Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Degroh, Kim K.; Banks, Bruce A.; Smith, Daniela C.

1994-01-01

Space solar power systems for use in the low Earth orbit (LEO) environment experience a variety of harsh environmental conditions. Materials used for solar power generation in LEO need to be durable to environmental threats such as atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeoroid and debris impact. Another threat to LEO solar power performance is due to contamination from other spacecraft components. This paper gives an overview of these LEO environmental issues as they relate to space solar power system materials. Issues addressed include atomic oxygen erosion of organic materials, atomic oxygen undercutting of protective coatings, UV darkening of ceramics, UV embrittlement of Teflon, effects of thermal cycling on organic composites, and contamination due to silicone and organic materials. Specific examples of samples from the Long Duration Exposure Facility (LDEF) and materials returned from the first servicing mission of the Hubble Space Telescope (HST) are presented. Issues concerning ground laboratory facilities which simulate the LEO environment are discussed along with ground-to-space correlation issues.

Sail film materials and supporting structure for a solar sail, a preliminary design, volume 4

NASA Technical Reports Server (NTRS)

Rowe, W. M. (Editor)

1978-01-01

Solar sailing technology was examined in relation to a mission to rendezvous with Halley's Comet. Development of an ultra-light, highly reflecting material system capable of operating at high solar intensity for long periods of time was emphasized. Data resulting from the sail materials study are reported. Topics covered include: basic film; coatings and thermal control; joining and handling; system performance; and supporting structures assessment for the heliogyro.

Organic Chemistry: From the Interstellar Medium to the Solar System

NASA Technical Reports Server (NTRS)

Sandford, Scott; Witteborn, Fred C. (Technical Monitor)

1997-01-01

This talk will review the various types of organic materials observed in different environments in the interstellar medium, discuss the processes by which these materials may have formed and been modified, and present the evidence supporting the contention that at least a fraction of this material survived incorporation, substantially unaltered, into our Solar System during its formation. The nature of this organic material is of direct interest to issues associated with the origin of life, both because this material represents a large fraction of the Solar System inventory of the biogenically-important elements, and because many of the compounds in this inventory have biogenic implications. Several specific examples of such molecules will be briefly discussed.

Technology assessment of solar-energy systems. Materials resource and hazardous materials impacts of solar deployment

NASA Astrophysics Data System (ADS)

Schiffman, Y. M.; Tahami, J. E.

1982-04-01

The materials-resource and hazardous-materials impacts were determined by examining the type and quantity of materials used in the manufacture, construction, installation, operation and maintenance of solar systems. The materials requirements were compared with US materials supply and demand data to determine if potential problems exist in terms of future availability of domestic supply and increased dependence on foreign sources of supply. Hazardous materials were evaluated in terms of public and occupational health hazards and explosive and fire hazards. It is concluded that: although large amounts of materials would be required, the US had sufficient industrial capacity to produce those materials; (2) postulated growth in solar technology deployment during the period 1995-2000 could cause some production shortfalls in the steel and copper industry; the U.S. could increase its import reliance for certain materials such as silver, iron ore, and copper; however, shifts to other materials such as aluminum and polyvinylchloride could alleviate some of these problems.

Lightweight Phase-Change Material For Solar Power

NASA Technical Reports Server (NTRS)

Stark, Philip

1993-01-01

Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

75 FR 61509 - Notice of Issuance of Final Determination Concerning Solar Photovoltaic Panel Systems

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... solar photovoltaic (``PV'') panel systems contain both U.S. and foreign-origin raw materials and... of origin of the solar PV panel system described above for the purposes of U.S. government... transformation has occurred; however, no one factor is determinative. In this case, the solar PV systems are...

Performance prediction evaluation of ceramic materials in point-focusing solar receivers

NASA Technical Reports Server (NTRS)

Ewing, J.; Zwissler, J.

1979-01-01

A performance prediction was adapted to evaluate the use of ceramic materials in solar receivers for point focusing distributed applications. System requirements were determined including the receiver operating environment and system operating parameters for various engine types. Preliminary receiver designs were evolved from these system requirements. Specific receiver designs were then evaluated to determine material functional requirements.

Third Working Meeting on Gallium Arsenide Solar Cells

NASA Technical Reports Server (NTRS)

Walker, G. H. (Compiler)

1976-01-01

Research results are reported for GaAs Schottky barrier solar cells, GaAlAs/GaAs heteroface solar cells, and GaAlAs graded band gap solar cells. Related materials studies are presented. A systems study for GaAs and Si solar concentrator systems is given.

In situ Probe Science at Saturn

NASA Technical Reports Server (NTRS)

Atkinson, D.H.; Lunine, J.I.; Simon-Miller, A. A.; Atreya, S. K.; Brinckerhoff, W.; Colaprete, A.; Coustenis, A.; Fletcher, L. N.; Guillot, T.; Lebreton, J.-P.;

Homemade Solar Systems

NASA Technical Reports Server (NTRS)

1981-01-01

Through the use of NASA Tech Briefs, Peter Kask, was able to build a solarized domestic hot water system. Also by applying NASA's solar energy design information, he was able to build a swimming pool heating system with minimal outlay for materials.

Solar energy

NASA Technical Reports Server (NTRS)

Rapp, D.

1981-01-01

The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

Solar Energy: Solar System Economics.

ERIC Educational Resources Information Center

Knapp, Henry H., III

This module on solar system economics is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies.…

Solar Energy: Solar System Design Fundamentals.

ERIC Educational Resources Information Center

Knapp, Henry H., III

This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…

Some potential material supply constraints in solar systems for heating and cooling of buildings and process heat. (A preliminary screening to identify critical materials)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watts, R.L.; Gurwell, W.E.; Nelson, T.A.

1979-06-01

Nine Solar Heating and Cooling of Buildings (SHACOB) designs and three Agricultural and Industrial Process Heat (AIPH) designs have been studied to identify potential future material constraints to their large scale installation and use. The nine SHACOB and three AIPH systems were screened and found to be free of serious future material constraints. The screening was carried out for each individual system design assuming 500 million m/sup 2/ of collector area installed by the year 2000. Also, two mixed design scenarios, containing equal portions of each system design, were screened. To keep these scenarios in perspective, note that a billionmore » m/sup 2/ containing a mixture of the nine SHACOB designs will yield an annual solar contribution of about 1.3 Quads or will displace about 4.2 Quads of fossil fuel used to generate electricity. For AIPH a billion square meters of the mixed designs will yield about 2.8 Quads/year. Three materials were identified that could possibly restrain the deployment of solar systems in the specific scenarios investigated. They are iron and steel, soda lime glass and polyvinyl fluoride. All three of these materials are bulk materials. No raw material supply constraints were found.« less

Constraints on the Detection of the Solar Nebula's Oxidation State Through Asteroid Observations

NASA Technical Reports Server (NTRS)

Abell, P. A.; Gaffey, M. J.; Hardersen, P. S.

2005-01-01

Introduction: Asteroids represent the only in situ surviving population of planetesimals from the formation of the inner solar system and therefore include materials from the very earliest stages of solar system formation. Hence, these bodies can provide constraints on the processes and conditions that were present during this epoch and can be used to test current models and theories describing the late solar nebula, the early solar system and subsequent planetary accretion. From detailed knowledge of asteroid mineralogic compositions the probable starting materials, thermal histories, and oxidation states of asteroid parent bodies can be inferred. If such data can be obtained from specific mainbelt source regions, then this information can be used to map out the formation conditions of the late solar nebula within the inner solar system and possibly distinguish any trends in oxidation state that may be present.

Aperture Shield Materials Characterized and Selected for Solar Dynamic Space Power System

NASA Technical Reports Server (NTRS)

1995-01-01

The aperture shield in a solar dynamic space power system is necessary to prevent thermal damage to the heat receiver should the concentrated solar radiation be accidentally or intentionally focused outside of the heat receiver aperture opening and onto the aperture shield itself. Characterization of the optical and thermal properties of candidate aperture shield materials was needed to support the joint U.S./Russian solar dynamic space power effort for Mir. The specific objective of testing performed at the NASA Lewis Research Center was to identify a high-temperature material with a low specular reflectance, a low solar absorptance, and a high spectral emittance so that during an off-pointing event, the amount of solar energy reflecting off the aperture shield would be small, the ratio of solar absorptance to spectral emittance would provide the lowest possible equilibrium temperature, and the integrity of the aperture shield would remain intact.

Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators.

PubMed

Good, Philipp; Cooper, Thomas; Querci, Marco; Wiik, Nicolay; Ambrosetti, Gianluca; Steinfeld, Aldo

2016-03-01

The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300-2500 nm at incidence angles 15-60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0-60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350-1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article "Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators" in Solar Energy Materials and Solar Cells.

Absolute and Mass-Dependent Titanium Isotope Compositions of Solar System Materials

NASA Astrophysics Data System (ADS)

Williams, N. H.; Fehr, M. A.; Akram, W. M.; Parkinson, I. J.; Schönbächler, M.

2013-09-01

Mass dependent Ti isotope data for various solar system material will be presented. This data has been obtained via double spike technique using ^47 Ti and ^49Ti as spikes. Absolute nucleosynthetic anomalie data for Ti will be presented also.

Bionics in textiles: flexible and translucent thermal insulations for solar thermal applications.

PubMed

Stegmaier, Thomas; Linke, Michael; Planck, Heinrich

2009-05-13

Solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. Based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. The developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. For incident light of the visible spectrum the system is translucent, but impermeable for ultraviolet radiation. Owing to its structure it shows a reduced heat loss by convection. Heat loss by the emission of long-wave radiation can be prevented by a suitable low-emission coating. Suitable treatment of the silicone surface protects it against soiling. In combination with further insulation materials and flow systems, complete flexible solar collector systems are in development.

From Dust to Planets: The Tale Told by Moderately Volatile Element Depletion (MOVED)

NASA Technical Reports Server (NTRS)

Yin, Qing-Zhu

2004-01-01

The pronounced depletion of moderately volatile elements (MOVE, that condense or evaporate at temperatures in the range 1350-650K) relative to the average solar composition is a characteristic feature in most primitive chondrites and bulk terrestrial planets. It differs from the composition of the Sun and from the materials further away from the Sun (CI chondrites). None of the remaining planets or even meteorites shows an enrichment of volatile elements that would balance the depletion in the inner Solar System. Whether this depletion occurred in solar nebular stage or in planetary formation stage has been the subject of long lasting debate. The search for mysterite initiated in 1973 continues today in search of lost planets. Here I show that the MOVED patterns demonstrate a clear connection between the rocky materials of the inner solar system and the interstellar dust. The inheritance of interstellar materials by the solar system is not only documented by the presence of presolar grains, various isotopic anomalies, but also expressed in the chemical element distribution in the inner solar system.

Early Solar System Alkali Fractionation Events Recorded by K-Ca Isotopes in the Yamato-74442 LL-Chondritic Breccia

NASA Technical Reports Server (NTRS)

Tatsunori, T.; Misawa, K.; Okano, O.; Shih, C.-Y.; Nyquist, L. E.; Simon, J. I.; Tappa, M. J.; Yoneda, S.

2015-01-01

Radiogenic ingrowth of Ca-40 due to decay of K-40 occurred early in the solar system history causing the Ca-40 abundance to vary within different early-former reservoirs. Marshall and DePaolo ] demonstrated that the K-40/Ca-40 decay system could be a useful radiogenic tracer for studies of terrestrial rocks. Shih et al. [3,4] determined 40K/40Ca ages of lunar granitic rock fragments and discussed the chemical characteristics of their source materials. Recently, Yokoyama et al. [5] showed the application of the K-40/Ca-40 chronometer for high K/Ca materials in ordinary chondrites (OCs). High-precision calcium isotopic data are needed to constrain mixing processes among early solar system materials and the time of planetesimal formation. To better constrain the solar system calcium isotopic compositions among astromaterials, we have determined the calcium isotopic compositions of OCs and an angrite. We further estimated a source K/Ca ratio for alkali-rich fragments in a chondritic breccia using the estimated solar system initial Ca-40/Ca-44.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites.

PubMed

Van Kooten, Elishevah M M E; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Larsen, Kirsten K; Olsen, Mia B; Nordlund, Åke; Krot, Alexander N; Bizzarro, Martin

2016-02-23

The short-lived (26)Al radionuclide is thought to have been admixed into the initially (26)Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent (54)Cr and (26)Mg*, the decay product of (26)Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling (26)Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived (26)Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a (26)Mg*-depleted and (54)Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived (26)Al. The (26)Mg* and (54)Cr compositions of bulk metal-rich chondrites require significant amounts (25-50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites

PubMed Central

Van Kooten, Elishevah M. M. E.; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Olsen, Mia B.; Nordlund, Åke; Krot, Alexander N.; Bizzarro, Martin

2016-01-01

The short-lived 26Al radionuclide is thought to have been admixed into the initially 26Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent 54Cr and 26Mg*, the decay product of 26Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling 26Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived 26Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a 26Mg*-depleted and 54Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived 26Al. The 26Mg* and 54Cr compositions of bulk metal-rich chondrites require significant amounts (25–50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants. PMID:26858438

Electrical research on solar cells and photovoltaic materials

NASA Technical Reports Server (NTRS)

Orehotsky, J.

1984-01-01

The flat-plate solar cell array program which increases the service lifetime of the photovoltaic modules used for terrestrial energy applications is discussed. The current-voltage response characteristics of the solar cells encapsulated in the modules degrade with service time and this degradation places a limitation on the useful lifetime of the modules. The most desirable flat-plate array system involves solar cells consisting of highly polarizable materials with similar electrochemical potentials where the cells are encapsulated in polymers in which ionic concentrations and mobilities are negligibly small. Another possible mechanism limiting the service lifetime of the photovoltaic modules is the gradual loss of the electrical insulation characteristics of the polymer pottant due to water absorption or due to polymer degradation from light or heat effects. The mechanical properties of various polymer pottant materials and of electrochemical corrosion mechanisms in solar cell material are as follows: (1) electrical and ionic resistivity; (2) water absorption kinetics and water solubility limits; and (3) corrosion characterization of various metallization systems used in solar cell construction.

Ice from the Solar System Edge Artist Concept

NASA Image and Video Library

2012-09-18

Researchers are brewing up icy, organic concoctions in the lab to mimic materials at the edge of our solar system and beyond. The lab is shown at right, and a very young solar system, with its swirling planet-forming disk is at left.

Materials compatibility issues related to thermal energy storage for a space solar dynamic power system

NASA Technical Reports Server (NTRS)

Faget, N. M.

1986-01-01

Attention is given to results obtained to date in developmental investigations of a thermal energy storage (TES) system for the projected NASA Space Station's solar dynamic power system; these tests have concentrated on issues related to materials compatibility for phase change materials (PCMs) and their containment vessels' materials. The five PCMs tested have melting temperatures that correspond to the operating temperatures of either the Brayton or Rankine heat engines, which were independently chosen for their high energy densities.

Potential Nucleosynthetic Sources of the Titanium Isotope Variations in Solar System Materials

NASA Astrophysics Data System (ADS)

Williams, N. H.; Fehr, M. A.; Akram, W. M.; Parkinson, I. J.; Schönbächler, M.

2012-09-01

The Ti isotope ratios of a comprehensive sample suite of solar system material were analyzed by MC-ICPMS. This data was then used to evaluate nucleosynthetic models for the source of isotopic correlations observed in Iron group elements and Zr.

Cryovolcanism in the outer solar system

USGS Publications Warehouse

Geissler, Paul E.

2015-01-01

Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout the outer solar system. This chapter examines the mechanisms and manifestations of cryovolcanism, beginning with a review of the materials that make up these unusual ‘‘magmas’’ and the means by which they might erupt and concluding with a volcanologist's tour of the farthest reaches of the solar system.

Space-based solar power conversion and delivery systems study. Volume 4: Energy conversion systems studies

NASA Technical Reports Server (NTRS)

1977-01-01

Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.

Evidence for supernova injection into the solar nebula and the decoupling of r-process nucleosynthesis

PubMed Central

Brennecka, Gregory A.; Borg, Lars E.; Wadhwa, Meenakshi

2013-01-01

The isotopic composition of our Solar System reflects the blending of materials derived from numerous past nucleosynthetic events, each characterized by a distinct isotopic signature. We show that the isotopic compositions of elements spanning a large mass range in the earliest formed solids in our Solar System, calcium–aluminum-rich inclusions (CAIs), are uniform, and yet distinct from the average Solar System composition. Relative to younger objects in the Solar System, CAIs contain positive r-process anomalies in isotopes A < 140 and negative r-process anomalies in isotopes A > 140. This fundamental difference in the isotopic character of CAIs around mass 140 necessitates (i) the existence of multiple sources for r-process nucleosynthesis and (ii) the injection of supernova material into a reservoir untapped by CAIs. A scenario of late supernova injection into the protoplanetary disk is consistent with formation of our Solar System in an active star-forming region of the galaxy. PMID:24101483

Evidence for supernova injection into the solar nebula and the decoupling of r-process nucleosynthesis.

PubMed

Brennecka, Gregory A; Borg, Lars E; Wadhwa, Meenakshi

2013-10-22

The isotopic composition of our Solar System reflects the blending of materials derived from numerous past nucleosynthetic events, each characterized by a distinct isotopic signature. We show that the isotopic compositions of elements spanning a large mass range in the earliest formed solids in our Solar System, calcium-aluminum-rich inclusions (CAIs), are uniform, and yet distinct from the average Solar System composition. Relative to younger objects in the Solar System, CAIs contain positive r-process anomalies in isotopes A < 140 and negative r-process anomalies in isotopes A > 140. This fundamental difference in the isotopic character of CAIs around mass 140 necessitates (i) the existence of multiple sources for r-process nucleosynthesis and (ii) the injection of supernova material into a reservoir untapped by CAIs. A scenario of late supernova injection into the protoplanetary disk is consistent with formation of our Solar System in an active star-forming region of the galaxy.

Solar Heating Systems: Instructor's Guide.

ERIC Educational Resources Information Center

Green, Joanne; And Others

This Instructor's Guide for a Solar Heating System Curriculum is designed to accompany the Student Manual and the Progress Checks and Test Manual for the course (see note), in order to facilitate the instruction of classes on solar heating systems. The Instructor's Guide contains a variety of materials used in teaching the courses, including…

Problem of nature of inert gases in lunar surface material

NASA Technical Reports Server (NTRS)

Levskiy, L. K.

1974-01-01

The origin of isotopes of inert gases in lunar surface material was investigated from the standpoint of the isotopic two-component status of inert gases in the solar system. Helium and neon represent the solar wind component, while krypton and xenon are planetary gases. Type A gases are trapped by the material of the regolith in the early stages of the existence of the solar system and were brought to the lunar surface together with dust. The material of the regolith therefore cannot be considered as the product of the erosion of the crystalline rocks of the moon and in this sense are extralunar. The regolith material containing type A gases must be identified with the high temperature minerals of the carbonaceous chondrites.

Selection and Manufacturing of Membrane Materials for Solar Sails

NASA Technical Reports Server (NTRS)

Bryant, Robert G.; Seaman, Shane T.; Wilkie, W. Keats; Miyaucchi, Masahiko; Working, Dennis C.

2013-01-01

Commercial metallized polyimide or polyester films and hand-assembly techniques are acceptable for small solar sail technology demonstrations, although scaling this approach to large sail areas is impractical. Opportunities now exist to use new polymeric materials specifically designed for solar sailing applications, and take advantage of integrated sail manufacturing to enable large-scale solar sail construction. This approach has, in part, been demonstrated on the JAXA IKAROS solar sail demonstrator, and NASA Langley Research Center is now developing capabilities to produce ultrathin membranes for solar sails by integrating resin synthesis with film forming and sail manufacturing processes. This paper will discuss the selection and development of polymer material systems for space, and these new processes for producing ultrathin high-performance solar sail membrane films.

Chemical aspects of the formation of the solar system

NASA Technical Reports Server (NTRS)

Arrhenius, G.

1978-01-01

Application of Alfven's theory for the formation of the solar system and the constraints imposed by the chemical composition of space materials are discussed with reference to chemical processes involved in the formation of the solar system. Evidence for the chemical properties of the space medium and the chemical consequences of the postulated physical differentiation processes are outlined, and interpretations based on structure and composition of meteorite material are indicated. A large range of topics, including processes involving chemical differentiation, temperature effects, and isotope fractionation, are examined.

Solar probe shield developmental testing

NASA Technical Reports Server (NTRS)

Miyake, Robert N.

1991-01-01

The objectives of the Solar Probe mission and the current status of the Solar Probe thermal shield subsystem development are described. In particular, the discussion includes a brief description of the mission concepts, spacecraft configuration and shield concept, material selection criteria, and the required material testing to provide a database to support the development of the shield system.

SWCX Emission from the Helium Focusing Cone - Preliminary Results

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Kuntz, K. D.; Collier, M. R.

2008-01-01

Preliminary results from an XMM-Newton campaign to study solar wind charge exchange (SWCX) emission from the heliospheric focusing cone of interstellar helium are presented. The detections of enhanced O VII and O VIII emission from the cone are at the 2(sigma) and 4(sigma) levels. The solar wind charge exchange (SWCX) emission in the heliosphere not associated with distinct objects (e.g., comets and planets including exospheric material in and near Earth s magnetosheath) is proportional to the flux of the solar wind and the space density of neutral material. The neutral material originates in the interstellar medium (ISM) and passes through the solar system due to the relative motion of the Sun and the ISM. The flow of the neutral material through the solar system is strongly perturbed by the Sun both by gravity and by radiation pressure. Because of the relative radiative scattering cross sections and the effect of solar gravitation the density of interstellar hydrogen near the Sun is reduced while interstellar helium is gravitationally focused. This creates a helium focusing cone downstream of the Sun [e.g., 1, and references therein].

DOE Office of Scientific and Technical Information (OSTI.GOV)

Litchfield, J.W.; Watts, R.L.; Gurwell, W.E.

A materials assessment methodology for identifying specific critical material requirements that could hinder the implementation of solar energy has been developed and demonstrated. The methodology involves an initial screening process, followed by a more detailed materials assessment. The detailed assessment considers such materials concerns and constraints as: process and production constraints, reserve and resource limitations, lack of alternative supply sources, geopolitical problems, environmental and energy concerns, time constraints, and economic constraints. Data for 55 bulk and 53 raw materials are currently available on the data base. These materials are required in the example photovoltaic systems. One photovoltaic system and thirteenmore » photovoltaic cells, ten solar heating and cooling systems, and two agricultural and industrial process heat systems have been characterized to define their engineering and bulk material requirements.« less

Interstellar and Solar Nebula Materials in Cometary Dust

NASA Technical Reports Server (NTRS)

Messenger, Scott; Nakamura-Messenger, Keiko; Keller, Lindsay; Nguyen, Ann; Clemett, Simon

2017-01-01

Laboratory studies of cometary dust collected in the stratosphere and returned from comet 81P/Wild 2 by the Stardust spacecraft have revealed ancient interstellar grains and molecular cloud organic matter that record a range of astrophysical processes and the first steps of planetary formation. Presolar materials are rarer meteorites owing to high temperature processing in the solar nebula and hydrothermal alteration on their asteroidal parent bodies. The greater preservation of presolar materials in comets is attributed to their low accretion temperatures and limited planetary processing. Yet, comets also contain a large complement of high temperature materials from the inner Solar System. Owing to the limited and biased sampling of comets to date, the proportions of interstellar and Solar System materials within them remains highly uncertain. Interstellar materials are identified by coordinated isotopic, mineralogical, and chemical measurements at the scale of individual grains. Chondritic porous interplanetary dust particles (CP IDPs) that likely derive from comets are made up of 0.1 - 10 micron-sized silicates, Fe-Ni-sulfides, oxides, and other phases bound by organic material. As much as 1% of the silicates are interstellar grains that have exotic isotopic compositions imparted by nucleosynthetic processes in their parent stars. Crystalline silicates in CP IDPs dominantly have normal isotopic compositions and probably formed in the Solar System. 81P samples include isotopically normal refractory minerals that resemble Ca-Al rich inclusions and chondrules common in meteorites. The origins of sub-micron amorphous silicates in IDPs are not certain, but at least a few % of them are interstellar grains. The remainder have isotopic compositions consistent with Solar System origins and elemental compositions that are inconsistent with interstellar grain properties, thus favoring formation in the solar nebula [4]. The organic component in comets and primitive meteorites has large enrichments in D/H and N-15/N-14 relative to terrestrial materials. These isotopic signatures are probably due to low temperature chemical processes in cold molecular clouds or the outermost reaches of the protoplanetary disk. The greatest isotopic anomalies are found in sub-micron organic nanoglobules that show chemical signatures of interstellar chemistry. The observation that cometary dust is mostly composed of isotopically normal minerals within isotopically anomalous organic matter is difficult to reconcile with the formation models of each component. The mineral component likely formed in high temperature processes in the inner Solar System, while the organic fraction shows isotopic and chemical signatures of formation near 10 K. Studying more primitive remnants of the Solar System starting materials would help in resolving this paradox. Comets formed across a vast expanse of the outer disk under differing thermal and collisional regimes, and some are likely to be better preserved than others. Finding truly pristine aggregates of presolar materials may require return of a pristine sample of comet nucleus material.

How to harvest efficient laser from solar light

NASA Astrophysics Data System (ADS)

Zhao, Changming; Guan, Zhe; Zhang, Haiyang

2018-02-01

Solar Pumped Solid State Lasers (SPSSL) is a kind of solid state lasers that can transform solar light into laser directly, with the advantages of least energy transform procedure, higher energy transform efficiency, simpler structure, higher reliability, and longer lifetime, which is suitable for use in unmanned space system, for solar light is the only form of energy source in space. In order to increase the output power and improve the efficiency of SPSSL, we conducted intensive studies on the suitable laser material selection for solar pump, high efficiency/large aperture focusing optical system, the optimization of concave cavity as the second focusing system, laser material bonding and surface processing. Using bonded and grooved Nd:YAG rod as laser material, large aperture Fresnel lens as the first stage focusing element, concave cavity as the second stage focusing element, we finally got 32.1W/m2 collection efficiency, which is the highest collection efficiency in the world up to now.

Solar industrial process heat systems: An assessment of standards for materials and components

NASA Astrophysics Data System (ADS)

Rossiter, W. J.; Shipp, W. E.

1981-09-01

A study was conducted to obtain information on the performance of materials and components in operational solar industrial process heat (PH) systems, and to provide recommendations for the development of standards including evaluative test procedures for materials and components. An assessment of the needs for standards for evaluating the long-term performance of materials and components of IPH systems was made. The assessment was based on the availability of existing standards, and information obtained from a field survey of operational systems, the literature, and discussions with individuals in the industry. Field inspections of 10 operational IPH systems were performed.

Lunar and Planetary Science XXXV: Special Session: Oxygen in the Solar System, I

NASA Technical Reports Server (NTRS)

2004-01-01

The Special Session: Oxygen in the Solar System, I, included the following reports:Oxygen in the Solar System: Origins of Isotopic and Redox Complexity; The Origin of Oxygen Isotope Variations in the Early Solar System; Solar and Solar-Wind Oxygen Isotopes and the Genesis Mission; Solar 18O/17O and the Setting for Solar Birth; Oxygen Isotopes in Early Solar System Materials: A Perspective Based on Microbeam Analyses of Chondrules from CV Carbonaceous Chondrites; Insight into Primordial Solar System Oxygen Reservoirs from Returned Cometary Samples; Tracing Meteorites to Their Sources Through Asteroid Spectroscopy; Redox Conditions Among the Terrestrial Planets; Redox Complexity in Martian Meteorites: Implications for Oxygen in the Terrestrial Planets; Implications of Sulfur Isotopes for the Evolution of Atmospheric Oxygen; Oxygen in the Outer Solar System; and On the Oxidation States of the Galilean Satellites: Implications for Internal Structures.

Research and Development for Novel Thermal Energy Storage Systems (TES) for Concentrating Solar Power (CSP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faghri, Amir; Bergman, Theodore L; Pitchumani, Ranga

2013-09-26

The overall objective was to develop innovative heat transfer devices and methodologies for novel thermal energy storage systems for concentrating solar power generation involving phase change materials (PCMs). Specific objectives included embedding thermosyphons and/or heat pipes (TS/HPs) within appropriate phase change materials to significantly reduce thermal resistances within the thermal energy storage system of a large-scale concentrating solar power plant and, in turn, improve performance of the plant. Experimental, system level and detailed comprehensive modeling approaches were taken to investigate the effect of adding TS/HPs on the performance of latent heat thermal energy storage (LHTES) systems.

Chemical Signatures of Interstellar Dusts Preserved in Primitive Chondrites and Inner Planets of the Solar System

NASA Technical Reports Server (NTRS)

Yin, Qing-Zhu

2002-01-01

We show that the inheritance of interstellar materials by the solar system is not only documented by the presence of presolar grains, various isotopic anomalies, but also expressed in the chemical element distribution in the inner solar system. Additional information is contained in the original extended abstract.

Inner solar system material discovered in the Oort cloud

PubMed Central

Meech, Karen J.; Yang, Bin; Kleyna, Jan; Hainaut, Olivier R.; Berdyugina, Svetlana; Keane, Jacqueline V.; Micheli, Marco; Morbidelli, Alessandro; Wainscoat, Richard J.

2016-01-01

We have observed C/2014 S3 (PANSTARRS), a recently discovered object on a cometary orbit coming from the Oort cloud that is physically similar to an inner main belt rocky S-type asteroid. Recent dynamical models successfully reproduce the key characteristics of our current solar system; some of these models require significant migration of the giant planets, whereas others do not. These models provide different predictions on the presence of rocky material expelled from the inner solar system in the Oort cloud. C/2014 S3 could be the key to verifying these predictions of the migration-based dynamical models. Furthermore, this object displays a very faint, weak level of comet-like activity, five to six orders of magnitude less than that of typical ice-rich comets on similar Orbits coming from the Oort cloud. For the nearly tailless appearance, we are calling C/2014 S3 a Manx object. Various arguments convince us that this activity is produced by sublimation of volatile ice, that is, normal cometary activity. The activity implies that C/2014 S3 has retained a tiny fraction of the water that is expected to be present at its formation distance in the inner solar system. We may be looking at fresh inner solar system Earth-forming material that was ejected from the inner solar system and preserved for billions of years in the Oort cloud. PMID:27386512

Inner solar system material discovered in the Oort cloud.

PubMed

Meech, Karen J; Yang, Bin; Kleyna, Jan; Hainaut, Olivier R; Berdyugina, Svetlana; Keane, Jacqueline V; Micheli, Marco; Morbidelli, Alessandro; Wainscoat, Richard J

2016-04-01

We have observed C/2014 S3 (PANSTARRS), a recently discovered object on a cometary orbit coming from the Oort cloud that is physically similar to an inner main belt rocky S-type asteroid. Recent dynamical models successfully reproduce the key characteristics of our current solar system; some of these models require significant migration of the giant planets, whereas others do not. These models provide different predictions on the presence of rocky material expelled from the inner solar system in the Oort cloud. C/2014 S3 could be the key to verifying these predictions of the migration-based dynamical models. Furthermore, this object displays a very faint, weak level of comet-like activity, five to six orders of magnitude less than that of typical ice-rich comets on similar Orbits coming from the Oort cloud. For the nearly tailless appearance, we are calling C/2014 S3 a Manx object. Various arguments convince us that this activity is produced by sublimation of volatile ice, that is, normal cometary activity. The activity implies that C/2014 S3 has retained a tiny fraction of the water that is expected to be present at its formation distance in the inner solar system. We may be looking at fresh inner solar system Earth-forming material that was ejected from the inner solar system and preserved for billions of years in the Oort cloud.

Solar heating and cooling technical data and systems analysis

NASA Technical Reports Server (NTRS)

Christensen, D. L.

1977-01-01

The research activities described herein were concentrated on the areas of economics, heating and cooling systems, architectural design, materials characteristics, climatic conditions, educational information packages, and evaluation of solar energy systems and components.

Solar-powered cooling system

DOEpatents

Farmer, Joseph C.

2015-07-28

A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

The Abundance and Distribution of Presolar Materials in Cluster IDPS

NASA Technical Reports Server (NTRS)

Messenger, Scott; Keller, Lindsay; Nakamura-Messenger, Keiko; Ito, Motoo

2007-01-01

Presolar grains and remnants of interstellar organic compounds occur in a wide range of primitive solar system materials, including meteorites, interplanetary dust particles (IDPs), and comet Wild-2 samples. Among the most abundant presolar phases are silicate stardust grains and molecular cloud material. However, these materials have also been susceptible to destruction and alteration during parent body and nebular processing. In addition to their importance as direct samples of remote and ancient astrophysical environments, presolar materials thus provide a measure of how well different primitive bodies have preserved the original solar system starting materials.

Observations of Isotope Fractionation in Prestellar Cores: Interstellar Origin of Meteoritic Hot Spot?

NASA Technical Reports Server (NTRS)

Milam, S. N.; Charnley, S. B.

2011-01-01

Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is thought, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing. Here, we show the results of models and observations of the nitrogen and carbon fractionation in proto-stellar cores.

Process feasibility study in support of silicon material task 1

NASA Technical Reports Server (NTRS)

Yaws, C. L.; Li, K. Y.; Hopper, J. R.; Fang, C. S.; Hansen, K. C.

1981-01-01

Results for process system properties, chemical engineering and economic analyses of the new technologies and processes being developed for the production of lower cost silicon for solar cells are presented. Analyses of process system properties are important for chemical materials involved in the several processes under consideration for semiconductor and solar cell grade silicon production. Major physical, thermodynamic and transport property data are reported for silicon source and processing chemical materials.

Dish concentrators for solar thermal energy - Status and technology development

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1981-01-01

Comparisons are presented of point-focusing, or 'dish' solar concentrator system features, development status, and performance levels demonstrated to date. In addition to the requirements of good optical efficiency and high geometric concentration ratios, the most important future consideration in solar thermal energy dish concentrator design will be the reduction of installed and lifetime costs, as well as the materials and labor costs of production. It is determined that technology development initiatives are needed in such areas as optical materials, design wind speeds and wind loads, structural configuration and materials resistance to prolonged exposure, and the maintenance of optical surfaces. The testing of complete concentrator systems, with energy-converting receivers and controls, is also necessary. Both reflector and Fresnel lens concentrator systems are considered.

Graphene-based Recyclable Photo-Absorbers for High-Efficiency Seawater Desalination.

PubMed

Wang, Xiangqing; Ou, Gang; Wang, Ning; Wu, Hui

2016-04-13

Today's scientific advances in water desalination dramatically increase our ability to transform seawater into fresh water. As an important source of renewable energy, solar power holds great potential to drive the desalination of seawater. Previously, solar assisted evaporation systems usually relied on highly concentrated sunlight or were not suitable to treat seawater or wastewater, severely limiting the large scale application of solar evaporation technology. Thus, a new strategy is urgently required in order to overcome these problems. In this study, we developed a solar thermal evaporation system based on reduced graphene oxide (rGO) decorated with magnetic nanoparticles (MNPs). Because this material can absorb over 95% of sunlight, we achieved high evaporation efficiency up to 70% under only 1 kW m(-2) irradiation. Moreover, it could be separated from seawater under the action of magnetic force by decorated with MNPs. Thus, this system provides an advantage of recyclability, which can significantly reduce the material consumptions. Additionally, by using photoabsorbing bulk or layer materials, the deposition of solutes offen occurs in pores of materials during seawater desalination, leading to the decrease of efficiency. However, this problem can be easily solved by using MNPs, which suggests this system can be used in not only pure water system but also high-salinity wastewater system. This study shows good prospects of graphene-based materials for seawater desalination and high-salinity wastewater treatment.

Reflectance spectrophotometry (about 0.5-1.0 micron) of oute-belt asteroids - Implications for primitive, organic solar system material

NASA Technical Reports Server (NTRS)

Vilas, F.; Smith, B. A.

1985-01-01

The surface compositions of outer-belt asteroids were used to obtain information about the origin of these asteroids. High-resolution CCD reflectance spectra of 21 asteroids, primarily P class, were examined for compositional information. Distinct slope changes are observed that suggest that these asteroids are the remnants of a compositional gradation of planetesimals in the outer solar system, which were retained selectively in location when other material was ejected from the solar system. Other data suggest that this gradation could extend through the orbits of Uranus and Neptune.

PROGRAM ASTEC (ADVANCED SOLAR TURBO ELECTRIC CONCEPT). PART 1. CANDIDATE MATERIALS LABORATORY TESTS

DTIC Science & Technology

A space power system of the type envisioned by the ASTEC program requires the development of a lightweight solar collector of high reflectance...capable of withstanding the space environment for an extended period. A survey of the environment of interest for ASTEC purposes revealed 4 potential...developed by the solar-collector industry for use in the ASTEC program, and to test the effects of space environment on these materials. Of 6 material

Solar home on the range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wainwright, K.

1999-10-01

Solar technologies and indigenous materials are used in this remote Texas ranch house. Passive solar, thermal mass of adobe walls, photovoltaics, wood stoves, native stone, a ventilated roof, reflective barrier, and porch overhangs surrounding the house combine to keep the house comfortable all summer. The PV system used a passive solar tracking system that increased the electrical output by an overall 29 percent.

Solar powered absorption cycle heat pump using phase change materials for energy storage

NASA Technical Reports Server (NTRS)

Middleton, R. L.

1972-01-01

Solar powered heating and cooling system with possible application to residential homes is described. Operating principles of system are defined and illustration of typical energy storage and exchange system is provided.

Decentralized solar photovoltaic energy systems

NASA Astrophysics Data System (ADS)

Krupka, M. C.

1980-09-01

Emphasis was placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ utilizing a unique solar cell array roof shingle combination. Silicon solar cells, rated at 13.5 percent efficiency at 28 C and 100 mW/sq cm insolation are used to generate 10 kW (peak). An all electric home is considered with lead acid battery storage, DC AC inversion and utility backup. The reference home is compared to others in regions of different insolation. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

An infrared search in our solar system as part of a more flexible search strategy

NASA Astrophysics Data System (ADS)

Papagiannis, M. D.

One of several explanations for the Fermi Paradox is that the whole Galaxy, including the solar system, has already been colonized, but that for a variety of reasons the extraterrestrials have chosen not to reveal their presence. IRAS has obtained a large volume of infrared data at 12, 25, 60, and 100 microns from which a special working group at JPL, is trying to establish a special catalog of solar system objects, the vast majority of which are asteroids. A careful search through this data bank for objects with peculiar infrared spectra would be the first step in the search for major artificial objects, such as space stations or materials processing plants, in the solar system. The asteroid belt is an ideal source of raw materials for space colonies, which could have easily escaped detection lost among the many thousands of natural asteroids. Checking them out for excesses in the infrared is an ideal screening test for artificial objects in the solar system.

Advanced reflector materials for solar concentrators

NASA Astrophysics Data System (ADS)

Jorgensen, Gary; Williams, Tom; Wendelin, Tim

1994-10-01

This paper describes the research and development at the US National Renewable Energy Laboratory (NREL) in advanced reflector materials for solar concentrators. NREL's research thrust is to develop solar reflector materials that maintain high specular reflectance for extended lifetimes under outdoor service conditions and whose cost is significantly lower than existing products. Much of this work has been in collaboration with private-sector companies that have extensive expertise in vacuum-coating and polymer-film technologies. Significant progress and other promising developments will be discussed. These are expected to lead to additional improvements needed to commercialize solar thermal concentration systems and make them economically attractive to the solar manufacturing industry. To explicitly demonstrate the optical durability of candidate reflector materials in real-world service conditions, a network of instrumented outdoor exposure sites has been activated.

Solar project cost report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hale, H.J.

1978-01-01

This report provides detailed cost information for the Reedy Creek Utilities solar space heating, cooling and service water heating project located in Walt Disney World, Florida. The solar energy system cools, heats and supplies service hot water for approximately 5625 ft/sup 2/ of office space in a general office building. The system was designed as an integral part of the building at the time the building was designed. The construction costs of this solar project are presented in this report. Category costs are listed by materials, direct labor, and subcontract costs. The subcontract costs include both materials, labor, overhead andmore » profit for electrical, control and other minor subcontractors.« less

Space Environmental Effects Testing and Characterization of the Candidate Solar Sail Material Aluminized Mylar

NASA Technical Reports Server (NTRS)

Edwards, D. L.; Hubbs, W. S.; Wertz, G. E.; Alstatt, R.; Munafo, Paul (Technical Monitor)

2001-01-01

The usage of solar sails as a propellantless propulsion system has been proposed for many years. The technical challenges associated with solar sails are fabrication of ultralightweight films, deploying the sails and controlling the spacecraft. Integral to all these challenges is the mechanical property integrity of the sail while exposed to the harsh environment of space. This paper describes testing and characterization of a candidate solar sail material, Aluminized Mylar. This material was exposed to a simulated Geosynchronous Transfer Orbit (GTO) and evaluated by measuring thermooptical and mechanical property changes. Testing procedures and results are presented.

Photovoltaic Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duty, C.; Angelini, J.; Armstrong, B.

The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties including defects, impurities, and grain boundaries affect the solar cell performance. ORNL also has unique processing capabilities to optimize the manufacturing process for fabrication ofmore » high efficiency and low cost solar cells. ORNL recently established the Center for Advanced Thin-film Systems (CATS), which contains a suite of optical and electrical characterization equipment specifically focused on solar cell research. Under this project, ORNL made these facilities available to industrial partners who were interested in pursuing collaborative research toward the improvement of their product or manufacturing process. Four specific projects were pursued with industrial partners: Global Solar Energy is a solar industry leader in full scale production manufacturing highly-efficient Copper Indium Gallium diSelenide (CIGS) thin film solar material, cells and products. ORNL worked with GSE to develop a scalable, non-vacuum, solution technique to deposit amorphous or nanocrystalline conducting barrier layers on untextured stainless steel substrates for fabricating high efficiency flexible CIGS PV. Ferro Corporation’s Electronic, Color and Glass Materials (“ECGM”) business unit is currently the world’s largest supplier of metallic contact materials in the crystalline solar cell marketplace. Ferro’s ECGM business unit has been the world's leading supplier of thick film metal pastes to the crystalline silicon PV industry for more than 30 years, and has had operational cells and modules in the field for 25 years. Under this project, Ferro leveraged world leading analytical capabilities at ORNL to characterize the paste-to-silicon interface microstructure and develop high efficiency next generation contact pastes. Ampulse Corporation is developing a revolutionary crystalline-silicon (c-Si) thin-film solar photovoltaic (PV) technology. Utilizing uniquely-textured substrates and buffer materials from the Oak Ridge National Laboratory (ORNL), and breakthroughs in Hot-Wire Chemical Vapor Deposition (HW-CVD) techniques in epitaxial silicon developed at the National Renewable Energy Laboratory (NREL), Ampulse is creating a solar technology that is tunable in silicon thickness, and hence in efficiency and economics, to meet the specific requirements of multiple solar PV applications. This project focused on the development of a high rate deposition process to deposit Si, Ge, and Si1-xGex films as an alternate to hot-wire CVD. Mossey Creek Solar is a start-up company with great expertise in the solar field. The primary interest is to create and preserve jobs in the solar sector by developing high-yield, low-cost, high-efficiency solar cells using MSC-patented and -proprietary technologies. The specific goal of this project was to produce large grain formation in thin, net-shape-thickness mc-Si wafers processed with high-purity silicon powder and ORNL's plasma arc lamp melting without introducing impurities that compromise absorption coefficient and carrier lifetime. As part of this project, ORNL also added specific pieces of equipment to enhance our ability to provide unique insight for the solar industry. These capabilities include a moisture barrier measurement system, a combined physical vapor deposition and sputtering system dedicated to cadmium-containing deposits, adeep level transient spectroscopy system useful for identifying defects, an integrating sphere photoluminescence system, and a high-speed ink jet printing system. These tools were combined with others to study the effect of defects on the performance of crystalline silicon and thin film solar cells, to explore non-vacuum ink-based approaches to solar cell production, as well as large-scale and low-cost deposition and processing of thin film CdTe material.« less

Ultrafast Electron Dynamics in Solar Energy Conversion.

