferometers as phase demodulators together with PM modulation suppression. The new design promises to obtain in the electro-optical domain the low-noise advantages previously achieved in RF and microwave oscillators by the use of carrier suppression but which have been achieved only to a limited extent in OEO's.
Miniaturized fifteen-channel telemetry modulator
Reception threshold for wideband frequency modulation
In certain configurations, the aromatic properties of benzene ring structured molecules allow for unpaired, reactive valence electrons (known as radicals). Clar’s goblets are such molecules. With an even number of unpaired radicals, these nanographenes are topologically frustrated hydrocarbons in which π-bonding network and topology of edges give rise to the magnetism. Clar’s goblets are therefore valued as prospective qubits provided they can be modulated between magnetic states. Here, using first-principles DFT, we demonstrate the effects of adsorption on both molecule and substrate in a graphene–Clar’s goblet heterostructure. We look at the energy difference bewteen FM and AFM states of the system and discuss underlying physical and chemical mechanisms in reference to the highest occupied molecular orbital (HOMO) and second HOMO (HOMO–1). We find that the HOMO of the molecule in the FM state is right at the Fermi surface, which leads to the hybridization between molecular state and the graphene state near the Dirac point. Furthermore, we investigate qualitative changes in charge realignment and magnetic state under a variable electric field. Transitions from FM to AFM and back to FM states are observed.
We report steady-state voltammetry of outer-sphere redox species at back-gated ultrathin ZnO working electrodes in order to determine electron transfer rate constants k ET as a function of independently-controlled gate bias, V G . We demonstrate that k ET can be modulated as much as 30-fold by application of V G ≤ 8 V. Key to this demonstration was integrating the ultrathin (5 nm) ZnO on a high dielectric constant (k) insulator, HfO 2 (30 nm), which was grown on a Pd metal gate. The high-k HfO 2 dramatically decreased the required V G values and increased the gate-induced charge in ZnO compared to previous studies. Importantly, the enhanced gating power of the Pd/HfO 2 /ZnO stack meant it was possible to observe a non-monotonic dependence of k ET on V G , which reflects the inherent density of redox acceptor states in solution. Furthermore, this work adds to the growing body of literature demonstrating that electrochemical kinetics (i.e., rate constants and overpotentials) at ultrathin working electrodes can be tuned by V G , independent of the conventional electrochemical working electrode potential.
Here metal-metal oxide (M-MO) inverse catalysts are broadly applied. Brønsted acid sites on the oxide overlayers are often hypothesized to drive selective C-O bond activation. However, the Brønsted acid site nature and dynamics under working conditions remain poorly understood due to multiple materials functionalities. Here, we investigate the formation and the dynamics of Brønsted acid and redox sites on PtWO x /C under working conditions. DFT-based thermodynamic calculations and microkinetic modeling reveal a complex interplay between Brønsted acid and redox sites and potentially fast catalyst dynamics at comparable time scales to the chemistry. Combining in situ characterization and probe chemistry, we demonstrate that the density of Brønsted acid sites on the PtWO x /C inverse catalyst could be modulated by up to two orders of magnitude by altering the reaction parameters and by the chemistry itself. We elicit an order of magnitude increase in the acid-catalyzed dehydration average reaction rate by periodic hydrogen pulsing.
Advanced Fuel Cycle Cost Basis Report cost module on contact handled fuel.
What standard tests are required for commercializing a new PV module technology such as perovskite photovoltaics? This summary document provides answers in the areas of (1) quality assurance for manufacturing, (2) safety and reliability testing, and (3) performance characterization.
Space science - torque modulation and instrument error detection concepts for gyroscopes and accelerometers
Pilot controlled simulation of lunar model docking with Apollo command module in lunar orbit
Resources requirements and cost analysis for Renovated Command Module /RCM/ using Block 2 recovered Apollo vehicle and RCM laboratories using Block 1 or Block 2 Apollo vehicles