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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 design, fabrication, test, and qualification of a third generation intermediate load solar cell module are presented. A technical discussion of the detailed module design, preliminary design review, design modifications, and environmental testing are included. A standardized pricing system is utilized to establish the cost competitiveness of this module design.
This report discusses the design, development, fabrication and testing of IR transparent solar array modules. Three modules, consisting of a baseline design using back surface reflector cells, and two modules using gridded back contact, IR transparent cells, were subjected to vacuum thermal balance testing to verify analytical predictions of lower operating emperature and increased efficiency. As a result of this test program, LMSC has verified that a significant degree of IR transparency can be designed into a flexible solar array. Test data correlates with both steady state and transient thermal analysis.
Efforts to model and simulate the Solar Dynamic Power Module (SDPM) for the Space Station are discussed. The SDPM configuration is given and the SDPM subsytems are described, including the concentrator assembly, the fine pointing and tracking system, the power generation system, the heat rejection assembly, the electrical equipment, the interface structure and integration hardware, and the beta gimbal assembly. Performance requirements and design considerations are given. The development of models to simulate the SDPM is examined, noting research on models such as the Electric Power System Transient Analysis Model, the Electric Power System on Orbit Performance model, and a spatial flux distribution function.
Requirements for performance of terrestrial solar cell modules intended for use in various test applications are established. During the 1979-80 time period, such applications are expected to be in the 20 to 500 kilowatt size range. A series of characterization and qualification tests necessary to certify the module design for production, and the necessary performance test for acceptance of modules are specified.
The photodegradation of synthetic polymers, used as pottants and/or cover sheets in the FSA solar cell module designs, is modeled.
A cost effective design and manufacturing process which would produce solar cell modules capable of meeting qualification test criteria was developed. Emphasis was placed on the development of an aluminum paste back contact process.
Observations of cosmic-ray helium energy spectra provide important constraints on cosmic ray origin and propagation. However, helium intensities measured at Earth are affected by solar modulation, especially below several GeV/nucleon. Observations of helium intensities over a solar cycle are important for understanding how solar modulation affects galactic cosmic ray intensities and for separating the contributions of anomalous and galactic cosmic rays. The Cosmic Ray Isotope Spectrometer (CRIS) on ACE has been measuring cosmic ray isotopes, including helium, since 1997 with high statistical precision. We present helium elemental intensities between approx. 10 to approx. 100 MeV/nucleon from the Solar Isotope Spectrometer (SIS) and CRIS observations over a solar cycle and compare these results with the observations from other satellite and balloon-borne instruments, and with GCR transport and solar modulation models.
Solar cycle time variations in trapped radiation belt proton flux, deriving proton transport equation from Boltzmann equation
Two programmable, high voltage DC power supplies were developed as part of the flight electronics for the Solar Array Module Plasma Interaction Experiment (SAMPIE). SAMPIE's primary objectives were to study and characterize the high voltage arcing and parasitic current losses of various solar cells and metal samples within the space plasma of low earth orbit (LEO). High voltage arcing can cause large discontinuous changes in spacecraft potential which lead to damage of the power system materials and significant Electromagnetic Interference (EMI). Parasitic currents cause a change in floating potential which lead to reduced power efficiency. These primary SAMPIE objectives were accomplished by applying artificial biases across test samples over a voltage range from -600 VDC to +300 VDC. This paper chronicles the design, final development, and test of the two programmable high voltage sources for SAMPIE. The technical challenges to the design for these power supplies included vacuum, space plasma effects, thermal protection, Shuttle vibrations and accelerations.
Measurements made with Pioneers 10 and 11 over the radial range of 1 to about 25 AU from 1972 to 1981 are presented to show that at solar minimum (1972-1977), the radial gradient for the anomalous helium component from 11 to 20 MeV/n is about 14%/AU. This result is significantly smaller than that predicted for either charge state of the component based on the observed spectrum and assumptions of conventional solar modulation for particles propagating inward from the heliospheric boundary. It is confirmed that the solar modulation mechanism that determines the level and distribution of low-energy galactic cosmic rays in the heliosphere, also modulates the He(A) spectrum. With increasing modulation between solar minimum and maximum, the 10-20 MeV/n He(A) flux decreases below the flux of modulated galactic He first at 1 AU and then progressively outward to 22-25 AU over an approximately two year period.
A progress report, starting with November 1973, is given in the design, development, and performance of lightweight flexible FET (Fluorinated Ethylene Propylene) encapsulated solar cell modules intended to form standardized building blocks for large roll-up or fold-up solar cell blankets with performances on the order of 100 W/sq m and 80 W/kg in near space. It is shown that interconnected FEP encapsulated modules of advanced design can withstand all typical ground handling, assembly, storage, and launch conditions, and are well suited for high-power space applications.
Solar modulating function form changes resulting in hysteresis near solar minimum
Near-term design, qualification and acceptance requirements are provided for terrestrial solar cell modules suitable for incorporation in photovoltaic power sources (2 kW to 10 kW) applied to single family residential installations. Requirement levels and recommended design limits for selected performance criteria are specified for modules intended principally for rooftop installations. Modules satisfying the requirements of this specification fall into one of two categories, residential panel or residential shingle, both meeting general performance requirements plus additional category peculiar constraints.
NASA-LeRC has conducted outdoor endurance tests on modules commercially produced as part of the 46-kW purchase of first generation (Block I) modules by the JPL Low Cost Silicon Solar Array Project. Block I modules from four manufacturers were installed at commercial testing sites in Florida, Puerto Rico, and Arizona and at noncommercial sites in Cleveland, Ohio. The conditions endured by these modules included hot and dry, hot and humid, tropical rain forest, sea-air, urban industrial and urban clean; exposures were for periods up to one year. Test results are presented and discussed.
The design, development, fabrication and tests of flexible integrated thin-film cadmium sulfide solar cells and modules are discussed. The development of low cost and high production rate methods for interconnecting cells into large solar arrays is described. Chromium thin films were applied extensively in the deposited cell structures as a means to: (1) achieve high adherence between the cadmium sulfide films and the vacuum-metallized copper substrates, (2) obtain an ohmic contact to the cadmium sulfide films, and (3) improve the adherence of gold films as grids or contact areas.
Digital regulated solar array module and performance characteristics of its electronic circuits
The paper presents the findings of material surveys intended to identify low cost materials which could be functional as encapsulants (by 1986) for terrestrial solar cell modules. Economic analyses have indicated that in order to meet the low cost goal of $2.70 per sq m, some or all of the following material technologies must be developed or advanced: (1) UV screening outer covers; (2) elastomeric acrylics; (3) weatherproofing and waterproofing of structural wood and paper products; (4) transparent UV stabilizers for the UV-sensitive transparent pottants; and (5) cost-effective utilization of silicone and fluorocarbon materials.
Soldering or epoxy bonding of cadmium sulfide thin film solar cells into modules and quality control testing