PubMed

Ponseca, Carlito S; Chábera, Pavel; Uhlig, Jens; Persson, Petter; Sundström, Villy

2017-08-23

Electrons are the workhorses of solar energy conversion. Conversion of the energy of light to electricity in photovoltaics, or to energy-rich molecules (solar fuel) through photocatalytic processes, invariably starts with photoinduced generation of energy-rich electrons. The harvesting of these electrons in practical devices rests on a series of electron transfer processes whose dynamics and efficiencies determine the function of materials and devices. To capture the energy of a photogenerated electron-hole pair in a solar cell material, charges of opposite sign have to be separated against electrostatic attractions, prevented from recombining and being transported through the active material to electrodes where they can be extracted. In photocatalytic solar fuel production, these electron processes are coupled to chemical reactions leading to storage of the energy of light in chemical bonds. With the focus on the ultrafast time scale, we here discuss the light-induced electron processes underlying the function of several molecular and hybrid materials currently under development for solar energy applications in dye or quantum dot-sensitized solar cells, polymer-fullerene polymer solar cells, organometal halide perovskite solar cells, and finally some photocatalytic systems.

State-of-the-art low-cost solar reflector materials

NASA Astrophysics Data System (ADS)

Kennedy, C.; Jorgensen, G.

1994-11-01

Solar thermal technologies generate power by concentrating sunlight with large mirrors. The National Renewable Energy Laboratory (NREL) is working with industrial partners to develop the optical reflector materials needed for the successful deployment of this technology. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes in severe outdoor environments. Currently, the best candidate materials for solar mirrors are silver-coated low-iron glass and silvered polymer films. Polymer reflectors are lighter in weight, offer greater flexibility in system design, and have the potential for lower cost than glass mirrors. In parallel with collaborative activities, several innovative candidate reflector-material constructions were investigated at NREL. The low-cost material requirement necessitates manufacturing compatible with mass-production techniques. Future cooperative efforts with the web-coating industry offers the promise of exciting new alternative materials and the potential for dramatic cost savings in developing advanced solar reflector materials.

Modeling and simulation of the solar concentrator in photovoltaic systems through the application of a new BRDF function model

NASA Astrophysics Data System (ADS)

Plachta, Kamil

2016-04-01

The paper presents a new algorithm that uses a combination of two models of BRDF functions: Torrance-Sparrow model and HTSG model. The knowledge of technical parameters of a surface is especially useful in the construction of the solar concentrator. The concentrator directs the reflected solar radiation on the surface of photovoltaic panels, increasing the amount of incident radiance. The software applying algorithm allows to calculate surface parameters of the solar concentrator. Performed simulation showing the share of diffuse component and directional component in reflected stream for surfaces made from particular materials. The impact of share of each component in reflected stream on the efficiency of the solar concentrator and photovoltaic surface has also been described. Subsequently, simulation change the value of voltage, current and power output of monocrystalline photovoltaic panels installed in a solar concentrator system has been made for selected surface of materials solar concentrator.

A passive solar residence using native and recycled materials, Bee Cave, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holder, L.M. III; King, L.H.

The Booth Residence at Bee Cave, Texas is a Passive Solar residence in a hot humid climate and a good example of both passive solar and renewable features. The design, operation, materials, and furnishings give the structure a regional and rustic character. Passive solar strategies employed include solar orientation, solar shading, natural ventilation, induced ventilation, night flushing, direct gain clearstory, high mass floors, daylighting, radiant barrier, and a double ventilated roof system. The project is in contrast to the existing compound which includes three identical buildings each rotated 120 degrees and intended to be energy efficient, but actual operation hasmore » pointed out some deficiencies in the design. Additional features include extensive use of natural, recycled, and materials reused from other buildings. The Boothe Residence is an example of building in harmony with the local climate, the use of locally available materials, craftsman, artists, manpower, and reuse of trim and furnishings.« less

Solar Concentrator Advanced Development Program, Task 1

NASA Technical Reports Server (NTRS)

1986-01-01

Solar dynamic power generation has been selected by NASA to provide power for the space station. Solar dynamic concentrator technology has been demonstrated for terrestrial applications but has not been developed for space applications. The object of the Solar Concentrator Advanced Development program is to develop the technology of solar concentrators which would be used on the space station. The first task of this program was to develop conceptual concentrator designs and perform trade-off studies and to develop a materials data base and perform material selection. Three unique concentrator concepts; Truss Hex, Spline Radial Panel and Domed Fresnel, were developed and evaluated against weighted trade criteria. The Truss Hex concept was recommended for the space station. Materials data base development demonstrated that several material systems are capable of withstanding extended periods of atomic oxygen exposure without undesirable performance degradation. Descriptions of the conceptual designs and materials test data are included.

Redox Conditions Among the Terrestrial Planets

NASA Technical Reports Server (NTRS)

Jones, J. H.

2004-01-01

Early solar system conditions should have been extremely reducing. The redox state of the early solar nebula was determined by the H2O/H2 of the gas, which is calculated (based on solar composition) to have been about IW-5. At high temperature under such conditions, ferrous iron would exist only as a trace element in silicates and the most common type of chondritic material should have been enstatite chondrites. The observation that E-chondrites form only a subset of the chondrite suite and that the terrestrial planets (Earth, Moon, Mars, Venus, 4 Vesta) contain ferrous and ferric iron as major and minor elements, respectively, implies that either most chondritic materials formed under conditions that were not solar or that early-formed metals oxidized at low temperature, producing FeO. For example, equilibrated ordinary chondrites (by definition, common chondritic materials), by their phase assemblage of olivine, orthopyroxene and metal, must fall not far from the QFI (Quartz-Fayalite-Iron) oxygen buffer. The QFI buffer is about IW-0.5 and, as we shall see, this fo2 is close to that inferred for many materials in the inner solar system.

NASA and energy

NASA Technical Reports Server (NTRS)

1974-01-01

NASA technology contributions to create energy sources include direct solar heating and cooling systems, wind generation of electricity, solar thermal energy turbine drives, solar cells, and techniques for locating, producing, and collecting organic materials for conversion into fuel.

Involving Scientists in the NASA / JPL Solar System Educators Program

NASA Astrophysics Data System (ADS)

Brunsell, E.; Hill, J.

2001-11-01

The NASA / JPL Solar System Educators Program (SSEP) is a professional development program with the goal of inspiring America's students, creating learning opportunities, and enlightening inquisitive minds by engaging them in the Solar System exploration efforts conducted by the Jet Propulsion Laboratory (JPL). SSEP is a Jet Propulsion Laboratory program managed by Space Explorers, Inc. (Green Bay, WI) and the Virginia Space Grant Consortium (Hampton, VA). The heart of the program is a large nationwide network of highly motivated educators. These Solar System Educators, representing more than 40 states, lead workshops around the country that show teachers how to successfully incorporate NASA materials into their teaching. During FY2001, more than 9500 educators were impacted through nearly 300 workshops conducted in 43 states. Solar System Educators attend annual training institutes at the Jet Propulsion Laboratory during their first two years in the program. All Solar System Educators receive additional online training, materials and support. The JPL missions and programs involved in SSEP include: Cassini Mission to Saturn, Galileo Mission to Jupiter, STARDUST Comet Sample Return Mission, Deep Impact Mission to a Comet, Mars Exploration Program, Outer Planets Program, Deep Space Network, JPL Space and Earth Science Directorate, and the NASA Office of Space Science Solar System Exploration Education and Public Outreach Forum. Scientists can get involved with this program by cooperatively presenting at workshops conducted in their area, acting as a content resource or by actively mentoring Solar System Educators. Additionally, SSEP will expand this year to include other missions and programs related to the Solar System and the Sun.

Toward cost-effective solar energy use.

PubMed

Lewis, Nathan S

2007-02-09

At present, solar energy conversion technologies face cost and scalability hurdles in the technologies required for a complete energy system. To provide a truly widespread primary energy source, solar energy must be captured, converted, and stored in a cost-effective fashion. New developments in nanotechnology, biotechnology, and the materials and physical sciences may enable step-change approaches to cost-effective, globally scalable systems for solar energy use.

Production of solar chemicals: gaining selectivity with hybrid molecule/semiconductor assemblies.

PubMed

Hennessey, Seán; Farràs, Pau

2018-05-29

Research on the production of solar fuels and chemicals has rocketed over the past decade, with a wide variety of systems proposed to harvest solar energy and drive chemical reactions. In this Feature Article we have focused on hybrid molecule/semiconductor assemblies in both powder and supported materials, summarising recent systems and highlighting the enormous possibilities offered by such assemblies to carry out highly demanding chemical reactions with industrial impact. Of relevance is the higher selectivity obtained in visible light-driven organic transformations when using molecular catalysts compared to photocatalytic materials.

Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

NASA Astrophysics Data System (ADS)

Charvat, P.; Pech, O.; Hejcik, J.

2013-04-01

The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature).

Handbook of experiences in the design and installation of solar heating and cooling systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, D.S.; Oberoi, H.S.

1980-07-01

A large array of problems encountered are detailed, including design errors, installation mistakes, cases of inadequate durability of materials and unacceptable reliability of components, and wide variations in the performance and operation of different solar systems. Durability, reliability, and design problems are reviewed for solar collector subsystems, heat transfer fluids, thermal storage, passive solar components, piping/ducting, and reliability/operational problems. The following performance topics are covered: criteria for design and performance analysis, domestic hot water systems, passive space heating systems, active space heating systems, space cooling systems, analysis of systems performance, and performance evaluations. (MHR)

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.

1976-01-01

The chemical vapor deposition (CVD) method for the growth of Si sheet on inexpensive substrate materials is investigated. The objective is to develop CVD techniques for producing large areas of Si sheet on inexpensive substrate materials, with sheet properties suitable for fabricating solar cells meeting the technical goals of the Low Cost Silicon Solar Array Project. Specific areas covered include: (1) modification and test of existing CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using standard and near-standard processing techniques.

Stable Magnesium Isotope Variation in Melilite Mantle of Allende Type B1 CAI EK 459-5-1

NASA Technical Reports Server (NTRS)

Kerekgyarto, A. G.; Jeffcoat, C. R.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.

2014-01-01

Ca-Al-rich inclusions (CAIs) are the earliest formed crystalline material in our solar system and they record early Solar System processes. Here we present petrographic and delta Mg-25 data of melilite mantles in a Type B1 CAI that records early solar nebular processes.

Fabrication and comparison of selective, transparent optics for concentrating solar systems

NASA Astrophysics Data System (ADS)

Taylor, Robert A.; Hewakuruppu, Yasitha; DeJarnette, Drew; Otanicar, Todd P.

2015-09-01

Concentrating optics enable solar thermal energy to be harvested at high temperature (<100oC). As the temperature of the receiver increases, radiative losses can become dominant. In many concentrating systems, the receiver is coated with a selectively absorbing surface (TiNOx, Black Chrome, etc.) to obtain higher efficiency. Commercial absorber coatings are well-developed to be highly absorbing for short (solar) wavelengths, but highly reflective at long (thermal emission) wavelengths. If a solar system requires an analogous transparent, non-absorbing optic - i.e. a cover material which is highly transparent at short wavelengths, but highly reflective at long wavelengths - the technology is simply not available. Low-e glass technology represents a commercially viable option for this sector, but it has only been optimized for visible light transmission. Optically thin metal hole-arrays are another feasible solution, but are often difficult to fabricate. This study investigates combinations of thin film coatings of transparent conductive oxides and nanoparticles as a potential low cost solution for selective solar covers. This paper experimentally compares readily available materials deposited on various substrates and ranks them via an `efficiency factor for selectivity', which represents the efficiency of radiative exchange in a solar collector. Out of the materials studied, indium tin oxide and thin films of ZnS-Ag-ZnS represent the most feasible solutions for concentrated solar systems. Overall, this study provides an engineering design approach and guide for creating scalable, selective, transparent optics which could potentially be imbedded within conventional low-e glass production techniques.

Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

NASA Technical Reports Server (NTRS)

Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

1991-01-01

A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack

NASA Technical Reports Server (NTRS)

Dinetta, L. C.; Hannon, M. H.; Mcneely, J. B.; Barnett, A. M.

1991-01-01

The AstroPower self-supporting, transparent AlGaAs top solar cell can be stacked upon any well-developed bottom solar cell for improved system performance. This is an approach to improve the performance and scale of space photovoltaic power systems. Mechanically stacked tandem solar cell concentrator systems based on the AlGaAs top concentrator solar cell can provide near term efficiencies of 36 percent (AMO, 100x). Possible tandem stack efficiencies greater than 38 percent (100x, AMO) are feasible with a careful selection of materials. In a three solar cell stack, system efficiencies exceed 41 percent (100x, AMO). These device results demonstrate a practical solution for a state-of-the-art top solar cell for attachment to an existing, well-developed solar cell.

Evaluation of alternative phase change materials for energy storage in solar dynamic applications

NASA Technical Reports Server (NTRS)

Crane, R. A.; Dustin, M. O.

1988-01-01

The performance of fluoride salt and metallic thermal energy storage materials are compared in terms of basic performance as applied to solar dynamic power generation. Specific performance considerations include uniformity of cycle inlet temperature, peak cavity temperature, TES utilization, and system weights. Also investigated were means of enhancing the thermal conductivity of the salts and its effect on the system performance.

Solar Greenhouses and Sunspaces: Lessons Learned.

ERIC Educational Resources Information Center

Thomas, Stephen G.; And Others

Solar technology systems are being studied, managed, built and offered as an effective alternative energy option. This publication presents background material for the building and operation of better sunspaces and greenhouses. Recent developments in solar technology are explained and information on solar greenhouse and sunspace is provided (in…

The pathways of C: from AGB stars, to the Interstellar Medium, and finally into the protoplanetary disk

NASA Astrophysics Data System (ADS)

Trigo-Rodriguez, J. M.; Garcia-Hernandez, D. A.

2011-05-01

The origin, and role of C in the formation of first solar system aggregates is described. Stellar grains evidence demonstrates that Asymptotic Giant Branch (AGB) stars were nearby to the solar nebula at the time of solar system formation. Such stars continue to burn H and He in shells that surround the C-O core. During their evolution, flashes occur in the He shell and the C, and O produced are eventually dredged up into the star's envelop and then to the stellar surface, and finally masively ejected to the interstellar medium (IM). Once in a molecular cloud, the electrophilicity of C makes this element reactable with the surrounding gas to produce different molecular species. Primitive meteorites, particularly these known as chondrites, preserved primeval materials of the disk. The abundances of short-lived radionuclides (SLN), inferred to have been present in the early solar system (ESS), are a constraint on the birth and early evolution of the solar system as their relatively short half lives do not allow the observed abundances to be explained by galactic chemical evolution processes. We present a model of a 6.5 solar masses star of solar metallicity that simultaneously match the abundances of SLNs inferred to have been present in the ESS by using a dilution factor of 1 part of AGB material per 300 parts of original solar nebula material, and taking into account a time interval between injection of SLNs and consolidation of chondrites equal to 0.53 Myr [2]. Such a polluting source does not overproduce 53Mn, as supernova models do, and only marginally affects isotopic ratios of stable elements. The AGB stars released O- and C-rich gas with important oxidizing implications to first solar system materials as recently detected in circumstellar environments [3]. REF: [1] Lada C.J. and Lada E.A. 2003. Ann. Rev. A&A. 41: 57; [2] Trigo-Rodriguez J.M. et al. 2009. MAPS 44: 627; [3] Decin L. et al. 2010. Nature 467: 64.

Use of ground-based telescopes in determining the composition of the surfaces of solar system objects

NASA Technical Reports Server (NTRS)

Mccord, T. B.; Adams, J. B.

1977-01-01

Recent evidence suggests that the way that the surfaces of the solar system objects reflect solar radiation is controlled by the composition and mineralogy of the surface materials. The way sunlight is reflected from the surface as a function of wavelength, i.e., the spectral reflectance, is the most important property. Laboratory efforts to use ground-based optical telescope measurements to determine the composition of the surfaces of the solar system objects are reviewed.

Considerations with respect to the design of solar photovoltaic power systems for terrestrial applications

NASA Technical Reports Server (NTRS)

Berman, P. A.

1972-01-01

The various factors involved in the development of solar photovoltaic power systems for terrestrial application are discussed. The discussion covers the tradeoffs, compromises, and optimization studies which must be performed in order to develop a viable terrestrial solar array system. It is concluded that the technology now exists for the fabrication of terrestrial solar arrays but that the economics are prohibitive. Various approaches to cost reduction are presented, and the general requirements for materials and processes to be used are delineated.

Why we need asteroid sample return mission?

NASA Astrophysics Data System (ADS)

Barucci, Maria Antonietta

2016-07-01

Small bodies retain evidence of the primordial solar nebula and the earliest solar system processes that shaped their evolution. They may also contain pre-solar material as well as complex organic molecules, which could have a major role to the development of life on Earth. For these reasons, asteroids and comets have been targets of interest for missions for over three decades. However, our knowledge of these bodies is still very limited, and each asteroid or comet visited by space mission has revealed unexpected scientific results, e.g. the structure and nature of comet 67P/Churyumov-Gerasimenko (67P/C-G) visited by the Rosetta mission. Only in the laboratory can instruments with the necessary precision and sensitivity be applied to individual components of the complex mixture of materials that forms a small body regolith, to determine their precise chemical and isotopic composition. Such measurements are vital for revealing the evidence of stellar, interstellar medium, pre-solar nebula and parent body processes that are retained in primitive material, unaltered by atmospheric entry or terrestrial contamination. For those reasons, sample return missions are considered a high priority by a number of the leading space agencies. Abundant within the inner Solar System and the main impactors on terrestrial planets, small bodies may have been the principal contributors of the water and organic material essential to create life on Earth. Small bodies can therefore be considered to be equivalent to DNA for unravelling our solar system's history, offering us a unique window to investigate both the formation of planets and the origin of life. A sample return mission to a primitive Near-Earth Asteroid (NEA) has been study at ESA from 2008 in the framework of ESA's Cosmic Vision (CV) programme, with the objective to answer to the fundamental CV questions "How does the Solar System work?" and "What are the conditions for life and planetary formations?". The returned material will allow us to study in terrestrial laboratories some of the most primitive materials available to investigate early solar system formation processes, to explore initial stages of habitable planet formation, to identify and characterize the organics and volatiles in a primitive asteroid. The ideal easy target body for such mission is a D type NEA. D types are the most abundant asteroids beyond the outer edge of the main belt. It is likely that they formed much further out in the Solar System, possibly as far as the transneptunian objects, and were subsequently captured in their present locations following the migration of the gas giants. Spectral features indicate that these bodies are organic rich, contain fine anhydrous minerals but also may be volatile rich and appear to be the most primitive rocky material present in the solar system. In addition to addressing the major science goals, sample return mission from a NEA also involved innovative European technologies. The key sample return capabilities, i.e. asteroid navigation, touch and go, sampling mechanism and the re-entry capsule have reached at ESA a validation status to enter implementation phase. The development of sample return technology represents in Europe a crucial element for planetary science and for the space technology development.

JPL solar power experiments

NASA Technical Reports Server (NTRS)

Yasui, R. K.

1976-01-01

Report describes evolution of photovoltaic power systems designed and built for terrestrial use. Discussion focuses on technological problems impeding further systems development. Experiments and test data on seven types of solar panels and six material test specimens are described in detail.

Graphene-Based Standalone Solar Energy Converter for Water Desalination and Purification.

PubMed

Yang, Yang; Zhao, Ruiqi; Zhang, Tengfei; Zhao, Kai; Xiao, Peishuang; Ma, Yanfeng; Ajayan, Pulickel M; Shi, Gaoquan; Chen, Yongsheng

2018-01-23

Harvesting solar energy for desalination and sewage treatment has been considered as a promising solution to produce clean water. However, state-of-the-art technologies often require optical concentrators and complicated systems with multiple components, leading to poor efficiency and high cost. Here, we demonstrate an extremely simple and standalone solar energy converter consisting of only an as-prepared 3D cross-linked honeycomb graphene foam material without any other supporting components. This simple all-in-one material can act as an ideal solar thermal converter capable of capturing and converting sunlight into heat, which in turn can distill water from various water sources into steam and produce purified water under ambient conditions and low solar flux with very high efficiency. High specific water production rate of 2.6 kg h -1 m -2 g -1 was achieved with near ∼87% under 1 sun intensity and >80% efficiency even under ambient sunlight (<1 sun). This scalable sheet-like material was used to obtain pure drinkable water from both seawater and sewage water under ambient conditions. Our results demonstrate a competent monolithic material platform providing a paradigm change in water purification by using a simple, point of use, reusable, and low-cost solar thermal water purification system for a variety of environmental conditions.

Thermal Storage Materials Laboratory | Energy Systems Integration Facility

Science.gov Websites

| NREL Materials Laboratory Thermal Storage Materials Laboratory In the Energy Systems Integration Facility's Thermal Storage Materials Laboratory, researchers investigate materials that can be used as high-temperature heat transfer fluids or thermal energy storage media in concentrating solar

Asteroid-comet continuum objects in the solar system.

PubMed

Hsieh, Henry H

2017-07-13

In this review presented at the Royal Society meeting, 'Cometary science after Rosetta', I present an overview of studies of small solar system objects that exhibit properties of both asteroids and comets (with a focus on so-called active asteroids). Sometimes referred to as 'transition objects', these bodies are perhaps more appropriately described as 'continuum objects', to reflect the notion that rather than necessarily representing actual transitional evolutionary states between asteroids and comets, they simply belong to the general population of small solar system bodies that happen to exhibit a continuous range of observational, physical and dynamical properties. Continuum objects are intriguing because they possess many of the properties that make classical comets interesting to study (e.g. relatively primitive compositions, ejection of surface and subsurface material into space where it can be more easily studied, and orbital properties that allow us to sample material from distant parts of the solar system that would otherwise be inaccessible), while allowing us to study regions of the solar system that are not sampled by classical comets.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Silicon material task - Low cost solar array project /JPL/DOE/

NASA Technical Reports Server (NTRS)

Lutwack, R.

1979-01-01

The paper describes the silicon material task of the low-cost solar array project, which has the objective of establishing a silicon production capability equivalent to 500 mW per year at a price less than 10 dollars/kg (1975 dollars) in 1986. The task program is divided into four phases: technical feasibility, scale-up studies (the present phase), experimental process system development units, and implementation of large-scale production plants, and it involves the development of processes for two groups of materials, that is, semiconductor grade and solar cell grade. In addition, the effects of impurities on solar cell performance are being investigated. Attention is given to problem areas of the task program, such as environmental protection, material compatibility between the reacting chemicals and materials of construction of the equipment, and waste disposal.

Recent progress in Si thin film technology for solar cells

NASA Astrophysics Data System (ADS)

Kuwano, Yukinori; Nakano, Shoichi; Tsuda, Shinya

1991-11-01

Progress in Si thin film technology 'specifically amorphous Si (a-Si) and polycrystalline Si (poly-Si) thin film' for solar cells is summarized here from fabrication method, material, and structural viewpoints. In addition to a-Si, primary results on poly-Si thin film research are discussed. Various applications for a-Si solar cells are mentioned, and consumer applications and a-Si solar cell photovoltaic systems are introduced. New product developments include see-through solar cells, solar cell roofing tiles, and ultra-light flexible solar cells. As for new systems, air conditioning equipment powered by solar cells is described. Looking to the future, the proposed GENESIS project is discussed.

Oxidation-Resistant Surfaces For Solar Reflectors

NASA Technical Reports Server (NTRS)

Gulino, Daniel A.; Egger, Robert A.; Banholzer, William F.

1988-01-01

Thin films on silver provide highly-reflective, corrosion-resistant mirrors. Study evaluated variety of oxidation-resistant reflective materials for use in solar dynamic power system, one that generates electricity by focusing Sunlight onto reciever of heat engine. Thin films of platinum and rhodium deposited by ion-beam sputtering on various substrate materials. Solar reflectances measured as function of time of exposure to radio-frequency-generated air plasma. Several protective coating materials deposited on silver-coated substrates and exposed to plasma. Analyzed before and after exposure by electon spectroscopy for chemical analysis and by Auger spectroscopy.

Improved solar heating systems

DOEpatents

Schreyer, J.M.; Dorsey, G.F.

1980-05-16

An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

Solar heating system

DOEpatents

Schreyer, James M.; Dorsey, George F.

1982-01-01

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Health and safety implications of alternative energy technologies. II. Solar

NASA Astrophysics Data System (ADS)

Etnier, E. L.; Watson, A. P.

1981-09-01

No energy technology is risk free when all aspects of its utilization are taken into account. Every energy technology has some attendant direct and indirect health and safety concerns. Solar technologies examined in this paper are wind, ocean thermal energy gradients, passive, photovoltaic, satellite power systems, low- and high-temperature collectors, and central power stations, as well as tidal power. For many of these technologies, insufficient historical data are available from which to assess the health risks and environmental impacts. However, their similarities to other projects make certain predictions possible. For example, anticipated problems in worker safety in constructing ocean thermal energy conversion systems will be similar to those associated with other large-scale construction projects, like deep-sea oil drilling platforms. Occupational hazards associated with photovoltaic plant operation would be those associated with normal electricity generation, although for workers involved in the actual production of photovoltaic materials, there is some concern for the toxic effects of the materials used, including silicon, cadmium, and gallium arsenide. Satellite power systems have several unique risks. These include the effects of long-term space travel for construction workers, effects on the ozone layer and the attendant risk of skin cancer in the general public, and the as-yet-undetermined effects of long-term, low-level microwave exposure. Hazards may arise from three sources in solar heating and cooling systems: water contamination from corrosion inhibitors, heat transfer fluids, and bactericides; collector over-heating, fires, and “out-gassing” and handling and disposal of system fluids and wastes. Similar concerns exist for solar thermal power systems. Even passive solar systems may increase indoor exposure levels to various air pollutants and toxic substances, eitherdirectly from the solar system itself or indirectly by trapping released pollutants from furnishings, building materials, and indoor combustion.

To See a World in a Grain of Sand: Insights into Solar System Formation and Evolution from Isotopic Analyses of Planetary Materials

NASA Astrophysics Data System (ADS)

Wadhwa, M.

2016-12-01

The last few decades have seen revolutionary advances in the planetary sciences through remote observations (by spacecraft and Earth-based observatories) of many Solar System destinations and, in more recent years, even exoplanets around other stars. In parallel with this, ground-breaking developments in analytical capabilities and access to a greater variety of Solar System materials (through systematic and sustained meteorite collection programs as well as sample return missions) have led to significant insights that are complementary to those from remote observations and measurements. I will discuss two examples where the combination of remote observations and sample analyses has the potential to provide a more holistic picture of Solar System formation and evolution: 1) High-precision analyses of radiogenic isotopes in primitive and differentiated meteoritic materials, which are yielding a detailed high-resolution chronology of the first 10 million years of Solar System history. Such investigations are providing the chronological framework for the formation and evolution of small bodies (including comets, asteroids and Kuiper Belt Objects) in our Solar System that are the targets of recent spacecraft missions such as NASA's Dawn and New Horizons missions and ESA's Rosetta mission. 2) In-situ analyses of hydrogen isotope compositions and H2O abundances in meteorites from Mars and Vesta, which are giving constraints on the inventory and source of water and other volatiles in these planetary bodies. These studies are providing insights complementary to those about Mars from NASA's Mars Science Laboratory and Mars Atmosphere and Volatile Evolution (MAVEN) missions, and about Vesta from NASA's Dawn mission.

Solar cells for lunar applications by vacuum evaporation of lunar regolith materials

NASA Technical Reports Server (NTRS)

Ignatiev, Alex

1991-01-01

The National Space Exploration Initiative, specifically the Lunar component, has major requirements for technology development of critical systems, one of which is electrical power. The availability of significant electrical power on the surface of the Moon is a principal driver defining the complexity of the lunar base. Proposals to generate power on the Moon include both nuclear and solar (photovoltaic) systems. A more efficient approach is to attempt utilization of the existing lunar resources to generate the power systems. Synergism may occur from the fact that there have already been lunar materials processing techniques proposed for the extraction of oxygen that would have, as by-products, materials that could be specifically used to generate solar cells. The lunar environment is a vacuum with pressures generally in the 1 x 10(exp -10) torr range. Such conditions provide an ideal environment for direct vacuum deposition of thin film solar cells using the waste silicon, iron, and TiO2 available from the lunar regolith processing meant to extract oxygen. It is proposed, therefore, to grow by vacuum deposition, thin film silicon solar cells from the improved regolith processing by-products.

Evaluation of Low-Earth-Orbit Environmental Effects on International Space Station Thermal Control Materials

NASA Technical Reports Server (NTRS)

Dever, Joyce A.

1998-01-01

Many spacecraft thermal control coatings in low Earth orbit (LEO) can be affected by solar ultraviolet radiation and atomic oxygen. Ultraviolet radiation can darken some polymers and oxides commonly used in thermal control materials. Atomic oxygen can erode polymer materials, but it may reverse the ultraviolet-darkening effect on oxides. Maintaining the desired solar absorptance for thermal control coatings is important to assure the proper operating temperature of the spacecraft. Thermal control coatings to be used on the International Space Station (ISS) were evaluated for their performance after exposure in the NASA Lewis Research Center's Atomic Oxygen-Vacuum Ultraviolet Exposure (AO-VUV) facility. This facility simulated the LEO environments of solar vacuum ultraviolet (VUV) radiation (wavelength range, 115 to 200 nanometers (nm)) and VUV combined with atomic oxygen. Solar absorptance was measured in vacuo to eliminate the "bleaching" effects of ambient oxygen on VUV-induced degradation. The objective of these experiments was to determine solar absorptance increases of various thermal control materials due to exposure to simulated LEO conditions similar to those expected for ISS. Work was done in support of ISS efforts at the requests of Boeing Space and Defense Systems and Lockheed Martin Vought Systems.

THE HIGH INTENSITY SOLAR ENVIRONMENT TEST SYSTEM

NASA Image and Video Library

2016-01-15

TODD SCHNEIDER LOOKS UP FROM WORK AT THE DOOR OF T HE HIGH INTENSITY SOLAR ENVIRONMENT TEST SYSTEM IN BUILDING 4605. SCHNEIDER IS A PHYSICIST IN THE MATERIALS AND PROCESSES DEPARTMENT AT MSFC AND IS PRINCIPAL INVESTIGATOR FOR HISET.

Alternative energy sources IV; Proceedings of the Fourth Miami International Conference, Miami Beach, FL, December 14-16, 1981. Volume 1 - Solar Collectors Storage

NASA Astrophysics Data System (ADS)

Veziroglu, T. N.

1982-10-01

Aspects of solar measurements, solar collectors, selective coatings, thermal storage, phase change storage, and heat exchangers are discussed. The analysis and testing of flat-plate solar collectors are addressed. The development and uses of plastic collectors, a solar water heating system, solar energy collecting oil barrels, a glass collector panel, and a two-phase thermosyphon system are considered. Studies of stratification in thermal storage, of packed bed and fluidized bed systems, and of thermal storage in solar towers, in wall passive systems, and in reversible chemical reactions are reported. Phase change storage by direct contact processes and in residential solar space heating and cooling is examined, as are new materials and surface characteristics for solar heat storage. The use of R-11 and Freon-113 in heat exchange is discussed. No individual items are abstracted in this volume

Microanalysis of Hypervelocity Impact Residues of Possible Interstellar Origin

NASA Technical Reports Server (NTRS)

Stroud, Rhonda M.; Achilles, Cheri; Allen, Carlton; Anasari, Asna; Bajt, Sasa; Bassim, Nabil; Bastien, Ron S.; Bechtel, H. A.; Borg, Janet; Brenker, Frank E.;

Investigation of test methods, material properties, and processes for solar cell encapsulants. Encapsulation task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

1977-01-01

During this quarter, flat-plate solar collector systems were considered and six basic construction elements were identified: outer coatings, superstrates, pottants, substrates, undercoats, and adhesives. Materials surveys were then initiated to discover either generic classes or/and specific products to function as each construction element. Cost data included in the surveys permit ready evaluation of each material. Silicones, fluorocarbons, glass, and acrylic polymers have the highest inherent weatherability of materials studied to date. Only acrylics, however, combine low costs, environmental resistance, and potential processability. This class will receive particular emphasis.

Space-Based Solar Power Conversion and Delivery Systems Study. Volume 1: Executive Summary

NASA Technical Reports Server (NTRS)

1977-01-01

The research concerning space-based solar power conversion and delivery systems is summarized. The potential concepts for a photovoltaic satellite solar power system was studied with emphasis on ground output power levels of 5,000 MW and 10,000 MW. A power relay satellite, and certain aspects of the economics of these systems were also studied. A second study phase examined in greater depth the technical and economic aspects of satellite solar power systems. Throughout this study, the focus was on the economics of satellite solar power. The results indicate technical feasibility of the concept, and provide a preliminary economic justification for the first phase of a substantial development program. A development program containing test satellites is recommended. Also, development of alternative solar cell materials (other than silicon) is recommended.

A three solar cell system based on a self-supporting, transparent AlGaAs top solar cell

NASA Technical Reports Server (NTRS)

Negley, Gerald H.; Rhoads, Sandra L.; Terranova, Nancy E.; Mcneely, James B.; Barnett, Allen M.

1989-01-01

Development of a three solar cell stack can lead to practical efficiencies greater than 30 percent (1x,AM0). A theoretical efficiency limitation of 43.7 percent at AM0 and one sun is predicted by this model. Including expected losses, a practical system efficiency of 36.8 percent is anticipated. These calculations are based on a 1.93eV/1.43eV/0.89eV energy band gap combination. AlGaAs/GaAs/GaInAsP materials can be used with a six-terminal wiring configuration. The key issues for multijunction solar cells are the top and middle solar cell performance and the sub-bandgap transparency. AstroPower has developed a technique to fabricate AlGaAs solar cells on rugged, self-supporting, transparent AlGaAs substrates. Top solar cell efficiencies greater than 11 percent AM0 have been achieved. State-of-the-art GaAs or InP devices will be used for the middle solar cell. GaInAsP will be used to fabricate the bottom solar cell. This material is lattice-matched to InP and offers a wide range of bandgaps for optimization of the three solar cell stack. Liquid phase epitaxy is being used to grow the quaternary material. Initial solar cells have shown open-circuit voltages of 462 mV for a bandgap of 0.92eV. Design rules for the multijunction three solar cell stack are discussed. The progress in the development of the self-supporting AlGaAs top solar cell and the GaInAsP bottom solar cell is presented.

Detection of solid C(triple bond)N bearing materials on solar system bodies

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.; Hartmann, W. K.; Tholen, David J.; Allamandola, L. J.; Brown, R. H.; Matthews, C. N.; Bell, J. F.

1991-01-01

We found observational evidence for the presence of C(triple bond)N-bearing solid materials on four classes of Solar System bodies: comets, asteroids, the rings of Uranus, and Saturn's satellite Iapetus. Gaseous CN was known in comet spectra, and the IR spectra of Comet P/Halley show emission of the CN fundamental at 4.5 microns interpreted as solids containing CN- group in the grains of the inner coma. The presented data offer the first evidence for chemically related material on the other objects.

Space Environment Stability and Physical Properties of New Materials for Space Power and Commercial Applications

NASA Technical Reports Server (NTRS)

Hambourger, Paul D.

1997-01-01

To test and evaluate suitability of materials for use in space power systems and related space and commercial applications, and to achieve sufficient understanding of the mechanisms by which, the materials perform in their intended applications. Materials and proposed applications included but were not limited to: Improved anodes for lithium ion batteries, highly-transparent arc-proof solar array coatings, and improved surface materials for solar dynamic concentrators and receivers. Cooperation and interchange of data with industrial companies as appropriate.

Solar hydrogen and solar electricity using mesoporous materials

NASA Astrophysics Data System (ADS)

Mahoney, Luther

The development of cost-effective materials for effective utilization of solar energy is a major challenge for solving the energy problems that face the world. This thesis work relates to the development of mesoporous materials for solar energy applications in the areas of photocatalytic water splitting and the generation of electricity. Mesoporous materials were employed throughout the studies because of their favorable physico-chemical properties such as high surface areas and large porosities. The first project was related to the use of a cubic periodic mesoporous material, MCM-48. The studies showed that chromium loading directly affected the phase of mesoporous silica formed. Furthermore, within the cubic MCM-48 structure, the loading of polychromate species determined the concentration of solar hydrogen produced. In an effort to determine the potential of mesoporous materials, titanium dioxide was prepared using the Evaporation-Induced Self-Assembly (EISA) synthetic method. The aging period directly determined the amount of various phases of titanium dioxide. This method was extended for the preparation of cobalt doped titanium dioxide for solar simulated hydrogen evolution. In another study, metal doped systems were synthesized using the EISA procedure and rhodamine B (RhB) dye sensitized and metal doped titania mesoporous materials were evaluated for visible light hydrogen evolution. The final study employed various mesoporous titanium dioxide materials for N719 dye sensitized solar cell (DSSC) materials for photovoltaic applications. The materials were extensively characterized using powder X-ray diffraction (XRD), nitrogen physisorption, diffuse reflectance spectroscopy (DRS), UV-Vis spectroscopy, Fourier-Transform-Infrared Spectroscopy (FT-IR), Raman spectroscopy, chemisorption, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). In addition, photoelectrochemical measurements were completed using current-voltage (I-V) curves, external quantum efficiency (EQE) curves, electrochemical impedance spectroscopy (EIS), and transient spectroscopy. The thesis work presented provides a better understanding of the role of mesoporous materials for solar hydrogen and solar electricity production.

Physics of the primitive solar nebula and of giant gaseous protoplanets

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1978-01-01

It has been proposed that the supernova responsible for injecting Al-26 into the early solar system was in fact responsible for triggering the collapse of an interstellar cloud in order to produce a system of stars, one of which would be the solar system. Details concerning the mechanism involved in such a process are discussed. Attention is given to the evolution of the primitive solar nebula, the instabilities in the primitive solar nebula, and the giant gaseous protoplanets. The principal conclusion to be drawn from the material presented is that the primitive solar nebula was a rather chaotic place, highly turbulent, with the multiple formation of giant gaseous protoplanets.

Star formation and extinct radioactivities

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1984-01-01

An assessment is made of the evidence for the existence of now-extinct radioactivities in primitive solar system material, giving attention to implications for the early stages of sun and solar system formation. The characteristics of possible disturbances in dense molecular clouds which can initiate the formation of cloud cores is discussed, with emphasis on these disturbances able to generate fresh radioactivities. A one-solar mass red giant star on the asymptotic giant branch appears to have been the best candidate to account for the short-lived extinct radioactivities in the early solar system.

The Stardust solar array

NASA Technical Reports Server (NTRS)

Gasner, S.; Sharmit, K.; Stella, P. M.; Craig, C.; Mumaw, S.

2003-01-01

The Stardust program, part of NASA's Discovery Missions was launched on February 7. 1999. It's seven-year mission is to gather interstellar dust and material from the comet Wild-2 and return the material to earth in January 2006. In order to accomplish this mission, the satellite will orbit the sun a total of three times, traversing distances from a little under 1 AU to 2.7 AU. On April 18 2002 , the Stardust spacecraft reached its furthest distance and broke the record for being the farthest spacecraft from the sun powered by solar energy, The Stardust solar panels were built with standard off the shelf 10 Ohm-cm high efficiency silicon solar cells. These solar cells are relatively inexpensive and have shown excellent characteristics under LILT conditions. In order to accommodate the varying temperature and intensity conditions on the electrical power subsystem, an electronic switch box was designed to reconfigure the string length and number of swings depending on the mission phase. This box allowed the use of an inexpensive direct energy transfer system for the electrical power system architecture. The solar panels and electrical power system have met all requirements. Telemetry data from the solar panels at 2.7 AU are in excellent agreement with flight predictions.

An efficient descriptor model for designing materials for solar cells

NASA Astrophysics Data System (ADS)

Alharbi, Fahhad H.; Rashkeev, Sergey N.; El-Mellouhi, Fedwa; Lüthi, Hans P.; Tabet, Nouar; Kais, Sabre

2015-11-01

An efficient descriptor model for fast screening of potential materials for solar cell applications is presented. It works for both excitonic and non-excitonic solar cells materials, and in addition to the energy gap it includes the absorption spectrum (α(E)) of the material. The charge transport properties of the explored materials are modelled using the characteristic diffusion length (Ld) determined for the respective family of compounds. The presented model surpasses the widely used Scharber model developed for bulk heterojunction solar cells. Using published experimental data, we show that the presented model is more accurate in predicting the achievable efficiencies. To model both excitonic and non-excitonic systems, two different sets of parameters are used to account for the different modes of operation. The analysis of the presented descriptor model clearly shows the benefit of including α(E) and Ld in view of improved screening results.

Solar energy emplacement developer

NASA Technical Reports Server (NTRS)

Mortensen, Michael; Sauls, Bob

1991-01-01

A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

NASA's What's Up Astronomy and Mission video series celebrates the Year of the Solar System: Fall 2010 - late summer 2012

NASA Astrophysics Data System (ADS)

Houston Jones, J.; Alice Wessen, Manager Of Solar System Eduction; Public Engagement

2010-12-01

NASA's What's Up video podcast supports the Year of the Solar System (YSS) October 2010 - August 2012. During YSS each podcast pairs a popular night sky viewing target (Moon, Comet, Planets, solar system features) with a mission event (launch, flyby, orbit insertion, landing). This product has proven popular with public, formal and informal audiences and will compliment and augment other programming material.

Optical Analysis of Transparent Polymeric Material Exposed to Simulated Space Environment

NASA Technical Reports Server (NTRS)

Edwards, David L.; Finckenor, Miria M.

2000-01-01

Many innovations in spacecraft power and propulsion have been recently tested at NASA, particularly in non-chemical propulsion. One improvement in solar array technology is solar concentration using thin polymer film Fresnel lenses. Weight and cost savings were proven with the Solar Concentrator Arrays with Refractive Linear Element Technology (SCARLET)-II array on NASA's Deep Space I spacecraft. The Fresnel lens concentrates solar energy onto high-efficiency solar cells, decreasing the area of solar cells needed for power. Continued efficiency of this power system relies on the thin film's durability in the space environment and maintaining transmission in the 300 - 1000 nm bandwidth. Various polymeric materials have been tested for use in solar concentrators, including Lexan(TM), polyethylene terephthalate (PET), several formulations of Tefzel(Tm) and Teflon(TM), and DC 93-500, the material selected for SCARLET-II. Also tested were several innovative materials including Langley Research Center's CPI and CP2 polymers and atomic oxygen- resistant polymers developed by Triton Systems, Inc. The Environmental Effects Group of the Marshall Space Flight Center's Materials, Processes, and Manufacturing Department exposed these materials to simulated space environment and evaluated them for any change in optical transmission. Samples were exposed to a minimum of 1000 equivalent Sun hours of near-UV radiation (250 - 400 nm wavelength). Materials that appeared robust after near-UV exposure were then exposed to charged particle radiation equivalent to a five-year dose in geosynchronous orbit. These exposures were performed in MSFC's Combined Environmental Effects Test Chamber, a unique facility with the capability to expose materials simultaneously or sequentially to protons, low-energy electrons, high-energy electrons, near UV radiation and vacuum UV radiation. Reflectance measurements can be made on the samples in vacuum. Prolonged exposure to the space environment will decrease the polymer film's transmission and thus reduce the conversion efficiency. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance to space environmental exposure. Spectral results and the material ranking according to transmission loss are presented.

Phase change energy storage for solar dynamic power systems

NASA Technical Reports Server (NTRS)

Chiaramonte, F. P.; Taylor, J. D.

1992-01-01

This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

Phase change energy storage for solar dynamic power systems

NASA Astrophysics Data System (ADS)

Chiaramonte, F. P.; Taylor, J. D.

This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

Astrophysics with Extraterrestrial Materials

NASA Astrophysics Data System (ADS)

Nittler, Larry R.; Ciesla, Fred

2016-09-01

Extraterrestrial materials, including meteorites, interplanetary dust, and spacecraft-returned asteroidal and cometary samples, provide a record of the starting materials and early evolution of the Solar System. We review how laboratory analyses of these materials provide unique information, complementary to astronomical observations, about a wide variety of stellar, interstellar and protoplanetary processes. Presolar stardust grains retain the isotopic compositions of their stellar sources, mainly asymptotic giant branch stars and Type II supernovae. They serve as direct probes of nucleosynthetic and dust formation processes in stars, galactic chemical evolution, and interstellar dust processing. Extinct radioactivities suggest that the Sun's birth environment was decoupled from average galactic nucleosynthesis for some tens to hundreds of Myr but was enriched in short-lived isotopes from massive stellar winds or explosions shortly before or during formation of the Solar System. Radiometric dating of meteorite components tells us about the timing and duration over which solar nebula solids were assembled into the building blocks of the planets. Components of the most primitive meteoritical materials provide further detailed constraints on the formation, processing, and transport of material and associated timescales in the Sun's protoplanetary disk as well as in other forming planetary systems.

