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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 1,243 records · Page 69
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Feasibility study of modern airships, phase 1. Volume 2: Parametric analysis (task 3)

Various types of lighter-than-air vehicles from fully buoyant to semibuoyant hybrids were examined. Geometries were optimized for gross lifting capabilities for ellipsoidal airships, modified delta planform lifting bodies, and a short-haul, heavy-lift vehicle concept. It is indicated that: (1) neutrally buoyant airships employing a conservative update of materials and propulsion technology provide significant improvements in productivity; (2) propulsive lift for VTOL and aerodynamic lift for cruise significantly improve the productivity of low to medium gross weight ellipsoidal airships; and (3) the short-haul, heavy-lift vehicle, consisting of a simple combination of an ellipsoidal airship hull and existing helicopter componentry, provides significant potential for low-cost, near-term applications for ultra-heavy lift missions.

Lancaster, J. W.↗
NASA NTRS1975

Head-eye tracking in two-dimensional pursuit tasks

The neurological control systems for the eye and head are studied by investigating dynamic eye and head rotations in two degrees of freedom using bandlimited, white noise stimuli, nominally wide field of view stimulus presentations of + or - 10 deg and power spectral analysis of the data to produce input/output transfer and coherence functions. Determined were frequency response characteristics of these systems, the linearity of the transfer functions in both coupled and decoupled vertical and horizontal stimulus/response reference axes and the amount of cross axis coupling present in system responses. A comparative study was also conducted to assess the differences in response characteristics between single axis and dual axis visual stimulation for the same subject.

Shirachi, D. K.↗
NASA NTRS1975

Vertex evoked potentials in a rating-scale detection task - Relation to signal probability

Results of vertex-evoked potential studies conducted to determine how decision confidence level and decision probability interact to determine P3 amplitude for both signal-present and signal-absent decisions. They support the contention that the form of the vertex-evoked response is closely correlated with the subject's psychophysical response regarding the presence or absence of a threshold-level signal.

Squires, K. C.↗
NASA NTRS1975

Shuttle LOX loading transient study. Task 2 milestone report. National space and technology laboratories (NSTL) LOX loading facility analysis

Transient thermodynamic analyses were made of the LOX loading system proposed for the space shuttle main propulsion test article (MPTA). This system is made up of a LOX replenish system and a main LOX line which include the barge tank, the lines, pumps, and valves between the barge and the orbiter (ORB) ground service equipment (GSE) interface, the MPTA fill system, the space shuttle main engine (SSME) chilldown bleed system, and the GSE vent system. System analyses include predictions of system performance sensitivity to operating sequence and LOX flowrate, temperature, and quality at the ORB/GSE interface. The transient thermodynamic conditions at the SSME feed line entrance, ET entrance (tank bottom), and the SSME bleed/GSE vent TEE are also included. The analyses are based on continuous SSME bleed flow during GSE facility chilldown.

Glasgow, V. L.↗
NASA NTRS1975

Task 3 Milestone Report, Kennedy Space Center (KSC) LOX Loading Facility Analyses

Transient thermodynamic analyses have been made for the Kennedy Space Center (KSC) LOX loading system proposed for the space shuttle. The primary objective of these analyses is to predict the sensitivity of system performance to operating procedures, flow rate, temperature, and quality at the orbiter (ORB)/ground service equipment (GSE) interface. A further objective is to establish required system chill-down times. These analyses also include the prediction of transient thermodynamic conditions for the facility vent line, shuttle main engine (SSME) feed line entrance, ORB/ET interface, and the ET entrance (tank bottom).

Glasgow, V. L.↗
NASA NTRS1975

Electrochemical carbon dioxide concentrator advanced technology tasks

Technology advancement studies are reported on the basic electrochemical CO2 removal process to provide a basis for the design of the next generation cell, module and subsystem hardware. An Advanced Electrochemical Depolarized Concentrator Module (AEDCM) is developed that has the characteristics of low weight, low volume, high CO2, removal, good electrical performance and low process air pressure drop. Component weight and noise reduction for the hardware of a six man capacity CO2 collection subsystem was developed for the air revitalization group of the Space Station Prototype (SSP).