Interactive Learning During Solar Maximum

NASA Technical Reports Server (NTRS)

Ashour-Abdalla, Maha; Curtis, Steven (Technical Monitor)

2001-01-01

The goal of this project is to develop and distribute e-educational material for space science during times of solar activity that emphasizes underlying basic science principles of solar disturbances and their effects on Earth. This includes materials such as simulations, animations, group projects and other on-line materials to be used by students either in high school or at the introductory college level. The on-line delivery tool originally intended to be used is known as Interactive Multimedia Education at a Distance (IMED), which is a web-based software system used at UCLA for interactive distance learning. IMED is a password controlled system that allows students to access text, images, bulletin boards, chat rooms, animation, simulations and individual student web sites to study science and to collaborate on group projects.

Material Science for High-Efficiency Photovoltaics: From Advanced Optical Coatings to Cell Design for High-Temperature Applications

NASA Astrophysics Data System (ADS)

Perl, Emmett Edward

Solar cells based on III-V compound semiconductors are ideally suited to convert solar energy into electricity. The highest efficiency single-junction solar cells are made of gallium arsenide, and have attained an efficiency of 28.8%. Multiple III-V materials can be combined to construct multijunction solar cells, which have reached record efficiencies greater than 45% under concentration. III-V solar cells are also well suited to operate efficiently at elevated temperatures, due in large part to their high material quality. These properties make III-V solar cells an excellent choice for use in concentrator systems. Concentrator photovoltaic systems have attained module efficiencies that exceed 40%, and have the potential to reach the lowest levelized cost of electricity in sunny places like the desert southwest. Hybrid photovoltaic-thermal solar energy systems can utilize high-temperature III-V solar cells to simultaneously achieve dispatchability and a high sunlight-to-electricity efficiency. This dissertation explores material science to advance the state of III-V multijunction solar cells for use in concentrator photovoltaic and hybrid photovoltaic-thermal solar energy systems. The first half of this dissertation describes work on advanced optical designs to improve the efficiency of multijunction solar cells. As multijunction solar cells move to configurations with four or more subcells, they utilize a larger portion of the solar spectrum. Broadband antireflection coatings are essential to realizing efficiency gains for these state-of-the-art cells. A hybrid design consisting of antireflective nanostructures placed on top of multilayer interference-based optical coatings is developed. Antireflection coatings that utilize this hybrid approach yield unparalleled performance, minimizing reflection losses to just 0.2% on sapphire and 0.6% on gallium nitride for 300-1800nm light. Dichroic mirrors are developed for bonded 5-junction solar cells that utilize InGaN as a top junction. These designs maximize reflection of high-energy light for an InGaN top junction while minimizing reflection of low-energy light that would be absorbed by the lower four junctions. Increasing the reflectivity of high-energy photons enables a second pass of light through the InGaN cell, leading to increased absorption and a higher photocurrent. These optical designs enhanced the efficiency of a 2.65eV InGaN solar cell to a value of 3.3% under the AM0 spectrum, the highest reported efficiency for a standalone InGaN solar cell. The second half of the dissertation describes the development of III-V solar cells for high-temperature applications. As the operating temperature of a solar cell is increased, the ideal bandgap of the top junction increases. AlGaInP solar cells with bandgaps ranging from 1.9eV to 2.2eV are developed. A 2.03eV AlGaInP solar cell is demonstrated with a bandgap-voltage offset of 440mV, the lowest of any AlGaInP solar cell reported to date. Single-junction AlGaInP, GaInP, and GaAs solar cells designed for high-temperature operation are characterized up to a temperature of 400°C. The cell properties are compared to an analytical drift-diffusion model, and we find that a fundamental increase in the intrinsic carrier concentration, ni, dominates the temperature dependence of the dark currents, open-circuit voltage, and cell efficiency. These findings provide a valuable guide to the design of any system that requires high-temperature solar cell operation.

Thermotropic and Thermochromic Polymer Based Materials for Adaptive Solar Control

PubMed Central

Seeboth, Arno; Ruhmann, Ralf; Mühling, Olaf

2010-01-01

The aim of this review is to present the actual status of development in adaptive solar control by use of thermotropic and organic thermochromic materials. Such materials are suitable for application in smart windows. In detail polymer blends, hydrogels, resins, and thermoplastic films with a reversible temperature-dependent switching behavior are described. A comparative evaluation of the concepts for these energy efficient materials is given as well. Furthermore, the change of strategy from ordinary shadow systems to intrinsic solar energy reflection materials based on phase transition components and a first remark about their realization is reported. Own current results concerning extruded films and high thermally stable casting resins with thermotropic properties make a significant contribution to this field. PMID:28883374

SOLTECH 1992 proceedings: Solar Process Heat Program, volume 1

NASA Astrophysics Data System (ADS)

1992-03-01

This document is a limited Proceedings, documenting the presentations given at the symposia conducted by the U.S. Department of Energy's (DOE) Solar Industrial Program and Solar Thermal Electrical Program at SOLTECH92. The SOLTECH92 national solar energy conference was held in Albuquerque, New Mexico during the period February 17-20, 1992. The National Renewable Energy Laboratory manages the Solar Industrial Program; Sandia National Laboratories (Albuquerque) manages the Solar Thermal Electric Program. The symposia sessions were as follows: (1) Solar Industrial Program and Solar Thermal Electric Program Overviews, (2) Solar Process Heat Applications, (3) Solar Decontamination of Water and Soil, (4) Solar Building Technologies, (5) Solar Thermal Electric Systems, and (6) Photovoltaic (PV) Applications and Technologies. For each presentation given in these symposia, these Proceedings provide a one- to two-page abstract and copies of the viewgraphs and/or 35 mm slides utilized by the speaker. Some speakers provided additional materials in the interest of completeness. The materials presented in this document were not subjected to a peer review process.

Nebula Scale Mixing Between Non-Carbonaceous and Carbonaceous Chondrite Reservoirs: Testing the Grand Tack Model with Almahata Sitta Stones

NASA Technical Reports Server (NTRS)

Yin, Q.-Z.; Sanborn, M. E.; Goodrich, C. A.; Zolensky, M.; Fioretti, A. M.; Shaddad, M.; Kohl, I. E.; Young, E. D.

2018-01-01

There is an increasing number of Cr-O-Ti isotope studies that show that solar system materials are divided into two main populations, one carbonaceous chondrite (CC)-like and the other is non-carbonaceous (NCC)-like, with minimal mixing between them attributed to a gap opened in the propoplanetary disk due to Jupiter's formation. The Grand Tack model suggests that there should be a particular time in the disk history when this gap is breached and ensuring a subsequent large-scale mixing between S- and C-type asteroids (inner solar system and outer solar system materials), an idea supported by our recent work on chondrule (Delta)17O-(epsilon)54Cr isotope systematics.

Real-time and accelerated outdoor endurance testing of solar cells

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Anagnostou, E.

1977-01-01

Real-time and accelerated outdoor endurance testing was performed on a variety of samples of interest to the National Photovoltaic Conversion Program. The real-time tests were performed at seven different sites and the accelerated tests were performed at one of those sites in the southwestern United States. The purpose of the tests were to help evaluate the lifetime of photovoltaic systems. Three types of samples were tested; transmission samples of possible cover materials, sub-modules constructed using these materials attached to solar cells, and solar cell modules produced by the manufacturers for the ERDA program. Results indicate that suitable cover materials are glass, FEP-A and PFA. Dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants.

Design and Analysis of the Aperture Shield Assembly for a Space Solar Receiver

NASA Technical Reports Server (NTRS)

Strumpf, Hal J.; Trinh, Tuan; Westelaken, William; Krystkowiak, Christopher; Avanessian, Vahe; Kerslake, Thomas W.

1997-01-01

A joint U.S./Russia program has been conducted to design, develop, fabricate, launch, and operate the world's first space solar dynamic power system on the Russian Space Station Mir. The goal of the program was to demonstrate and confirm that solar dynamic power systems are viable for future space applications such as the International Space Station (ISS). The major components of the system include a solar receiver, a closed Brayton cycle power conversion unit, a power conditioning and control unit, a solar concentrator, a radiator, a thermal control system, and a Space Shuttle carrier. Unfortunately, the mission was demanifested from the ISS Phase 1 Space Shuttle Program in 1996. However, NASA Lewis is proposing to use the fabricated flight hardware as part of an all-American flight demonstration on the ISS in 2002. The present paper concerns the design and analysis of the solar receiver aperture shield assembly. The aperture shield assembly comprises the front face of the cylindrical receiver and is located at the focal plane of the solar concentrator. The aperture shield assembly is a critical component that protects the solar receiver structure from highly concentrated solar fluxes during concentrator off-pointing events. A full-size aperture shield assembly was fabricated. This unit was essentially identical to the flight configuration, with the exception of materials substitution. In addition, a thermal shock test aperture shield assembly was fabricated. This test article utilized the flight materials and was used for high-flux testing in the solar simulator test rig at NASA Lewis. This testing is described in a companion paper.

Increasing the efficiency of solar thermal panels

NASA Astrophysics Data System (ADS)

Dobrnjac, M.; Latinović, T.; Dobrnjac, S.; Živković, P.

2016-08-01

The popularity of solar heating systems is increasing for several reasons. These systems are reliable, adaptable and pollution-free, because the renewable solar energy is used. There are many variants of solar systems in the market mainly constructed with copper pipes and absorbers with different quality of absorption surface. Taking into account the advantages and disadvantages of existing solutions, in order to increase efficiency and improve the design of solar panel, the innovative solution has been done. This new solar panel presents connection of an attractive design and the use of constructive appropriate materials with special geometric shapes. Hydraulic and thermotechnical tests that have been performed on this panel showed high hydraulic and structural stability. Further development of the solar panel will be done in the future in order to improve some noticed disadvantages.

Researcher and Mechanic with Solar Collector in Solar Simulator Cell

NASA Image and Video Library

1976-08-21

Researcher Susan Johnson and a mechanic examine a flat-plate solar collector in the Solar Simulator Cell in the High Temperature Composites Laboratory at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The Solar Simulator Cell allowed the researchers to control the radiation levels, air temperature, airflow, and fluid flow. The flat-plate collector, seen in a horizontal position here, was directed at the solar simulator, seen above Johnson, during the tests. Lewis researchers were studying the efficiency of various flat- plate solar collector designs in the 1970s for temperature control systems in buildings. The collectors consisted of a cover material, absorber plate, and parallel flow configuration. The collector’s absorber material and coating, covers, honeycomb material, mirrors, vacuum, and tube attachment could all be modified. Johnson’s study analyzed 35 collectors. Johnson, a lifelong pilot, joined NASA Lewis in 1974. The flat-plate solar collectors, seen here, were her first research project. Johnson also investigated advanced heat engines for general aviation and evaluated variable geometry combustors and liners. Johnson earned the Cleveland Technical Society’s Technical Achievement Award in 1984.

High-Efficiency, Multijunction Solar Cells for Large-Scale Solar Electricity Generation

NASA Astrophysics Data System (ADS)

Kurtz, Sarah

2006-03-01

A solar cell with an infinite number of materials (matched to the solar spectrum) has a theoretical efficiency limit of 68%. If sunlight is concentrated, this limit increases to about 87%. These theoretical limits are calculated using basic physics and are independent of the details of the materials. In practice, the challenge of achieving high efficiency depends on identifying materials that can effectively use the solar spectrum. Impressive progress has been made with the current efficiency record being 39%. Today's solar market is also showing impressive progress, but is still hindered by high prices. One strategy for reducing cost is to use lenses or mirrors to focus the light on small solar cells. In this case, the system cost is dominated by the cost of the relatively inexpensive optics. The value of the optics increases with the efficiency of the solar cell. Thus, a concentrator system made with 35%- 40%-efficient solar cells is expected to deliver 50% more power at a similar cost when compare with a system using 25%-efficient cells. Today's markets are showing an opportunity for large concentrator systems that didn't exist 5-10 years ago. Efficiencies may soon pass 40% and ultimately may reach 50%, providing a pathway to improved performance and decreased cost. Many companies are currently investigating this technology for large-scale electricity generation. The presentation will cover the basic physics and more practical considerations to achieving high efficiency as well as describing the current status of the concentrator industry. This work has been authored by an employee of the Midwest Research Institute under Contract No. DE- AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States Government purposes.

Optical system design of solar-blind UV target simulator with long focal length

NASA Astrophysics Data System (ADS)

Chen, Yu; Huo, Furong; Zheng, Liqin

2014-11-01

Ultraviolet (UV) radiation of 200nm-300nm waveband from the sun is absorbed by atmosphere, which is often referred to the solar-blind region of the solar spectrum. Solar-blind characteristics of this waveband have important application value, especially in military fields. The application of solar-blind waveband has developed very rapidly, which is receiving more and more attention. Sometimes, to test the performance of a UV optical system, a standard solar-blind UV target simulator is needed as the UV light source. In this paper, an optical system of a solar-blind UV target simulator is designed with waveband 240nm-280nm. To simulate a far UV target, the focal length of this UV optical system needs to be long. Besides, different field of view (FOV) of the system should meet aplanatic condition. The optional materials are very few for UV optical systems, in which only CaF2 and JGS1 are commonly used. Various aberrations are difficult to be corrected. To save production cost and enhance the precision of fabrication and test, aspheric surfaces and binary elements are not adopted in the system. Moreover, doublet or triplet cannot be used in UV optical system considering possible cracking for different thermal expansion coefficients of different materials. After optimization, the system is composed of 4 lenses with focal length 500mm. MTF curves of different FOV coincide together. The maximum RMS radius of the optimized system has almost the same size as Airy disk, which proves the good image quality after system optimization. The aplanatic condition is met very well in this system. In the spot diagram, root mean square (RMS) radius changes from 3 microns to 3.6 microns, which has similar size with Airy disk and meets aplanatic condition very well. This optical system of solar-blind UV target simulator also has relatively loose tolerance data, which can prove the system is designed in an optimal state.

Distribution of p-process 174Hf in early solar system materials and the origin of nucleosynthetic Hf and W isotope anomalies in Ca-Al rich inclusions

NASA Astrophysics Data System (ADS)

Peters, Stefan T. M.; Münker, Carsten; Pfeifer, Markus; Elfers, Bo-Magnus; Sprung, Peter

2017-02-01

Some nuclides that were produced in supernovae are heterogeneously distributed between different meteoritic materials. In some cases these heterogeneities have been interpreted as the result of interaction between ejecta from a nearby supernova and the nascent solar system. Particularly in the case of the oldest objects that formed in the solar system - Ca-Al rich inclusions (CAIs) - this view is confirm the hypothesis that a nearby supernova event facilitated or even triggered solar system formation. We present Hf isotope data for bulk meteorites, terrestrial materials and CAIs, for the first time including the low-abundance isotope 174Hf (∼0.16%). This rare isotope was likely produced during explosive O/Ne shell burning in massive stars (i.e., the classical "p-process"), and therefore its abundance potentially provides a sensitive tracer for putative heterogeneities within the solar system that were introduced by supernova ejecta. For CAIs and one LL chondrite, also complementary W isotope data are reported for the same sample cuts. Once corrected for small neutron capture effects, different chondrite groups, eucrites, a silicate inclusion of a IAB iron meteorite, and terrestrial materials display homogeneous Hf isotope compositions including 174Hf. Hafnium-174 was thus uniformly distributed in the inner solar system when planetesimals formed at the <50 ppm level. This finding is in good agreement with the evidently homogeneous distributions of p-process isotopes 180W, 184Os and possibly 190Pt between different iron meteorite groups. In contrast to bulk meteorite samples, CAIs show variable depletions in p-process 174Hf with respect to the inner solar system composition, and also variable r-process (or s-process) Hf and W contributions. Based on combined Hf and W isotope compositions, we show that CAIs sampled at least one component in which the proportion of r- and s-process derived Hf and W deviates from that of supernova ejecta. The Hf and W isotope anomalies in CAIs are therefore best explained by selective processing of presolar carrier phases prior to CAI formation, and not by a late injection of supernova materials. Likewise, other isotope anomalies in additional elements in CAIs relative to the bulk solar system may reflect the same process. The isotopic heterogeneities between the first refractory condensates may have been eradicated partially during CAI formation, because W isotope anomalies in CAIs appear to decrease with increasing W concentrations as inferred from time-integrated 182W/184W. Importantly, the 176Lu-176Hf and 182Hf-182W chronometers are not significantly affected by nucleosynthetic heterogeneity of Hf isotopes in bulk meteorites, but may be affected in CAIs.

A Distant Solar System Artist Concept

NASA Image and Video Library

2004-12-09

This artist concept depicts a distant hypothetical solar system, similar in age to our own. Looking inward from the system outer fringes, a ring of dusty debris can be seen, and within it, planets circling a star the size of our Sun. This debris is all that remains of the planet-forming disk from which the planets evolved. Planets are formed when dusty material in a large disk surrounding a young star clumps together. Leftover material is eventually blown out by solar wind or pushed out by gravitational interactions with planets. Billions of years later, only an outer disk of debris remains. These outer debris disks are too faint to be imaged by visible-light telescopes. They are washed out by the glare of the Sun. However, NASA's Spitzer Space Telescope can detect their heat, or excess thermal emission, in infrared light. This allows astronomers to study the aftermath of planet building in distant solar systems like our own. http://photojournal.jpl.nasa.gov/catalog/PIA07096

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1981-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Solar power satellite system definition study, phase 2.

NASA Technical Reports Server (NTRS)

1979-01-01

A program plan for the Solar Power Satellite Program is presented. The plan includes research, development, and evaluation phase, engineering and development and cost verification phase, prototype construction, and commercialization. Cost estimates and task requirements are given for the following technology areas: (1) solar arrays; (2) thermal engines and thermal systems; (3) power transmission (to earth); (4) large space structures; (5) materials technology; (6) system control; (7) space construction; (8) space transportation; (9) power distribution, and space environment effects.

Photovoltaics and solar thermal conversion to electricity - Status and prospects

NASA Technical Reports Server (NTRS)

Alper, M. E.

1979-01-01

Photovoltaic power system technology development includes flat-plate silicon solar arrays and concentrating solar cell systems, which use silicon and other cell materials such as gallium arsenide. System designs and applications include small remote power systems ranging in size from tens of watts to tens of kilowatts, intermediate load-center applications ranging in size from tens to hundreds of kilowatts, and large central plant installations, as well as grid-connected rooftop applications. The thermal conversion program is concerned with large central power systems and small power applications.

Design of a Solar Sail Mission to Mars

NASA Technical Reports Server (NTRS)

Eastridge, Richard; Funston, Kerry; Okia, Aminat; Waldrop, Joan; Zimmerman, Christopher

1989-01-01

An evaluation of the design of the solar sail includes key areas such as structures, sail deployment, space environmental effects, materials, power systems, telemetry, communications, attitude control, thermal control, and trajectory analysis. Deployment and material constraints determine the basic structure of the sail, while the trajectory of the sail influences the choice of telemetry, communications, and attitude control systems. The thermal control system of the sail for the structures and electronics takes into account the effects of the space environment. Included also are a cost and weight estimate for the sail.

Chandra Observations of the Solar System

NASA Astrophysics Data System (ADS)

Lisse, Carey

2014-11-01

Many solar system objects are now known to emit X-rays due to charge-exchange between highly charged solar wind (SW) minor ions and neutrals in their extended atmospheres, including Earth, Venus, Mars, Jupiter, and the heliosphere, with total power outputs on the MW - GW scale. (Currently only upper limits exist for Saturn and Pluto.) Chandra observations of their morphology, spectra, and time dependence provide important information about the neutral atmosphere structure and the SW flux and charge state. Chandra observations of solar x-ray scattering from Earth, Venus, Mars, Jupiter, Saturn, and the Moon have also provided important clues for the scattering material and the solar radiation field at the body. We present here a 15 year summary of Chandra's solar system observations.

Solar photovoltaic reflective trough collection structure

DOEpatents

Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

2015-11-19

A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

Complex Organic Materials on Planetary Satellites and Other Small Bodies of the Solar System

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.

2006-01-01

The search for organic materials on small bodies of the Solar System is conducted spectroscopically from Earth-based telescopes and from spacecraft. Although the carbonaceous meteorites carry a significant inventory of complex organic solids, the sources of these meteorites have not been identified. Infrared spectra of a sample of the suspected sources, the C- and D-class asteroids, including new data from the Spitzer Space Telescope, show signatures of silicates, but none diagnostic of organic compounds. In the absence of discrete spectral features, the low albedos and colors in the visible and near-IR spectral regions are the principal links between the organic-bearing meteorites and the asteroids. While Pluto and a few trans-neptunian objects show spectral signatures of frozen CH4. Solid CH3OH has been identified on two Centaur objects in the outer Solar System. In some cases the red colors of those objects suggest the presence of tholins. The VIMS instrument aboard the Cassini spacecraft in orbit around Saturn has detected near-IR spectral features on at least three of Saturn's satellites that are indicative or suggestive of organic molecules. One entire hemisphere of the satellite Iapetus is covered with low-albedo material that shows a spectral signature of aromatic hydrocarbons (3.3 microns) and the -CH2 stretching mode bands of an aliphatic component. Organics absorbing at 3.44 microns are suspected in the region of the south pole of Enceladus, and also on the surface of Phoebe. Organic material may originate on icy bodies in the current epoch by various processes of energy deposition into native material, or they may fall to the surface from an external (probably cometary) source. Some organic material may be pre-solar, having originated in the interstellar medium before the formation of the Solar System. Using the techniques of remote sensing, its detection and analysis are slow and difficult.

Solar energy concentrator system for crystal growth and zone refining in space

NASA Technical Reports Server (NTRS)

Mcdermit, J. H.

1975-01-01

The technological feasibility of using solar concentrators for crystal growth and zone refining in space has been performed. Previous studies of space-deployed solar concentrators were reviewed for their applicability to materials processing and a new state-of-the-art concentrator-receiver radiation analysis was developed. The radiation analysis is in the form of a general purpose computer program. It was concluded from this effort that the technology for fabricating, orbiting and deploying large solar concentrators has been developed. It was also concluded that the technological feasibility of space processing materials in the focal region of a solar concentrator depends primarily on two factors: (1) the ability of a solar concentrator to provide sufficient thermal energy for the process and (2) the ability of a solar concentrator to provide a thermal environment that is conductive to the processes of interest. The analysis indicate that solar concentrators can satisfactorily provide both of these factors.

Design, development and fabrication of a Solar Experiment Alignment Sensor (SEAS)

NASA Technical Reports Server (NTRS)

Bancroft, J. R.; Fain, M. Z.; Johnson, D. F.

1971-01-01

The design, development and testing of a laboratory SEAS (Solar Experiment Alignment Sensor) system are presented. The system is capable of overcoming traditional alignment and calibration problems to permit pointing anywhere on the solar disc to an accuracy of five arc seconds. The concept, development and laboratory testing phases of the program are discussed, and particular attention has been given to specific problems associated with selection of materials, and components. The conclusions summarize performance capability and discuss areas for further study including the effects of solar limb darkening and effects of annual variations in the apparent solar diameter.

Opto-electro-modulated transient photovoltage and photocurrent system for investigation of charge transport and recombination in solar cells.

PubMed

Shi, Jiangjian; Li, Dongmei; Luo, Yanhong; Wu, Huijue; Meng, Qingbo

2016-12-01

An opto-electro-modulated transient photovoltage/photocurrent system has been developed to probe microscopic charge processes of a solar cell in its adjustable operating conditions. The reliability of this system is carefully determined by electric circuit simulations and experimental measurements. Using this system, the charge transport, recombination and storage properties of a conventional multicrystalline silicon solar cell under different steady-state bias voltages, and light illumination intensities are investigated. This system has also been applied to study the influence of the hole transport material layer on charge extraction and the microscopic charge processes behind the widely considered photoelectric hysteresis in perovskite solar cells.

A performance evaluation of various coatings, substrate materials, and solar collector systems

NASA Technical Reports Server (NTRS)

Dolan, F. J.

1976-01-01

An experimental apparatus was constructed and utilized in conjunction with both a solar simulator and actual sunlight to test and evaluate various solar panel coatings, panel designs, and scaled-down collector subsystems. Data were taken by an automatic digital data acquisition system and reduced and printed by a computer system. The solar collector test setup, data acquisition system, and data reduction and printout systems were considered to have operated very satisfactorily. Test data indicated that there is a practical or useful limit in scaling down beyond which scaled-down testing cannot produce results comparable to results of larger scale tests. Test data are presented as are schematics and pictures of test equipment and test hardware.

Space Solar Power: Satellite Concepts

NASA Technical Reports Server (NTRS)

Little, Frank E.

1999-01-01

Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

Coordinated Isotopic and Mineral Characterization of Highly Fractionated 18O-Rich Silicates in the Queen Alexandra Range 99177 CR3 Chondrite

NASA Technical Reports Server (NTRS)

Nguyen, A. N.; Keller, L. P.; Messenger, S.; Rahman, Z.

2016-01-01

Carbonaceous chondrites contain a mixture of solar system condensates, pre-solar grains, and primitive organic matter. Each of these materials record conditions and processes in different regions of the solar nebula, on the meteorite parent body, and beyond the solar system. Oxygen isotopic studies of meteorite components can trace interactions of distinct oxygen isotopic reservoirs in the early solar system and secondary alteration processes. The O isotopic compositions of the earliest solar system condensates fall along a carbonaceous chondrite anhydrous mineral (CCAM) line of slope approximately 1 in a plot of delta 17O against delta 18O. This trend is attributed to mixing of material from 16O-poor and 16O-rich reservoirs. Secondary processing can induce mass-dependent fractionation of the O isotopes, shifting these compositions along a line of slope approximately 0.52. Substantial mass-dependent fractionation of O isotopes has been observed in secondary minerals in CAIs, calcite, and FUN inclusions. These fractionations were caused by significant thermal or aqueous alteration. We recently reported the identification of four silicate grains with extremely fractionated O isotopic ratios (delta 18O equals 37 - 55 per mille) in the minimally altered CR3 chondrite QUE 99177. TEM analysis of one grain indicates it is a nebular condensate that did not experience substantial alteration. The history of these grains is thus distinct from those of the aforementioned fractionated materials. To constrain the origin of the silicate grains, we conducted further Mg and Fe isotopic studies and TEM analyses of two grains.

Symposium on Space Industrialization, Huntsville, Ala., May 26, 27, 1976, Proceedings

NASA Technical Reports Server (NTRS)

1976-01-01

Space habitats are considered, with attention given the evolution of space station systems, space station habitability, space settlement planning methodology, and orbital assembly. Various aspects of the Space Transportation System are discussed, including Shuttle booster/propulsion growth concept, advanced earth orbital transportation systems technology, single-stage-to-orbit vehicles and aeromaneuvering orbit transfer vehicles. Materials processing in space is examined, with emphasis on biological materials, metallurgical materials, the uses of space ultrahigh vacuum, and extraterrestrial mining and industrial processing. Solar space power is investigated, with attention given the potential of satellite solar power stations, thermal engine power satellites and microwave power transmission to earth. Individual items are announced in this issue.

Nebular and Interstellar Materials in a Giant Cluster IDP of Probable Cometary Origin

NASA Technical Reports Server (NTRS)

Messenger, S.; Brownlee, D. E.; Joswiak, D. J.; Nguyen, A. N.

2015-01-01

Comets contain a complex mixture of materials with presolar and Solar System origins. Chondritic porous interplanetary dust particles (CP-IDPs) are associated with comets by their fragile nature, unequilibrated anhydrous mineralogy and high abundances of circumstellar grains and isotopically anomalous organic materials. Comet 81P/Wild 2 samples returned by the Stardust spacecraft contain presolar materials as well as refractory 16O-rich Ca-Al-rich inclusion- (CAI), chondrule-, and AOA-like materials. We are conducting coordinated chemical, mineralogical, and isotopic studies of a giant cluster CP-IDP (U2-20-GCA) to determine the proportions of inner Solar System and interstellar materials. We previously found that this IDP contains abundant presolar silicates (approx. 1,800 ppm) and 15N-rich hotspots [6].

The effect of sunshine testing on terrestrial solar cell system components

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Anagnostou, E.

1975-01-01

Samples of FEP encapsulated silicon solar cells and various potential encapsulation or cover materials were subjected to accelerated and real time testing. By measuring changes in solar cell output or optical transmission as a function of exposure the durability of the samples was evaluated. Results are presented.

Photovoltaic concepts inspired by coherence effects in photosynthetic systems

NASA Astrophysics Data System (ADS)

Brédas, Jean-Luc; Sargent, Edward H.; Scholes, Gregory D.

2017-01-01

The past decade has seen rapid advances in our understanding of how coherent and vibronic phenomena in biological photosynthetic systems aid in the efficient transport of energy from light-harvesting antennas to photosynthetic reaction centres. Such coherence effects suggest strategies to increase transport lengths even in the presence of structural disorder. Here we explore how these principles could be exploited in making improved solar cells. We investigate in depth the case of organic materials, systems in which energy and charge transport stand to be improved by overcoming challenges that arise from the effects of static and dynamic disorder -- structural and energetic -- and from inherently strong electron-vibration couplings. We discuss how solar-cell device architectures can evolve to use coherence-exploiting materials, and we speculate as to the prospects for a coherent energy conversion system. We conclude with a survey of the impacts of coherence and bioinspiration on diverse solar-energy harvesting solutions, including artificial photosynthetic systems.

Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 3: Appendix E - N

NASA Technical Reports Server (NTRS)

Clark, T. B. (Editor)

1979-01-01

The design of a solar electric power plant for a small community is reported. Topics covered include: (1) control configurations and interface requirements for the baseline power system; (2) annual small power system output; (3) energy requirements for operation of the collectors and control building; (4) life cycle costs and reliability predictions; (5) thermal conductivities and costs of receiver insulation materials; (6) transient thermal modelling for the baseline receiver/thermal transport system under normal and inclement operating conditions; (7) high temperature use of sodium; (8) shading in a field of parabolic collectors; and (9) buffer storage materials.

Search for Primitive Matter in the Solar System

NASA Technical Reports Server (NTRS)

Libourel, G.; Michel, P.; Delbo, M.; Ganino, C.; Recio-Blanco, A.; de Laverny, P.; Zolensky, M. E.; Krot, A. N.

2017-01-01

Recent astronomical observations and theoretical modeling led to a consensus regarding the global scenario of the formation of young stellar objects (YSO) from a cold molecular cloud of interstellar dust (organics and minerals) and gas that, in some cases, leads to the formation of a planetary system. In the case of our Solar System, which has already evolved for approximately 4567 Ma, the quest is to access, through the investigation of planets, moons, cometary and asteroidal bodies, meteorites, micrometeorites, and interplanetary dust particles, the primitive material that contains the key information about the early Solar System processes and its evolution. However, laboratory analyses of extraterrestrial samples, astronomical observations and dynamical models of the Solar System evolution have not brought yet any conclusive evidence on the nature and location of primitive matter in the Solar System, preventing a clear understanding of its early stages.

Corrosion and scaling in solar heating systems

NASA Astrophysics Data System (ADS)

Foresti, R. J., Jr.

1981-12-01

Corrosion, as experienced in solar heating systems, is described in simplistic terms to familiarize designers and installers with potential problems and their solutions. The role of a heat transfer fluid in a solar system is briefly discussed, and the choice of an aqueous solution is justified. The complexities of the multiple chemical and physical reactions are discussed in order that uncertainties of corrosion behavior can be anticipated. Some basic theories of corrosion are described, aggressive environments for some common metals are identified, and the role of corrosion inhibitors is delineated. The similarities of thermal and material characteristics of a solor system and an automotive cooling system are discussed. Based on the many years of experience with corrosion in automotive systems, it is recommended that similar antifreezes and corrosion inhibitors should be used in solar systems. The importance of good solar system design and fabrication is stressed and specific characteristics that affect corrosion are identified.

An Introduction to the Solar System

NASA Astrophysics Data System (ADS)

McBride, Neil; Gilmour, Iain

2004-03-01

Compiled by a team of experts, this textbook has been designed for elementary university courses in planetary science. It starts with a tour of the Solar System and an overview of its formation that reviews in detail the terrestrial planets, giant planets and minor bodies. It concludes with a discussion of the origin of the Solar System. The text contains numerous useful learning features such as boxed summaries, student exercises with full solutions, and a glossary of terms. It is also supported by a website hosting further teaching materials.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Campbell, A. G.; Johnson, R. E.; Kenty, J. L.; Moudy, L. A.; Shaw, G. L.; Simpson, W. I.; Yang, J. J.

1978-01-01

The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of an existing vertical-chamber CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.

A thermal shield concept for the Solar Probe mission

NASA Technical Reports Server (NTRS)

Miyake, Robert N.; Millard, Jerry M.; Randolph, James E.

1991-01-01

The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center while performing a variety of fundamental experiments in space physics. Exposure to 2900 earth suns (400 W/sq cm) at perihelion imposes severe thermal and material demands on a solar shield system designed to protect the payload that will reside within the shield's shadow envelope or umbra. The design of the shield subsystem is a thermal/materials challenge requiring new technology development. While currently in the preproject study phase, anticipating a 1995 project start, shield preliminary design efforts are currently underway. This paper documents the current status of the mission concept, the materials issues, the configuration concept for the shield subsystem, the current configuration studies performed to date, and the required material testing to provide a database to support a design effort required to develop the shield subsystem.

Develop Silicone Encapsulation Systems for Terrestrial Silicon Solar Arrays

NASA Technical Reports Server (NTRS)

1979-01-01

The results of a study for Task 3 of the Low Cost Solar Array Project, directed toward the development of a cost effective encapsulation system for photovoltaic modules using silicon based materials, are reported. Results of the following are discussed: (1) weather-ometer stressing vs. weathering history of silicon and silicon modified materials; (2) humidity/temperature cycling exposure; (3) exposure at high humidity/high temperature; (4) outdoor exposure stress; (5) thermal cycling stress; and (6) UV screening agents. The plans for the next quarter are outlined.

Dark matter in the outer solar system

NASA Technical Reports Server (NTRS)

Owen, T.; Cruikshank, D.; De Bergh, C.; Geballe, T.

1994-01-01

There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.

Implantation of Martian Materials in the Inner Solar System by a Mega Impact on Mars

NASA Astrophysics Data System (ADS)

Hyodo, Ryuki; Genda, Hidenori

2018-04-01

Observations and meteorites indicate that the Martian materials are enigmatically distributed within the inner solar system. A mega impact on Mars creating a Martian hemispheric dichotomy and the Martian moons can potentially eject Martian materials. A recent work has shown that the mega-impact-induced debris is potentially captured as the Martian Trojans and implanted in the asteroid belt. However, the amount, distribution, and composition of the debris has not been studied. Here, using hydrodynamic simulations, we report that a large amount of debris (∼1% of Mars’ mass), including Martian crust/mantle and the impactor’s materials (∼20:80), are ejected by a dichotomy-forming impact, and distributed between ∼0.5–3.0 au. Our result indicates that unmelted Martian mantle debris (∼0.02% of Mars’ mass) can be the source of Martian Trojans, olivine-rich asteroids in the Hungarian region and the main asteroid belt, and some even hit the early Earth. The evidence of a mega impact on Mars would be recorded as a spike of 40Ar–39Ar ages in meteorites. A mega impact can naturally implant Martian mantle materials within the inner solar system.

Solar heated fluidized bed gasification system

NASA Technical Reports Server (NTRS)

Qader, S. A. (Inventor)

1981-01-01

A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

Solar system lithograph set for earth and space science

NASA Technical Reports Server (NTRS)

1995-01-01

A color lithographs of many of the celestial bodies within our solar system are contained in this educational set of materials. Printed on the back of each lithograph is information regarding the particular celestial body. A sheet with information listing NASA resources and electronic resources for education is included.

Solar thermal technology evaluation, fiscal year 1982. Volume 2: Technical

NASA Technical Reports Server (NTRS)

1983-01-01

The technology base of solar thermal energy is investigated. The materials, components, subsystems, and processes capable of meeting specific energy cost targets are emphasized, as are system efficiency and reliability.

Search for water and life's building blocks in the universe: A summary

NASA Astrophysics Data System (ADS)

Ehrenfreund, Pascale; Kwok, Sun; Bergin, Edwin

2015-08-01

Water and organic compounds are essential ingredients for life on Earth and possibly elsewhere. In gaseous form water acts as a coolant that allows interstellar gas clouds to collapse to form stars, whereas water ice covers small dust particles that agglomerate to form planetesimals and planets. The variety of organic compounds identified in interstellar and circumstellar regions reflects complex reaction schemes in the gaseous and icy/solid state. Interstellar volatiles and refractory materials were processed and radially mixed within the protostellar disk from which our solar system formed. But the dynamic solar nebula was also a source for new materials and the search for water and life’s building blocks on terrestrial planets, most of the outer-solar-system satellites as well as small solar system bodies reveals exciting new findings. The analysis of small bodies and their fragments, meteorites and interplanetary dust particles, sheds lights onto the extraterrestrial delivery process of prebiotic molecules to young planets and the pathways to life’s origin on Earth and possibly elsewhere. We summarize the results of invited and contributed papers of this Focus Meeting which will allow us to better assess the habitability of objects in our solar system and provide constraints for exoplanets.

Achieving High Performance Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Yang, Yang

2015-03-01

Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

Isotopic, Chemical and Mineralogical Investigation's of Extraterrestrial Materials

NASA Technical Reports Server (NTRS)

Lugmair, G. W.

2003-01-01

During the grant period we have concentrated on the following main topics: 1. Enstatite meteorites and original heterogeneity of Mn-53 distribution in the solar nebula. We have completed our studies of the enstatite chondrites. 2. Processes of planetary differentiation. We have completed our study of silicate clasts from the mesosiderite Vaca Muerta and found that the global Mn/Cr fractionation event that established mantle source reservoirs on the parent body of the Vaca Muerta silicate clasts occurred approx. 2 Ma after a similar event on the howardite-eucrite-diogenite (HED) parent body. 3. Carbonaceous chondrites. Much effort has been devoted during the last three years to the investigation of this important class of meteorites. 4. Early solar system timescales. Based on the studies of the Mn-53 - Cr-53 isotope system in various meteorites and using results obtained with other isotope chronometers we constructed an absolute time-scale for events in the early solar system. 5.Unusual meteorites. We have studied the anomalous pallasite Eagle Station. 6. The chromium isotopic composition as a tracer for extraterrestrial material on Earth. Based on the observed difference in the Cr-53/Cr-52 ratios between Earth and the other solar system objects we developed a method for detecting cosmic materials on Earth using the Cr-53/Cr-52 ratio as a tracer.

Encapsulation task of the low-cost silicon solar array project. Investigation of test methods, material properties, and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.; Baum, B.; White, R. A.

1978-01-01

The results of an investigation of solar module encapsulation systems applicable to the Low-Cost Solar Array Project 1986 cost and performance goals are presented. Six basic construction elements were identified and their specific uses in module construction defined. A uniform coating basis was established for each element. The survey results were also useful in revealing price ranges for classes of materials and estimating the cost allocation for each element within the encapsulating cost goal. The six construction elements were considered to be substrates, superstrates, pottants, adhesives, outer covers and back covers.

Radiation Processing of Polycyclic Aromatic Hydrocarbons (PAHs) in Space: ICEE PoC

NASA Technical Reports Server (NTRS)

Mattioda, Andrew; Cruz-Diaz, Gustavo; Barnhardt, Michael; Ging, Andrew; Schneider, Todd; Vaughn, Jason; Quigley, Emmett; Phillips, Brandon

2017-01-01

Small Polycyclic Aromatic Hydrocarbon molecules or PAHs (<30 carbon atoms) have been identified in comets, meteorites, asteroids, and interplanetary dust particles in our Solar System, while PAHs in the Interstellar Medium (ISM) tend to be much larger, usually between 50 to 100 carbon atoms in size. The cause of the size disparity between PAHs found in the ISM and Solar System as well as their influence on Solar System organics is not yet understood. Two chemical evolutionary paths have been proposed to explain the inventory of solar system organics. In one the prebiotic material was formed from the radiation induced modification of large pre-solar carbon-bearing species (e.g. ISM PAHs). The second path suggests that Solar System prebiotic matter is the result of bottom-up synthesis from small reactive molecules after the Solar System was formed. In this second scenario very few ISM PAHs survived the harsh pre-solar radiation as aromatic structures. ICEE PoC (ICEE Proof of Concept) investigated factors impacting the chemical evolution of large PAHs irradiated under conditions similar to the proto-solar nebula. Likewise ICEE PoC will refine the technical parameters of the proposed ICEE (Institute for Carbon Evolution Experiment) laboratory.

Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

NASA Astrophysics Data System (ADS)

Sholin, Veronica

Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the efficiency of LSCs based on small molecule laser dyes and on quantum dots. Factors affecting the optical efficiency of the system such as the luminescing properties of the fluorophors were examined. The experimental results were compared to Monte-Carlo simulations. Our results suggest that commercially available quantum dots cannot serve as viable LSC dyes because of large absorption/emission band overlap and relatively low quantum yield. Materials such as Red F demonstrate that semi-conducting polymers with high quantum yield and small absorption/emission band overlap are good candidates for LSCs. Recently, a solar cell system based purely on CdSe and Cite nanoparticles as the absorbing materials was proposed ans it was suggested that its operational mechanism was that of polymer donor/acceptor systems. Here we present solar cells consisting of a sintered active bilayer of CdSe and PbSe nanoparticles in the structure ITO/CdSe/interlayer/PbSe/Al, where an interlayer of LiF or Al2O3 was found necessary to prevent low shunt resistance from suppressing the photovoltaic behavior. We fabricated unoptimized solar cells with a short-circuit current of 6 mA/cm2, an open-circuit voltage of 0.18 V, and a fill factor of 41%. External quantum efficiency spectra revealed that photons from the infrared portion of the spectrum were not collected, suggesting that the low bandgap PbSe film did not contribute to the photocurrent of the structure despite exhibiting photoconductivity. Other measurements, however, showed that the PbSe film was indeed necessary to produce a photovoltage and transport electrons. Through sintering, the nanoparticle films acquired bandgaps similar to those of the corresponding bulk materials and became more conductive. Because the PbSe films were found to be considerably more conductive than the CdSe ones, we suggest that the PbSe layer is effectively behaving like a low conductivity electrical contact. Therefore, in contrast to the photovoltaics presented in the seminal research on CdSe/Cite solar cells, the CdSe/PbSe solar cell system presented here does not follow typical type-II heterojunction donor/acceptor models used to describe organic polymer solar cells.

Microgravity fluid management requirements of advanced solar dynamic power systems

NASA Technical Reports Server (NTRS)

Migra, Robert P.

1987-01-01

The advanced solar dynamic system (ASDS) program is aimed at developing the technology for highly efficient, lightweight space power systems. The approach is to evaluate Stirling, Brayton and liquid metal Rankine power conversion systems (PCS) over the temperature range of 1025 to 1400K, identify the critical technologies and develop these technologies. Microgravity fluid management technology is required in several areas of this program, namely, thermal energy storage (TES), heat pipe applications and liquid metal, two phase flow Rankine systems. Utilization of the heat of fusion of phase change materials offers potential for smaller, lighter TES systems. The candidate TES materials exhibit large volume change with the phase change. The heat pipe is an energy dense heat transfer device. A high temperature application may transfer heat from the solar receiver to the PCS working fluid and/or TES. A low temperature application may transfer waste heat from the PCS to the radiator. The liquid metal Rankine PCS requires management of the boiling/condensing process typical of two phase flow systems.

Solar power satellite system definition study. Part 3: Preferred concept system definition

NASA Technical Reports Server (NTRS)

1978-01-01

A concise but complete system description for the preferred concept of the Solar Power Satellite System is presented. Significant selection decisions included the following: (1) single crystal silicon solar cells; (2) glass encapsulated solar cell blankets; (3) concentration ratio 1; (4) graphite composite materials for primary structure; (5) electric propulsion for attitude control; (6) klystron RF amplifier tubes for the transmitter; (7) one kilometer diameter transmitter with a design trans mission link output power of 5,000 megawatts; (8) construction in low earth orbit with self-powered transfer of satellite modules to geosynchronous orbit; and (9) two-stage winged fully reusable rocket vehicle for transportation to low earth orbit.

The future of Stardust science

NASA Astrophysics Data System (ADS)

Westphal, A. J.; Bridges, J. C.; Brownlee, D. E.; Butterworth, A. L.; de Gregorio, B. T.; Dominguez, G.; Flynn, G. J.; Gainsforth, Z.; Ishii, H. A.; Joswiak, D.; Nittler, L. R.; Ogliore, R. C.; Palma, R.; Pepin, R. O.; Stephan, T.; Zolensky, M. E.

2017-09-01

Recent observations indicate that >99% of the small bodies in the solar system reside in its outer reaches—in the Kuiper Belt and Oort Cloud. Kuiper Belt bodies are probably the best-preserved representatives of the icy planetesimals that dominated the bulk of the solid mass in the early solar system. They likely contain preserved materials inherited from the protosolar cloud, held in cryogenic storage since the formation of the solar system. Despite their importance, they are relatively underrepresented in our extraterrestrial sample collections by many orders of magnitude ( 1013 by mass) as compared with the asteroids, represented by meteorites, which are composed of materials that have generally been strongly altered by thermal and aqueous processes. We have only begun to scratch the surface in understanding Kuiper Belt objects, but it is already clear that the very limited samples of them that we have in our laboratories hold the promise of dramatically expanding our understanding of the formation of the solar system. Stardust returned the first samples from a known small solar system body, the Jupiter-family comet 81P/Wild 2, and, in a separate collector, the first solid samples from the local interstellar medium. The first decade of Stardust research resulted in more than 142 peer-reviewed publications, including 15 papers in Science. Analyses of these amazing samples continue to yield unexpected discoveries and to raise new questions about the history of the early solar system. We identify nine high-priority scientific objectives for future Stardust analyses that address important unsolved problems in planetary science.

Develop Silicone Encapsulation Systems for Terrestrial Silicon Solar Arrays

NASA Technical Reports Server (NTRS)

1979-01-01

A cost effective encapsulant system was identified and a silicone acrylic cover material containing a durable ultraviolet screening agent was prepared. The effectiveness of the cover material in protecting photo-oxidatively sensitive polymers was demonstrated.

Design package for instrumentation of the Decade 80 house in Tucson, Arizona

NASA Technical Reports Server (NTRS)

1978-01-01

A design package covering instrumentation and system design for the Decade 80 House in Tucson, Arizona is presented. The solar house is instrumented for the purpose of gathering data to determine the solar heating and cooling system performance. The use of copper in the construction of the house is a first choice construction material because it conducts heat and resists corrosion better than other materials and therefore provides a more efficient and economical system. Equipment and site specifications are reported, along with floor plans showing the location of the site instrumentation hardware.

Thermal control system and method for a passive solar storage wall

DOEpatents

Ortega, Joseph K. E.

1984-01-01

The invention provides a system and method for controlling the storing and elease of thermal energy from a thermal storage wall wherein said wall is capable of storing thermal energy from insolation of solar radiation. The system and method includes a device such as a plurality of louvers spaced a predetermined distance from the thermal wall for regulating the release of thermal energy from the thermal wall. This regulating device is made from a material which is substantially transparent to the incoming solar radiation so that when it is in any operative position, the thermal storage wall substantially receives all of the impacting solar radiation. The material in the regulating device is further capable of being substantially opaque to thermal energy so that when the device is substantially closed, thermal release of energy from the storage wall is substantially minimized. An adjustment device is interconnected with the regulating mechanism for selectively opening and closing it in order to regulate the release of thermal energy from the wall.

Solar project cost report for Ingham County, Medical Care Facility, Okemos, Michigan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The solar energy system supplies service hot water for a 204 bed medical and geriatric care facility with laundry and kitchen. The system was designed at the time the building was designed. The 9,374 ft/sup 2/ of collectors were manufactured by Revere Copper and Brass, Inc., and are mounted at grade level behind the building. Solar heated water for use in heating service water is stored in a 5000 gallon hot water storage tank. The heaviest use of hot water occurs during the day so the requirement for thermal storage is modest. The construction costs of this solar project aremore » presented. Category costs are listed by materials, direct labor, ad subcontract costs. The subcontract costs include both materials, labor, overhead and profit for electrical, control and other minor subcontractors. The installed cost of the system was $312,825 not including prime contractor overhead and profit and general and administrative costs. (MHR)« less

Photovoltaic Research | NREL

Science.gov Websites

the cost of solar cells, modules, and systems; and improving the reliability of PV components and Science-funded Center for Next Generation of Materials by Design. Reliability. Real-Time PV and Solar Research Solar panels line the rooftop of the parking garage at the south table mountain campus of

Observations and Laboratory Data of Planetary Organics

NASA Technical Reports Server (NTRS)

Roush, Ted L.

2002-01-01

Many efforts are underway to search for evidence of prebiotic materials in the outer solar system. Current and planned Mars missions obtain remote sensing observations that can be used to address the potential presence of prebiotic materials. Additional missions to, and continuing earth-based observations of, more distant solar system objects will also provide remote sensing observations that can be used to address the potential presence of prebiotic materials. I will present an overview of on-going observations, associated laboratory investigations of candidate materials, and theoretical modeling of observational data. In the past the room temperature reflectance spectra of many residues created from HC-bearing gases and solids have been reported. The results of an investigation of what effect temperatures more representative of outer solar system surfaces (50-140K) have on the reflectance spectra of these residues, and the associated interpretations, will be presented. The relatively organic-rich Tagish Lake Meteorite has been suggested as a spectral analog for Dtype asteroids. Using a new approach that relies upon iterative use of Hapke theory and Kraniers-Kronig analysis the optical constants of TLM were estimated. The approach and results of the analysis will be presented. Use of optical constants in scattering theories, such as the Hapke theory, provide the ability to determine quantitative estimates of the relative abundances and grain sizes of candidate surface components. This approach has been applied to interpret the reflectance spectra of several outer solar system surfaces. A summary will be provided describing the results of such modeling efforts.

Refraction-Assisted Solar Thermoelectric Generator based on Phase-Change Lens

PubMed Central

Kim, Myoung-Soo; Kim, Min-Ki; Jo, Sung-Eun; Joo, Chulmin; Kim, Yong-Jun

2016-01-01

Solar thermoelectric generators (STEGs), which are used for various applications, (particularly small size electronic devices), have optical concentration systems for high energy conversion efficiency. In this study, a refraction-assisted STEG (R-STEG) is designed based on phase-change materials. As the phase-change material (PCM) changes phase from solid to liquid, its refractive index and transmittance also change, resulting in changes in the refraction of the sunlight transmitted through it, and concentration of solar energy in the phase-change lens. This innovative design facilitates double focusing the solar energy through the optical lens and a phase-change lens. This mechanism resulted in the peak energy conversion efficiencies of the R-STEG being 60% and 86% higher than those of the typical STEG at solar intensities of 1 kW m−2 and 1.5 kW m−2, respectively. In addition, the energy stored in PCM can help to generate steady electrical energy when the solar energy was removed. This work presents significant progress regarding the optical characteristic of PCM and optical concentration systems of STEGs. PMID:27283350

Refraction-Assisted Solar Thermoelectric Generator based on Phase-Change Lens.

PubMed

Kim, Myoung-Soo; Kim, Min-Ki; Jo, Sung-Eun; Joo, Chulmin; Kim, Yong-Jun

2016-06-10

Solar thermoelectric generators (STEGs), which are used for various applications, (particularly small size electronic devices), have optical concentration systems for high energy conversion efficiency. In this study, a refraction-assisted STEG (R-STEG) is designed based on phase-change materials. As the phase-change material (PCM) changes phase from solid to liquid, its refractive index and transmittance also change, resulting in changes in the refraction of the sunlight transmitted through it, and concentration of solar energy in the phase-change lens. This innovative design facilitates double focusing the solar energy through the optical lens and a phase-change lens. This mechanism resulted in the peak energy conversion efficiencies of the R-STEG being 60% and 86% higher than those of the typical STEG at solar intensities of 1 kW m(-2) and 1.5 kW m(-2), respectively. In addition, the energy stored in PCM can help to generate steady electrical energy when the solar energy was removed. This work presents significant progress regarding the optical characteristic of PCM and optical concentration systems of STEGs.

Probing the energy levels of perovskite solar cells via Kelvin probe and UV ambient pressure photoemission spectroscopy.

PubMed

Harwell, J R; Baikie, T K; Baikie, I D; Payne, J L; Ni, C; Irvine, J T S; Turnbull, G A; Samuel, I D W

2016-07-20

The field of organo-lead halide perovskite solar cells has been rapidly growing since their discovery in 2009. State of the art devices are now achieving efficiencies comparable to much older technologies like silicon, while utilising simple manufacturing processes and starting materials. A key parameter to consider when optimising solar cell devices or when designing new materials is the position and effects of the energy levels in the materials. We present here a comprehensive study of the energy levels present in a common structure of perovskite solar cell using an advanced macroscopic Kelvin probe and UV air photoemission setup. By constructing a detailed map of the energy levels in the system we are able to predict the importance of each layer to the open circuit voltage of the solar cell, which we then back up through measurements of the surface photovoltage of the cell under white illumination. Our results demonstrate the effectiveness of air photoemission and Kelvin probe contact potential difference measurements as a method of identifying the factors contributing to the open circuit voltage in a solar cell, as well as being an excellent way of probing the physics of new materials.

Development of user guidelines for ECAS display design. Volume 2: Tasks 9 and 10. [educating the public to the benefits of spacelab and the space transportation system

NASA Technical Reports Server (NTRS)

Bathurst, D. B.

1979-01-01

Lay-oriented speakers aids, articles, a booklet, and a press kit were developed to inform the press and the general public with background information on the space transportation system, Spacelab, and Spacelab 1 experiments. Educational materials relating to solar-terrestrial physics and its potential benefits to mankind were also written. A basic network for distributing audiovisual and printed materials to regional secondary schools and universities was developed. Suggested scripts to be used with visual aids describing materials science and technology and astronomy and solar physics are presented.

Space Environmental Effects on the Optical Properties of Selected Transparent Polymers

NASA Technical Reports Server (NTRS)

Edwards, David L.; Willowby, Douglas J.; Hubbs, Whitney C.; Piszczor, Michael F., Jr.; Bowden, Mary L.

1997-01-01

Transparent polymer films are currently considered for use as solar concentrating lenses for spacecraft power and propulsion systems. These polymer films concentrate solar energy onto energy conversion devices such as solar cells and thermal energy systems. Conversion efficiency is directly related to the polymer transmission. Space environmental effects will decrease the transmission and thus reduce the conversion efficiency. This investigation focuses on the effects of ultraviolet and charged particle radiation on the transmission of selected transparent polymers. Multiple candidate polymer samples were exposed to near ultraviolet (NUV) radiation to screen the materials and select optimum materials for further study. All materials experienced transmission degradation of varying degree. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance of NUV. Teflon(Tm) FEP and Teflon(Tm) PFA were selected for further study. These materials were subjected to a combined charged particle dose equivalent to 5 years in a typical geosynchronous Earth orbit (GEO). Results from these NUV screening tests and the 5 year GEO equivalent dose are presented.

Exchange of meteorites (and life?) between stellar systems.

PubMed

Melosh, H J

2003-01-01

It is now generally accepted that meteorite-size fragments of rock can be ejected from planetary bodies. Numerical studies of the orbital evolution of such planetary ejecta are consistent with the observed cosmic ray exposure times and infall rates of these meteorites. All of these numerical studies agree that a substantial fraction (up to one-third) of the ejecta from any planet in our Solar System is eventually thrown out of the Solar System during encounters with the giant planets Jupiter and Saturn. In this paper I examine the probability that such interstellar meteorites might be captured into a distant solar system and fall onto a terrestrial planet in that system within a given interval of time. The overall conclusion is that it is very unlikely that even a single meteorite originating on a terrestrial planet in our solar system has fallen onto a terrestrial planet in another stellar system, over the entire period of our Solar System's existence. Although viable microorganisms may be readily exchanged between planets in our solar system through the interplanetary transfer of meteoritic material, it seems that the origin of life on Earth must be sought within the confines of the Solar System, not abroad in the galaxy.

Infrared Spectroscopy of Anhydrous Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Keller, L. P.; Flynn, G. J.

2003-01-01

Infrared (IR) spectroscopy is the primary means of mineralogical analysis of materials outside our solar system. The identity and properties of circumstellar grains are inferred from spectral comparisons between astronomical observations and laboratory data from natural and synthetic materials. These comparisons have been facilitated by the Infrared Space Observatory (ISO), which obtained IR spectra from numerous astrophysical objects over a wide spectral range (out to 50/cm) where crystalline silicates and other phases have distinct features. The anhydrous interplanetary dust particles (IDPs) are particularly important comparison materials because some IDPs contain carbonaceous material with non-solar D/H and N-15/N-14 ratios and amorphous and crystalline silicates with non-solar 0- isotopic ratios, demonstrating that these IDPs contain preserved interstellar material. Here, we report on micro- Fourier transform (FT) IR spectrometry of IDPs, focusing on the inorganic components of primitive IDPs (FTIR spectra from the organic/carbonacecous materials in IDPs are described elsewhere).

Life of the Earth in the solar atmosphere (multimedia manual)

NASA Astrophysics Data System (ADS)

Kononovich, E. V.; Smirnova, O. B.; Matveychuk, T. V.; Jakunina, G. V.; Krasotkin, S. A.

2006-08-01

The purpose of this manual is to illustrate the major physical processes occurring in the Sun - Earth system and ecology of the planet life. The material includes three individual parts: "The Earth", "The Sun" and "The solar-terrestrial connections". Sections do not require cross-references since each of them is self-complete. Inside the sections the material is located in sequences based on the principle: from simple to complex. The material is designed for students of the senior classes of high school and junior university level interested by the problem. The section "The Earth" is devoted to the description of the basic characteristics of the planet: internal structure, magnetic field, lithosphere and an atmosphere together with various occurring in them tectonic, hydro- and atmospheric processes. The top layers of an atmosphere, an ionosphere, a zone of polar lights, radiating belts, magnetosphere are also considered. The section "The Sun" includes the following subsections: the Sun as a star, internal structure of the Sun, Solar atmosphere, solar activity, cyclicity of the solar activity, helioseismology. In the section "The solar-terrestrial connections" the previous material is used to present the influence of the active solar processes on the most various aspects of a terrestrial life: ecological, biological, mental, social, economic and so forth. The problem of forecasting of the solar activity as the key parameter determining a condition of the so-called space weather is considered.

Solar energy collection system

NASA Technical Reports Server (NTRS)

Miller, C. G.; Stephens, J. B. (Inventor)

1979-01-01

A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.

Pristine extraterrestrial material with unprecedented nitrogen isotopic variation.

PubMed

Briani, Giacomo; Gounelle, Matthieu; Marrocchi, Yves; Mostefaoui, Smail; Leroux, Hugues; Quirico, Eric; Meibom, Anders

2009-06-30

Pristine meteoritic materials carry light element isotopic fractionations that constrain physiochemical conditions during solar system formation. Here we report the discovery of a unique xenolith in the metal-rich chondrite Isheyevo. Its fine-grained, highly pristine mineralogy has similarity with interplanetary dust particles (IDPs), but the volume of the xenolith is more than 30,000 times that of a typical IDP. Furthermore, an extreme continuum of N isotopic variation is present in this xenolith: from very light N isotopic composition (delta(15)N(AIR) = -310 +/- 20 per thousand), similar to that inferred for the solar nebula, to the heaviest ratios measured in any solar system material (delta(15)N(AIR) = 4,900 +/- 300 per thousand). At the same time, its hydrogen and carbon isotopic compositions exhibit very little variation. This object poses serious challenges for existing models for the origin of light element isotopic anomalies.

Thermal and chemical evolution in the early solar system as recorded by FUN CAIs: Part I - Petrology, mineral chemistry, and isotopic composition of Allende FUN CAI CMS-1

NASA Astrophysics Data System (ADS)

Williams, C. D.; Ushikubo, T.; Bullock, E. S.; Janney, P. E.; Hines, R. R.; Kita, N. T.; Hervig, R. L.; MacPherson, G. J.; Mendybaev, R. A.; Richter, F. M.; Wadhwa, M.

2017-03-01

Detailed petrologic, geochemical and isotopic analyses of a new FUN CAI from the Allende CV3 meteorite (designated CMS-1) indicate that it formed by extensive melting and evaporation of primitive precursor material(s). The precursor material(s) condensed in a 16O-rich region (δ17O and δ18O ∼ -49‰) of the inner solar nebula dominated by gas of solar composition at total pressures of ∼10-3-10-6 bar. Subsequent melting of the precursor material(s) was accompanied by evaporative loss of magnesium, silicon and oxygen resulting in large mass-dependent isotope fractionations in these elements (δ25Mg = 30.71-39.26‰, δ29Si = 14.98-16.65‰, and δ18O = -41.57 to -15.50‰). This evaporative loss resulted in a bulk composition similar to that of compact Type A and Type B CAIs, but very distinct from the composition of the original precursor condensate(s). Kinetic fractionation factors and the measured mass-dependent fractionation of silicon and magnesium in CMS-1 suggest that ∼80% of the silicon and ∼85% of the magnesium were lost from its precursor material(s) through evaporative processes. These results suggest that the precursor material(s) of normal and FUN CAIs condensed in similar environments, but subsequently evolved under vastly different conditions such as total gas pressure. The chemical and isotopic differences between normal and FUN CAIs could be explained by sorting of early solar system materials into distinct physical and chemical regimes, in conjunction with discrete heating events, within the protoplanetary disk.

A low-cost efficient and durable low-temperature solar collector

NASA Astrophysics Data System (ADS)

Odonnell, T. P.

The considered collector utilizes a material made of ethylene-propylene-diene-monomer (EPDM). This material has been used in solar systems to heat domestic water, pools, spas, and homes by radiant energy. EPDM or ethylene propylene rubber compounds are synthetic elastomers. EPDM elastomers combine superior ozone, good heat and oxygen resistance, and very good low temperature properties to produce a compound with excellent overall age resistance. The material is extruded into 4.4 inch wide mats. Each mat has six small tubes alternating with thin webbing. The absorber mat will adhere to any clean building surface with the use of thermosetting construction-grade mastic adhesive. Carbon black contained in the mat material acts to increase the solar absorptivity. Their low cost makes the elastomers commercially very attractive. The efficiency and durability of the material are discussed.

Organic solar cells based on high dielectric constant materials: An approach to increase efficiency

NASA Astrophysics Data System (ADS)

Hamam, Khalil Jumah Tawfiq

The efficiency of organic solar cells still lags behind inorganic solar cells due to their low dielectric constant which results in a weakly screened columbic attraction between the photogenerated electron-hole system, therefore the probability of charge separating is low. Having an organic material with a high dielectric constant could be the solution to get separated charges or at least weakly bounded electron-hole pairs. Therefore, high dielectric constant materials have been investigated and studied by measuring modified metal-phthalocyanine (MePc) and polyaniline in pellets and thin films. The dielectric constant was investigated as a function of temperature and frequency in the range of 20Hz to1MHz. For MePc we found that the high dielectric constant was an extrinsic property due to water absorption and the formation of hydronuim ion allowed by the ionization of the functional groups such as sulphonated and carboxylic groups. The dielectric constant was high at low frequencies and decreasing as the frequency increase. Investigated materials were applied in fabricated bilayer heterojunction organic solar cells. The application of these materials in an organic solar cells show a significant stability under room conditions rather than improvement in their efficiency.

Develop Silicone Encapsulation Systems for Terrestrial Silicon Solar Arrays

NASA Technical Reports Server (NTRS)

1979-01-01

The results for Task 3 of the Low Cost Solar Array Project are presented. Task 3 is directed toward the development of a cost effective encapsulating system for photovoltaic modules using silicon based materials. The technical approach of the contract effort is divided into four special tasks: (1) technology review; (2) generation of concepts for screening and processing silicon encapsulation systems; (3) assessment of encapsulation concepts; and (4) evaluation of encapsulation concepts. The candidate silicon materials are reviewed. The silicon and modified silicon resins were chosen on the basis of similarity to materials with known weatherability, cost, initial tangential modulus, accelerated dirt pick-up test results and the ratio of the content of organic phenyl substitution of methyl substitution on the backbone of the silicon resin.

Recondensation of chondritic material in the early solar system: Results of thermodynamic simulation

NASA Technical Reports Server (NTRS)

Dorofeyeva, V. A.; Makalkin, A. B.; Mironenko, M. V.; Vityazev, A. V.

1993-01-01

We have performed a thermodynamic simulation of the recondensation of evaporated meteoritic material. We suggest that evaporation and recondensation occurred in impact events during the intercollision of planetesimals during the early evolution of the solar system. The source materials adopted for our model are the chondrites CI Orgueil and H5 Richardton. These chondrites are representative examples of the two extremes regarding volatile content and oxidation state. We calculated equilibrium mineral compositions of the closed systems of the Orgueil's and Richardton's elemental composition at the P-T conditions characteristic of the explosion cloud formed at a planetesimal collision. The P-T conditions are as follows: 10(exp -4) bar, and 1500 and 2000 K. The results are presented.

Solar Energy: System Sizing, Design, and Retrofit: Student Material. First Edition.

ERIC Educational Resources Information Center

Younger, Charles; Orsak, Charles G., Jr.

Designed for student use in "System Sizing, Design, and Retrofit," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, exercises, worksheets, bibliographies, and illustrations for 13 course modules. The manual, which corresponds to an instructor guide for the same course, covers the…

77 FR 26507 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

...: FEI Company, Czech Republic. Intended Use: The instrument will be used for research on primitive solar system materials extracted from meteorites as well as on samples from NASA sample return missions, such... chemical origin of the solar system and the processes by which its small bodies evolved. Justification for...

Aerospace-Oriented Units for Use in Secondary School Classes.

ERIC Educational Resources Information Center

Williams, Mary H.; And Others

This set of nine units is intended to furnish aerospace-oriented resource material to help teachers include recent scientific and technological advances in the secondary school science curriculum. The units provided are as follows: history of astronomy, the solar system, beyond the solar system, history of flight, spaceflight facts, aerology,…

The Johnson Space Center Experimental Impact Lab: Contributions Toward Understanding the Evolution of the Solar System

NASA Technical Reports Server (NTRS)

See, T. H.; Montes, R.

2012-01-01

Impact is the most common and only weathering phenomenon affecting all the planetary bodies (e.g., planets, satellites, asteroids, comets, etc.) in the solar system. NASA Johnson Space Center s Experimental Impact Laboratory (EIL) includes three accelerators that are used in support of research into the effects of impact on the formation and evolution of the solar system. They permit researchers to study a wide variety of phenomena associated with high-velocity impacts into a wide range of geologic targets and materials relevant to astrobiological studies. By studying these processes, researchers can investigate the histories and evolution of planetary bodies and the solar system as a whole. While the majority of research conducted in the EIL addresses questions involving planetary impacts, work involving spacecraft components has been performed on occasion. An example of this is the aerogel collector material flown on the Stardust spacecraft that traveled to Comet Wild-2. This capture medium was tested and flight qualified using the 5 mm Light-Gas Gun located in the EIL.

High-Temperature Thermochemical Storage with Redox-Stable Perovskites for Concentrating Solar Power, CRADA Number: CRD-14-554

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Zhiwen

As part of a Federal Opportunity Announcement (FOA) Award, the project will be led by Colorado School of Mines (CSM) to explore and demonstrate the efficacy of highly reducible, redox-stable oxides to provide efficient thermochemical energy storage for heat release at temperatures of 900 degrees Celcius or more. NREL will support the material development for its application in a concentrating solar power (CSP) plant. In the project, NREL will provide its inventive system design, chemical looping for CSP, and use it as a platform to accommodate the chemical processes using a cost effective perovskite materials identified by CSM. NREL willmore » design a 5-10kW particle receiver for perovskite reduction to store solar energy and help the development of a fluidized-bed reoxidation reactor and system integration. NREL will develop the demonstration receiver for on-sun test in the 5-10 kWt range in NREL's high flux solar furnace. NREL will assist in system analysis and provide techno-economic inputs for the overall system configuration.« less

Particulate photocatalysts for overall water splitting

NASA Astrophysics Data System (ADS)

Chen, Shanshan; Takata, Tsuyoshi; Domen, Kazunari

2017-10-01

The conversion of solar energy to chemical energy is a promising way of generating renewable energy. Hydrogen production by means of water splitting over semiconductor photocatalysts is a simple, cost-effective approach to large-scale solar hydrogen synthesis. Since the discovery of the Honda-Fujishima effect, considerable progress has been made in this field, and numerous photocatalytic materials and water-splitting systems have been developed. In this Review, we summarize existing water-splitting systems based on particulate photocatalysts, focusing on the main components: light-harvesting semiconductors and co-catalysts. The essential design principles of the materials employed for overall water-splitting systems based on one-step and two-step photoexcitation are also discussed, concentrating on three elementary processes: photoabsorption, charge transfer and surface catalytic reactions. Finally, we outline challenges and potential advances associated with solar water splitting by particulate photocatalysts for future commercial applications.

Near Earth Asteroid Scout: NASA's Solar Sail Mission to a NEA

NASA Technical Reports Server (NTRS)

Johnson, Les; Lockett, Tiffany

2017-01-01

NASA is developing a solar sail propulsion system for use on the Near Earth Asteroid (NEA) Scout reconnaissance mission and laying the groundwork for their use in future deep space science and exploration missions. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high Delta V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. The Near Earth Asteroid (NEA) Scout mission, funded by NASA's Advanced Exploration Systems Program and managed by NASA MSFC, will use the sail as primary propulsion allowing it to survey and image Asteroid 1991VG and, potentially, other NEA's of interest for possible future human exploration. NEA Scout uses a 6U cubesat (to be provided by NASA's Jet Propulsion Laboratory), an 86 m(exp. 2) solar sail and will weigh less than 12 kilograms. NEA Scout will be launched on the first flight of the Space Launch System in 2018. The solar sail for NEA Scout will be based on the technology developed and flown by the NASA NanoSail-D and The Planetary Society's Lightsail-A. Four approximately 7 m stainless steel booms wrapped on two spools (two overlapping booms per spool) will be motor deployed and pull the sail from its stowed volume. The sail material is an aluminized polyimide approximately 2.5 microns thick. As the technology matures, solar sails will increasingly be used to enable science and exploration missions that are currently impossible or prohibitively expensive using traditional chemical and electric propulsion systems. This paper will summarize the status of the NEA Scout mission and solar sail technology in general.

New materials for thermal energy storage in concentrated solar power plants

NASA Astrophysics Data System (ADS)

Guerreiro, Luis; Collares-Pereira, Manuel

2016-05-01

Solar Thermal Electricity (STE) is an important alternative to PV electricity production, not only because it is getting more cost competitive with the continuous growth in installed capacity, engineering and associated innovations, but also, because of its unique dispatch ability advantage as a result of the already well established 2-tank energy storage using molten salts (MS). In recent years, research has been performed, on direct MS systems, to which features like modularity and combinations with other (solid) thermal storage materials are considered with the goal of achieving lower investment cost. Several alternative materials and systems have been studied. In this research, storage materials were identified with thermo-physical data being presented for different rocks (e.g. quartzite), super concrete, and other appropriate solid materials. Among the new materials being proposed like rocks from old quarries, an interesting option is the incorporation of solid waste material from old mines belonging to the Iberian Pyritic Belt. These are currently handled as byproducts of past mine activity, and can potentially constitute an environmental hazard due to their chemical (metal) content. This paper presents these materials, as part of a broad study to improve the current concept of solar energy storage for STE plants, and additionally presents a potentially valuable solution for environmental protection related to re-use of mining waste.

2015 Materials Research Society Spring Meeting

DTIC Science & Technology

2016-05-12

State University, Raleigh, NC 27695  Eicke R. Weber, Fraunhofer Institute for  Solar  Energy Systems, Freiburg, Germany    Symposium Highlights:  The...emission from fossil fuels.  Materials hold the key to  advanced renewable energy technologies including  solar  cells, batteries, fuel cells, and catalysis...systems. For example, among renewable energy technologies,  solar  energy is  a limitless source of energy, and photovoltaic energy conversion is one of the

Ship Integration of Energy Scavenging Technology for Sea Base Operations

DTIC Science & Technology

2009-07-01

operates similar to the common commercial refrigerating system in reverse like a heat pump.3 However, cold water pipes do pose a 12 Naval Surface...sunlight at the focal point in a solar collector , more light can be converted to electricity for less solar cell material. Solar concentrators come in...Kotter, D.K., et al. (2008). Proceeding from ES2008: Solar Nantenna Electromagnetic Collectors . Jacksonville, Florida: Energy Sustainability 2008

Owens-Illinois liquid solar collector materials assessment

NASA Technical Reports Server (NTRS)

Nichols, R. L.

1978-01-01

From the beginning, it was noted that the baseline drawings for the liquid solar collector exhibited a distinct weakness concerning materials specification where elastomers, plastics, and foam insulation materials were utilized. A relatively small effort by a competent design organization would alleviate this deficiency. Based on results obtained from boilout and stagnation tests on the solar simulator, it was concluded that proof testing of the collector tubes prior to use helps to predict their performance for limited service life. Fracture mechanics data are desirable for predicting extended service life and establishing a minimum proof pressure level requirement. The temperature capability of this collector system was increased as the design matured and the coating efficiency improved. This higher temperature demands the use of higher temperature materials at critical locations in the collector.

Progress in the development of advanced solar reflectors

NASA Astrophysics Data System (ADS)

Kennedy, C.; Jorgensen, G.

1994-01-01

Solar thermal technologies require large mirrors to provide concentrated sunlight for renewable power generation. Such materials must be inexpensive and maintain high specular reflectance for extended lifetimes in severe outdoor environments. Polymer reflectors are lighter than glass mirrors, offer greater system design flexibility, and have the potential for lower cost. During the past year, collaborative cost-shared research and development between the National Renewable Energy Laboratory (NREL) and industrial partners has identified candidate materials that perform better than the state-of-the-art commercial silvered-polymer reflectors in terms of corrosion degradation and resistance to delamination failure. Additional cooperative efforts will produce new alternative materials with reduced costs due to high speed production line capability. NREL welcomes continued and expanded interest and web coating industry involvement in developing advanced solar reflector materials.

Degradation of thermal control materials under a simulated radiative space environment

NASA Astrophysics Data System (ADS)

Sharma, A. K.; Sridhara, N.

2012-11-01

A spacecraft with a passive thermal control system utilizes various thermal control materials to maintain temperatures within safe operating limits. Materials used for spacecraft applications are exposed to harsh space environments such as ultraviolet (UV) and particle (electron, proton) irradiation and atomic oxygen (AO), undergo physical damage and thermal degradation, which must be considered for spacecraft thermal design optimization and cost effectiveness. This paper describes the effect of synergistic radiation on some of the important thermal control materials to verify the assumptions of beginning-of-life (BOL) and end-of-life (EOL) properties. Studies on the degradation in the optical properties (solar absorptance and infrared emittance) of some important thermal control materials exposed to simulated radiative geostationary space environment are discussed. The current studies are purely related to the influence of radiation on the degradation of the materials; other environmental aspects (e.g., thermal cycling) are not discussed. The thermal control materials investigated herein include different kind of second-surface mirrors, white anodizing, white paints, black paints, multilayer insulation materials, varnish coated aluminized polyimide, germanium coated polyimide, polyether ether ketone (PEEK) and poly tetra fluoro ethylene (PTFE). For this purpose, a test in the constant vacuum was performed reproducing a three year radiative space environment exposure, including ultraviolet and charged particle effects on North/South panels of a geostationary three-axis stabilized spacecraft. Reflectance spectra were measured in situ in the solar range (250-2500 nm) and the corresponding solar absorptance values were calculated. The test methodology and the degradations of the materials are discussed. The most important degradations among the low solar absorptance materials were found in the white paints whereas the rigid optical solar reflectors remained quite stable. Among the high solar absorptance elements, as such the change in the solar absorptance was very low, in particular the germanium coated polyimide was found highly stable.

History of Nebular Processing Traced by Silicate Stardust in IDPS

NASA Technical Reports Server (NTRS)

Messenger, Scott R.; Keller, L. P.; Nakamura-Messenger, K.

2010-01-01

Chondritic porous interplanetary dust particles (CP-IDPs) may be the best preserved remnants of primordial solar system materials, in part because they were not affected by parent body hydrothermal alteration. Their primitive characteristics include fine grained, unequilibrated, anhydrous mineralogy, enrichment in volatile elements, and abundant molecular cloud material and silicate stardust. However, while the majority of CP-IDP materials likely derived from the Solar System, their formation processes and provenance are poorly constrained. Stardust abundances provide a relative measure of the extent of processing that the Solar System starting materials has undergone in primitive materials. For example, among primitive meteorites silicate stardust abundances vary by over two orders of magnitude (less than 10-200 ppm). This range of abundances is ascribed to varying extents of aqueous processing in the meteorite parent bodies. The higher average silicate stardust abundances among CP-IDPs (greater than 375 ppm) are thus attributable to the lack of aqueous processing of these materials. Yet, silicate stardust abundances in IDPs also vary considerably. While the silicate stardust abundance in IDPs having anomalous N isotopic compositions was reported to be 375 ppm, the abundance in IDPs lacking N anomalies is less than 10 ppm. Furthermore, these values are significantly eclipsed among some IDPs with abundances ranging from 2,000 ppm to 10,000 ppm. Given that CP-IDPs have not been significantly affected by parent body processes, the difference in silicate stardust abundances among these IDPs must reflect varying extents of nebular processing. Here we present recent results of a systematic coordinated mineralogical/isotopic study of large cluster IDPs aimed at (1) characterizing the mineralogy of presolar silicates and (2) delineating the mineralogical and petrographic characteristics of IDPs with differing silicate stardust abundances. One of the goals of this study is to better understand the earliest stages of evolution of the Solar System starting materials.

Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/

NASA Technical Reports Server (NTRS)

Glaser, P. E.; Almgren, D. W.

1978-01-01

In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

Solar cell array design handbook - The principles and technology of photovoltaic energy conversion

NASA Technical Reports Server (NTRS)

Rauschenbach, H. S.

1980-01-01

Photovoltaic solar cell array design and technology for ground-based and space applications are discussed from the user's point of view. Solar array systems are described, with attention given to array concepts, historical development, applications and performance, and the analysis of array characteristics, circuits, components, performance and reliability is examined. Aspects of solar cell array design considered include the design process, photovoltaic system and detailed array design, and the design of array thermal, radiation shielding and electromagnetic components. Attention is then given to the characteristics and design of the separate components of solar arrays, including the solar cells, optical elements and mechanical elements, and the fabrication, testing, environmental conditions and effects and material properties of arrays and their components are discussed.

Aqueous Solution-Deposited Molybdenum Oxide Films as an Anode Interfacial Layer for Organic Solar Cells.

PubMed

Yi, Qinghua; Zhai, Pengfei; Sun, Yinghui; Lou, Yanhui; Zhao, Jie; Sun, Baoquan; Patterson, Brian; Luo, Hongmei; Zhang, Wenrui; Jiao, Liang; Wang, Haiyan; Zou, Guifu

2015-08-26

In this study, we report the growth of molybdenum oxide (MoOx) film by polymer-assisted deposition (PAD), an environmentally friendly strategy in an aqueous system. The MoOx film has good crystal quality and is dense and smooth. The transparency of the film is >95% in the wavelength range of 300-900 nm. The device based on P3HT:PCBM absorber material was fabricated. The solar cell with PAD-MoOx as an anode interfacial layer exhibits great performance, even better than that of a solar cell with PSS or evaporated MoOx as an anode interfacial layer. More importantly, the solar cells based on the growth of MoOx have a longer term stability than that of solar cells based on PSS. These results demonstrate the aqueous PAD technology provides an alternative strategy not only for the thin films' growth of applied materials but also for the solution processing for the low-cost fabrication of future materials to be applied in the field of solar cells.

Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting

DOE PAGES

Kang, Dongseok; Young, James L.; Lim, Haneol; ...

2017-03-27

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here in this paper we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfacesmore » for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.« less

Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting

NASA Astrophysics Data System (ADS)

Kang, Dongseok; Young, James L.; Lim, Haneol; Klein, Walter E.; Chen, Huandong; Xi, Yuzhou; Gai, Boju; Deutsch, Todd G.; Yoon, Jongseung

2017-03-01

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfaces for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.

A photocatalyst-enzyme coupled artificial photosynthesis system for solar energy in production of formic acid from CO2.

PubMed

Yadav, Rajesh K; Baeg, Jin-Ook; Oh, Gyu Hwan; Park, No-Joong; Kong, Ki-jeong; Kim, Jinheung; Hwang, Dong Won; Biswas, Soumya K

2012-07-18

The photocatalyst-enzyme coupled system for artificial photosynthesis process is one of the most promising methods of solar energy conversion for the synthesis of organic chemicals or fuel. Here we report the synthesis of a novel graphene-based visible light active photocatalyst which covalently bonded the chromophore, such as multianthraquinone substituted porphyrin with the chemically converted graphene as a photocatalyst of the artificial photosynthesis system for an efficient photosynthetic production of formic acid from CO(2). The results not only show a benchmark example of the graphene-based material used as a photocatalyst in general artificial photosynthesis but also the benchmark example of the selective production system of solar chemicals/solar fuel directly from CO(2).

Analysis of Surface Charging for a Candidate Solar Sail Mission Using NASCAP-2K

NASA Technical Reports Server (NTRS)

Parker, Linda Neergaard; Minow, Joseph L.; Davis, V. A.; Mandell, Myron; Gardner, Barbara

2005-01-01

The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design tasks. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.9 AU LI solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k. the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

Analysis of Surface Charging for a Candidate Solar Sail Mission Using Nascap-2k

NASA Technical Reports Server (NTRS)

Parker, Linda Neergaard; Minow, Joseph I.; Davis, Victoria; Mandell, Myron; Gardner, Barbara

2005-01-01

The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design task. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.0 AU L1 solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

The Main-belt Asteroid and NEO Tour with Imaging and Spectroscopy (MANTIS)

NASA Astrophysics Data System (ADS)

Rivkin, A.; Cohen, B. A.; Barnouin, O. S.; Chabot, N. L.; Ernst, C. M.; Klima, R. L.; Helbert, J.; Sternovsky, Z.

2015-12-01

The asteroids preserve information from the earliest times in solar system history, with compositions in the population reflecting the material in the solar nebula and experiencing a wide range of temperatures. Today they experience ongoing processes, some of which are shared with larger bodies but some of which are unique to their size regime. They are critical to humanity's future as potential threats, resource sites, and targets for human visitation. However, over twenty years since the first spacecraft encounters with asteroids, they remain poorly understood. The mission we propose here, the Main-belt Asteroid and NEO Tour with Imaging and Spectroscopy (MANTIS), explores the diversity of asteroids to understand our solar system's past history, its present processes, and future opportunities and hazards. MANTIS addresses many of NASA's highest priorities as laid out in its 2014 Science Plan and provides additional benefit to the Planetary Defense and Human Exploration communities via a low-risk, cost-effective tour of the near-Earth and inner asteroid belt. MANTIS visits the materials that witnessed solar system formation and its earliest history, addressing the NASA goal of exploring and observing the objects in the solar system to understand how they formed and evolve. MANTIS measures OH, water, and organic materials via several complementary techniques, visiting and sampling objects known to have hydrated minerals and addressing the NASA goal of improving our understanding of the origin and evolution of life on Earth. MANTIS studies the geology and geophysics of nine diverse asteroids, with compositions ranging from water-rich to metallic, representatives of both binary and non-binary asteroids, and sizes covering over two orders of magnitude, providing unique information about the chemical and physical processes shaping the asteroids, addressing the NASA goal of advancing the understanding of how the chemical and physical processes in our solar system operate, interact, and evolve. Finally, the set of measurements carried out by MANTIS at near-Earth and main-belt asteroids will by definition characterize objects in the solar system that pose threats to Earth or offer resources for human exploration, a final goal in the NASA Science Plan.

Solar Power Satellite Development: Advances in Modularity and Mechanical Systems

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Dorsey, John T.; Watson, Judith J.

2010-01-01

Space solar power satellites require innovative concepts in order to achieve economically and technically feasible designs. The mass and volume constraints of current and planned launch vehicles necessitate highly efficient structural systems be developed. In addition, modularity and in-space deployment will be enabling design attributes. This paper reviews the current challenges of launching and building very large space systems. A building block approach is proposed in order to achieve near-term solar power satellite risk reduction while promoting the necessary long-term technology advances. Promising mechanical systems technologies anticipated in the coming decades including modularity, material systems, structural concepts, and in-space operations are described

Nonterrestrial material processing and manufacturing of large space systems

NASA Technical Reports Server (NTRS)

Von Tiesenhausen, G.

1979-01-01

Nonterrestrial processing of materials and manufacturing of large space system components from preprocessed lunar materials at a manufacturing site in space is described. Lunar materials mined and preprocessed at the lunar resource complex will be flown to the space manufacturing facility (SMF), where together with supplementary terrestrial materials, they will be final processed and fabricated into space communication systems, solar cell blankets, radio frequency generators, and electrical equipment. Satellite Power System (SPS) material requirements and lunar material availability and utilization are detailed, and the SMF processing, refining, fabricating facilities, material flow and manpower requirements are described.

Evaluation of solar cells for potential space satellite power applications

NASA Technical Reports Server (NTRS)

1977-01-01

The evaluation focused on the following subjects: (1) the relative merits of alternative solar cell materials, based on performance and availability, (2) the best manufacturing methods for various solar cell options and the effects of extremely large production volumes on their ultimate costs and operational characteristics, (3) the areas of uncertainty in achieving large solar cell production volumes, (4) the effects of concentration ratios on solar array mass and system performance, (5) the factors influencing solar cell life in the radiation environment during transport to and in geosynchronous orbit, and (6) the merits of conducting solar cell manufacturing operations in space.

Extraterrestrial applications of solar optics for interior illumination

NASA Technical Reports Server (NTRS)

Eijadi, David A.; Williams, Kyle D.

1992-01-01

Solar optics is a terrestrial technology that has potential extraterrestrial applications. Active solar optics (ASO) and passive solar optics (PSO) are two approaches to the transmission of sunlight to remote interior spaces. Active solar optics is most appropriate for task illumination, while PSO is most appropriate for general illumination. Research into solar optics, motivated by energy conservation, has produced lightweight and low-cost materials, products that have applications to NASA's Controlled Ecological Life Support System (CELSS) program and its lunar base studies. Specifically, prism light guides have great potential in these contexts. Several applications of solar optics to lunar base concepts are illustrated.

The Cambridge Guide to the Solar System

NASA Astrophysics Data System (ADS)

Lang, Kenneth R.

2003-10-01

The Cambridge Guide to the Solar System provides a comprehensive, funamental, and up-to-date description of the solar system. It is written in a concise, light and uniform style, without being unnecessarily weighted down with specialized materials or the variable writing of multiple authors. It is filled with vital facts and information for astronomers of all types and for anyone with a scientific interest in the Earth, our Moon, all the other planets and their satellites, and related topics such as asteroids, comets, meteorites and meteors. The language, style, ideas and profuse illustrations will attract the general reader as well as professionals. A thorough report for general readers, it includes much compact reference data. Metaphors, similes and analogies will be of immense help to the lay person or non-science student, and they add to the enjoyment of the material. Vignettes containing historical, literary and even artistic material make this book unusual and interesting, and enhance its scientific content. Kenneth Lang is professor of astronomy in the Physics and Astronomy Department at Tufts University. He is the author of several astrophysics books, including The Sun from Space (Springer Verlag, 2000), Astrophysical Formulae: Radiation, Gas Processes, and High Energy Physics (Springer Verlag, 1999), Sun, Earth and Sky (Copernicus Books, 1997), Astrophysical Data: Planets and Stars (Springer Verlag, 1993), and Wanderers in Space: Exploration and Discovery in the Solar System (Cambridge, 1991),

High Throughput Discovery of Solar Fuels Photoanodes in the CuO-V 2 O 5 System

DOE PAGES

Zhou, Lan; Yan, Qimin; Shinde, Aniketa; ...