Schneider, J. J.↗
NASA NTRS1975

Biomedical applications team tasks

The status of the biomedical applications team is discussed along with its activity in applications engineering. Various technology requests are summarized.

Laenger, C. J., Sr.↗
NASA NTRS1974

Technology forecasting for space communication. Task one report: Cost and weight tradeoff studies for EOS and TDRS

Weight and cost optimized EOS communication links are determined for 2.25, 7.25, 14.5, 21, and 60 GHz systems and for a 10.6 micron homodyne detection laser system. EOS to ground links are examined for 556, 834, and 1112 km EOS orbits, with ground terminals at the Network Test and Tracking Facility and at Goldstone. Optimized 21 GHz and 10.6 micron links are also examined. For the EOS to Tracking and Data Relay Satellite to ground link, signal-to-noise ratios of the uplink and downlink are also optimized for minimum overall cost or spaceborne weight. Finally, the optimized 21 GHz EOS to ground link is determined for various precipitation rates. All system performance parameters and mission dependent constraints are presented, as are the system cost and weight functional dependencies. The features and capabilities of the computer program to perform the foregoing analyses are described.

Source record↗
NASA NTRS1975

Trade study for water and waste management concepts. Task 7: Support special analysis

Cost analyses and tradeoff studies are given for waste management in the Space Station, Lunar Surface Bases, and interplanetary space missions. Crew drinking water requirements are discussed and various systems to recycle water are examined. The systems were evaluated for efficiency and weight savings. The systems considered effective for urine water recovery were vapor compression, flash evaporation, and air evaporation with electrolytic pretreatment. For wash water recovery, the system of multifiltration was selected. A wet oxidation system, which can process many kinds of wastes, is also considered.

Source record↗
NASA NTRS1976

Silicon materials task of the low cost solar array project, part 2

Purity requirements for solar cell grade silicon material was developed and defined by evaluating the effects of specific impurities and impurity levels on the performance of silicon solar cells. Also, data was generated forming the basis for cost-tradeoff analyses of silicon solar cell material. Growth, evaluation, solar cell fabrication and testing was completed for the baseline boron-doped Czochralski material. Measurements indicate Cn and Mn seriously degrade cell performance, while neither Ni nor Cu produce any serious reduction in cell efficiency.

Hopkins, R. H.↗
NASA NTRS1975

Dip coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

The research program to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon is reported. The initial effort concentrated on the design and construction of the experimental dip-coating facility. The design was completed and its experimental features are discussed. Current status of the program is reported, including progress toward solar cell junction diffusion and miscellaneous ceramic substrate procurement.

Heaps, J. D.↗
NASA NTRS1976

Dip coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

To date, an experimental dip-coating facility was constructed. Using this facility, relatively thin (1 mm) mullite and alumina substrates were successfully dip-coated with 2.5 - 3.0 ohm-cm, p-type silicon with areas of approximately 20 sq cm. The thickness and grain size of these coatings are influenced by the temperature of the melt and the rate at which the substrate is pulled from the melt. One mullite substrate had dendrite-like crystallites of the order of 1 mm wide and 1 to 2 cm long. Their axes were aligned along the direction of pulling. A large variety of substrate materials were purchased or developed enabling the program to commence a substrate definition evaluation. Due to the insulating nature of the substrate, the bottom layer of the p-n junction may have to be made via the top surface. The feasibility of accomplishing this was demonstrated using single crystal wafers.

Heaps, J. D.↗
NASA NTRS1976

Laser-zone growth in a Ribbon-To-Ribbon (RTR) process, silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

The objective of this research is to fully investigate the Ribbon-To-Ribbon (R-T-R) approach to silicon ribbon growth. Initial work has concentrated on modification and characterization of an existing R-T-R apparatus. In addition, equipment for auxiliary heating of the melt is being evaluated and acquired. Modification of the remote viewing system and mechanical staging are nearly complete. Characterization of the laser and other components is in progress and several auxiliary heating techniques are being investigated.

Gurtler, R. W.↗