2015-08-26

Solar photoelectrochemical generation of fuel is a promising energy technology yet the lack of an efficient, robust photoanode remains a primary materials challenge in the development and deployment of solar fuels generators. Metal oxides comprise the most promising class of photoanode materials, but no known material meets the demanding requirements of low band gap energy, photoelectrocatalysis of the oxygen evolution reaction, and stability under highly oxidizing conditions. Here, we report the identification of new photoelectroactive materials through a strategic combination of combinatorial materials synthesis, high-throughput photoelectrochemistry, optical spectroscopy, and detailed electronic structure calculations. We identify 4 photoelectrocatalyst phases - α-Cumore » 2V 2O 7, β-Cu 2V 2O 7, γ-Cu 3V 2O 8, and Cu 11V 6O 26 - with band gap energy at or below 2 eV. The photoelectrochemical properties and 30-minute stability of these copper vanadate phases are demonstrated in 3 different aqueous electrolytes (pH 7, pH 9, and pH 13), with select combinations of phase and electrolyte exhibiting unprecedented photoelectrocatalytic stability for metal oxides with sub-2 eV band gap. Through integration of experimental and theoretical techniques, we determine new structure-property relationships and establish CuO-V 2O 5 as the most prominent composition system for OER photoelectrocatalysts, providing crucial information for materials genomes initiatives and paving the way for continued development of solar fuels photoanodes.« less

Direct solar-pumped iodine laser amplifier

NASA Technical Reports Server (NTRS)

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1987-01-01

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

MSFC hot air collectors

NASA Technical Reports Server (NTRS)

Anthony, K.

1978-01-01

A description of the hot air collector is given that includes a history of development, a history of the materials development, and a program summary. The major portion of the solar energy system cost is the collector. Since the collector is the heart of the system and the most costly subsystem, reducing the cost of producing collectors in large quantities is a major goal. This solar collector is designed to heat air and/or water cheaply and efficiently through the use of solar energy.

Cyborgian Material Design for Solar Fuel Production: The Emerging Photosynthetic Biohybrid Systems.

PubMed

Sakimoto, Kelsey K; Kornienko, Nikolay; Yang, Peidong

2017-03-21

Photosynthetic biohybrid systems (PBSs) combine the strengths of inorganic materials and biological catalysts by exploiting semiconductor broadband light absorption to capture solar energy and subsequently transform it into valuable CO 2 -derived chemicals by taking advantage of the metabolic pathways in living organisms. In this work, we first traverse through a brief history of recent PBSs, demonstrating the modularity and diversity of possible architectures to rival and, in many cases, surpass the performance of chemistry or biology alone before envisioning the future of these hybrid systems, opportunities for improvement, and its role in sustainable living here on earth and beyond.

Isotopic compositions of cometary matter returned by Stardust.

PubMed

McKeegan, Kevin D; Aléon, Jerome; Bradley, John; Brownlee, Donald; Busemann, Henner; Butterworth, Anna; Chaussidon, Marc; Fallon, Stewart; Floss, Christine; Gilmour, Jamie; Gounelle, Matthieu; Graham, Giles; Guan, Yunbin; Heck, Philipp R; Hoppe, Peter; Hutcheon, Ian D; Huth, Joachim; Ishii, Hope; Ito, Motoo; Jacobsen, Stein B; Kearsley, Anton; Leshin, Laurie A; Liu, Ming-Chang; Lyon, Ian; Marhas, Kuljeet; Marty, Bernard; Matrajt, Graciela; Meibom, Anders; Messenger, Scott; Mostefaoui, Smail; Mukhopadhyay, Sujoy; Nakamura-Messenger, Keiko; Nittler, Larry; Palma, Russ; Pepin, Robert O; Papanastassiou, Dimitri A; Robert, François; Schlutter, Dennis; Snead, Christopher J; Stadermann, Frank J; Stroud, Rhonda; Tsou, Peter; Westphal, Andrew; Young, Edward D; Ziegler, Karen; Zimmermann, Laurent; Zinner, Ernst

2006-12-15

Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single (17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is (16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.

Sampling South Pole-Aitken Basin: The Moonrise Approach

NASA Technical Reports Server (NTRS)

Jolliff, B. L.; Shearer, C. K.; Cohen, B. A.

2012-01-01

The South Pole-Aitken basin (SPA) is the largest of the giant impact basins in the inner Solar System, and its location on Earth s Moon makes it the most accessible. Exploration of SPA through direct collection and analysis of representative materials addresses issues as fundamental as the characteristics of the chemical reservoir from which the Moon originated, early differentiation and production of crust and development of global asymmetry, relationships between magmatic activity and internal thermal evolution, and effects of giant impact events on the terrestrial planets. Owing to its great size and superposition relationships with other lunar impact basins, SPA is the oldest and as such anchors the lunar chronology. Moreover, numerous large impact craters and basins are contained within it such that materials (rocks) of the SPA basin contain a record of the early impact chronology, one less likely to have been affected by the large, late nearside basins (e.g., Imbrium). Understanding the early basin chronology is key to deciphering the sequence and effects of early giant impact bombardment of the inner Solar System. That record exists on the Moon, and materials of the SPA basin will allow us to read that record. Knowledge of the early bombardment history will test - and may reshape - a key paradigm relating to early Solar System evolution. Did the planets form with the alignment of today, or was there a major reorientation of the giant planets that led to destabilization of asteroid orbits, and a cataclysmic bombardment of the inner Solar System hundreds of millions of years after accretion of the planets? Implications include understanding environments for early life-supporting habitats on Earth and Mars, and relationships to new observations of extra-solar planetary systems.

Photovoltaic materials and devices 2016

DOE PAGES

Sopori, Bhushan; Basnyat, Prakash; Mehta, Vishal

2016-01-01

Photovoltaic energy continues to grow with about 59 GW of solar PV installed in 2015. While most of the PV production (about 93%) was Si wafer based, both CdTe and CI(G)S are growing in their shares. There is also continued progress at the laboratory scale in OPV and dye sensitized solar cells. As the market grows, emphasis on reducing the cost of modules and systems continues to grow. This is the fourth special issue of this journal that is dedicated to gathering selected papers on recent advances in materials, devices, and modules/PV systems. This issue contains sixteen papers on variousmore » aspects of photovoltaics. As a result, these fall in four broad categories of novel materials, device design and fabrication, modules, and systems.« less

Er(3+)/Yb(3+) upconverters for InGaP solar cells under concentrated broadband illumination.

PubMed

Feenstra, J; Six, I F; Asselbergs, M A H; van Leest, R H; de Wild, J; Meijerink, A; Schropp, R E I; Rowan, A E; Schermer, J J

2015-05-07

The inability of solar cell materials to convert all incident photon energy into electrical current, provides a fundamental limit to the solar cell efficiency; the so called Shockley-Queisser (SQ) limit. A process termed upconversion provides a pathway to convert otherwise unabsorbed low energy photons passing through the solar cell into higher energy photons, which subsequently can be redirected back to the solar cell. The combination of a semi-transparent InGaP solar cell with lanthanide upconverters, consisting of ytterbium and erbium ions doped in three different host materials (Gd2O2S, Y2O3 and NaYF4) is investigated. Using sub-band gap light of wavelength range 890 nm to 1045 nm with a total accumulated power density of 2.7 kW m(-2), a distinct photocurrent was measured in the solar cell when the upconverters were applied whereas a zero current was measured without upconverter. Furthermore, a time delay between excitation and emission was observed for all upconverter systems which can be explained by energy transfer upconversion. Also, a quadratic dependence on the illumination intensity was observed for the NaYF4 and Y2O3 host material upconverters. The Gd2O2S host material upconverter deviated from the quadratic illumination intensity dependence towards linear behaviour, which can be attributed to saturation effects occurring at higher illumination power densities.

Research and technology, fiscal year 1982

NASA Technical Reports Server (NTRS)

1982-01-01

Advanced studies are reviewed. Atmospheric sciences, magnetospheric physics, solar physics, gravitational physics, astronomy, and materials processing in space comprise the research programs. Large space systems, propulsion technology, materials and processes, electrical/electronic systems, data bases/design criteria, and facilities development comprise the technology development activities.

Optical Analysis of Transparent Polymeric Material Exposed to Simulated Space Environment

NASA Technical Reports Server (NTRS)

Edwards, David L.; Finckenor, Miria M.

1999-01-01

Transparent polymeric materials are being designed and utilized as solar concentrating lenses for spacecraft power and propulsion systems. These polymeric lenses concentrate solar energy onto energy conversion devices such as solar cells and thermal energy systems. The conversion efficiency is directly related to the transmissivity of the polymeric lens. The Environmental Effects Group of the Marshall Space Flight Center's Materials, Processes, and Manufacturing Department exposed a variety of materials to a simulated space environment and evaluated them for an, change in optical transmission. These materials include Lexan(TM), polyethylene terephthalate (PET). several formulations of Tefzel(TM). and Teflon(TM), and silicone DC 93-500. Samples were exposed to a minimum of 1000 Equivalent Sun Hours (ESH) of near-UV radiation (250 - 400 nm wavelength). Data will be presented on materials exposed to charged particle radiation equivalent to a five-year dose in geosynchronous orbit. These exposures were performed in MSFC's Combined Environmental Effects Test Chamber, a unique facility with the capability to expose materials simultaneously or sequentially to protons, low-energy electrons, high-energy electrons, near UV radiation and vacuum UV radiation.Prolonged exposure to the space environment will decrease the polymer film's transmission and thus reduce the conversion efficiency. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance to space environmental exposure. Spectral results and the material ranking according to transmission loss are presented.

Cleaning at the Edge of Science: NASA's Genesis Mission

NASA Technical Reports Server (NTRS)

Stansbery, Eileen K.; Biesinger, Paul H.

2000-01-01

As part of NASA's continuing exploration of the origins of our solar system, the California Institute of Technology, Jet Propulsion Laboratory, Lockheed Martin Astronautics, Los Alamos National Laboratory, and the Johnson Space Center are working together to develop the Genesis mission to return solar matter for analysis in terrestrial laboratories. These samples will be used to define a baseline for the chemical and isotopic composition of the solar nebula. Deviations from the baseline resulted as the solar system evolved; thus, providing a tracer for materials incorporated into meteorites, comets and planetary bodies. These differences represent "fossil residues" that provide invaluable insight into how the solar nebula evolved to form the planets. We cannot collect a sample of the Sun as we would for a planet; fortunately, solar material comes to us in the form of the solar wind. Ultrapure materials will be exposed at the Earth-Sun L1, outside the Earth's magnetic influence, where solar wind nuclei will be captured for 2 years before returning to Earth in January 2001. The key challenge to obtaining a good sample of solar wind, uncontaminated by terrestrial atoms, is a clean collection surface in a clean sample canister and clean facilities with which to handle the samples for allocation and future reference. The Johnson Space Center QSQ is responsible for contamination control for the mission, for ensuring the cleanliness of collection surfaces and providing a clean environment for their subsequent handling. The level of cleanliness required is high; at the time of analysis (after sample return), the surface contamination by C, N, O must each be less than 10(exp 15) atoms per centimeter squared and for elements other than C, N, O, the number of atoms per centimeter squared of each surface contaminant shall not exceed the estimated solar wind fluence of the species (varies by element between U at approx. 10 (exp 4) atoms per centimeter squared to Fe, Si, Mg, and Ne at approx. 10(exp 12), atoms per centimeter squared). Typical spacecraft assembly is done in class 10,000 cleanrooms. The final cleaning and reintegration of the Genesis payload canister as well as all sample material handling will be done within a class 10 cleanroom using Dryden suits to protect the collector materials from any human debris. Each component is unique, no standard size, shape, material, or precleaning history. We are developing new final cleaning techniques utilizing ultra-pure water to minimize molecular residues on the hardware components.

Using Solar Energy to Desalinate Water.

ERIC Educational Resources Information Center

Tabor, Harry Z.

1978-01-01

Material presented is adapted from Desalination with Solar Energy, a paper presented before the International Symposium on Energy Sources and Development, held in Spain in 1977. Desalination systems energized by the sun, conditions governing their efficiency, and their costs are discussed. (HM)

Ingham County Medical Care Facility solar energy project (Engineering Materials)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

A complete set of as-built drawings for the Ingham County Geriatric Medical Care Facility's solar water heating system is included. These drawings accompany report No. DOE/CS/32382-T1 and DOE/CS/32382-T2. (LS)

Density Functional Theory Investigations of D-A-D' Structural Molecules as Donor Materials in Organic Solar Cell.

PubMed

Chen, Junxian; Liu, Qingyu; Li, Hao; Zhao, Zhigang; Lu, Zhiyun; Huang, Yan; Xu, Dingguo

2018-01-01

Squaraine core based small molecules in bulk heterojunction organic solar cells have received extensive attentions due to their distinguished photochemical properties in far red and infrared domain. In this paper, combining theoretical simulations and experimental syntheses and characterizations, three major factors (fill factor, short circuit and open-cirvuit voltage) have been carried out together to achieve improvement of power conversion efficiencies of solar cells. As model material systems with D-A-D' framework, two asymmetric squaraines (CNSQ and CCSQ-Tol) as donor materials in bulk heterojunction organic solar cell were synthesized and characterized. Intensive density functional theory computations were applied to identify some direct connections between three factors and corresponding molecular structural properties. It then helps us to predict one new molecule of CCSQ'-Ox that matches all the requirements to improve the power conversion efficiency.

Latest results on solarization of optical glasses with pulsed laser radiation

NASA Astrophysics Data System (ADS)

Jedamzik, Ralf; Petzold, Uwe

2017-02-01

Femtosecond lasers are more and more used for material processing and lithography. Femtosecond laser help to generate three dimensional structures in photoresists without using masks in micro lithography. This technology is of growing importance for the field of backend lithography or advanced packaging. Optical glasses used for beam shaping and inspection tools need to withstand high laser pulse energies. Femtosecond laser radiation in the near UV wavelength range generates solarization effects in optical glasses. In this paper results are shown of femtosecond laser solarization experiments on a broad range of optical glasses from SCHOTT. The measurements have been performed by the Laser Zentrum Hannover in Germany. The results and their impact are discussed in comparison to traditional HOK-4 and UVA-B solarization measurements of the same materials. The target is to provide material selection guidance to the optical designer of beam shaping lens systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Dongseok; Young, James L.; Lim, Haneol

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here in this paper we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfacesmore » for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.« less

Edge coating apparatus with movable roller applicator for solar cell substrates

DOEpatents

Pavani, Luca; Abas, Emmanuel

2012-12-04

A non-contact edge coating apparatus includes an applicator for applying a coating material on an edge of a solar cell substrate and a control system configured to drive the applicator. The control system may drive the applicator along an axis to maintain a distance with an edge of the substrate as the substrate is rotated to have the edge coated with a coating material. The applicator may include a recessed portion into which the edge of the substrate is received for edge coating. For example, the applicator may be a roller with a groove. Coating material may be introduced into the groove for application onto the edge of the substrate. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.

Phase-change materials aid in heat recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parkinson, G.

1979-07-16

Research into a wide range of compounds which absorb heat during fusion and then release it as they cool and solidify is being encouraged by the U.S. Department of Energy, which has budgeted $18 million for thermal energy storage systems for 1980, about half of it for systems using phase-change materials. Pipe Systems Inc. is marketing a low-temperature thermal-energy storage system which uses Dow Chemical Co.'s calcium chloride hexahydrate material. Systems based on Glauber's salt, i.e., sodium sulfate decahydrate, are sold by Architectural Research Corp., Valmont Energy Systems Inc., and Solar Inc.; and F. Addison Products Co. sells a systemmore » based on paraffin wax. These low-temperature systems are suitable for space heating. Applications for systems which release heat at up to 1500/sup 0/F include hot water for domestic use, industrial process heat, and solar thermal electric power generation. The specific research and development under way at various organizations are discussed.« less

Comparison and simulation of salt-ceramic composites for use in high temperature concentrated solar power

NASA Astrophysics Data System (ADS)

Fossile, Lauren Michelle

Due to the inherently intermittent nature of solar energy caused by cloud cover among other sources, thermal storage systems are needed to make solar energy more consistent. This same technology could be used to prolong the daily number of useful hours of solar energy power plants. Salt-ceramic materials are a relatively new prospect for heat storage, but have been researched mostly with magnesium oxide and several different carbonate salts. Salt ceramics are a phase change material where the salt changes phase inside the ceramic structure allowing for the system to use the sensible heat of both materials and the latent heat of the salt to store thermal energy. Capillary forces within the ceramic structure hold in the salt when the salt melts. The focus here is on the possibility of creating a low-cost salt-ceramic storage material for high temperature solar energy applications. A theoretical analysis of the resulting materials is performed. While most of the existing salt ceramics have been made from magnesium oxide, aluminum oxide is more readily available from various companies in the area. Magnesium oxide is often considered a custom ceramic, so it is more expensive. A cost and material property comparison has been completed between these two materials to determine which is better suited for solar storage. Many of the existing salt-ceramics use carbonate salts, but nitrate salts are commonly used in graphite/salt composites. Therefore, a cost and theoretical performance comparison is between these materials also. For comparisons' sake, zirconia and graphite have also been analyzed as the filler in the composite. Each combination of salt and ceramic or graphite has been analyzed. In order to make the use of salt-ceramics more cost-effective and available to Nevada's energy providers, research has been done into which ceramics have high availability in Nevada, low cost, and the best material properties for this application. The thermal properties and cost of these materials have been compared to the price that Nevada's energy utilities are willing to pay per unit of stored energy, which was approximated through a survey conducted by the National Science Foundation (NSF) - Experimental Project to Stimulate Competitive Research (EPSCoR) at the University of Nevada, Las Vegas. The surveys were completed on Nevadan energy purveyors concerning climate change attitudes, but included questions regarding the usefulness and cost of solar storage. The cost per unit of energy has also been calculated and whether the utilities would be willing to pay for each combination will be determined using information obtained from the surveys mentioned above. This information will dictate which combination will be best for use in the state of Nevada at solar energy power plants.

Quantitative relations between interaction parameter, miscibility and function in organic solar cells

NASA Astrophysics Data System (ADS)

Ye, Long; Hu, Huawei; Ghasemi, Masoud; Wang, Tonghui; Collins, Brian A.; Kim, Joo-Hyun; Jiang, Kui; Carpenter, Joshua H.; Li, Hong; Li, Zhengke; McAfee, Terry; Zhao, Jingbo; Chen, Xiankai; Lai, Joshua Lin Yuk; Ma, Tingxuan; Bredas, Jean-Luc; Yan, He; Ade, Harald

2018-03-01

Although it is known that molecular interactions govern morphology formation and purity of mixed domains of conjugated polymer donors and small-molecule acceptors, and thus largely control the achievable performance of organic solar cells, quantifying interaction-function relations has remained elusive. Here, we first determine the temperature-dependent effective amorphous-amorphous interaction parameter, χaa(T), by mapping out the phase diagram of a model amorphous polymer:fullerene material system. We then establish a quantitative `constant-kink-saturation' relation between χaa and the fill factor in organic solar cells that is verified in detail in a model system and delineated across numerous high- and low-performing materials systems, including fullerene and non-fullerene acceptors. Our experimental and computational data reveal that a high fill factor is obtained only when χaa is large enough to lead to strong phase separation. Our work outlines a basis for using various miscibility tests and future simulation methods that will significantly reduce or eliminate trial-and-error approaches to material synthesis and device fabrication of functional semiconducting blends and organic blends in general.

Radiolysis and Photolysis of Icy Satellite Surfaces: Experiments and Theory

NASA Technical Reports Server (NTRS)

Cassidy, T.; Coll, P.; Raulin, F.; Carlson, R. W.; Hand, K. P.; Johnson, R. E.; Loeffler, M. J.; Baragiola, R. A.

2010-01-01

The transport and exchange of material between bodies in the outer solar system is often facilitated by their exposure to ionizing radiation. With this in mind we review the effects of energetic ions, electrons and UV photons on materials present in the outer solar system. We consider radiolysis, photolysis, and sputtering of low temperature solids. Radiolysis and photolysis are the chemistry that follows the bond breaking and ionization produced by incident radiation, producing, e.g., O2 and H2 from irradiated H2O ice. Sputtering is the ejection of molecules by incident radiation. Both processes are particularly effective on ices in the outer solar system. Materials reviewed include H2O ice, sulfur-containing compounds (such as S02 and S8), carboncontajning compounds (such as CH4), nitrogen-containing compounds (such as NH3 and N2), and mixtures of those compounds. We also review the effects of ionizing radiation on a mixture of N2 and CH4 gases, as appropriate to Titan's upper atmosphere, where radiolysis and photolysis produce complex organic compounds (tholins).

Concentrating solar power (CSP) power cycle improvements through application of advanced materials

NASA Astrophysics Data System (ADS)

Siefert, John A.; Libby, Cara; Shingledecker, John

2016-05-01

Concentrating solar power (CSP) systems with thermal energy storage (TES) capability offer unique advantages to other renewable energy technologies in that solar radiation can be captured and stored for utilization when the sun is not shining. This makes the technology attractive as a dispatchable resource, and as such the Electric Power Research Institute (EPRI) has been engaged in research and development activities to understand and track the technology, identify key technical challenges, and enable improvements to meet future cost and performance targets to enable greater adoption of this carbon-free energy resource. EPRI is also involved with technically leading a consortium of manufacturers, government labs, and research organizations to enable the next generation of fossil fired power plants with advanced ultrasupercritical (A-USC) steam temperatures up to 760°C (1400°F). Materials are a key enabling technology for both of these seemingly opposed systems. This paper discusses how major strides in structural materials for A-USC fossil fired power plants may be translated into improved CSP systems which meet target requirements.

Thermal Energy Storage using PCM for Solar Domestic Hot Water Systems: A Review

NASA Astrophysics Data System (ADS)

Khot, S. A.; Sane, N. K.; Gawali, B. S.

2012-06-01

Thermal energy storage using phase chase materials (PCM) has received considerable attention in the past two decades for time dependent energy source such as solar energy. From several experimental and theoretical analyses that have been made to assess the performance of thermal energy storage systems, it has been demonstrated that PCM-based systems are reliable and viable options. This paper covers such information on PCMs and PCM-based systems developed for the application of solar domestic hot water system. In addition, economic analysis of thermal storage system using PCM in comparison with conventional storage system helps to validate its commercial possibility. From the economic analysis, it is found that, PCM based solar domestic hot water system (SWHS) provides 23 % more cumulative and life cycle savings than conventional SWHS and will continue to perform efficiently even after 15 years due to application of non-metallic tank. Payback period of PCM-based system is also less compared to conventional system. In conclusion, PCM based solar water heating systems can meet the requirements of Indian climatic situation in a cost effective and reliable manner.

Transformative Small Body Science Enabled with Pan-STARSS Survey Data

NASA Astrophysics Data System (ADS)

Meech, Karen J.; Kleyna, Jan T.; Keane, Jacqueline V.; Hainaut, Olivier R.; MIcheli, Marco

2018-01-01

In the first 5 Myr of Solar System formation, gas imprinted a local chemical signature on the planetesimals which were subsequently redistributed during planet formation. Decades-long ground- and space-based studies have tried to map our solar system’s protoplanetary disk chemistry using volatiles in comets. We now know that comet volatiles (H2O, CO, CO2 and organics) have distinct chemical classes. This data contradicts traditional ideas that all volatile-rich bodies formed in the outer disk. In-situ space comet missions have suggested, however, that comets preserve their pristine volatile inventory, and perhaps even their heritage of ices prior to the protoplanetary disk. Recently, a profusion of dynamical models has been developed that can reproduce some of the key characteristics of today’s solar system. Some models require significant giant planet migration, while others do not. The UH-led Pan-STARRS1 survey (PS1) can offer transformative insight into small bodies and the early solar system, providing a preview of LSST. In 2013 PS1 discovered an asteroidal object on a long-period comet orbit, the first of a class of tailless objects informally called Manxes. The second Manx discovered had a surface composition similar to inner solar system rocky S-type material, suggesting the intriguing possibility that we are looking at fresh inner solar system Earth-forming material, preserved for billions of years in the Oort cloud. Currently 10-15 of these objects are discovered each year, with PS1 dominating the discoveries. The number of rocky inner solar system Manx objects can be used to constrain solar system formation models. PS1 is also very good at discovering faint active objects at large distances, including the remarkable discovery of a comet active beyond 16 au from the sun. By searching the PS1 database once these discoveries are made, it is possible to extend the orbit arc backwards in time, allowing us to model the activity, and understand the chemistry and physics of ices and activity in the outer solar system. These discoveries will help us tie together chemistry and dynamics in our solar system with new resolved ALMA observations of protoplanetary disks. Support from NSF grants AST-1617015, 1413736.

University of South Florida- Phase Change Materials (PCM)

ScienceCinema

Goswami, Yogi; Stefanakos, Lee

2018-05-30

USF is developing low-cost, high-temperature phase-change materials (PCMs) for use in thermal energy storage systems. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night--when the sun is not out--to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Most PCMs do not conduct heat very well. Using an innovative, electroless encapsulation technique, USF is enhancing the heat transfer capability of its PCMs. The inner walls of the capsules will be lined with a corrosion-resistant, high-infrared emissivity coating, and the absorptivity of the PCM will be controlled with the addition of nano-sized particles. USF's PCMs remain stable at temperatures from 600 to 1,000°C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.

Utilizing Stable Isotopes and Isotopic Anomalies to Study Early Solar System Formation Processes

NASA Technical Reports Server (NTRS)

Simon, Justin

2017-01-01

Chondritic meteorites contain a diversity of particle components, i.e., chondrules and calcium-, aluminum-rich refractory inclusions (CAIs), that have survived since the formation of the Solar System. The chemical and isotopic compositions of these materials provide a record of the conditions present in the protoplanetary disk where they formed and can aid our understanding of the processes and reservoirs in which solids formed in the solar nebula, an important step leading to the accretion of planetesimals. Isotopic anomalies associated with nucleosynthetic processes are observed in these discrete materials, and can be compared to astronomical observations and astrophysical formation models of stars and more recently proplyds. The existence and size of these isotopic anomalies are typically thought to reflect a significant state of isotopic heterogeneity in the earliest Solar System, likely left over from molecular cloud heterogeneities on the grain scale, but some could also be due to late stellar injection. The homogenization of these isotopic anomalies towards planetary values can be used to track the efficiency and timescales of disk wide mixing,

The Search for Life in the Solar System

NASA Astrophysics Data System (ADS)

Ehrenfreund, Pascale

2016-07-01

To unravel the origins of life on Earth and possibly elsewhere remains one of mankind's most important discoveries. Basic building blocks of life are widespread in planetary systems in our Milky Way and other galaxies. Extraterrestrial material delivered to young terrestrial planetary surfaces in the early history of our solar system through asteroids, comets and meteorites may have provided significant raw material for the emergence of life on Earth. Since August 2014 the comet rendezvous mission Rosetta has monitored the evolution of comet 67P/Churyumov-Gerasimenko during its approach to the Sun and observed numerous volatiles and complex organic compounds on the comet surface. Several asteroid sample return missions as well as the improved analyses of key meteorites increase our knowledge about the organic inventory that seeded the young planets. Prokaryotic, anaerobic bacteria, which are approximately 3.5 billion years old, represent the first evidence for life on Earth. Since then, life has evolved to high complexity and adapted to nearly every explored environment on our planet. Extreme life on Earth has expanded the list of potentially habitable solar system environments. However, our neighbor planet Mars is the most promising target to search for life within our solar system. Data from the Curiosity rover show regions that were habitable in the past, traces of organic carbon and active CH_4 in the Martian atmosphere at present. Recent discoveries such as the plumes from the southern polar region of Enceladus and plume activity on Europa strengthen the long-standing hypothesis that moons in our solar system contain substantial bodies of water and are probably habitable. Since decades, a fleet of robotic space missions target planets, moons and small bodies to reveal clues on the origin of our solar system and life beyond Earth. This lecture will review and discuss past, current and future space missions investigating habitability and biosignatures in our solar system and the science and technology preparation for robotic and human exploration efforts.

Novel Thermal Storage Technologies for Concentrating Solar Power Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neti, Sudhakar; Oztekin, Alparslan; Chen, John

2013-06-20

The technologies that are to be developed in this work will enable storage of thermal energy in 100 MW e solar energy plants for 6-24 hours at temperatures around 300°C and 850°C using encapsulated phase change materials (EPCM). Several encapsulated phase change materials have been identified, fabricated and proven with calorimetry. Two of these materials have been tested in an airflow experiment. A cost analysis for these thermal energy storage systems has also been conducted that met the targets established at the initiation of the project.

Development of an All-Metal Thick Film Cost Effective Metallization System for Solar Cells

NASA Technical Reports Server (NTRS)

Ross, B.

1980-01-01

Materials including copper powders, silver-fluoride, and silicon wafers were procured and copper pastes were prepared. Electrodes made with copper pastes were analyzed and compared with the raw materials. A needle-like structure was observed on the electroded solar cells, and was identified as eutectic copper-silicon by electron probe X-ray spectroscopy. The existence of this phase was thought to benefit electrical and metallurgical properties of the contact. Subsequently electrodes made from new material were also shown to contain this phase while simultaneously having poor adhesion.

Impact and Collisional Processes in the Solar System

NASA Technical Reports Server (NTRS)

Ahrens, Thomas J.

2001-01-01

In the past year, we have successfully developed the techniques necessary to conduct impact experiments on ice at very low temperatures. We employ the method of embedding gauges within a target to measure the shock wave and material properties. This means that our data are not model dependent; we directly measure the essential parameters needed for numerical simulations of impact cratering. Since then we have developed a new method for temperature control of icy targets that ensures temperature equilibrium throughout a porous target. Graduate student, Sarah Stewart-Mukhopadhyay, is leading the work on ices and porous materials as the main thrust of her thesis research. Our previous work has focused on icy materials with no porosity, and we propose to extend our research to include porous ice and porous ice-silicate mixtures. There is little shockwave data for porous ice, and none of the data was acquired under conditions applicable to the outer solar system. The solid ice Hugoniot is only defined for initial temperatures above -20 C. Our program uniquely measures the properties of ice at temperatures directly applicable to the solar system. Previous experiments were conducted at ambient temperatures soon after removing the target from a cold environment, usually just below freezing, or in a room just below freezing. Since ice has an extremely complicated phase diagram, it is important to conduct experiments at lower temperatures to determine the true outcome of impacts in the outer solar system. This research is complementary to other programs on icy materials. Our work focuses on the inherent material properties by measuring the shock wave directly; this complements the macroscopic observations and immediately provides the parameters necessary to extend this research to the gravity regime. Our numerical simulations of impacts in porous ice under very low gravity conditions, such as found on comets, show that the final crater size and shape is very dependent on the dynamic strength of the material.

NREL's Education Program in Action in the Concentrating Solar Power Program Advanced Materials Task

NASA Astrophysics Data System (ADS)

Kennedy, Cheryl

2010-03-01

Concentrating solar power (CSP) technologies use large mirrors to concentrate sunlight and the thermal energy collected is converted to electricity. The CSP industry is growing rapidly and is expected to reach 25 GW globally by 2020. Cost target goals are for CSP technologies to produce electricity competitive with intermediate-load power generation (i.e., natural gas) by 2015 with 6 hours of thermal storage and competitive in carbon constrained base load power markets (i.e., coal) by 2020 with 12-17 hours of thermal storage. The solar field contributes more than 40% of the total cost of a parabolic trough plant and together the mirrors and receivers contribute more than 25% of the installed solar field cost. CSP systems cannot hit these targets without aggressive cost reductions and revolutionary performance improvements from technology advances. NREL's Advanced Materials task in the CSP Advanced R&D project performs research to develop low cost, high performance, durable solar reflector and high-temperature receiver materials to meet these needs. The Advanced Materials task leads the world in this research and the task's reliance on NREL's educational program will be discussed.

Isotopic homogeneity of iron in the early solar nebula.

PubMed

Zhu, X K; Guo, Y; O'Nions, R K; Young, E D; Ash, R D

2001-07-19

The chemical and isotopic homogeneity of the early solar nebula, and the processes producing fractionation during its evolution, are central issues of cosmochemistry. Studies of the relative abundance variations of three or more isotopes of an element can in principle determine if the initial reservoir of material was a homogeneous mixture or if it contained several distinct sources of precursor material. For example, widespread anomalies observed in the oxygen isotopes of meteorites have been interpreted as resulting from the mixing of a solid phase that was enriched in 16O with a gas phase in which 16O was depleted, or as an isotopic 'memory' of Galactic evolution. In either case, these anomalies are regarded as strong evidence that the early solar nebula was not initially homogeneous. Here we present measurements of the relative abundances of three iron isotopes in meteoritic and terrestrial samples. We show that significant variations of iron isotopes exist in both terrestrial and extraterrestrial materials. But when plotted in a three-isotope diagram, all of the data for these Solar System materials fall on a single mass-fractionation line, showing that homogenization of iron isotopes occurred in the solar nebula before both planetesimal accretion and chondrule formation.

The NASA Langley building solar project and the supporting Lewis solar technology program

NASA Technical Reports Server (NTRS)

Ragsdale, R. G.; Namkoong, D.

1974-01-01

The use of solar energy to heat and cool a new office building that is now under construction is reported. Planned for completion in December 1975, the 53,000 square foot, single story building will utilize 15,000 square feet of various types of solar collectors in a test bed to provide nearly all of the heating demand and over half of the air conditioning demand. Drawing on its space-program-developed skills and resources in heat transfer, materials, and systems studies, NASA-Lewis will provide technology support for the Langley building project. A solar energy technology program underway at Lewis includes solar collector testing in an indoor solar simulator facility and in an outdoor test facility, property measurements of solar panel coatings, and operation of a laboratory-scale solar model system test facility. Based on results obtained in this program, NASA-Lewis will select and procure the solar collectors for the Langley test bed.

Selection of high temperature thermal energy storage materials for advanced solar dynamic space power systems

NASA Technical Reports Server (NTRS)

Lacy, Dovie E.; Coles-Hamilton, Carolyn; Juhasz, Albert

1987-01-01

Under the direction of NASA's Office of Aeronautics and Technology (OAST), the NASA Lewis Research Center has initiated an in-house thermal energy storage program to identify combinations of phase change thermal energy storage media for use with a Brayton and Stirling Advanced Solar Dynamic (ASD) space power system operating between 1070 and 1400 K. A study has been initiated to determine suitable combinations of thermal energy storage (TES) phase change materials (PCM) that result in the smallest and lightest weight ASD power system possible. To date the heats of fusion of several fluoride salt mixtures with melting points greater than 1025 K have been verified experimentally. The study has indicated that these salt systems produce large ASD systems because of their inherent low thermal conductivity and low density. It is desirable to have PCMs with high densities and high thermal conductivities. Therefore, alternate phase change materials based on metallic alloy systems are also being considered as possible TES candidates for future ASD space power systems.

Matter from Outside Our Solar System -- New Insights, Part II. Experimental Measurements and Interpretation.

ERIC Educational Resources Information Center

Wefel, John P.

1982-01-01

The second of two parts (part 1 in v20 n4, p222, Apr 1982) focuses on experimental techniques used to study cosmic-ray isotopic composition, experimental results, and comparison between cosmic-ray source matter and solar-system material. Several models for nucleosynthesis and evolution of cosmic-source matter are also discussed. (Author/JN)

General volume sizing strategy for thermal storage system using phase change material for concentrated solar thermal power plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Ben; Li, Peiwen; Chan, Cholik

With an auxiliary large capacity thermal storage using phase change material (PCM), Concentrated Solar Power (CSP) is a promising technology for high efficiency solar energy utilization. In a thermal storage system, a dual-media thermal storage tank is typically adopted in industry for the purpose of reducing the use of the heat transfer fluid (HTF) which is usually expensive. While the sensible heat storage system (SHSS) has been well studied, a dual-media latent heat storage system (LHSS) still needs more attention and study. The volume sizing of the thermal storage tank, considering daily cyclic operations, is of particular significance. In thismore » paper, a general volume sizing strategy for LHSS is proposed, based on an enthalpy-based 1D transient model. One example was presented to demonstrate how to apply this strategy to obtain an actual storage tank volume. With this volume, a LHSS can supply heat to a thermal power plant with the HTF at temperatures above a cutoff point during a desired 6 hours of operation. This general volume sizing strategy is believed to be of particular interest for the solar thermal power industry.« less

General volume sizing strategy for thermal storage system using phase change material for concentrated solar thermal power plant

DOE PAGES

Xu, Ben; Li, Peiwen; Chan, Cholik; ...

2014-12-18

With an auxiliary large capacity thermal storage using phase change material (PCM), Concentrated Solar Power (CSP) is a promising technology for high efficiency solar energy utilization. In a thermal storage system, a dual-media thermal storage tank is typically adopted in industry for the purpose of reducing the use of the heat transfer fluid (HTF) which is usually expensive. While the sensible heat storage system (SHSS) has been well studied, a dual-media latent heat storage system (LHSS) still needs more attention and study. The volume sizing of the thermal storage tank, considering daily cyclic operations, is of particular significance. In thismore » paper, a general volume sizing strategy for LHSS is proposed, based on an enthalpy-based 1D transient model. One example was presented to demonstrate how to apply this strategy to obtain an actual storage tank volume. With this volume, a LHSS can supply heat to a thermal power plant with the HTF at temperatures above a cutoff point during a desired 6 hours of operation. This general volume sizing strategy is believed to be of particular interest for the solar thermal power industry.« less

Solar Weather Ice Monitoring Station (SWIMS). A low cost, extreme/harsh environment, solar powered, autonomous sensor data gathering and transmission system

NASA Astrophysics Data System (ADS)

Chetty, S.; Field, L. A.

2013-12-01

The Arctic ocean's continuing decrease of summer-time ice is related to rapidly diminishing multi-year ice due to the effects of climate change. Ice911 Research aims to develop environmentally respectful materials that when deployed will increase the albedo, enhancing the formation and/preservation of multi-year ice. Small scale deployments using various materials have been done in Canada, California's Sierra Nevada Mountains and a pond in Minnesota to test the albedo performance and environmental characteristics of these materials. SWIMS is a sophisticated autonomous sensor system being developed to measure the albedo, weather, water temperature and other environmental parameters. The system (SWIMS) employs low cost, high accuracy/precision sensors, high resolution cameras, and an extreme environment command and data handling computer system using satellite and terrestrial wireless communication. The entire system is solar powered with redundant battery backup on a floating buoy platform engineered for low temperature (-40C) and high wind conditions. The system also incorporates tilt sensors, sonar based ice thickness sensors and a weather station. To keep the costs low, each SWIMS unit measures incoming and reflected radiation from the four quadrants around the buoy. This allows data from four sets of sensors, cameras, weather station, water temperature probe to be collected and transmitted by a single on-board solar powered computer. This presentation covers the technical, logistical and cost challenges in designing, developing and deploying these stations in remote, extreme environments. Image captured by camera #3 of setting sun on the SWIMS station One of the images captured by SWIMS Camera #4

An introduction to the Astro Edge solar array

NASA Technical Reports Server (NTRS)

Spence, B. R.; Marks, G. W.

1994-01-01

The Astro Edge solar array is a new and innovative low concentrator power generating system which has been developed for applications requiring high specific power, high stiffness, low risk, light modular construction which utilizes conventional materials and technology, and standard photovoltaic solar cells and laydown processes. Mechanisms, restraint/release devices, wiring harnesses, substrates, and support structures are designed to be simple, functional, lightweight, and modular. A brief overview of the Astro Edge solar array is discussed.

Urey Prize Lecture - Planetary evolution and the origin of life

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.

1991-01-01

One of the principal questions concerning planetary evolution and life's origins relates to the early-earth organic material's origination in situ, outer solar system importation, or simple irrelevance to the emergence of organisms. Additional considerations encompass the character of interstellar organic material and its relationship to outer solar system organic compounds, and the possibility of life's emergence in the early Mars. Attention is given to the essentiality of liquid water for life-forms, in the role not only of a reaction medium among molecules but that of a basis for hydrophylic and hydrophobic groups' bonding.

The origin of inner Solar System water

NASA Astrophysics Data System (ADS)

Alexander, Conel M. O'D.

2017-04-01

Of the potential volatile sources for the terrestrial planets, the CI and CM carbonaceous chondrites are closest to the planets' bulk H and N isotopic compositions. For the Earth, the addition of approximately 2-4 wt% of CI/CM material to a volatile-depleted proto-Earth can explain the abundances of many of the most volatile elements, although some solar-like material is also required. Two dynamical models of terrestrial planet formation predict that the carbonaceous chondrites formed either in the asteroid belt (`classical' model) or in the outer Solar System (5-15 AU in the Grand Tack model). To test these models, at present the H isotopes of water are the most promising indicators of formation location because they should have become increasingly D-rich with distance from the Sun. The estimated initial H isotopic compositions of water accreted by the CI, CM, CR and Tagish Lake carbonaceous chondrites were much more D-poor than measured outer Solar System objects. A similar pattern is seen for N isotopes. The D-poor compositions reflect incomplete re-equilibration with H2 in the inner Solar System, which is also consistent with the O isotopes of chondritic water. On balance, it seems that the carbonaceous chondrites and their water did not form very far out in the disc, almost certainly not beyond the orbit of Saturn when its moons formed (approx. 3-7 AU in the Grand Tack model) and possibly close to where they are found today. This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.

Potential active materials for photo-supercapacitor: A review

NASA Astrophysics Data System (ADS)

Ng, C. H.; Lim, H. N.; Hayase, S.; Harrison, I.; Pandikumar, A.; Huang, N. M.

2015-11-01

The need for an endless renewable energy supply, typically through the utilization of solar energy in most applications and systems, has driven the expansion, versatility, and diversification of marketed energy storage devices. Energy storage devices such as hybridized dye-sensitized solar cell (DSSC)-capacitors and DSSC-supercapacitors have been invented for energy reservation. The evolution and vast improvement of these devices in terms of their efficiencies and flexibilities have further sparked the invention of the photo-supercapacitor. The idea of coupling a DSSC and supercapacitor as a complete energy conversion and storage device arose because the solar energy absorbed by dye molecules can be efficiently transferred and converted to electrical energy by adopting a supercapacitor as the energy delivery system. The conversion efficiency of a photo-supercapacitor is mainly dependent on the use of active materials during its fabrication. The performances of the dye, photoactive metal oxide, counter electrode, redox electrolyte, and conducting polymer are the primary factors contributing to high-energy-efficient conversion, which enhances the performance and shelf-life of a photo-supercapacitor. Moreover, the introduction of compact layer as a primary adherent film has been earmarked as an effort in enhancing power conversion efficiency of solar cell. Additionally, the development of electrolyte-free solar cell such as the invention of hole-conductor or perovskite solar cell is currently being explored extensively. This paper reviews and analyzes the potential active materials for a photo-supercapacitor to enhance the conversion and storage efficiencies.

A high specific power solar array for low to mid-power spacecraft

NASA Technical Reports Server (NTRS)

Jones, P. Alan; White, Stephen F.; Harvey, T. Jeffery; Smith, Brian S.

1993-01-01

UltraFlex is the generic term for a solar array system which delivers on-orbit power in the 400 to 6,000 watt per wing sizes with end-of-life specific power performance ranging to 150 watts-per-kilogram. Such performance is accomplished with off-the-shelf solar cells and state-of the-art materials and processes. Much of the recent work in photovoltaics is centered on advanced solar cell development. Successful as such work has been, no integrated solar array system has emerged which meets NASA's stated goals of 'increasing the end-of-life performance of space solar cells and arrays while minimizing their mass and cost.' This issue is addressed; namely, is there an array design that satisfies the usual requirements for space-rated hardware and that is inherently reliable, inexpensive, easily manufactured and simple, which can be used with both advanced cells currently in development and with inexpensive silicon cells? The answer is yes. The UltraFlex array described incorporates use of a blanket substrate which is thermally compatible with silicon and other materials typical of advanced multi-junction devices. The blanket materials are intrinsically insensitive to atomic oxygen degradation, are space rated, and are compatible with standard cell bonding processes. The deployment mechanism is simple and reliable and the structure is inherently stiff (high natural frequency). Mechanical vibration modes are also readily damped. The basic design is presented as well as supporting analysis and development tests.

A high specific power solar array for low to mid-power spacecraft

NASA Astrophysics Data System (ADS)

Jones, P. Alan; White, Stephen F.; Harvey, T. Jeffery; Smith, Brian S.

1993-05-01

UltraFlex is the generic term for a solar array system which delivers on-orbit power in the 400 to 6,000 watt per wing sizes with end-of-life specific power performance ranging to 150 watts-per-kilogram. Such performance is accomplished with off-the-shelf solar cells and state-of the-art materials and processes. Much of the recent work in photovoltaics is centered on advanced solar cell development. Successful as such work has been, no integrated solar array system has emerged which meets NASA's stated goals of 'increasing the end-of-life performance of space solar cells and arrays while minimizing their mass and cost.' This issue is addressed; namely, is there an array design that satisfies the usual requirements for space-rated hardware and that is inherently reliable, inexpensive, easily manufactured and simple, which can be used with both advanced cells currently in development and with inexpensive silicon cells? The answer is yes. The UltraFlex array described incorporates use of a blanket substrate which is thermally compatible with silicon and other materials typical of advanced multi-junction devices. The blanket materials are intrinsically insensitive to atomic oxygen degradation, are space rated, and are compatible with standard cell bonding processes. The deployment mechanism is simple and reliable and the structure is inherently stiff (high natural frequency). Mechanical vibration modes are also readily damped. The basic design is presented as well as supporting analysis and development tests.

Solar Sail Propulsion for Interplanetary Cubesats

NASA Technical Reports Server (NTRS)

Johnson, Les; Sobey, Alex; Sykes, Kevin

2015-01-01

NASA is developing two small satellite missions as part of the Advanced Exploration Systems (AES) Program, both of which will use a solar sail to enable their scientific objectives. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high (Delta)V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. Solar sail technology is rapidly maturing for space propulsion applications within NASA and around the world.

Space Weathering on Icy Satellites in the Outer Solar System

NASA Technical Reports Server (NTRS)

Clark, R. N.; Perlman, Z.; Pearson, N.; Cruikshank, D. P.

2014-01-01

Space weathering produces well-known optical effects in silicate minerals in the inner Solar System, for example, on the Moon. Space weathering from solar wind and UV (ultraviolet radiation) is expected to be significantly weaker in the outer Solar System simply because intensities are low. However, cosmic rays and micrometeoroid bombardment would be similar to first order. That, combined with the much higher volatility of icy surfaces means there is the potential for space weathering on icy outer Solar System surfaces to show optical effects. The Cassini spacecraft orbiting Saturn is providing evidence for space weathering on icy bodies. The Cassini Visible and Infrared Mapping Spectrometer (VIMS) instrument has spatially mapped satellite surfaces and the rings from 0.35-5 microns and the Ultraviolet Imaging Spectrograph (UVIS) instrument from 0.1 to 0.2 microns. These data have sampled a complex mixing space between H2O ice and non-ice components and they show some common spectral properties. Similarly, spectra of the icy Galilean satellites and satellites in the Uranian system have some commonality in spectral properties with those in the Saturn system. The UV absorber is spectrally similar on many surfaces. VIMS has identified CO2, H2 and trace organics in varying abundances on Saturn's satellites. We postulate that through the spatial relationships of some of these compounds that they are created and destroyed through space weathering effects. For example, the trapped H2 and CO2 observed by VIMS in regions with high concentrations of dark material may in part be space weathering products from the destruction of H2O and organic molecules. The dark material, particularly on Iapetus which has the highest concentration in the Saturn system, is well matched by space-weathered silicates in the .4 to 2.6 micron range, and the spectral shapes closely match those of the most mature lunar soils, another indicator of space weathered material.

Flat-plate solar array project. Volume 7: Module encapsulation

NASA Astrophysics Data System (ADS)

Cuddihy, E.; Coulbert, C.; Gupta, A.; Liang, R.

1986-10-01

The objective of the Encapsulation Task was to develop, demonstrate, and qualify photovoltaic (PV) module encapsulation systems that would provide 20 year (later decreased to 30 year) life expectancies in terrestrial environments, and which would be compatible with the cost and performance goals of the Flat-Plate Solar Array (FSA) Project. The scope of the Encapsulation Task included the identification, development, and evaluation of material systems and configurations required to support and protect the optically and electrically active solar cell circuit components in the PV module operating environment. Encapsulation material technologies summarized include the development of low cost ultraviolet protection techniques, stable low cost pottants, soiling resistant coatings, electrical isolation criteria, processes for optimum interface bonding, and analytical and experimental tools for evaluating the long term durability and structural adequacy of encapsulated modules. Field testing, accelerated stress testing, and design studies have demonstrated that encapsulation materials, processes, and configurations are available that meet the FSA cost and performance goals.

Flat-plate solar array project. Volume 7: Module encapsulation

NASA Technical Reports Server (NTRS)

Cuddihy, E.; Coulbert, C.; Gupta, A.; Liang, R.

1986-01-01

The objective of the Encapsulation Task was to develop, demonstrate, and qualify photovoltaic (PV) module encapsulation systems that would provide 20 year (later decreased to 30 year) life expectancies in terrestrial environments, and which would be compatible with the cost and performance goals of the Flat-Plate Solar Array (FSA) Project. The scope of the Encapsulation Task included the identification, development, and evaluation of material systems and configurations required to support and protect the optically and electrically active solar cell circuit components in the PV module operating environment. Encapsulation material technologies summarized include the development of low cost ultraviolet protection techniques, stable low cost pottants, soiling resistant coatings, electrical isolation criteria, processes for optimum interface bonding, and analytical and experimental tools for evaluating the long term durability and structural adequacy of encapsulated modules. Field testing, accelerated stress testing, and design studies have demonstrated that encapsulation materials, processes, and configurations are available that meet the FSA cost and performance goals.

Photovoltaic-Pyroelectric Coupled Effect Induced Electricity for Self-Powered Photodetector System.

PubMed

Ma, Nan; Zhang, Kewei; Yang, Ya

2017-12-01

Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7-4 eV) suffer from low power conversion efficiency of less than 0.5% due to absorbing only 8-20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near-UV irradiations. Here, a ferroelectric BaTiO 3 film-based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled. As compared with photovoltaic effect, both the responsivity and the specific detectivity of the photodetector can be dramatically enhanced by larger than 260% due to the light-induced photovoltaic-pyroelectric coupled effect. A self-powered photodetector array system can be utilized to achieve spatially resolved light intensity detection by recording the output voltage signals as a mapping figure. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental study on flat plate air solar collector using a thin sand layer

NASA Astrophysics Data System (ADS)

Lati, Moukhtar; Boughali, Slimane; Bouguettaia, Hamza; Mennouche, Djamel; Bechki, Djamel

2016-07-01

A flat plate air solar collector was constructed in the laboratory of New and Renewable Energy in Arid Zones LENREZA, Ouargla University-South East Algeria. The absorber of the flat plate air solar collector was laminated with a thin layer of local sand. This acted as a thermal storage system (packed bed) with a collecting area of 2.15 m2 (0.86 m × 2.5 m). It was noticed that the solar heater integrated with the thermal storage material delivered comparatively higher temperatures; thus, giving a better efficiency than the air heater without the thermal storage system.

Hydrocarbons on Saturns Satellites: Relationship to Interstellar Dust and the Solar Nebula

NASA Technical Reports Server (NTRS)

Cruikshank, D. P.

2012-01-01

To understand the origin and evolution of our Solar System, and the basic components that led to life on Earth, we study interstellar and planetary spectroscopic signatures. The possible relationship of organic material detected in carbonaceous meteorites, interplanetary dust particles (IDPs), comets and the interstellar medium have been the source of speculation over the years as the composition and processes that governed the early solar nebula have been explored to understand the extent to which primitive material survived or became processed. The Cassini VIMS has provided new data relevant to this problem. Three of Saturn's satellites, Phoebe, Iapetus, and Hyperion, are found to have aromatic and aliphatic hydrocarbons on their surfaces. The aromatic hydrocarbon signature (C-H stretching mode at 3.28 micrometers) is proportionally significantly stronger (relative to the aliphatic bands) than that seen in other Solar System bodies (e.g., comets) and materials (Stardust samples, IDPs, meteorites) and the distinctive sub-features of the 3.4 micrometer aliphatic band (CH2 and CH3 groups) are reminiscent of those widely detected throughout the diffuse ISM. Phoebe may be a captured object that originated in the region beyond the present orbit of Neptune, where the solar nebula contained a large fraction of original interstellar ice and dust that was less processed than material closer to the Sun. Debris from Phoebe now resident on Iapetus and Hyperion, as well as o Phoebe itself, thus presents a unique blend of hydrocarbons, amenable to comparisons with interstellar hydrocarbons and other Solar System materials. The dust ring surrounding Saturn, in which Phoebe is embedded, probably originated from a collision with Phoebe. Dust ring particles are the likely source of the organic-bearing materials, and perhaps the recently identified small particles of Fe detected on Saturn's satellites. Lab measurements of the absolute band strengths of representative aliphatic and aromatic molecules, together with measurements from the VIMS data, allow us to calculate the number of C atoms to find the relative abundances of C atoms in the two kinds of organic molecules. The strength of the prominent aromatic C-H stretch band relative to the aliphatic band complex in Phoebe and Iapetus indicates that the relative abundance of aromatic to aliphatic carbon is very large (greater than 200). In contract, the aromatic band is nearly imperceptible in spectra of interplanetary dust particles (IDP), returned samples from comet 91P/Wild 2, insoluable carbonaceous material in most meteorites, and the diffuse interstellar dust (DISM) (although aromatics are known in all these materials-here we consider only the spectroscopic signature)

77 FR 23707 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-20

...-000. Applicants: NRG Solar Alpine LLC. Description: NRG Solar Alpine, LLC Notice of Self Certification...-000. Applicants: Exelon Corporation. Description: Notice of Material Change in Facts of Exelon... are accessible in the Commission's eLibrary system by clicking on the links or querying the docket...

The carbon budget in the outer solar nebula

NASA Technical Reports Server (NTRS)

Simonelli, Damon P.; Pollack, James B.; Mckay, Christopher P.; Reynolds, Ray T.; Summers, Audrey L.

1989-01-01

The compositional contrast between the giant-planet satellites and the significantly rockier Pluto/Charon system is indicative of different formation mechanisms; cosmic abundance calculations, in conjunction with an assumption of the Pluto/Charon system's direct formation from solar nebula condensates, strongly suggest that most of the carbon in the outer solar nebula was in CO form, in keeping with both the inheritance from the dense molecular clouds in the interstellar medium, and/or the Lewis and Prinn (1980) kinetic-inhibition model of solar nebula chemistry. Laboratory studies of carbonaceous chondrites and Comet Halley flyby studies suggest that condensed organic material, rather than elemental carbon, is the most likely candidate for the small percentage of the carbon-bearing solid in the outer solar nebula.

Low cost solar energy collection system

NASA Technical Reports Server (NTRS)

Miller, C. G.; Stephans, J. B. (Inventor)

1977-01-01

A fixed, linear, ground-based primary reflector having an extended, curved sawtooth contoured surface covered with a metallized polymeric reflecting material, reflected solar energy to a movably supported collector that was kept at the concentrated line focus of the reflector primary. Efficient utilization leading to high temperatures from the reflected solar energy was obtained by cylindrical shaped secondary reflectors that directed off-angle energy to the absorber pipe.

Degradation of FEP thermal control materials returned from the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Zuby, Thomas M.; Degroh, Kim K.; Smith, Daniela C.

1995-01-01

After an initial 3.6 years of space flight, the Hubble Space Telescope was serviced through a joint effort with the NASA and the European Space Agency. Multi-layer insulation (MLI) was retrieved from the electronics boxes of the two magnetic sensing systems (MSS), also called the magnetometers, and from the returned solar array (SA-I) drive arm assembly. The top layer of each MLI assembly is fluorinated ethylene propylene (FEP, a type of Teflon). Dramatic changes in material properties were observed when comparing areas of high solar fluence to areas of low solar fluence. Cross sectional analysis shows atomic oxygen (AO) erosion values up to 25.4 mu m (1 mil). Greater occurrences of through-thickness cracking and surface microcracking were observed in areas of high solar exposure. Atomic force microscopy (AFM) showed increases in surface microhardness measurements with increasing solar exposure. Decreases in FEP tensile strength and elongation were measured when compared to non-flight material. Erosion yield and tensile results are compared with FEP data from the Long Duration Exposure Facility. AO erosion yield data, solar fluence values, contamination, micrometeoroid or debris impact sites, and optical properties are presented.

Cometary Dust in the Debris of HD 31648 and HD163296: Two "Baby" Beta pictoris Stars

NASA Technical Reports Server (NTRS)

Sitko, Michael L.; Grady, Carol A.; Lynch, David K.; Russell, Ray W.; Hanner, Martha S.

1999-01-01

The debris disks surrounding the pre-main-sequence stars HD 31648 and HD 163296 were observed spectroscopically between 3 and 14 microns. Both stars possess a silicate emission feature at 10 Am that resembles that of the star P Pictoris and those observed in solar system comets. The structure of the band is consistent with a mixture of olivine and pyroxene material, plus an underlying continuum of unspecified origin. The similarity in both size and structure of the silicate band suggests that the material in these systems had a processing history similar to that in our own solar system prior to the time that the grains were incorporated into comets.

Cometary Dust in the Debris Disks of HD 31648 and HD 163296: Two "Baby" (BETA) Pictoris Stars

NASA Technical Reports Server (NTRS)

Sitko, Michael L.; Grady, Carol A.; Lynch, David K.; Russell, Ray W.; Hanner, Martha S.; Hanner, Martha S.

1999-01-01

The debris disks surrounding the pre-main-sequence stars HD 31648 and HD 163296 were observed spectroscopically between 3 and 14 microns. Both stars possess a silicate emission feature at 10 microns that resembles that of the star beta Pictoris and those observed in solar system comets. The structure of the band is consistent with a mixture of olivine and pyroxene material, plus an underlying continuum of unspecified origin. The similarity in both size and structure of the silicate band suggests that the material in these systems had a processing history similar to that in our own solar system prior to the time that the grains were incorporated into comets.

Recent Advances in Solar Sail Propulsion at NASA

NASA Technical Reports Server (NTRS)

Johnson, Les; Young, Roy M.; Montgomery, Edward E., IV

2006-01-01

Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing solar sail propulsion for use in robotic science and exploration of the solar system. Solar sail propulsion will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-meter solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L'Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. This sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails-perhaps as much as 150 meters on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (>150 meters) required for first generation solar sails missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing.

Forward Technology Solar Cell Experiment First On-Orbit Data

NASA Technical Reports Server (NTRS)

Walters, R. J.; Garner, J. C.; Lam, S. N.; Vazquez, J. A.; Braun, W. R.; Ruth, R. E.; Warner, J. H.; Lorentzen, J. R.; Messenger, S. R.; Bruninga, R.;

Technology Challenges and Opportunities for Very Large In-Space Structural Systems

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Dorsey, John T.; Watson, Judith J.

2009-01-01

Space solar power satellites and other large space systems will require creative and innovative concepts in order to achieve economically viable designs. The mass and volume constraints of current and planned launch vehicles necessitate highly efficient structural systems be developed. In addition, modularity and in-space deployment/construction will be enabling design attributes. While current space systems allocate nearly 20 percent of the mass to the primary structure, the very large space systems of the future must overcome subsystem mass allocations by achieving a level of functional integration not yet realized. A proposed building block approach with two phases is presented to achieve near-term solar power satellite risk reduction with accompanying long-term technology advances. This paper reviews the current challenges of launching and building very large space systems from a structures and materials perspective utilizing recent experience. Promising technology advances anticipated in the coming decades in modularity, material systems, structural concepts, and in-space operations are presented. It is shown that, together, the current challenges and future advances in very large in-space structural systems may provide the technology pull/push necessary to make solar power satellite systems more technically and economically feasible.

Measurement and Characterization of Concentrator Solar Cells II

NASA Technical Reports Server (NTRS)

Scheiman, Dave; Sater, Bernard L.; Chubb, Donald; Jenkins, Phillip; Snyder, Dave

2005-01-01

Concentrator solar cells are continuing to get more consideration for use in power systems. This interest is because concentrator systems can have a net lower cost per watt in solar cell materials plus ongoing improvements in sun-tracking technology. Quantitatively measuring the efficiency of solar cells under concentration is difficult. Traditionally, the light concentration on solar cells has been determined by using a ratio of the measured solar cell s short circuit current to that at one sun, this assumes that current changes proportionally with light intensity. This works well with low to moderate (<20 suns) concentration levels on "well-behaved" linear cells but does not apply when cells respond superlinearly, current increases faster than intensity, or sublinearly, current increases more slowly than intensity. This paper continues work on using view factors to determine the concentration level and linearity of the solar cell with mathematical view factor analysis and experimental results [1].

High performance a-Si solar cells and new fabrication methods for a-Si solar cells

NASA Astrophysics Data System (ADS)

Nakano, S.; Kuwano, Y.; Ohnishi, M.

1986-12-01

The super chamber, a separated UHV reaction-chamber system has been developed. A conversion efficiency of 11.7% was obtained for an a-Si solar cell using a high-quality i-layer deposited by the super chamber, and a p-layer fabricated by a photo-CVD method. As a new material, amorphous superlattice-structure films were fabricated by the photo-CVD method for the first time. Superlattice structure p-layer a-Si solar cells were fabricated, and a conversion efficiency of 10.5% was obtained. For the fabrication of integrated type a-Si solar cell modules, a laser pattering method was investigated. A thermal analysis of the multilayer structure was done. It was confirmed that selective scribing for a-Si, TCO and metal film is possible by controlling the laser power density. Recently developed a-Si solar power generation systems and a-Si solar cell roofing tiles are also described.

Ice chemistry on outer solar system bodies: Carboxylic acids, nitriles, and urea detected in refractory residues produced from the UV photolysis of N{sub 2}:CH{sub 4}:CO-containing ices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.

Radiation processing of the surface ices of outer solar system bodies may result in the production of new chemical species even at low temperatures. Many of the smaller, more volatile molecules that are likely produced by the photolysis of these ices have been well characterized by laboratory experiments. However, the more complex refractory material formed in these experiments remains largely uncharacterized. In this work, we present a series of laboratory experiments in which low-temperature (15-20 K) N{sub 2}:CH{sub 4}:CO ices in relative proportions 100:1:1 are subjected to UV irradiation, and the resulting materials are studied with a variety of analyticalmore » techniques including infrared spectroscopy, X-ray absorption near-edge structure spectroscopy, gas chromatography coupled with mass spectrometry, and high-resolution mass spectroscopy. Despite the simplicity of the reactants, these experiments result in the production of a highly complex mixture of molecules from relatively low-mass volatiles (tens of daltons) to high-mass refractory materials (hundreds of daltons). These products include various carboxylic acids, nitriles, and urea, which are also expected to be present on the surface of outer solar system bodies, including Pluto and other transneptunian objects. If these compounds occur in sufficient concentrations in the ices of outer solar system bodies, their characteristic bands may be detectable in the near-infrared spectra of these objects.« less

Development of a concentrating solar power system using fluidized-bed technology for thermal energy conversion and solid particles for thermal energy storage

DOE PAGES

Ma, Z.; Mehos, M.; Glatzmaier, G.; ...

2015-05-01

Concentrating solar power (CSP) is an effective way to convert solar energy into electricity with an economic energy-storage capability for grid-scale, dispatchable renewable power generation. However, CSP plants need to reduce costs to be competitive with other power generation methods. Two ways to reduce CSP cost are to increase solar-to-electric efficiency by supporting a high-efficiency power conversion system, and to use low-cost materials in the system. The current nitrate-based molten-salt systems have limited potential for cost reduction and improved power-conversion efficiency with high operating temperatures. Even with significant improvements in operating performance, these systems face challenges in satisfying the costmore » and performance targets. This paper introduces a novel CSP system with high-temperature capability that can be integrated into a high-efficiency CSP plant and that meets the low-cost, high-performance CSP targets. Unlike a conventional salt-based CSP plant, this design uses gas/solid, two-phase flow as the heat-transfer fluid (HTF); separated solid particles as storage media; and stable, inexpensive materials for the high-temperature receiver and energy storage containment. We highlight the economic and performance benefits of this innovative CSP system design, which has thermal energy storage capability for base-load power generation.« less

Basic Energy Science | NREL

Science.gov Websites

scientific understanding-of molecular, nanoscale, semiconductor, and biological materials, systems, and molecular, nanoscale, and semiconductor systems to capture, control, and convert solar radiation with high

Near Earth Asteroid Scout: NASA's Solar Sail Mission to a NEA

NASA Technical Reports Server (NTRS)

Johnson, Les; Castillo-Rogez, Julie; Dervan, Jared

2017-01-01

NASA is developing a solar sail propulsion system for use on the Near Earth Asteroid (NEA) Scout reconnaissance mission and laying the groundwork for their use in future deep space science and exploration missions. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellant-less thrust, allowing for very high delta V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. The Near Earth Asteroid (NEA) Scout mission, funded by NASA’s Advanced Exploration Systems Program and managed by NASA MSFC, will use the sail as primary propulsion allowing it to survey and image Asteroid 1991VG and, potentially, other NEA’s of interest for possible future human exploration. The NEA Scout spacecraft is housed in a 6U CubeSat-form factor and utilizes an 86 square meter solar sail for a total mass less than 14 kilograms. The mission is in partnership with the Jet Propulsion Laboratory with support from Langley Research Center and science participants from various institutions. NEA Scout will be launched on the maiden flight of the Space Launch System in 2019. The solar sail for NEA Scout will be based on the technology developed and flown by the NASA NanoSail-D and flown on The Planetary Society’s Lightsail-A. Four approximately-7-meter stainless steel booms wrapped on two spools (two overlapping booms per spool) will be motor driven and pull the sail from its stowed volume. The sail material is an aluminized polyimide approximately 2.5 microns thick. As the technology matures, solar sails will increasingly be used to enable science and exploration missions that are currently impossible or prohibitively expensive using traditional chemical and electric propulsion systems. This paper will summarize the status of the NEA Scout mission and solar sail technology in general.

Introduction to Solar Heating and Cooling Systems. D.O.T. 637.281 and .381. Student's Manual.

ERIC Educational Resources Information Center

Grimes, L. A., Jr.

This manual on solar heating and cooling systems is one of a series of individualized instructional materials for students. The manual is self-paced, but is designed to be used under the supervision of a coordinator or an instructor. The manual contains 15 assignments, each with all the information needed, a list of objectives that should be met,…

Volatiles in the Earth and Moon: Constraints on planetary formation and evolution

NASA Astrophysics Data System (ADS)

Parai, Rita

The volatile inventories of the Earth and Moon reflect unique histories of volatile acquisition and loss in the early Solar System. The terrestrial volatile inventory was established after the giant impact phase of accretion, and the planet subsequently settled into a regime of long-term volatile exchange between the mantle and surface reservoirs in association with plate tectonics. Therefore, volatiles in the Earth and Moon shed light on a diverse array of processes that shaped planetary bodies in the Solar System as they evolved to their present-day states. Here we investigate new constraints on volatile depletion in the early Solar System, early outgassing of the terrestrial mantle, and the long-term evolution of the deep Earth volatile budget. We develop a Monte Carlo model of long-term water exchange between the mantle and surface reservoirs. Previous estimates of the deep Earth return flux of water are up to an order of magnitude too large, and incorporation of recycled slabs on average rehydrates the upper mantle but dehydrates the plume source. We find evidence for heterogeneous recycling of atmospheric argon and xenon into the upper mantle from noble gases in Southwest Indian Ridge basalts. Xenon isotope systematics indicate that xenon budgets of mid-ocean ridge and plume-related mantle sources are dominated by recycled atmospheric xenon, though the two sources have experienced different degrees of degassing. Differences between the mid-ocean ridge and plume sources were initiated within the first 100 million years of Earth history, and the two sources have never subsequently been homogenized. New high-precision xenon isotopic data contribute to an emerging portrait of two mantle reservoirs with distinct histories of outgassing and incorporation of recycled material in association with plate tectonics. Xenon isotopes indicate that the Moon likely formed within ˜70 million years of the start of the Solar System. To further investigate early Solar System chronology, we determined strontium isotopic compositions in a suite of planetary materials. If the Moon is derived from proto-Earth material, then rubidium-strontium systematics in the lunar anorthosite 60025 and Moore County plagioclase indicate that Moon formation occurred within ~62 million years of the start of the Solar System.

Workshop proceedings: Photovoltaic conversion of solar energy for terrestrial applications. Volume 2: Invited papers

NASA Technical Reports Server (NTRS)

1973-01-01

A photovoltaic device development plan is reported that considers technological as well as economical aspects of single crystal silicon, polycrystal silicon, cadmium sulfide/copper sulfide thin films, as well as other materials and devices for solar cell energy conversion systems.

Chemical heat pump

DOEpatents

Greiner, Leonard

1980-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

Durable thin film coatings for reflectors used in low earth orbit

NASA Technical Reports Server (NTRS)

Mcclure, Donald J.

1989-01-01

This paper discusses the properties of thin film coatings used to provide a durable reflective surface for solar concentrators used in the solar dynamic system designed for the Space Station. The material system to be used consists of an adhesion promotion layer, a silver reflective layer, and a protective layer of aluminum oxide and silicon dioxide. The performance characteristics of this system are described and compared to those of several alternative systems which use aluminum as the reflective layer.

Solar technology assessment project. Volume 6: Photovoltaic technology assessment

NASA Astrophysics Data System (ADS)

Backus, C. E.

1981-04-01

Industrial production of photovoltaic systems and volume of sales are reviewed. Low cost silicon production techniques are reviewed, including the Czochralski process, heat exchange method, edge defined film fed growth, dentritic web growth, and silicon on ceramic process. Semicrystalline silicon, amorphous silicon, and low cost poly-silicon are discussed as well as advanced materials and concentrator systems. Balance of system components beyond those needed to manufacture the solar panels are included. Nontechnical factors are assessed. The 1986 system cost goals are briefly reviewed.

High-temperature molten salt thermal energy storage systems for solar applications

NASA Technical Reports Server (NTRS)

Petri, R. J.; Claar, T. D.; Ong, E.

1983-01-01

Experimental results of compatibility screening studies of 100 salt/containment/thermal conductivity enhancement (TCE) combinations for the high temperature solar thermal application range of 704 deg to 871 C (1300 to 1600 F) are presented. Nine candidate containment/HX alloy materials and two TCE materials were tested with six candidate solar thermal alkali and alkaline earth carbonate storage salts (both reagent and technical grade of each). Compatibility tests were conducted with salt encapsulated in approx. 6.0 inch x 1 inch welded containers of test material from 300 to 3000 hours. Compatibility evaluations were end application oriented, considering the potential 30 year lifetime requirement of solar thermal power plant components. Analyses were based on depth and nature of salt side corrosion of materials, containment alloy thermal aging effects, weld integrity in salt environment, air side containment oxidation, and chemical and physical analyses of the salt. A need for more reliable, and in some cases first time determined thermophysical and transport property data was also identified for molten carbonates in the 704 to 871 C temperature range. In particular, accurate melting point (mp) measurements were performed for Li2CO3 and Na2CO3 while melting point, heat of fusion, and specific heat determinations were conducted on 81.3 weight percent Na2CO3-18.7 weight percent K2CO3 and 52.2 weight percent BaCO3-47.8 weight percent Na2CO3 to support future TES system design and ultimate scale up of solar thermal energy storage (TES) subsystems.

Comets

NASA Astrophysics Data System (ADS)

Brownlee, D. E.

2003-12-01

Comets are surviving members of a formerly vast distribution of solid bodies that formed in the cold regions of the solar nebula. Cometary bodies escaped incorporation into planets and ejection from the solar system and they have been stored in two distant reservoirs, the Oort cloud and the Kuiper Belt, for most of the age of the solar system. Observed comets appear to have formed between 5 AU and 55 AU. From a cosmochemical viewpoint, comets are particularly interesting bodies because they are preserved samples of the solar nebula's cold ice-bearing regions that occupied 99% of the areal extent of the solar nebula disk. All comets formed beyond the "snow line" of the nebula, where the conditions were cold enough for water ice to condense, but they formed from environments that significantly differed in temperature. Some formed in the comparatively "warm" regions near Jupiter where the nebular temperature may have been greater than 120 K and others clearly formed beyond Neptune where temperatures may have been less than 30 K (Bell et al., 1997). Although comets are the best-preserved materials from the early solar system, they should be a mix of nebular and presolar materials that accreted over a vast range of distances from the Sun in environments that differed in temperature, pressure, and accretional conditions such as impact speed.Comets, by conventional definition, are unstable near the Sun; they contain highly volatile ices that vigorously sublime within 2-3 AU of the Sun. When heated, they release gas and solids due to "cometary activity," a series of processes usually detected from afar by the presence of a coma of gas and dust surrounding the cometary nucleus and or elongated tails composed of dust and gas. Active comets clearly have not been severely modified by the moderate to extreme heating that has affected all other solar system materials, including planets, moons, and even the asteroids that produced the most primitive meteorites. Comets have been widely described as the most primitive solar system materials, preserved at cryogenic temperature and low pressure since the formation of the Sun. This is likely to be true, in general, but there is a growing body of recent evidence suggesting that comets are both more physically complex and have had more complex histories than formerly believed. They formed over an order of magnitude range of distances from the Sun; some are fragments of relatively large bodies and collisional effects must have processed at least some comets, as they have processed asteroids (McSween and Weissman, 1989).Comet-like materials are presumed to be the building blocks of Uranus and Neptune (the ice giants); they may have played a role in the formation of Jupiter and Saturn (the gas giants) and they also played some role in transporting outer solar system volatile materials to inner planets (Delsemme, 2000). The inner solar system flux of comets may have been much higher in the past and comets may have played a role in producing the late heavy bombardment on terrestrial planets ( Levison et al., 2001). Comets also exist outside the solar system and there is good evidence that they orbit a major fraction of Sun-like stars. Circumstellar dust, which appears to have been generated by comets, is detected as thermal infrared emission and sometimes as scattered starlight ( Backman et al., 1997; Weissman, 1984; Jewitt and Luu, 1995). It is particularly interesting that the amount of dust around stars declines with stellar age and is highest around stars younger than a few hundred million years. The common presence of what appears to be comet-generated dust around other stars suggests that comet formation is a normal and common consequence of star formation ( Figure 1). (6K)Figure 1. The ratio of infrared excess/stellar luminosity is a measure of the fraction of starlight absorbed by circumstellar dust and re-radiated in the infrared. The plot from Spangler et al. (2001) shows the temporal decline of dust around "Vega-like" stars (points) and stars in clusters with measured ages (circles). At least for the longer ages, the dust is most probably generated by comets.

Star Formation and the Solar System

NASA Technical Reports Server (NTRS)

Bally, John; Boss, Alan; Papanastassiou, Dimitri; Sandford, Scott; Sargent, Anneila

1988-01-01

We have seen that studies of nearby star-forming regions are beginning to reveal the first signs of protoplanetary disks. Studies of interstellar and interplanetary grains are starting to provide clues about the processing and incorporation of matter into the Solar System. Studies of meteorites have yielded isotopic anomalies which indicate that some of the grains and inclusions in these bodies are very primitive. Although we have not yet detected a true interstellar grain, some of these materials have not been extensively modified since their removal from the ISM. We are indeed close to seeing our interstellar heritage. The overlap between astronomical and Solar System studies is in its infancy. What future experiments, observations, and missions can be performed in the near future that will greatly enhance our understanding of star formation and the formation of the Solar System?

Solar selective performance of metal nitride/oxynitride based magnetron sputtered thin film coatings: a comprehensive review

NASA Astrophysics Data System (ADS)

Ibrahim, Khalil; Taha, Hatem; Mahbubur Rahman, M.; Kabir, Humayun; Jiang, Zhong-Tao

2018-03-01

Since solar-thermal collectors are considered to be the most direct way of converting solar energy into usable forms, in the last few years growing attention has been paid to the development of transition metal nitride and metal oxynitride based thin film selective surfaces for solar-thermal collectors, in order to harvest more solar energy. A solar-thermal energy system, generally, shows very high solar absorption of incident solar radiation from the solar-thermal collectors in the visible range (0.3 to 2.5 μm) and extremely low thermal losses through emission (or high reflection) in the infrared region (≥2.5 μm). The efficiency of a solar-thermal energy conversion system can be improved by the use of solar selective surfaces consisting of novel metallic nanoparticles embedded in metal nitride/oxynitride systems. In order to enhance the effectiveness of solar-thermal devices, solar selective surfaces with high thermal stability are a prerequisite. Over the years, substantial efforts have been made in the field of solar selective surfaces to attain higher solar absorptance and lower thermal emittance in high temperature (above 400 °C) applications. In this article, we review the present state-of-the-art transition metal nitride and/or oxynitride based vacuum sputtered nanostructured thin film coatings, with respect to their optical and solar selective surface applications. We have also summarized the solar selectivity data from recently published investigations, including discussion on some potential applications for these materials.

Solar Sail Propulsion Technology at NASA

NASA Technical Reports Server (NTRS)

Johnson, Charles Les

2007-01-01

NASA's In-Space Propulsion Technology Program developed the first generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an area density of less than 13 grams per square meter. A rigorous, multi-year technology development effort culminated in 2005 with the testing of two different 20-m solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In addition, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. The presentation will describe the status of solar sail propulsion within NASA, near-term solar sail mission applications, and near-term plans for further development.

A Study of Solar Thermal Propulsion System Enhancement via Thermal Storage and Thermal-electric Conversion

DTIC Science & Technology

2010-03-24

currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 24-03-2010 2. REPORT TYPE...Technical Paper 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER A Study of Solar Thermal Propulsion System...explored here are the optimization of thermal storage using a phase change material, design considerations assuming a microsatellite system in low Earth

Solar water heater design package

NASA Technical Reports Server (NTRS)

1981-01-01

Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

The origin of inner Solar System water.

PubMed

Alexander, Conel M O'D

2017-05-28

Of the potential volatile sources for the terrestrial planets, the CI and CM carbonaceous chondrites are closest to the planets' bulk H and N isotopic compositions. For the Earth, the addition of approximately 2-4 wt% of CI/CM material to a volatile-depleted proto-Earth can explain the abundances of many of the most volatile elements, although some solar-like material is also required. Two dynamical models of terrestrial planet formation predict that the carbonaceous chondrites formed either in the asteroid belt ('classical' model) or in the outer Solar System (5-15 AU in the Grand Tack model). To test these models, at present the H isotopes of water are the most promising indicators of formation location because they should have become increasingly D-rich with distance from the Sun. The estimated initial H isotopic compositions of water accreted by the CI, CM, CR and Tagish Lake carbonaceous chondrites were much more D-poor than measured outer Solar System objects. A similar pattern is seen for N isotopes. The D-poor compositions reflect incomplete re-equilibration with H 2 in the inner Solar System, which is also consistent with the O isotopes of chondritic water. On balance, it seems that the carbonaceous chondrites and their water did not form very far out in the disc, almost certainly not beyond the orbit of Saturn when its moons formed (approx. 3-7 AU in the Grand Tack model) and possibly close to where they are found today.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

Materials research for passive solar systems: Solid-state phase-change materials

NASA Astrophysics Data System (ADS)

Benson, D. K.; Webb, J. D.; Burrows, R. W.; McFadden, J. D. O.; Christensen, C.

1985-03-01

A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C5H12O4), pentaglycerinve (C5H12O3), and neopentyl glycol (C5H12O2). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature between 25 C and 188 C, and have latent heats of transformation etween 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier.

Hypervelocity Impact Testing of Space Station Freedom Solar Cells

NASA Technical Reports Server (NTRS)

Christie, Robert J.; Best, Steve R.; Myhre, Craig A.

1994-01-01

Solar array coupons designed for the Space Station Freedom electrical power system were subjected to hypervelocity impacts using the HYPER facility in the Space Power Institute at Auburn University and the Meteoroid/Orbital Debris Simulation Facility in the Materials and Processes Laboratory at the NASA Marshall Space Flight Center. At Auburn, the solar cells and array blanket materials received several hundred impacts from particles in the micron to 100 micron range with velocities typically ranging from 4.5 to 10.5 km/s. This fluence of particles greatly exceeds what the actual components will experience in low earth orbit. These impacts damaged less than one percent of total area of the solar cells and most of the damage was limited to the cover glass. There was no measurable loss of electrical performance. Impacts on the array blanket materials produced even less damage and the blanket materials proved to be an effective shield for the back surface of the solar cells. Using the light gas gun at MSFC, one cell of a four cell coupon was impacted by a 1/4 inch spherical aluminum projectile with a velocity of about 7 km/s. The impact created a neat hole about 3/8 inch in diameter. The cell and coupon were still functional after impact.

High-temperature solar receiver integrated with a short-term storage system

NASA Astrophysics Data System (ADS)

Giovannelli, Ambra; Bashir, Muhammad Anser; Archilei, Erika Maria

2017-06-01

Small-Scale Concentrated Solar Power Plants could have a potential market for off-grid applications in rural contexts with limited access to the electrical grid and favorable environmental characteristics. Some Small-Scale plants have already been developed, like the 25-30 kWe Dish-Stirling engine. Other ones are under development as, for example, plants based on Parabolic Trough Collectors coupled with Organic Rankine Cycles. Furthermore, the technological progress achieved in the development of new small high-temperature solar receiver, makes possible the development of interesting systems based on Micro Gas Turbines coupled with Dish collectors. Such systems could have several advantages in terms of costs, reliability and availability if compared with Dish-Stirling plants. In addition, Dish-Micro Gas Turbine systems are expected to have higher performance than Solar Organic Rankine Cycle plants. The present work focuses the attention on some challenging aspects related to the design of small high-temperature solar receivers for Dish-Micro Gas Turbine systems. Natural fluctuations in the solar radiation can reduce system performance and damage seriously the Micro Gas Turbine. To stabilize the system operation, the solar receiver has to assure a proper thermal inertia. Therefore, a solar receiver integrated with a short-term storage system based on high-temperature phase-change materials is proposed in this paper. Steady-state and transient analyses (for thermal storage charge and discharge phases) have been carried out using the commercial CFD code Ansys-Fluent. Results are presented and discussed.

Availability of solar energy reports from the National Solar Data Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-07-01

This booklet discusses the various types of reports published by the National Solar Data Program, lists the reports issued prior to July 15, 1981, and provides order blanks for obtaining copies of reports. The reports identified in the following pages are segmented into nine types: monthly performance reports; solar energy performance evaluation reports; solar performance bulletins;environmental data reports;solar project description reports;solar project cost reports;program information reports;comparative reports; and reliability and material assessment reports. For convenience, available site-specific reports are listed alphabetically by site name, solar system type, and by state. These reports are disseminated through the US Department of Energy,more » Technical Information Center, P.O. Box 62, Oak Ridge, Tennessee 37830.« less

Near Earth Asteroid Solar Sail Engineering Development Unit Test Program

NASA Technical Reports Server (NTRS)

Lockett, Tiffany Russell; Few, Alexander; Wilson, Richard

2017-01-01

The Near Earth Asteroid (NEA) Scout project is a 30x20x10cm (6U) cubesat reconnaissance mission to investigate a near Earth asteroid utilizing an 86m2 solar sail as the primary propulsion system. This will be the largest solar sail NASA will launch to date. NEA Scout is a secondary payload currently manifested on the maiden voyage of the Space Launch System in 2018. In development of the solar sail subsystem, design challenges were identified and investigated for packaging within a 6U form factor and deployment in cis-lunar space. Analysis furthered understanding of thermal, stress, and dynamics of the stowed system and matured an integrated sail membrane model for deployed flight dynamics. This paper will address design, fabrication, and lessons learned from the NEA Scout solar sail subsystem engineering development unit. From optical properties of the sail material to folding and spooling the single 86m2 sail, the team has developed a robust deployment system for the solar sail. This paper will also address expected and received test results from ascent vent, random vibration, and deployment tests.

Spatial distribution of carbon dust in the early solar nebula and the carbon content of planetesimals

NASA Astrophysics Data System (ADS)

Gail, Hans-Peter; Trieloff, Mario

2017-09-01

Context. A high fraction of carbon bound in solid carbonaceous material is observed to exist in bodies formed in the cold outskirts of the solar nebula, while bodies in the region of terrestrial planets contain only very small mass fractions of carbon. Most of the solid carbon component is lost and converted into CO during the spiral-in of matter as the Sun accretes matter from the solar nebula. Aims: We study the fate of the carbonaceous material that entered the proto-solar disc by comparing the initial carbon abundance in primitive solar system material and the abundance of residual carbon in planetesimals and planets in the asteroid belt and the terrestrial planet region. Methods: We constructed a model for the composition of the pristine carbonaceous material from observational data on the composition of the dust component in comets and of interplanetary dust particles and from published data on pyrolysis experiments. This material entered the inner parts of the solar nebula during the course of the build-up of the proto-sun by accreting matter from the proto-stellar disc. Based on a one-zone evolution model of the solar nebula, we studied the pyrolysis of the refractory and volatile organic component and the concomitant release of hydrocarbons of high molecular weight under quiescent conditions of disc evolution, while matter migrates into the central parts of the solar nebula. We also studied the decomposition and oxidation of the carbonaceous material during violent flash heating events, which are thought to be responsible for the formation of chondrules. To do this, we calculated pyrolysis and oxidation of the carbonaceous material in temperature spikes that were modeled according to cosmochemical models for the temperature history of chondrules. Results: We find that the complex hydrocarbon components of the carbonaceous material are removed from the disc matter in the temperature range between 250 and 400 K, but the amorphous carbon component survives to temperatures of 1200 K. Without efficient carbon destruction during flash-heating associated with chondrule formation, the carbon abundance of terrestrial planets, except for Mercury, would be of several percent and not as low as it is found in cosmochemical studies. Chondrule formation seems to be a crucial process for the carbon-poor composition of the material of terrestrial planets.

Silicon Carbide Solar Cells Investigated

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Raffaelle, Ryne P.

2001-01-01

The semiconductor silicon carbide (SiC) has long been known for its outstanding resistance to harsh environments (e.g., thermal stability, radiation resistance, and dielectric strength). However, the ability to produce device-quality material is severely limited by the inherent crystalline defects associated with this material and their associated electronic effects. Much progress has been made recently in the understanding and control of these defects and in the improved processing of this material. Because of this work, it may be possible to produce SiC-based solar cells for environments with high temperatures, light intensities, and radiation, such as those experienced by solar probes. Electronics and sensors based on SiC can operate in hostile environments where conventional silicon-based electronics (limited to 350 C) cannot function. Development of this material will enable large performance enhancements and size reductions for a wide variety of systems--such as high-frequency devices, high-power devices, microwave switching devices, and high-temperature electronics. These applications would supply more energy-efficient public electric power distribution and electric vehicles, more powerful microwave electronics for radar and communications, and better sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines. The 6H-SiC polytype is a promising wide-bandgap (Eg = 3.0 eV) semiconductor for photovoltaic applications in harsh solar environments that involve high-temperature and high-radiation conditions. The advantages of this material for this application lie in its extremely large breakdown field strength, high thermal conductivity, good electron saturation drift velocity, and stable electrical performance at temperatures as high as 600 C. This behavior makes it an attractive photovoltaic solar cell material for devices that can operate within three solar radii of the Sun.

Solar satellites

NASA Astrophysics Data System (ADS)

Poher, C.

A reference system design, projected costs, and the functional concepts of a satellite solar power system (SSPS) for converting sunlight falling on solar panels of a satellite in GEO to a multi-GW beam which could be received by a rectenna on earth are outlined. Electricity transmission by microwaves has been demonstrated, and a reference design system for supplying 5 GW dc to earth was devised. The system will use either monocrystalline Si or concentrator GaAs solar cells for energy collection in GEO. Development is still needed to improve the lifespan of the cells. Currently, the cell performance degrades 50 percent in efficiency after 7-8 yr in space. Each SSPS satellite would weigh either 34,000 tons (Si) or 51,000 tons (GaAs), thereby requiring the fabrication of a heavy lift launch vehicle or a single-stage-to-orbit transport in order to minimize launch costs. Costs for the solar panels have been estimated at $500/kW using the GaAs technology, with transport costs for materials to GEO being $40/kg.

KSC-08pd1685

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers check the movement of the wing toward the Pegasus XL launch vehicle. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd2410

NASA Image and Video Library

2008-07-30

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, technicians follow the movement of NASA's Interstellar Boundary Explorer, or IBEX, mission spacecraft toward the mobile stand in the foreground. The IBEX satellite will make the first map of the boundary between the Solar System and interstellar space. IBEX is the first mission designed to detect the edge of the Solar System. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the Solar System and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the Solar System that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. IBEX is targeted for launch from the Pegasus XL rocket on Oct. 5. Photo credit: NASA

KSC-08pd2409

NASA Image and Video Library

2008-07-30

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, technicians prepare a mobile stand to receive NASA's Interstellar Boundary Explorer, or IBEX, mission spacecraft. The IBEX satellite will make the first map of the boundary between the Solar System and interstellar space. IBEX is the first mission designed to detect the edge of the Solar System. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the Solar System and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the Solar System that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. IBEX is targeted for launch from the Pegasus XL rocket on Oct. 5. Photo credit: NASA

KSC-08pd1682

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1677

NASA Image and Video Library

2008-04-28

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, the wings of the Pegasus XL launch vehicle are checked for fit. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1686

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers check the fit of the wing on the Pegasus XL launch vehicle. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1683

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle in the background for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1676

NASA Image and Video Library

2008-04-28

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, the wings of the Pegasus XL launch vehicle are checked for fit. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1684

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle in the background for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

Lunar Science Conference, 8th, Houston, Tex., March 14-18, 1977, Proceedings. Volume 1 - The moon and the inner solar system. Volume 2 - Petrogenetic studies of mare and highland rocks. Volume 3 - Planetary and lunar surfaces

NASA Technical Reports Server (NTRS)

Merril, R. B.

1977-01-01

Solar system processes are considered along with the origin and evolution of the moon, planetary geophysics, lunar basins and crustal layering, lunar magnetism, the lunar surface as a planetary probe, remote observations of lunar and planetary surfaces, earth-based measurements, integrated studies, physical properties of lunar materials, and asteroids, meteorites, and the early solar system. Attention is also given to studies of mare basalts, the kinetics of basalt crystallization, topical studies of mare basalts, highland rocks, experimental studies of highland rocks, geochemical studies of highland rocks, studies of materials of KREEP composition, a consortium study of lunar breccia 73215, topical studies on highland rocks, Venus, and regional studies of the moon. Studies of surface processes, are reported, taking into account cratering mechanics and fresh crater morphology, crater statistics and surface dating, effects of exposure and gardening, and the chemistry of surfaces.

Functionally Graded Materials Database

NASA Astrophysics Data System (ADS)

Kisara, Katsuto; Konno, Tomomi; Niino, Masayuki

2008-02-01

Functionally Graded Materials Database (hereinafter referred to as FGMs Database) was open to the society via Internet in October 2002, and since then it has been managed by the Japan Aerospace Exploration Agency (JAXA). As of October 2006, the database includes 1,703 research information entries with 2,429 researchers data, 509 institution data and so on. Reading materials such as "Applicability of FGMs Technology to Space Plane" and "FGMs Application to Space Solar Power System (SSPS)" were prepared in FY 2004 and 2005, respectively. The English version of "FGMs Application to Space Solar Power System (SSPS)" is now under preparation. This present paper explains the FGMs Database, describing the research information data, the sitemap and how to use it. From the access analysis, user access results and users' interests are discussed.

The Composition of the Protosolar Disk and the Formation Conditions for Comets

NASA Astrophysics Data System (ADS)

Willacy, K.; Alexander, C.; Ali-Dib, M.; Ceccarelli, C.; Charnley, S. B.; Doronin, M.; Ellinger, Y.; Gast, P.; Gibb, E.; Milam, S. N.; Mousis, O.; Pauzat, F.; Tornow, C.; Wirström, E. S.; Zicler, E.

2015-12-01

Conditions in the protosolar nebula have left their mark in the composition of cometary volatiles, thought to be some of the most pristine material in the solar system. Cometary compositions represent the end point of processing that began in the parent molecular cloud core and continued through the collapse of that core to form the protosun and the solar nebula, and finally during the evolution of the solar nebula itself as the cometary bodies were accreting. Disentangling the effects of the various epochs on the final composition of a comet is complicated. But comets are not the only source of information about the solar nebula. Protostellar disks around young stars similar to the protosun provide a way of investigating the evolution of disks similar to the solar nebula while they are in the process of evolving to form their own solar systems. In this way we can learn about the physical and chemical conditions under which comets formed, and about the types of dynamical processing that shaped the solar system we see today.

Solar Schematic

NASA Technical Reports Server (NTRS)

1979-01-01

The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

Feasibility study of a 110 watt per kilogram lightweight solar array system

NASA Technical Reports Server (NTRS)

Shepard, N. F.; Stahle, C. V.; Schneider, A.; Hanson, K. L.

1972-01-01

An investigation of the feasibility of a solar array panel subsystem which will produce 10,000 watts of electrical output at 1 A.U. with an overall beginning-of-life power-to-weight ratio of at least 110 watt/kg is reported. A description of the current baseline configuration which meets these requirements is presented. A parametric analysis of the single boom, two blanket planar solar array system was performed to arrive at the optimum system aspect ratio. A novel concept for the stiffening of a lightweight solar array by canting the solar cell blankets at a small angle to take advantage of the inherent in-plane stiffness to increase the symmetric out-of-plane frequency is introduced along with a preliminary analysis of the stiffening effect. A comparison of welded and soldered solar cell interconnections leads to the conclusion that welding is required on this ultralightweight solar array. The use of a boron/aluminum composite material in a BI-STEM type deployable boom is investigated as a possible advancement in the state-of-the-art.

Solar energy collector

DOEpatents

Brin, Raymond L.; Pace, Thomas L.

1978-01-01

The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

Low cost solar array project production process and equipment task. A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1981-01-01

Technical readiness for the production of photovoltaic modules using single crystal silicon dendritic web sheet material is demonstrated by: (1) selection, design and implementation of solar cell and photovoltaic module process sequence in a Module Experimental Process System Development Unit; (2) demonstration runs; (3) passing of acceptance and qualification tests; and (4) achievement of a cost effective module.

Intriguing Dehydrated Phyllosilicates Found in an Unusual Clast in the LL3.15 Chondrite NWS6925

NASA Technical Reports Server (NTRS)

Johnson, Jessica M.; Zolensky, Michael E.; Chan, Queenie; Kring, David A.

2016-01-01

Meteorites provide us with valuable insights into the conditions of the early solar system. Collisions often occur in our solar system that can result in materials accreting to other bodies as foreign clasts. These foreign pieces may have multiple origins that can sometimes be easily identified as a particular type of meteorite. It is important to interpret the origins of these clasts in order to understand dynamics of the solar system, especially throughout its early history. The Nice Model, as modified, proposes a reordering of planetary orbits that is hypothesized to have triggered the Late Heavy Bombardment. Clasts found within meteorites that came from objects in the solar system not commonly associated as an impactor could be indicative of such an event suggested by the Nice Model. Impacts also redistribute material from one region of an asteroid to another, and so clasts are found that reveal portions of the geological history of a body that are not recorded by typical samples. These would be cognate clasts. The goal of this investigation was to examine meteorites that had particularly interesting foreign and cognate clasts enclosed in them. We focus here on an unusual clast located in the ordinary chondrite, NWA 6925. This is one of three clasts analyzed during the LPI summer internship of Jessica Johnson.

The Oxygen Isotopic Composition of the Sun

NASA Astrophysics Data System (ADS)

McKeegan, K. D.; Kallio, A.; Heber, V. S.; Jarzebinski, G.; Mao, P.; Coath, C.; Kunihiro, T.; Wiens, R. C.; Judith, A.; Burnett, D. S.

2010-12-01

An accurate and precise determination of the oxygen isotopic composition of the Sun is the highest priority scientific goal of the Genesis Mission [1] as such data would provide a baseline from which one could interpret the oxygen isotopic anomalies found at all spatial scales in inner solar system materials. We have measured oxygen isotope compositions of implanted solar wind in 40 spots along a radial traverse of the Genesis SiC target sample 60001 by depth profiling with the UCLA MegaSIMS [2]. Mass-dependent fractionation induced by the solar wind concentrator [3] ion optics was corrected by comparison of the concentrator 22Ne/20Ne with that measured in a bulk solar wind target (diamond-like carbon on Si, [4]). The solar wind captured at L1 has an isotopic composition of (δ18O, δ17O) ≈ (-99, -79)‰, a value which is far removed from the terrestrial mass fractionation line. Profiles from the central portion of the target, where solar concentrations are highest and background corrections minimal, yield a mean Δ17O = -28.3 ± 1.8 ‰ indicating that the Earth and other planetary materials from the inner solar system are highly depleted in 16O relative to the solar wind. A mass-dependent fractionation of ~ -20%/amu in the acceleration of solar wind is required if we hypothesize that the photospheric oxygen isotope value, which represents the bulk starting composition of the solar system, is on the 16O-mixing line characteristic of refractory phase in primitive meteorites [5]. With this assumption, our preferred value for the bulk solar oxygen isotope composition is δ18O ≈ δ17O ≈ -57‰. A mechanism is required to fractionate oxygen isotopes in a non-mass-dependent manner to deplete 16O by ~6 to 7% in the rocky materials of the solar nebula. As oxygen is the third most abundant element in the solar system, and the most abundant in the terrestrial planets, this mechanism must operate on a large scale. Isotope-selective photochemistry, for example as in self-shielding of CO, operating in the solar nebula [6,7] or its precursor cloud [8] is a leading candidate; other models involving molecular symmetry-dependent reactions are also viable [9,10]. References: [1] D. Burnett et al. (2003) Space Sci. Rev. 105, 509. [2] K. McKeegan et al. (2008) LPSC XXIX, #2020. [3] R.Wiens et al. (2003) Space Sci. Rev. 105, 601. [4] V. Heber et al. Space Sci. Rev. 130, 309. [5] R. Clayton and T. Mayeda (1978) EPSL 40, 168. [6] R. Clayton (2002) Nature 415, 860. [7] J. Lyons and E. Young (2005) Nature 434, 317. [8] H. Yurimoto and K. Kuramoto (2004) Science 305, 1763. [9] M. Thiemens (1999) Science 283, 341. [10] R. Marcus (2004) J. Chem. Phys. 121, 8201.

Application of porous medium for efficiency improvement of a concentrated solar air heating system

NASA Astrophysics Data System (ADS)

Prasartkaew, Boonrit

2018-01-01

The objective of this study is to evaluate the thermal efficiency of a concentrated solar collector for a high temperature air heating system. The proposed system consists of a 25-m2 focused multi-flat-mirror solar heliostat equipped with a porous medium solar collector/receiver which was installed on the top of a 3-m tower, called ‘tower receiver’. To know how the system efficiency cloud be improved by using porous medium, the proposed system with and without porous medium were tested and the comparative study was performed. The experimental results reveal that, for the proposed system, application of porous medium is promising, the efficiency can be increased about 2 times compared to the conventional one. In addition, due to the porous medium used in this study was the waste material with very low cost. It can be summarized that the substantial efficiency improvement with very low investment cost of the proposed system seem to be a vital measures for addressing the energy issues.

Testing and optical modeling of novel concentrating solar receiver geometries to increase light trapping and effective solar absorptance

NASA Astrophysics Data System (ADS)

Yellowhair, Julius; Ho, Clifford K.; Ortega, Jesus D.; Christian, Joshua M.; Andraka, Charles E.

2015-09-01

Concentrating solar power receivers are comprised of panels of tubes arranged in a cylindrical or cubical shape on top of a tower. The tubes contain heat-transfer fluid that absorbs energy from the concentrated sunlight incident on the tubes. To increase the solar absorptance, black paint or a solar selective coating is applied to the surface of the tubes. However, these coatings degrade over time and must be reapplied, which reduces the system performance and increases costs. This paper presents an evaluation of novel receiver shapes and geometries that create a light-trapping effect, thereby increasing the effective solar absorptance and efficiency of the solar receiver. Several prototype shapes were fabricated from Inconel 718 and tested in Sandia's solar furnace at an irradiance of ~30 W/cm2. Photographic methods were used to capture the irradiance distribution on the receiver surfaces. The irradiance profiles were compared to results from raytracing models. The effective solar absorptance was also evaluated using the ray-tracing models. Results showed that relative to a flat plate, the new geometries could increase the effective solar absorptance from 86% to 92% for an intrinsic material absorptance of 86%, and from 60% to 73% for an intrinsic material absorptance of 60%.

Heat Transfer Phenomena in Concentrating Solar Power Systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armijo, Kenneth Miguel; Shinde, Subhash L.

Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxidemore » (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .« less

Research and technology 1988

NASA Technical Reports Server (NTRS)

1988-01-01

This report presents the on-going research activities at the NASA Marshall Space Flight Center for the year 1988. The subjects presented are space transportation systems, shuttle cargo vehicle, materials processing in space, environmental data base management, microgravity science, astronomy, astrophysics, solar physics, magnetospheric physics, aeronomy, atomic physics, rocket propulsion, materials and processes, telerobotics, and space systems.

Phase equilibrium modeling for high temperature metallization on GaAs solar cells

NASA Technical Reports Server (NTRS)

Chung, M. A.; Davison, J. E.; Smith, S. R.

1991-01-01

Recent trends in performance specifications and functional requirements have brought about the need for high temperature metallization technology to be developed for survivable DOD space systems and to enhance solar cell reliability. The temperature constitution phase diagrams of selected binary and ternary systems were reviewed to determine the temperature and type of phase transformation present in the alloy systems. Of paramount interest are the liquid-solid and solid-solid transformations. Data are being utilized to aid in the selection of electrical contact materials to gallium arsenide solar cells. Published data on the phase diagrams for binary systems is readily available. However, information for ternary systems is limited. A computer model is being developed which will enable the phase equilibrium predictions for ternary systems where experimental data is lacking.

Thermal Energy for Lunar In Situ Resource Utilization: Technical Challenges and Technology Opportunities

NASA Technical Reports Server (NTRS)

Gordon, Pierce E. C.; Colozza, Anthony J.; Hepp, Aloysius F.; Heller, Richard S.; Gustafson, Robert; Stern, Ted; Nakamura, Takashi

2011-01-01

Oxygen production from lunar raw materials is critical for sustaining a manned lunar base but is very power intensive. Solar concentrators are a well-developed technology for harnessing the Sun s energy to heat regolith to high temperatures (over 1375 K). The high temperature and potential material incompatibilities present numerous technical challenges. This study compares and contrasts different solar concentrator designs that have been developed, such as Cassegrains, offset parabolas, compound parabolic concentrators, and secondary concentrators. Differences between concentrators made from lenses and mirrors, and between rigid and flexible concentrators are also discussed. Possible substrate elements for a rigid mirror concentrator are selected and then compared, using the following (target) criteria: (low) coefficient of thermal expansion, (high) modulus of elasticity, and (low) density. Several potential lunar locations for solar concentrators are compared; environmental and processing-related challenges related to dust and optical surfaces are addressed. This brief technology survey examines various sources of thermal energy that can be utilized for materials processing on the lunar surface. These include heat from nuclear or electric sources and solar concentrators. Options for collecting and transporting thermal energy to processing reactors for each source are examined. Overall system requirements for each thermal source are compared and system limitations, such as maximum achievable temperature are discussed.

Solar Sails

NASA Technical Reports Server (NTRS)

Young, Roy

2006-01-01

The Solar Sail Propulsion investment area has been one of the three highest priorities within the In-Space Propulsion Technology (ISPT) Project. In the fall of 2003, the NASA Headquarters' Science Mission Directorate provided funding and direction to mature the technology as far as possible through ground research and development from TRL 3 to 6 in three years. A group of experts from government, industry, and academia convened in Huntsville, Alabama to define technology gaps between what was needed for science missions to the inner solar system and the current state of the art in ultra1ightweight materials and gossamer structure design. This activity set the roadmap for development. The centerpiece of the development would be the ground demonstration of scalable solar sail systems including masts, sails, deployment mechanisms, and attitude control hardware and software. In addition, new materials would be subjected to anticipated space environments to quantify effects and assure mission life. Also, because solar sails are huge structures, and it is not feasible to validate the technology by ground test at full scale, a multi-discipline effort was established to develop highly reliable analytical models to serve as mission assurance evidence in future flight program decision-making. Two separate contractor teams were chosen to develop the SSP System Ground Demonstrator (SGD). After a three month conceptual mission/system design phase, the teams developed a ten meter diameter pathfinder set of hardware and subjected it to thermal vacuum tests to compare analytically predicted structural behavior with measured characteristics. This process developed manufacturing and handling techniques and refined the basic design. In 2005, both contractor teams delivered 20 meter, four quadrant sail systems to the largest thermal vacuum chamber in the world in Plum Brook, Ohio, and repeated the tests. Also demonstrated was the deployment and articulation of attitude control mechanisms. In conjunction with these tests, the stowed sails were subjected to launch vibration and ascent vent tests. Other investments studied radiation effects on the solar sail materials, investigated spacecraft charging issues, developed shape measuring techniques and instruments, produced advanced trajectory modeling capabilities, and identified and resolved gossamer structure dynamics issues. Technology validation flight and application to a He1iophysics science mission is on the horizon.

Solar system formation and the distribution of volatile species

NASA Technical Reports Server (NTRS)

Lunine, Jonathan I.

1994-01-01

To understand how the solar system formed we must understand the compositional distribution of the current system. Volatile species are particularly important in that their stability as condensed phases is limited in temperature-pressure space, and hence variations in their distribution at present potentially contain an imprint of processes by which temperature and pressure varied in the solar nebula. In this talk we restrict ourselves to species more volatile than water ice, and address issues related to processes in the outer solar system and the formation of bodies there; others in this conference will cover volatile species relevant to inner solar system processes. Study of the outer solar system is relevant both to understanding the interface between the solar nebula and the progenitor giant molecular cloud (since the chemical links to present-day observables in molecular clouds are species like methane, carbon monoxide, etc.), as well as the origin of terrestrial planet atmospheres and oceans (the latter to be covered by Owen). The wealth of compositional information on outer solar system bodies which has become available from spacecraft and ground-based observations challenges traditional simplistic views of the composition and hence dynamics of the solar nebula. The basic assumption of thermochemical equilibrium, promulgated in the 1950's, in which methane and ammonia dominate nitrogen- and carbon-bearing species, is demonstrably incorrect on both observational and theoretical grounds. However, the kinetic inhibition model which replaced it, in which carbon monoxide and molecular nitrogen dominate a nebula which is fully mixed and hence cycles outer solar system gases through a hot, chemically active zone near the disk center, is not supported either by observations. Instead, a picture of the outer solar system emerges in which the gas and grains are a mixture of relatively unaltered, or modestly altered, molecular cloud material, along with a fraction which has been chemically altered in the solar nebula itself (and perhaps giant planet nebulae).

Beyond Our Boundaries: Research and Technology

NASA Technical Reports Server (NTRS)

1996-01-01

Topics considered include: Propulsion and Fluid Management; Structures and Dynamics; Materials and Manufacturing Processes; Sensor Technology; Software Technology; Optical Systems; Microgravity Science; Earth System Science; Astrophysics; Solar Physics; and Technology Transfer.

Phase Change Energy Storage Material Suitable for Solar Heating System

NASA Astrophysics Data System (ADS)

Li, Xiaohui; Li, Haihua; Zhang, Lihui; Liu, Zhenfa

2018-01-01

Differential scanning calorimetry (DSC) was used to investigate the thermal properties of palmitic acid, myristic acid, laurel acid and the binary composite of palmitic/laurel acid and palmitic/myristic acid. The results showed that the phase transition temperatures of the three monomers were between 46.9-65.9°C, and the latent heats were above 190 J/g, which could be used as solar energy storage material. When the mass ratio of Palmitic acid and myristic was 1:1, the eutectic mixture could be formed. The latent heat of the eutectic mixture was 186.6 J/g, the melting temperature and the solidification temperature was 50.6°C and 43.8°C respectively. The latent heat of phase change and the melting temperature had not obvious variations after 400 thermal cycles, which proved that the binary composite had good thermal stability and was suitable for solar floor radiant heating system.

Comet 81P/Wild 2 under a microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brownlee, D; Tsou, P; Aleon, J

2006-10-12

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixingmore » on the grandest scales. Stardust was the first mission to return solid samples from a specific astronomical body other than the Moon. The mission, part of the NASA Discovery program, retrieved samples from a comet that is believed to have formed at the outer fringe of the solar nebula, just beyond the most distant planet. The samples, isolated from the planetary region of the solar system for billions of years, provide new insight into the formation of the solar system. The samples provide unprecedented opportunities both to corroborate astronomical (remote sensing) and sample analysis information (ground truth) on a known primitive solar system body and to compare preserved building blocks from the edge of the planetary system with sample-derived and astronomical data for asteroids, small bodies that formed more than an order of magnitude closer to the Sun. The asteroids, parents of most meteorites, formed by accretion of solids in warmer, denser, more collisionally evolved inner regions of the solar nebula where violent nebular events were capable of flash-melting millimeter-sized rocks, whereas comets formed in the coldest, least dense region. The samples collected by Stardust are the first primitive materials from a known body, and as such they provide contextual insight for all primitive meteoritic samples. About 200 investigators around the world participated in the preliminary analysis of the returned samples, and the papers in this issue summarize their findings.« less

Preliminary results of accelerated exposure testing of solar cell system components

NASA Technical Reports Server (NTRS)

Anagnostou, E.; Forestieri, A. F.

1977-01-01

Plastic samples and solar cell sub modules were exposed to an accelerated outdoor environment in Arizona and an accelerated simulated environment in a cyclic ultraviolet exposure tester which included humidity exposure. These tests were for preliminary screening of materials suitable for use in the manufacture of solar cell modules which are to have a 20-year lifetime. The samples were exposed for various times up to six months, equivalent to a real time exposure of four years. Suitable materials were found to be FEP-A, FEP-C, PFA, acrylic, silicone compounds and adhesives and possibly parylene. The method of packaging the sub modules was also found to be important to their performance.

Theoretical Analysis of Two Novel Hybrid Thermoelectric-Photovoltaic Systems Based on Cu₂ZnSnS₄ Solar Cells.

PubMed

Lorenzi, Bruno; Contento, Gaetano; Sabatelli, Vincenzo; Rizzo, Antonella; Narducci, Dario

2017-03-01

The development and commercialization of Photovoltaic (PV) cells with good cost-efficiency trade-off not using critical raw materials (CRMs) is one of the strategies chosen by the European Community (EC) to address the Energy Roadmap 2050. In this context Cu2ZnSnS4 (CZTS) solar cells are attracting a major interest since they have the potential to combine low price with relatively high conversion efficiencies. Although a ≈9% lab scale efficiency has already been reported for CZTS this technology is still far from being competitive in terms of cost per peak-power (€/Wp) with other common materials. One possible near-future solution to increase the CZTS competiveness comes from thermoelectrics. Actually it has already been shown that Hybrid Thermoelectric-Photovoltaic Systems (HTEPVs) based on CIGS, another kesterite very similar to CZTS, can lead to a significant efficiency improvement. However it has been also clarified how the optimal hybridization strategy cannot come from the simple coupling of solar cells with commercial TEGs, but special layouts have to be implemented. Furthermore, since solar cell performances are well known to decrease with temperature, thermal decoupling strategies of the PV and TEG sections have to be taken. To address these issues, we developed a model for two different HTEPV solutions, both coupled with CZTS solar cells. In the first case we considered a Thermally-Coupled HTEPV device (TC-HTEPV) in which the TEG is placed underneath the solar cell and in thermal contact with it. The second system consists instead of an Optically-Coupled but thermally decoupled device (OC-HTEPV) in which part of the solar spectrum is focused by a non-imaging optical concentrator on the TEG hot side. For both solutions the model returns conversion efficiencies higher than that of the CZTS solar cell alone. Specifically, increases of ≈30% are predicted for both kind of systems considered.

Humid free efficient solar panel

NASA Astrophysics Data System (ADS)

Panjwani, Manoj Kumar; Panjwani, Suresh Kumar; Mangi, Fareed Hussain; Khan, Danish; Meicheng, Li

2017-09-01

The paper examines the impact of the humidity on the Solar panels which makes a space for the drastic variation in the power generated and makes the device less efficient. Humidity readily affects the efficiency of the solar cells and creates a minimal layer of water on its surface. It also decreases the efficiency by 10-20% of the total power output produced. Moreover, to handle this issue, all around characterized measures are required to be taken to guarantee the smooth working of the solar panels utilized in humid areas. In connection with this issue, Karachi, the biggest city of Pakistan which is located near the costal line touching Arabian Sea, was taken as a reference city to measure the humidity range. In Karachi, the average humidity lies between 25-70% (as per Pakistan Meteorological Department PMD), that indirectly leads in decreasing power acquired from a Solar Panel and develops various complexities for the solar system. The system on average experiences stability issues, such as those of power fluctuations etc., due to which, the whole solar system installed observes abnormal variations in acquired power. Silica Gel was used as a desiccant material in order to assure dryness over the solar panel. More than four experiments were conducted with the usage of water absorbent to improve the efficiency and to make system more power efficient.

Condensation and Evaporation of Solar System Materials

NASA Astrophysics Data System (ADS)

Davis, A. M.; Richter, F. M.

2003-12-01

It is widely believed that the materials making up the solar system were derived from a nebular gas and dust cloud that went through an early high-temperature stage during which virtually all of the material was in the gas phase. At one time, it was thought that the entire inner solar nebula was hot, but it is now believed that most material was processed through regions where high temperatures were achieved. Certainly some material, such as presolar grains (cf., Mendybaev et al., 2002a), has never been exposed to high temperatures. As the system cooled, solids and perhaps liquids began to condense, but at some point the partially condensed materials became isolated from the remaining gas. Various lines of evidence support this view. At the largest scale, there is the observation that the Earth, Moon, Mars, and all chondritic meteorites except for the CI chondrites are depleted to varying degrees in the abundances of moderately volatile elements relative to bulk solar system composition. The CI chondrites reflect the bulk composition of the solar system for all but hydrogen, carbon, nitrogen, oxygen, and the rare gases, the most volatile elements (see Chapter 1.03; Palme et al., 1988; McDonough and Sun, 1995; Humayun and Cassen, 2000). The depletions in moderately volatile elements are, to a significant degree, correlated with condensation temperature, suggesting progressive removal of gas as condensation proceeded ( Cassen, 1996). Additional observations that can be explained by partial condensation are that various particularly primitive components of meteorites (e.g., calcium-, aluminum-rich refractory inclusions, and certain metal grains) have mineralogy and/or details of their chemical composition that are remarkably similar to what is calculated for equilibrium condensates from a solar composition gas. For example, the calcium-, aluminum-rich inclusions (CAIs) in chondritic meteorites have compositions very similar to that calculated for the first 5% of total condensable matter (see Chapter 1.08; Grossman, 1973; Wänke et al., 1974; Grossman and Ganapathy, 1976; Grossman et al., 1977), where CI chondrites are taken to represent total condensable matter.Elemental abundance patterns ordered by volatility certainly could have been produced by partial condensation, but they could also have been caused by partial evaporation. The relative importance of these opposite processes is still subject to debate and uncertainty. It should be remembered that condensation calculations typically assume chemical equilibrium in a closed system, in which case the system has no memory of the path by which it arrived at a given state, and thus the chemical and isotopic composition of the condensed phase cannot be used to distinguish between partial condensation and partial evaporation. Humayun and Clayton (1995) have taken a somewhat different view by arguing that condensation and evaporation are distinguishable, in that evaporation, but not condensation, will produce isotopically fractionated residues. With this idea in mind, they carefully measured the potassium isotopic compositions of a broad range of solar system materials with different degrees of potassium depletion and found them to be indistinguishable. This they took as evidence that evaporation could not have been a significant process in determining the diverse elemental abundance patterns of the various solar system materials they measured, because had evaporation been important in fractionating potassium it would have also fractionated the potassium isotopes. We will qualify this line of reasoning by arguing that evaporation and condensation can under certain conditions produce isotopically fractionated condensed phases (i.e., that partial evaporation can produce isotopically heavy residues and that partial condensation can produce isotopically light condensates) but that under other conditions both can produce elemental fractionations without significant isotopic fractionation. The absence of isotopic fractionation in a volatile element-depleted condensed phase is more a measure of the degree to which the system maintained thermodynamic equilibrium than a diagnostic of whether the path involved condensation or evaporation.The pervasive volatile element depletion of inner solar system planets and the asteroidal parent bodies of most meteorites is a major, but by no means the only reason to consider evaporation and condensation processes in the early history of the solar system. Chondrules appear to have been rapidly heated and then cooled over a period of minutes to hours (see Chapter 1.07). If this occurred in a gas of solar composition under nonequilibrium conditions, chondrules should have partially evaporated and an isotopic fractionation record should remain. The absence of such effects can be used to chonstrain the conditions of chondrule formation (e.g., Alexander et al., 2000; Alexander and Wang, 2001). There is good petrologic, chemical, and isotopic evidence suggesting that certain solar system materials such as the coarse-grained CAIs are likely evaporation residues. For example, the type B CAIs are often found to have correlated enrichments in the heavy isotopes of silicon and magnesium ( Figure 1), and these isotopic fractionations are very much like those of evaporation residues produced in laboratory experiments. Condensation also appears to be a major control of elemental zoning patterns in metal grains in CH chondrites (Meibom et al., 1999, 2001; Campbell et al., 2001; Petaev et al., 2001; Campbell et al., 2002). A more contemporary example is the isotopic and chemical compositions of deep-sea spherules that have been significantly affected by evaporative loss during atmospheric entry ( Davis et al., 1991a; Davis and Brownlee, 1993; Herzog et al., 1994, 1999; Xue et al., 1995; Alexander et al., 2002). (7K)Figure 1. Isotopic mass fractionation effects in CAIs. Most coarse-grained CAIs have enrichments of a few ‰ amu-1 in magnesium and silicon, whereas "fractionation and unknown nuclear" (FUN) CAIs are isotopically heavier. The volatile element depletion patterns of planetary size objects and the chemical and isotopic composition of numerous smaller objects such as chondrules and CAIs provide the motivation to consider evaporation and condensation process in the early solar system. The key point is that the processes that led to chondrules and planets appear to have occurred under conditions very close to equilibrium, whereas the processes that led to CAIs involved significant departures from equilibrium.

Solar Adaptive Optics.

PubMed

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

Early solar system. Stellar origin of the ¹⁸²Hf cosmochronometer and the presolar history of solar system matter.

PubMed

Lugaro, Maria; Heger, Alexander; Osrin, Dean; Goriely, Stephane; Zuber, Kai; Karakas, Amanda I; Gibson, Brad K; Doherty, Carolyn L; Lattanzio, John C; Ott, Ulrich

2014-08-08

Among the short-lived radioactive nuclei inferred to be present in the early solar system via meteoritic analyses, there are several heavier than iron whose stellar origin has been poorly understood. In particular, the abundances inferred for (182)Hf (half-life = 8.9 million years) and (129)I (half-life = 15.7 million years) are in disagreement with each other if both nuclei are produced by the rapid neutron-capture process. Here, we demonstrate that contrary to previous assumption, the slow neutron-capture process in asymptotic giant branch stars produces (182)Hf. This has allowed us to date the last rapid and slow neutron-capture events that contaminated the solar system material at ~100 million years and ~30 million years, respectively, before the formation of the Sun. Copyright © 2014, American Association for the Advancement of Science.

The search for and analysis of direct samples of early Solar System aqueous fluids.

PubMed

Zolensky, Michael E; Bodnar, Robert J; Yurimoto, Hisayoshi; Itoh, Shoichi; Fries, Marc; Steele, Andrew; Chan, Queenie H-S; Tsuchiyama, Akira; Kebukawa, Yoko; Ito, Motoo

2017-05-28

We describe the current state of the search for direct, surviving samples of early, inner Solar System fluids-fluid inclusions in meteorites. Meteoritic aqueous fluid inclusions are not rare, but they are very tiny and their characterization is at the state of the art for most analytical techniques. Meteoritic fluid inclusions offer us a unique opportunity to study early Solar System brines in the laboratory. Inclusion-by-inclusion analyses of the trapped fluids in carefully selected samples will, in the immediate future, provide us detailed information on the evolution of fluids as they interacted with anhydrous solid materials. Thus, real data can replace calculated fluid compositions in thermochemical calculations of the evolution of water and aqueous reactions in comets, asteroids, moons and the terrestrial planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

Stardust: Catching a Comet and Bringing it Home

NASA Technical Reports Server (NTRS)

Brownlee, Donald E.

2007-01-01

The NASA STARDUST mission collected thousands of particles from Comet Wild 2 that are now being studied by two hundred scientists around the world. The spacecraft captured the samples during a close flyby of the comet in 2004 and returned them to Earth with a dramatic entry into the atmosphere early in 2006. The precious cargo of comet dust is being studied to determine new information about the origin of the Sun and planets. The comet formed at the edge of the solar system, beyond the orbit of Neptune, and is a sample of the material from which the solar system was formed. One of the most dramatic early findings from the mission was that a comet that formed in the coldest place in the solar system contained minerals that formed in the hottest place in the solar system. The comet samples are telling stories of fire and ice and they providing fascinating and unexpected information about our origins.

Sample Return from Small Solar System Bodies

NASA Astrophysics Data System (ADS)

Orgel, L.; A'Hearn, M.; Bada, J.; Baross, J.; Chapman, C.; Drake, M.; Kerridge, J.; Race, M.; Sogin, M.; Squyres, S.

With plans for multiple sample return missions in the next decade, NASA requested guidance from the National Research Council's SSB on how to treat samples returned from solar system bodies such as planetary satellites, asteroids and comets. A special Task Group assessed the potential for a living entity to be included in return samples from various bodies as well as the potential for large scale effects if such an entity were inadvertently introduced into the Earth's biosphere. The Group also assessed differences among solar system bodies, identified investigations that could reduce uncertainty about the bodies, and considered risks of returned samples compared to natural influx of material to the Earth in the form of interplanetary dust particles, meteorites and other small impactors. The final report (NRC, 1998) provides a decision making framework for future missions and makes recommendations on how to handle samples from different planetary satellites and primitive solar system bodies

Organic Analysis in the Miller Range 090657 CR2 Chondrite: Part 3 C and N Isotopic Imaging

NASA Technical Reports Server (NTRS)

Messenger, S.; Nakamura-Messenger, K.; Elsila, J. E.; Berger, E. L.; Burton, A. S.; Clemett, S. J.; Cao, T.

2016-01-01

Primitive carbonaceous chondrites contain a wide variety of organic material, ranging from soluble discrete molecules to insoluble nanoglobules of macro-molecular carbon. The relationship between the soluble organic molecules, macromolecular organic material, and host minerals are poorly understood. Large H, C and N isotopic anomalies suggest some organic components formed in low-T interstellar or outer Solar System environments. The highest isotope anomalies occur in m-scale inclusions in the most primitive materials, such as cometary dust and the least altered carbonaceous chondrites. Often, the hosts of these isotopically anomalous 'hotspots' are discrete organic nanoglobules that probably formed in the outermost reaches of the protosolar disk or cold molecular cloud. Molecular and isotopic studies of meteoritic organic matter are aimed at identifying the chemical properties and formation processes of interstellar organic materials and the subsequent chemical evolutionary pathways in various Solar System environments. The combination of soluble and insoluble analyses with in situ and bulk studies provides powerful constraints on the origin and evolution of organic matter in the Solar System. Using macroscale extraction and analysis techniques as well as microscale in situ observations we have been studying both insoluble and soluble organic material in primitive astromaterial samples. Here, we present results of bulk C and N isotopic measurements and coordinated in situ C and N isotopic imaging and mineralogical and textural studies of carbonaceous materials in a Cr2 carbonaceous chondrite. In accompanying abstracts we discuss the morphology and distribution of carbonaceous components and soluble organic species of this meteorite.

Closed Cycle Engine Program Used in Solar Dynamic Power Testing Effort

NASA Technical Reports Server (NTRS)

Ensworth, Clint B., III; McKissock, David B.

1998-01-01

NASA Lewis Research Center is testing the world's first integrated solar dynamic power system in a simulated space environment. This system converts solar thermal energy into electrical energy by using a closed-cycle gas turbine and alternator. A NASA-developed analysis code called the Closed Cycle Engine Program (CCEP) has been used for both pretest predictions and post-test analysis of system performance. The solar dynamic power system has a reflective concentrator that focuses solar thermal energy into a cavity receiver. The receiver is a heat exchanger that transfers the thermal power to a working fluid, an inert gas mixture of helium and xenon. The receiver also uses a phase-change material to store the thermal energy so that the system can continue producing power when there is no solar input power, such as when an Earth-orbiting satellite is in eclipse. The system uses a recuperated closed Brayton cycle to convert thermal power to mechanical power. Heated gas from the receiver expands through a turbine that turns an alternator and a compressor. The system also includes a gas cooler and a radiator, which reject waste cycle heat, and a recuperator, a gas-to-gas heat exchanger that improves cycle efficiency by recovering thermal energy.

The Moon as a recorder of organic evolution in the early solar system: a lunar regolith analog study.

PubMed

Matthewman, Richard; Court, Richard W; Crawford, Ian A; Jones, Adrian P; Joy, Katherine H; Sephton, Mark A

2015-02-01

The organic record of Earth older than ∼3.8 Ga has been effectively erased. Some insight is provided to us by meteorites as well as remote and direct observations of asteroids and comets left over from the formation of the Solar System. These primitive objects provide a record of early chemical evolution and a sample of material that has been delivered to Earth's surface throughout the past 4.5 billion years. Yet an effective chronicle of organic evolution on all Solar System objects, including that on planetary surfaces, is more difficult to find. Fortunately, early Earth would not have been the only recipient of organic matter-containing objects in the early Solar System. For example, a recently proposed model suggests the possibility that volatiles, including organic material, remain archived in buried paleoregolith deposits intercalated with lava flows on the Moon. Where asteroids and comets allow the study of processes before planet formation, the lunar record could extend that chronicle to early biological evolution on the planets. In this study, we use selected free and polymeric organic materials to assess the hypothesis that organic matter can survive the effects of heating in the lunar regolith by overlying lava flows. Results indicate that the presence of lunar regolith simulant appears to promote polymerization and, therefore, preservation of organic matter. Once polymerized, the mineral-hosted newly formed organic network is relatively protected from further thermal degradation. Our findings reveal the thermal conditions under which preservation of organic matter on the Moon is viable.

Tholins as Coloring Agents on Solar System Bodies

NASA Technical Reports Server (NTRS)

Cruikshank, D. P.; Ore, C. M. Dalle; Imanaka, H.

2004-01-01

Pre-biotic organic materials appear to be common on many small bodies in the outer Solar System, as evidenced by the color properties of these objects. We report on our continuing study of color properties in connection with the presence of complex organic solids (tholins) among the planets and their satellites, the asteroids, and the trans- Neptunian objects (Kuiper Belt objects). Most small, icy bodies in the Solar System, whether they have high or low surface reflectance (albedo), show a pronounced downward slope in reflectance at wavelengths shorter than approx. 1 micron. This increasing absorption of sunlight toward shorter wavelengths is characteristic of pi-bonds in hydrocarbons having chains or rings of conjugated C atoms. Tholins, which contain polycyclic aromatic and aliphatic hydrocarbons, exhibit these color properties. Using the complex refractive indices of tholins in models of the reflectance spectra of icy bodies in the Solar System, we find that these complex organic materials satisfactorily account for the coloration so widely observed. The new results presented here show that the wide variety of colors of Kuiper Belt objects can be fit very well with tholins, as can the colors of Pluto and Triton. The implications of these fits of Kuiper Belt objects is that complex organic material is created on their surfaces by energetic particle bombardment of native ices, and also may be accreted from external sources. In the cases of Pluto and Triton, photochemistry of their weak N2 + CH4 + CO atmospheres produces complex organic molecules that precipitate to the surface, providing local color.

Continuous-flow solar UVB disinfection reactor for drinking water.

PubMed

Mbonimpa, Eric Gentil; Vadheim, Bryan; Blatchley, Ernest R

2012-05-01

Access to safe, reliable sources of drinking water is a long-standing problem among people in developing countries. Sustainable solutions to these problems often involve point-of-use or community-scale water treatment systems that rely on locally-available resources and expertise. This philosophy was used in the development of a continuous-flow, solar UVB disinfection system. Numerical modeling of solar UVB spectral irradiance was used to define temporal variations in spectral irradiance at several geographically-distinct locations. The results of these simulations indicated that a solar UVB system would benefit from incorporation of a device to amplify ambient UVB fluence rate. A compound parabolic collector (CPC) was selected for this purpose. Design of the CPC was based on numerical simulations that accounted for the shape of the collector and reflectance. Based on these simulations, a prototype CPC was constructed using materials that would be available and inexpensive in many developing countries. A UVB-transparent pipe was positioned in the focal area of the CPC; water was pumped through the pipe to allow exposure of waterborne microbes to germicidal solar UVB radiation. The system was demonstrated to be effective for inactivation of Escherichia coli, and DNA-weighted UV dose was shown to govern reactor performance. The design of the reactor is expected to scale linearly, and improvements in process performance (relative to results from the prototype) can be expected by use of larger CPC geometry, inclusion of better reflective materials, and application in areas with greater ambient solar UV spectral irradiance than the location of the prototype tests. The system is expected to have application for water treatment among communities in (developing) countries in near-equatorial and tropical locations. It may also have application for disaster relief or military field operations, as well as in water treatment in areas of developed countries that receive relatively intense solar UVB radiation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Materials on the International Space Station - Forward Technology Solar Cell Experiment

NASA Technical Reports Server (NTRS)

Walters, R. J.; Garner, J. C.; Lam, S. N.; Vazquez, J. A.; Braun, W. R.; Ruth, R. E.; Lorentzen, J. R.; Bruninga, R.; Jenkins, P. P.; Flatico, J. M.

2005-01-01

This paper describes a space solar cell experiment currently being built by the Naval Research Laboratory (NRL) in collaboration with NASA Glenn Research Center (GRC), and the US Naval Academy (USNA). The experiment has been named the Forward Technology Solar Cell Experiment (FTSCE), and the purpose is to rapidly put current and future generation space solar cells on orbit and provide validation data for these technologies. The FTSCE is being fielded in response to recent on-orbit and ground test anomalies associated with space solar arrays that have raised concern over the survivability of new solar technologies in the space environment and the validity of present ground test protocols. The FTSCE is being built as part of the Fifth Materials on the International Space Station (MISSE) Experiment (MISSE-5), which is a NASA program to characterize the performance of new prospective spacecraft materials when subjected to the synergistic effects of the space environment. Telemetry, command, control, and communication (TNC) for the FTSCE will be achieved through the Amateur Satellite Service using the PCSat2 system, which is an Amateur Radio system designed and built by the USNA. In addition to providing an off-the-shelf solution for FTSCE TNC, PCSat2 will provide a communications node for the Amateur Radio satellite system. The FTSCE and PCSat2 will be housed within the passive experiment container (PEC), which is an approximately 2ft x2ft x 4in metal container built by NASA Langley Research Center (NASA LaRC) as part of the MISSE-5 program. NASA LaRC has also supplied a thin film materials experiment that will fly on the exterior of the thermal blanket covering the PCSat2. The PEC is planned to be transported to the ISS on a Shuttle flight. The PEC will be mounted on the exterior of the ISS by an astronaut during an extravehicular activity (EVA). After nominally one year, the PEC will be retrieved and returned to Earth. At the time of writing this paper, the subsystems of the experiment are being integrated at NRL, and we are preparing to commence environmental testing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, Jeffrey

Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed tomore » achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector development, multiple concepts including high thermal resistance thermal barrier coatings (TBC), oxide dispersion strengthened (ODS) alloys, continuous fiber ceramic composites (CFCC), and monolithic ceramics were evaluated before down-selection to the most promising candidate materials for field evaluation. Preliminary, component and sub-scale testing was conducted to determine material properties and demonstrate proof-of-concept. Full-scale rig and engine testing was used to validated engine performance prior to field evaluation at a Qualcomm Inc. cogeneration site located in San Diego, California. To ensure that the CFCC liners with the EBC proposed under this program would meet the target life, field evaluations of ceramic matrix composite liners in Centaur{reg_sign} 50 gas turbine engines, which had previously been conducted under the DOE sponsored Ceramic Stationary Gas Turbine program (DE-AC02-92CE40960), was continued under this program at commercial end-user sites under Program Subtask 1A - Extended CFCC Materials Durability Testing. The goal of these field demonstrations was to demonstrate significant component life, with milestones of 20,000 and 30,000 hours. Solar personnel monitor the condition of the liners at the field demonstration sites through periodic borescope inspections and emissions measurements. This program was highly successful at evaluating advanced materials and down-selecting promising solutions for use in gas turbine combustions systems. The addition of the advanced materials technology has enabled the predicted life of the Mercury 50 combustion system to reach 30,000 hours, which is Solar's typical time before overhaul for production engines. In particular, a 40 mil thick advanced Thermal Barrier Coating (TBC) system was selected over various other TBC systems, ODS liners and CFCC liners for the 4,000-hour field evaluation under the program. This advanced TBC is now production bill-of-material at various thicknesses up to 40 mils for all of Solar's advanced backside-cooled combustor liners (Centaur 50, Taurus 60, Mars 100, Taurus 70, Taurus 65, Titan 130, Titan 250 and Mercury 50). This TBC coating system significantly outperformed all other TBC systems evaluated under the program. The initial field unit, with the 40 mil advanced TBC developed under this program, has far exceeded the 4,000-hour requirement of the program, accumulating over 20,000 hours of commercial operation at Qualcomm Inc. in San Diego, CA. The 40 mil advanced TBC remains in excellent condition, with no evidence of chipping or spalling. The engine will continue operation until the unit is due for overhaul at approximately 30,000 hours. The Oxide Dispersion Strengthened (ODS) alloy injector tip testing and evaluation was also successful, however, the ODS injector tip development on this program was terminated, primarily due to the fact that the Mercury 50 injector tip was redesigned (Generation 3) by Combustion Engineering.« less

A review on solar cells from Si-single crystals to porous materials and quantum dots

PubMed Central

Badawy, Waheed A.

2013-01-01

Solar energy conversion to electricity through photovoltaics or to useful fuel through photoelectrochemical cells was still a main task for research groups and developments sectors. In this article we are reviewing the development of the different generations of solar cells. The fabrication of solar cells has passed through a large number of improvement steps considering the technological and economic aspects. The first generation solar cells were based on Si wafers, mainly single crystals. Permanent researches on cost reduction and improved solar cell efficiency have led to the marketing of solar modules having 12–16% solar conversion efficiency. Application of polycrystalline Si and other forms of Si have reduced the cost but on the expense of the solar conversion efficiency. The second generation solar cells were based on thin film technology. Thin films of amorphous Si, CIS (copper–indium–selenide) and t-Si were employed. Solar conversion efficiencies of about 12% have been achieved with a remarkable cost reduction. The third generation solar cells are based on nano-crystals and nano-porous materials. An advanced photovoltaic cell, originally developed for satellites with solar conversion efficiency of 37.3%, based on concentration of the solar spectrum up to 400 suns was developed. It is based on extremely thin concentration cells. New sensitizer or semiconductor systems are necessary to broaden the photo-response in solar spectrum. Hybrids of solar and conventional devices may provide an interim benefit in seeking economically valuable devices. New quantum dot solar cells based on CdSe–TiO2 architecture have been developed. PMID:25750746

A review on solar cells from Si-single crystals to porous materials and quantum dots.

PubMed

Badawy, Waheed A

2015-03-01

Solar energy conversion to electricity through photovoltaics or to useful fuel through photoelectrochemical cells was still a main task for research groups and developments sectors. In this article we are reviewing the development of the different generations of solar cells. The fabrication of solar cells has passed through a large number of improvement steps considering the technological and economic aspects. The first generation solar cells were based on Si wafers, mainly single crystals. Permanent researches on cost reduction and improved solar cell efficiency have led to the marketing of solar modules having 12-16% solar conversion efficiency. Application of polycrystalline Si and other forms of Si have reduced the cost but on the expense of the solar conversion efficiency. The second generation solar cells were based on thin film technology. Thin films of amorphous Si, CIS (copper-indium-selenide) and t-Si were employed. Solar conversion efficiencies of about 12% have been achieved with a remarkable cost reduction. The third generation solar cells are based on nano-crystals and nano-porous materials. An advanced photovoltaic cell, originally developed for satellites with solar conversion efficiency of 37.3%, based on concentration of the solar spectrum up to 400 suns was developed. It is based on extremely thin concentration cells. New sensitizer or semiconductor systems are necessary to broaden the photo-response in solar spectrum. Hybrids of solar and conventional devices may provide an interim benefit in seeking economically valuable devices. New quantum dot solar cells based on CdSe-TiO2 architecture have been developed.

The Origin of Organic Matter in the Solar System: Evidence from Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.; Jacobsen, C.; Wirick, S.

2001-01-01

The origin of the organic matter in interplanetary materials has not been established. A variety of mechanisms have been proposed, with two extreme cases being a Fisher-Tropsch type process operating in the gas phase of the solar nebula or a Miller-Urey type process, which requires interaction with an aqueous fluid, presumably occurring on an asteroid. In the Fisher-Tropsch case, we might expect similar organic matter in hydrated and anhydrous interplanetary materials. However, aqueous alteration is required in the case of the Miller-Urey process, and we would expect to see organic matter preferentially in interplanetary materials that exhibit evidence of aqueous activity, such as the presence of hydrated silicates. The types and abundance of organic matter in meteorites have been used as an indicator of the origin of organic matter in the Solar System. Indigenous complex organic matter, including amino acids, has been found in hydrated carbonaceous chondrite meteorites, such as Murchison. Much lower amounts of complex organic matter, possibly only terrestrial contamination, have been found in anhydrous carbonaceous chondrite meteorites, such as Allende, that contain most of their carbon in elemental form. These results seem to favor production of the bulk of the organic matter in the Solar System by aqueous processing on parent bodies such as asteroids, a Miller-Urey process. However, the hydrated carbonaceous chondrite meteorites have approximately solar abundances of the moderately volatile elements, while all anhydrous carbonaceous chondrite meteorites have significantly lower contents of these moderately volatile elements. Two mechanisms, incomplete condensation or evaporation, both of which involve processing at approx. 1200 C, have been suggested to explain the lower content of the moderately volatile elements in all anhydrous meteorites. Additional information is contained in the original extended abstract.

The Origin and Significance of the CCAM Line: Evidence from Chondrules and Dark Inclusions in Allende (CV3)

NASA Technical Reports Server (NTRS)

Greenwood, R. C.; Franchi, I. A.; Zolensky, M. E.; Buchanan, P. C.

2016-01-01

The process responsible for the mass independent oxygen isotope variation observed in Solar System materials remains poorly understood. While self-shielding of CO, either in the early solar nebula, or precursor molecular cloud, appears to be a viable mechanism, alternative models have also been proposed.

Solar power satellite: Analysis of alternatives for transporting material to geosynchronous orbit

NASA Technical Reports Server (NTRS)

Graff, W. J.; Huang, C. J.

1976-01-01

A systems design study of the alternative methods and relative merits of various approaches to transporting and assembling a solar power satellite in geosynchronous orbit was conducted. State of the art alternatives for chemical and electrical interorbital propulsion were studied, and several possible scenarios for construction were proposed.

Study of a ternary blend system for bulk heterojunction thin film solar cells

NASA Astrophysics Data System (ADS)

Ahmad, Zubair; Touati, Farid; Shakoor, R. A.; Al-Thani, N. J.

2016-08-01

In this research, we report a bulk heterojunction (BHJ) solar cell consisting of a ternary blend system. Poly(3-hexylthiophene) P3HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester (PCBM) plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO) is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT:PSS/ternary BHJ blend/Al structure. The power conversion efficiencies of the ITO/ PEDOT:PSS/P3HT:PCBM/Al and ITO/PEDOT:PSS/ P3HT:PCBM:VOPcPhO/Al solar cells are found to be 2.3% and 3.4%, respectively. This publication was made possible by PDRA (Grant No. PDRA1-0117-14109) from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors.

The Onset of the Cataclysm: In Situ Dating of a Nearside Basin Impact-Melt Sheet Or, There and Not Back Again

NASA Technical Reports Server (NTRS)

Cohen, Barbara A.

2017-01-01

Impact-melt samples from Apollo Luna are 3.85-4.1 Ga, tied to Imbrium, Serenitatis, Crisium, Nectaris, plus other craters? May have been caused by destabilization of material in early solar system by dynamic forces such as gas drag and gravitational interactions Coincident with the oldest rocks on the Earth and later than the earliest isotopic signs of life on Earth. Earth was already a planet with oceans, plate tectonics, and single celled life What was happening on the Moon before 3.9 Ga affected the course of life on Earth, the structure of our Solar System, and the dynamics of extra solar planetary systems.

Mid-level Solar Flare

NASA Image and Video Library

2017-12-08

SDO View of M7.3 Class Solar Flare on Oct. 2, 2014 NASA's Solar Dynamics Observatory captured this image of an M7.3 class solar flare on Oct. 2, 2014. The solar flare is the bright flash of light on the right limb of the sun. A burst of solar material erupting out into space can be seen just below it. Credit: NASA/Goddard/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Fresnel Concentrators for Space Solar Power and Solar Thermal Propulsion

NASA Technical Reports Server (NTRS)

Bradford, Rodney; Parks, Robert W.; Craig, Harry B. (Technical Monitor)

2001-01-01

Large deployable Fresnel concentrators are applicable to solar thermal propulsion and multiple space solar power generation concepts. These concentrators can be used with thermophotovoltaic, solar thermionic, and solar dynamic conversion systems. Thin polyimide Fresnel lenses and reflectors can provide tailored flux distribution and concentration ratios matched to receiver requirements. Thin, preformed polyimide film structure components assembled into support structures for Fresnel concentrators provide the capability to produce large inflation-deployed concentrator assemblies. The polyimide film is resistant to the space environment and allows large lightweight assemblies to be fabricated that can be compactly stowed for launch. This work addressed design and fabrication of lightweight polyimide film Fresnel concentrators, alternate materials evaluation, and data management functions for space solar power concepts, architectures, and supporting technology development.

Mid-level Solar Flare

NASA Image and Video Library

2014-10-02

NASA's Solar Dynamics Observatory captured these images of a solar flare on Oct. 2, 2014. The solar flare is the bright flash of light on the right limb of the sun. A burst of solar material erupting out into space can be seen just below it. Read more: 1.usa.gov/1mW8rel Credit: NASA/Goddard/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Technology development program for an advanced microsheet glass concentrator

NASA Technical Reports Server (NTRS)

Richter, Scott W.; Lacy, Dovie E.

1990-01-01

Solar Dynamic Space Power Systems are candidate electrical power generating systems for future NASA missions. One of the key components in a solar dynamic power system is the concentrator which collects the sun's energy and focuses it into a receiver. In 1985, the NASA Lewis Research Center initiated the Advanced Solar Dynamic Concentrator Program with funding from NASA's Office of Aeronautics and Space Technology (OAST). The objectives of the Advanced Concentrator Program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived (7 to 10 years) space solar dynamic concentrators. The Advanced Concentrator Program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. The Advanced Microsheet Glass Concentrator Program, a reflector concept, that is currently being investigated both in-house and under contract is discussed.

Materials Needs for Future In-space Propulsion Systems

NASA Technical Reports Server (NTRS)

Johnson, Charles Les

2008-01-01

NASA is developing the next generation of in-space propulsion systems in support of robotic exploration missions throughout the solar system. The propulsion technologies being developed are non-traditional and have stressing materials performance requirements. (Chemical Propulsion) Earth-storable chemical bipropellant performance is constrained by temperature limitations of the columbium used in the chamber. Iridium/rhenium (Ir/Re) is now available and has been implemented in initial versions of Earth-Storable rockets with specific impulses (Isp) about 10 seconds higher than columbium rocket chambers. New chamber fabrication methods that improve process and performance of Ir/Re and other promising material systems are needed. (Solar Sail Propulsion) The solar sail is a propellantless propulsion system that gains momentum by reflecting sunlight. The sails need to be very large in area (from 10000 m2 up to 62500 m2) yet be very lightweight in order to achieve adequate accelerations for realistic mission times. Lightweight materials that can be manufactured in thicknesses of less than 1 micron and that are not harmed by the space environment are desired. (Aerocapture) Blunt Body Aerocapture uses aerodynamic drag to slow an approaching spacecraft and insert it into a science orbit around any planet or moon with an atmosphere. The spacecraft is enclosed by a rigid aeroshell that protects it from the entry heating and aerodynamic environment. Lightweight, high-temperature structural systems, adhesives, insulators, and ablatives are key components for improving aeroshell efficiencies at heating rates of 1000-2000 W/cu cm and beyond. Inflatable decelerators in the forms of ballutes and inflatable aeroshells will use flexible polymeric thin film materials, high temperature fabrics, and structural adhesives. The inflatable systems will be tightly packaged during cruise and will be inflated prior to entry interface at the destination. Materials must maintain strength and flexibility while packaged at cold temperatures (_100oC) for up to 10 years and then withstand the high temperatures (500oC) encountered during aerocapture. The presentation will describe the status of each propulsion technology and summarize the materials needed for their implementation.

Use of ceramics in point-focus solar receivers

NASA Technical Reports Server (NTRS)

Smoak, R. H.; Kudirka, A. A.

1981-01-01

One of the research and development efforts in the Solar Thermal Energy Systems Project at the Jet Propulsion Laboratory has been focused on application of ceramic components for advanced point-focus solar receivers. The impetus for this effort is a need for high efficiency, low cost solar receivers which operate in a temperature regime where use of metal components is impractical. The current status of the work on evaluation of ceramic components at JPL and elsewhere is outlined and areas where lack of knowledge is currently slowing application of ceramics are discussed. Future developments of ceramic processing technology and reliability assurance methodology should open up applications for the point-focus solar concentrator system in fuels and chemicals production, in thermochemical energy transport and storage, in detoxification of hazardous materials and in high temperature process heat as well as for electric power generation.

Concentrated Solar Thermoelectric Power

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Gang; Ren, Zhifeng

2015-07-09

The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accuratemore » measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.« less

Evaluation of solar cell materials for a Solar Power Satellite

NASA Technical Reports Server (NTRS)

Glaser, P. E.; Almgren, D. W.; Csigi, K. I.

1980-01-01

Alternative solar cell materials being considered for the solar power satellite are described and price, production, and availability projections through the year 2000 are presented. The chief materials considered are silicon and gallium arsenide.

Solar synthesis of advanced materials: A solar industrial program initiative

NASA Astrophysics Data System (ADS)

Lewandowski, A.

1992-06-01

This is an initiative for accelerating the use of solar energy in the advanced materials manufacturing industry in the United States. The initiative will be based on government-industry collaborations that will develop the technology and help US industry compete in the rapidly expanding global advanced materials marketplace. Breakthroughs in solar technology over the last 5 years have created exceptional new tools for developing advanced materials. Concentrated sunlight from solar furnaces can produce intensities that approach those on the surface of the sun and can generate temperatures well over 2000 C. Very thin layers of illuminated surfaces can be driven to remarkably high temperatures in a fraction of a second. Concentrated solar energy can be delivered over large areas, allowing for rapid processing and high production rates. By using this technology, researchers are transforming low-cost raw materials into high-performance products. Solar synthesis of advanced materials uses bulk materials and energy more efficiently, lowers processing costs, and reduces the need for strategic materials -- all with a technology that does not harm the environment. The Solar Industrial Program has built a unique, world class solar furnace at NREL to help meet the growing need for applied research in advanced materials. Many new advanced materials processes have been successfully demonstrated in this facility, including metalorganic deposition, ceramic powders, diamond-like carbon materials, rapid heat treating, and cladding (hard coating).

Conservation and Renewable Energy Program: Bibliography, 1988 edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughan, K.H.

The 831 references covering the period 1980 through Feb. 1988, are arranged under the following: analysis and evaluation, building equipment, building thermal envelope systems and materials, community systems and cogeneration, residential conservation service, retrofit, advanced heat engine ceramics, alternative fuels, microemulsion fuels, industrial chemical heat pumps, materials for waste heat utilization, energy conversion and utilization materials, tribology, emergency energy conservation,inventions, electric energy systems, thermal storage, biofuels production, biotechnology, solar technology, geothermal, and continuous chromatography in multicomponent separations. An author index is included.

Astrobiology: The Case for Venus

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2003-01-01

The scientific discipline of astrobiology addresses one of the most fundamental unanswered questions of science: are we alone? Is there life elsewhere in the universe, or is life unique to Earth? The field of astrobiology includes the study of the chemical precursors for life in the solar system; it also includes the search for both presently existing life and fossil signs of previously existing life elsewhere in our own solar system, as well as the search for life outside the solar system. Two of the promising environments within the solar system being currently considered are the surface of the planet Mars, and the hypothesized oceans underneath the ice covering the moon Europa. Both of these environments differ in several key ways from the environments where life is found on Earth; the Mars environment in most places too cold and at too low pressure for liquid water to be stable, and the sub-ice environment of Europa lacking an abundance of free energy in the form of sunlight. The only place in the solar system where we know that life exists today is the Earth. To look for life elsewhere in the solar system, one promising search strategy would be to find and study the environment in the solar system with conditions that are most similar to the environmental conditions where life thrives on the Earth. Specifically, we would like to study a location in the solar system with atmospheric pressure near one bar; temperature in the range where water is liquid, 0 to 100 C; abundant solar energy; and with the primary materials required for life, carbon, oxygen, nitrogen, and hydrogen, present. Other than the surface of the Earth, the only other place where these conditions exist is the atmosphere of Venus, at an altitude of about fifty kilometers above the surface.

Fast Litho-Panspermia in Tightly-Packed Systems Around M Dwarfs

NASA Astrophysics Data System (ADS)

Krijt, S.; Bowling, T. J.; Lyons, R. J.; Ciesla, F. J.

2017-11-01

We investigate the fate of impact ejecta in tightly-packed planetary architectures like the TRAPPIST-1 system, finding that material transfer in such configurations is many orders of magnitude faster compared to the inner solar system.

Interfacial Materials for Organic Solar Cells: Recent Advances and Perspectives

PubMed Central

Yin, Zhigang; Wei, Jiajun

2016-01-01

Organic solar cells (OSCs) have shown great promise as low‐cost photovoltaic devices for solar energy conversion over the past decade. Interfacial engineering provides a powerful strategy to enhance efficiency and stability of OSCs. With the rapid advances of interface layer materials and active layer materials, power conversion efficiencies (PCEs) of both single‐junction and tandem OSCs have exceeded a landmark value of 10%. This review summarizes the latest advances in interfacial layers for single‐junction and tandem OSCs. Electron or hole transporting materials, including metal oxides, polymers/small‐molecules, metals and metal salts/complexes, carbon‐based materials, organic‐inorganic hybrids/composites, and other emerging materials, are systemically presented as cathode and anode interface layers for high performance OSCs. Meanwhile, incorporating these electron‐transporting and hole‐transporting layer materials as building blocks, a variety of interconnecting layers for conventional or inverted tandem OSCs are comprehensively discussed, along with their functions to bridge the difference between adjacent subcells. By analyzing the structure–property relationships of various interfacial materials, the important design rules for such materials towards high efficiency and stable OSCs are highlighted. Finally, we present a brief summary as well as some perspectives to help researchers understand the current challenges and opportunities in this emerging area of research. PMID:27812480

Efficient Perovskite Solar Cells Depending on TiO2 Nanorod Arrays.

PubMed

Li, Xin; Dai, Si-Min; Zhu, Pei; Deng, Lin-Long; Xie, Su-Yuan; Cui, Qian; Chen, Hong; Wang, Ning; Lin, Hong

2016-08-24

Perovskite solar cells (PSCs) with TiO2 materials have attracted much attention due to their high photovoltaic performance. Aligned TiO2 nanorods have long been used for potential application in highly efficient perovskite solar cells, but the previously reported efficiencies of perovskite solar cells based on TiO2 nanorod arrays were underrated. Here we show a solvothermal method based on a modified ketone-HCl system with the addition of organic acids suitable for modulation of the TiO2 nanorod array films to fabricate highly efficient perovskite solar cells. Photovoltaic measurements indicated that efficient nanorod-structured perovskite solar cells can be achieved with the length of the nanorods as long as approximately 200 nm. A record efficiency of 18.22% under the reverse scan direction has been optimized by avoiding direct contact between the TiO2 nanorods and the hole transport materials, eliminating the organic residues on the nanorod surfaces using UV-ozone treatment and tuning the nanorod array morphologies through addition of different organic acids in the solvothermal process.

The GENESIS Mission: Solar Wind Isotopic and Elemental Compositions and Their Implications

NASA Astrophysics Data System (ADS)

Wiens, R. C.; Burnett, D. S.; McKeegan, K. D.; Kallio, A. P.; Mao, P. H.; Heber, V. S.; Wieler, R.; Meshik, A.; Hohenberg, C. M.; Mabry, J. C.; Gilmour, J.; Crowther, S. A.; Reisenfeld, D. B.; Jurewicz, A.; Marty, B.; Pepin, R. O.; Barraclough, B. L.; Nordholt, J. E.; Olinger, C. T.; Steinberg, J. T.

2008-12-01

The GENESIS mission was a novel NASA experiment to collect solar wind at the Earth's L1 point for two years and return it for analysis. The capsule crashed upon re-entry in 2004, but many of the solar-wind collectors were recovered, including separate samples of coronal hole, interstream, and CME material. Laboratory analyses of these materials have allowed higher isotopic precision than possible with current in-situ detectors. To date GENESIS results have been obtained on isotopes of O, He, Ne, Ar, Kr, and Xe on the order of 1% accuracy and precision, with poorer uncertainty on Xe isotopes and significantly better uncertainties on the lighter noble gases. Elemental abundances are available for the above elements as well as Mg, Si, and Fe. When elemental abundances are compared with other in situ solar wind measurements, agreement is generally quite good. One exception is the Ne elemental abundance, which agrees with Ulysses and Apollo SWC results, but not with ACE. Neon is of particular interest because of the uncertainty in the solar Ne abundance, which has significant implications for the standard solar model. Helium isotopic results of material from the different solar wind regimes collected by GENESIS is consistent with isotopic fractionation predictions of the Coulomb drag model, suggesting that isotopic fractionation corrections need to be applied to heavier elements as well when extrapolating solar wind to solar compositions. Noble gas isotopic compositions from GENESIS are consistent with those obtained for solar wind trapped in lunar grains, but have for the first time yielded a very precise Ar isotopic result. Most interesting for cosmochemistry is a preliminary oxygen isotopic result from GENESIS which indicates a solar enrichment of ~4% in 16O relative to the planets, consistent with a photolytic self-shielding phenomenon during solar system formation. Analyses of solar wind N and C isotopes may further elucidate this phenomenon. Preliminary results from GENESIS have been reported for N, and results are still pending for C.

Design of a Solar Sail Mission to Mars

NASA Technical Reports Server (NTRS)

Feaux, K.; Jordan, W.; Killough, G.; Miller, R.; Plunk, V.

1989-01-01

A new area of interest in space vehicles is the solar sail. Various applications for which it has been considered are attitude control of satellites, focusing light on the jungles of Vietnam, and a Halley's comet rendezvous. Although for various reasons these projects were never completed, new interest in solar sails has arisen. The solar sail is an alternative to the rocket-propelled space vehicle as an interplanetary cargo vehicle, and manufacture of solar sails on the space station is a possibility. Solar sails have several advantages over rockets, including an unlimited power supply and low maintenance. The purpose of this project is to design a solar sail mission to Mars. The spacecraft will efficiently journey to Mars powered only by a solar sail. The vehicle weighs 487.16 kg and will be launchable on an expendable launch vehicle. The project includes an investigation of options to minimize cost, weight, and flight duration. The design of the sail and its deployment system are a major part of the project, as is the actual mission planning. Various topics researched include solar power, material, space environment, thermal control, trajectories, and orbit transfer. Various configurations are considered in order to determine the optimal structure. Another design consideration is the control system of the vehicle. This system includes the attitude control and the communication system of the sail. This project will aid in determining the feasibility of a solar sail and will raise public interest in space research.

The Growth of InGaAsN for High Efficiency Solar Cells by Metalorganic Chemical Vapor Deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

ALLERMAN,ANDREW A.; BANKS,JAMES C.; GEE,JAMES M.

1999-09-16

InGaAsN alloys are a promising material for increasing the efficiency of multi-junction solar cells now used for satellite power systems. However, the growth of these dilute N containing alloys has been challenging with further improvements in material quality needed before the solar cell higher efficiencies are realized. Nitrogen/V ratios exceeding 0.981 resulted in lower N incorporation and poor surface morphologies. The growth rate was found to depend on not only the total group III transport for a fixed N/V ratio but also on the N/V ratio. Carbon tetrachloride and dimethylzinc were effective for p-type doping. Disilane was not an effectivemore » n-type dopant while SiCl4 did result in n-type material but only a narrow range of electron concentrations (2-5e17cm{sup -3}) were achieved.« less

Study on corrosion of metal materials in nitrate molten salts

NASA Astrophysics Data System (ADS)

Zhai, Wei; Yang, Bo; Li, Maodong; Li, Shiping; Xin, Mingliang; Zhang, Shuanghong; Huang, Guojia

2017-01-01

High temperature molten salts as a heat transfer heat storage medium has been more widely used in the field of concentrated solar thermal power generation. In the thermal heat storage system, metal material stability and performance at high temperatures are of one major limitation in increasing this operating temperature. In this paper, study on corrosion of 321H, 304, 316L, P91 metal materials in modified solar two molten salts. The corrosion kinetics of 304, 316L, 321H, P91 metal material in the modified solar two molten salts at 450°C, 500°C is also investigated. Under the same condition it was found that 304, 321H corroded at a rate of 40% less than P91. Spallation of corrosion products was observed on P91 steel, while no obvious observed on other kinds of stainless steel. Corrosion rates of 304, 321H, and 316L slowly increased with temperature. Oxidation mechanisms little varied with temperature. Corrosion products of metal materials observed at 450°C, 500°C were primarily Fe oxide and Fe, Cr oxide.

SOLAR COSMIC-RAY INTERACTION WITH PROTOPLANETARY DISKS: PRODUCTION OF SHORT-LIVED RADIONUCLIDES AND AMORPHIZATION OF CRYSTALLINE MATERIAL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trappitsch, R.; Ciesla, F. J., E-mail: trappitsch@uchicago.edu

2015-05-20

Solar cosmic-ray (SCR) interactions with a protoplanetary disk have been invoked to explain several observations of primitive planetary materials. In our own Solar System, the presence of short-lived radionuclides (SLRs) in the oldest materials has been attributed to spallation reactions induced in phases that were irradiated by energetic particles in the solar nebula. Furthermore, observations of other protoplanetary disks show a mixture of crystalline and amorphous grains, though no correlation between grain crystallinity and disk or stellar properties have been identified. As most models for the origin of crystalline grains would predict such correlations, it was suggested that amorphization bymore » stellar cosmic-rays may be masking or erasing such correlations. Here we quantitatively investigate these possibilities by modeling the interaction of energetic particles emitted by a young star with the surrounding protoplanetary disk. We do this by tracing the energy evolution of SCRs emitted from the young star through the disk and model the amount of time that dust grains would spend in regions where they would be exposed to these particles. We find that this irradiation scenario cannot explain the total SLR content of the solar nebula; however, this scenario could play a role in the amorphization of crystalline material at different locations or epochs of the disk over the course of its evolution.« less

Theoretical limits of the multistacked 1D and 2D microstructured inorganic solar cells

NASA Astrophysics Data System (ADS)

Yengel, Emre; Karaagac, Hakan; VJ, Logeeswaran; Islam, M. Saif

2015-09-01

Recent studies in monocrystalline semiconductor solar cells are focused on mechanically stacking multiple cells from different materials to increase the power conversion efficiency. Although, the results show promising increase in the device performance, the cost remains as the main drawback. In this study, we calculated the theoretical limits of multistacked 1D and 2D microstructered inorganic monocrstalline solar cells. This system is studied for Si and Ge material pair. The results show promising improvements in the surface reflection due to enhanced light trapping caused by photon-microstructures interactions. The theoretical results are also supported with surface reflection and angular dependent power conversion efficiency measurements of 2D axial microwall solar cells. We address the challenge of cost reduction by proposing to use our recently reported mass-manufacturable fracture-transfer- printing method which enables the use of a monocrystalline substrate wafer for repeated fabrication of devices by consuming only few microns of materials in each layer of devices. We calculated thickness dependent power conversion efficiencies of multistacked Si/Ge microstructured solar cells and found the power conversion efficiency to saturate at 26% with a combined device thickness of 30 μm. Besides having benefits of fabricating low-cost, light weight, flexible, semi-transparent, and highly efficient devices, the proposed fabrication method is applicable for other III-V materials and compounds to further increase the power conversion efficiency above 35% range.

Filling in the Gaps: Xenoliths in Meteorites are Samples of "Missing" Asteroid Lithologies

NASA Technical Reports Server (NTRS)

Zolensky, Mike

2016-01-01

We know that the stones that fall to earth as meteorites are not representative of the full diversity of small solar system bodies, because of the peculiarities of the dynamical processes that send material into Earth-crossing paths [1] which result in severe selection biases. Thus, the bulk of the meteorites that fall are insufficient to understand the full range of early solar system processes. However, the situation is different for pebble- and smaller-sized objects that stream past the giant planets and asteroid belts into the inner solar system in a representative manner. Thus, micrometeorites and interplanetary dust particles have been exploited to permit study of objects that do not provide meteorites to earth. However, there is another population of materials that sample a larger range of small solar system bodies, but which have received little attention - pebble-sized foreign clasts in meteorites (also called xenoliths, dark inclusions, clasts, etc.). Unfortunately, most previous studies of these clasts have been misleading, in that these objects have simply been identified as pieces of CM or CI chondrites. In our work we have found this to be generally erroneous, and that CM and especially CI clasts are actually rather rare. We therefore test the hypothesis that these clasts sample the full range of small solar system bodies. We have located and obtained samples of clasts in 81 different meteorites, and have begun a thorough characterization of the bulk compositions, mineralogies, petrographies, and organic compositions of this unique sample set. In addition to the standard e-beam analyses, recent advances in technology now permit us to measure bulk O isotopic compositions, and major- though trace-element compositions of the sub-mm-sized discrete clasts. Detailed characterization of these clasts permit us to explore the full range of mineralogical and petrologic processes in the early solar system, including the nature of fluids in the Kuiper belt and the outer main asteroid belt, as revealed by the mineralogy of secondary phases.

Process Research of Polycrystalline Silicon Material (PROPSM)

NASA Technical Reports Server (NTRS)

Culik, J. S.

1984-01-01

A passivation process (hydrogenation) that will improve the power generation of solar cells fabricated from presently produced, large grain, cast polycrystalline silicon (Semix), a potentially low cost material are developed. The first objective is to verify the operation of a DC plasma hydrogenation system and to investigate the effect of hydrogen on the electrical performance of a variety of polycrystalline silicon solar cells. The second objective is to parameterize and optimize a hydrogenation process for cast polycrystalline silicon, and will include a process sensitivity analysis. The sample preparation for the first phase is outlined. The hydrogenation system is described, and some early results that were obtained using the hydrogenation system without a plasma are summarized. Light beam induced current (LBIC) measurements of minicell samples, and their correlation to dark current voltage characteristics, are discussed.

Stable Chlorine Isotope Study: Application to Early Solar System Materials

NASA Technical Reports Server (NTRS)

Mala,ira. M/; Nyquist, L. E.; Reese, Y.; Shih, C-Y; Fujitani, T.; Okano, O.

2010-01-01

A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the Cl-37/Cl-35 ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For example, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the 37Cl/35Cl ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For eample, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. In order to clarify the stable chlorine isotope features of early solar system materials, we have initiated development of the TIMS technique at NASA JSC applicable to analysis of small amounts of meteoritic and planetary materials. We report here the current status of chlorine isotope analysis at NASA JSC.

Physics and chemistry of the solar nebula.

PubMed

Lunine, J I

1997-06-01

The solar system is thought to have begun in a flattened disk of gas and dust referred to traditionally as the solar nebula. Such a construct seems to be a natural product of the collapse of dense parts of giant molecular clouds, the vast star-forming regions that pepper the Milky Way and other galaxies. Gravitational, magnetic and thermal forces within the solar nebula forced a gradual evolution of mass toward the center (where the sun formed) and angular momentum (borne by a small fraction of the mass) toward the outer more distant regions of the disk. This evolution was accompanied by heating and a strong temperature contrast from the hot, inner regions to the cold, more remote parts of the disk. The resulting chemistry in the disk determined the initial distribution of organic matter in the planets; most of the reduced carbon species, in condensed form, were located beyond the asteroid belt (the 'outer' solar system). The Earth could have received much of its inventory of pre-biological material from comets and other icy fragments of the process of planetary formation in the outer solar system.

A Dual-Responsive Nanocomposite toward Climate-Adaptable Solar Modulation for Energy-Saving Smart Windows.

PubMed

Lee, Heng Yeong; Cai, Yufeng; Bi, Shuguang; Liang, Yen Nan; Song, Yujie; Hu, Xiao Matthew

2017-02-22

In this work, a novel fully autonomous photothermotropic material made by hybridization of the poly(N-isopropylacrylamide) (PNIPAM) hydrogel and antimony-tin oxide (ATO) is presented. In this photothermotropic system, the near-infrared (NIR)-absorbing ATO acts as nanoheater to induce the optical switching of the hydrogel. Such a new passive smart window is characterized by excellent NIR shielding, a photothermally activated switching mechanism, enhanced response speed, and solar modulation ability. Systems with 0, 5, 10, and 15 atom % Sb-doped ATO in PNIPAM were investigated, and it was found that a PNIPAM/ATO nanocomposite is able to be photothermally activated. The 10 atom % Sb-doped PNIPAM/ATO exhibits the best response speed and solar modulation ability. Different film thicknesses and ATO contents will affect the response rate and solar modulation ability. Structural stability tests at 15 cycles under continuous exposure to solar irradiation at 1 sun intensity demonstrated the performance stability of such a photothermotropic system. We conclude that such a novel photothermotropic hybrid can be used as a new generation of autonomous passive smart windows for climate-adaptable solar modulation.

Birth of an Earth-like Planet (Artist concept)

NASA Technical Reports Server (NTRS)

2007-01-01

This artist's conception shows a binary-star, or two-star, system, called HD 113766, where astronomers suspect a rocky Earth-like planet is forming around one of the stars. At approximately 10 to 16 million years old, astronomers suspect this star is at just the right age for forming rocky planets. The system is located approximately 424 light-years away from Earth.

The two yellow spots in the image represent the system's two stars. The brown ring of material circling closest to the central star depicts a huge belt of dusty material, more than 100 times as much as in our asteroid belt, or enough to build a Mars-size planet or larger. The rocky material in the belt represents the early stages of planet formation, when dust grains clump together to form rocks, and rocks collide to form even more massive rocky bodies called planetesimals. The belt is located in the middle of the system's terrestrial habitable zone, or the region around a star where liquid water could exist on any rocky planets that might form. Earth is located in the middle of our sun's terrestrial habitable zone.

Using NASA's Spitzer Space Telescope, astronomers learned that the belt material in HD 113866 is more processed than the snowball-like stuff that makes up infant solar systems and comets, which contain pristine ingredients from the early solar system. However, it is not as processed as the stuff found in mature planets and asteroids. This means that the dust belt is made out of just the right mix of materials to be forming an Earth-like planet. It is composed mainly of rocky silicates and metal sulfides (like fool's gold), similar to the material found in lava flows.

The white outer ring shows a concentration of icy dust also detected in the system. This material is at the equivalent position of the asteroid belt in our solar system, but only contains about one-sixth as much material as the inner ring. Astronomers say it is not clear from the Spitzer observations if anything is occurring in the icy belt, but they believe it could be a source of water later on for the planet that grows from the inner warm ring.

Status of Solar Sail Technology Within NASA

NASA Technical Reports Server (NTRS)

Johnson, Les; Young, Roy; Montgomery, Edward; Alhorn, Dean

2010-01-01

In the early 2000s, NASA made substantial progress in the development of solar sail propulsion systems for use in robotic science and exploration of the solar system. Two different 20-m solar sail systems were produced and they successfully completed functional vacuum testing in NASA Glenn Research Center's (GRC's) Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L Garde, respectively. The sail systems consist of a central structure with four deployable booms that support the sails. These sail designs are robust enough for deployment in a one-atmosphere, one-gravity environment and were scalable to much larger solar sails perhaps as large as 150 m on a side. Computation modeling and analytical simulations were also performed to assess the scalability of the technology to the large sizes required to implement the first generation of missions using solar sails. Life and space environmental effects testing of sail and component materials were also conducted. NASA terminated funding for solar sails and other advanced space propulsion technologies shortly after these ground demonstrations were completed. In order to capitalize on the $30M investment made in solar sail technology to that point, NASA Marshall Space Flight Center (MSFC) funded the NanoSail-D, a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board the ill-fated Falcon-1 Rocket launched August 2, 2008, and due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare will be flown in the Fall of 2010. This paper will summarize NASA's investment in solar sail technology to-date and discuss future opportunities

Status of solar sail technology within NASA

NASA Astrophysics Data System (ADS)

Johnson, Les; Young, Roy; Montgomery, Edward; Alhorn, Dean

2011-12-01

In the early 2000s, NASA made substantial progress in the development of solar sail propulsion systems for use in robotic science and exploration of the solar system. Two different 20-m solar sail systems were produced. NASA has successfully completed functional vacuum testing in their Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by Alliant Techsystems Space Systems and L'Garde, respectively. The sail systems consist of a central structure with four deployable booms that support each sail. These sail designs are robust enough for deployment in a one-atmosphere, one-gravity environment and are scalable to much larger solar sails - perhaps as large as 150 m on a side. Computation modeling and analytical simulations were performed in order to assess the scalability of the technology to the larger sizes that are required to implement the first generation of missions using solar sails. Furthermore, life and space environmental effects testing of sail and component materials was also conducted.NASA terminated funding for solar sails and other advanced space propulsion technologies shortly after these ground demonstrations were completed. In order to capitalize on the $30 M investment made in solar sail technology to that point, NASA Marshall Space Flight Center funded the NanoSail-D, a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board a Falcon-1 rocket, launched August 2, 2008. As a result of the failure of that rocket, the NanoSail-D was never successfully given the opportunity to achieve orbit. The NanoSail-D flight spare was flown in the Fall of 2010. This review paper summarizes NASA's investment in solar sail technology to date and discusses future opportunities.

Elemental and isotopic abundances in the solar wind

NASA Technical Reports Server (NTRS)

Geiss, J.

1972-01-01

The use of collecting foils and lunar material to assay the isotopic composition of the solar wind is reviewed. Arguments are given to show that lunar surface correlated gases are likely to be most useful in studying the history of the solar wind, though the isotopic abundances are thought to give a good approximation to the solar wind composition. The results of the analysis of Surveyor material are also given. The conditions leading to a significant component of the interstellar gas entering the inner solar system are reviewed and suggestions made for experimental searches for this fraction. A critical discussion is given of the different ways in which the basic solar composition could be modified by fractionation taking place between the sun's surface and points of observation such as on the Moon or in interplanetary space. An extended review is made of the relation of isotopic and elemental composition of the interplanetary gas to the dynamic behavior of the solar corona, especially processes leading to fractionation. Lastly, connection is made between the subject of composition, nucleosynthesis and the convective zone of the sun, and processes leading to modification of initial accretion of certain gases on the Earth and Moon.

Thermal analysis of a Phase Change Material for a Solar Organic Rankine Cycle

NASA Astrophysics Data System (ADS)

Iasiello, M.; Braimakis, K.; Andreozzi, A.; Karellas, S.

2017-11-01

Organic Rankine Cycle (ORC) is a promising technology for low temperature power generation, for example for the utilization of medium temperature solar energy. Since heat generated from solar source is variable throughout the day, the implementation of Thermal Energy Storage (TES) systems to guarantee the continuous operation of solar ORCs is a critical task, and Phase Change Materials (PCM) rely on latent heat to store large amounts of energy. In the present study, a thermal analysis of a PCM for a solar ORC is carried out. Three different types of PCMs are analyzed. The energy equation for the PCM is modeled by using the heat capacity method, and it is solved by employing a 1Dexplicit finite difference scheme. The solar source is modeled with a time-variable temperature boundary condition, with experimental data taken from the literature for two different solar collectors. Results are presented in terms of temperature profiles and stored energy. It has been shown that the stored energy depends on the heat source temperature, on the employed PCM and on the boundary conditions. It has been demonstrated that the use of a metal foam can drastically enhance the stored energy due to the higher overall thermal conductivity.

The genesis solar-wind sample return mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiens, Roger C

2009-01-01

The compositions of the Earth's crust and mantle, and those of the Moon and Mars, are relatively well known both isotopically and elementally. The same is true of our knowledge of the asteroid belt composition, based on meteorite analyses. Remote measurements of Venus, the Jovian atmosphere, and the outer planet moons, have provided some estimates of their compositions. The Sun constitutes a large majority, > 99%, of all the matter in the solar system. The elemental composition of the photosphere, the visible 'surface' of the Sun, is constrained by absorption lines produced by particles above the surface. Abundances for manymore » elements are reported to the {+-}10 or 20% accuracy level. However, the abundances of other important elements, such as neon, cannot be determined in this way due to a relative lack of atomic states at low excitation energies. Additionally and most importantly, the isotopic composition of the Sun cannot be determined astronomically except for a few species which form molecules above sunspots, and estimates derived from these sources lack the accuracy desired for comparison with meteoritic and planetary surface samples measured on the Earth. The solar wind spreads a sample of solar particles throughout the heliosphere, though the sample is very rarified: collecting a nanogram of oxygen, the third most abundant element, in a square centimeter cross section at the Earth's distance from the Sun takes five years. Nevertheless, foil collectors exposed to the solar wind for periods of hours on the surface of the Moon during the Apollo missions were used to determine the helium and neon solar-wind compositions sufficiently to show that the Earth's atmospheric neon was significantly evolved relative to the Sun. Spacecraft instruments developed subsequently have provided many insights into the composition of the solar wind, mostly in terms of elemental composition. These instruments have the advantage of observing a number of parameters simultaneously, including charge state distributions, velocities, and densities, all of which have been instrumental in characterizing the nature of the solar wind. However, these instruments have lacked the ability to make large dynamic range measurements of adjacent isotopes (i.e., {sup 17}O/{sup 16}O {approx} 2500) or provide the permil (tenths of percent) accuracy desirable for comparison with geochemical isotopic measurements. An accurate knowledge of the solar and solar-wind compositions helps to answer important questions across a number of disciplines. It aids in understanding the acceleration mechanisms of the solar wind, gives an improved picture of the charged particle environment near the photosphere, it constrains processes within the Sun over its history, and it provides a database by which to compare differences among planetary systems with the solar system's starting composition, providing key information on planetary evolution. For example, precise knowledge of solar isotopic and elemental compositions of volatile species in the Sun provides a baseline for models of atmospheric evolution over time for Earth, Venus, and Mars. Additionally, volatile and chemically active elements such as C, H, O, N, and S can tell us about processes active during the evolution of the solar nebula. A classic example of this is the oxygen isotope system. In the 1970s it was determined that the oxygen isotopic ratio in refractory inclusions in primitive meteorites was enriched {approx}4% in {sup 16}O relative to the average terrestrial, lunar, and thermally processed meteorite materials. In addition, all processed solar-system materials appeared to each have a unique oxygen isotopic composition (except the Moon and Earth, which are thought to be formed from the same materials), though differences are in the fraction of a percent range, much smaller than the refractory material {sup 16}O enrichment. Several theories were developed over the years to account for the oxygen isotope heterogeneity, each theory predicting a different solar isotopic composition and each invoking a different early solar-system process to produce the heterogeneity. Other volatiles such as C, N, and H may also have experienced similar effects, but with only two isotopes it is often impossible to distinguish with these elements between mass-dependent fractionation and other effects such as mixing or mass-independent fractionation. Table 1 provides a summary of the major measurement objectives of the Genesis mission. Determining the solar oxygen isotopic composition is at the top of the list. Volatile element and isotope ratios constitute six of the top seven priorities. A number of disciplines stand to gain from information from the Genesis mission, as will be discussed later. Based on the Apollo solar-wind foil experiment, the Genesis mission was designed to capture solar wind over orders of magnitude longer duration and in a potentially much cleaner environment than the lunar surface.« less

Formation and processing of organics in the early solar system.

PubMed

Kerridge, J F

1999-01-01

Until pristine samples can be returned from cometary nuclei, primitive meteorites represent our best source of information about organic chemistry in the early solar system. However, this material has been affected by secondary processing on asteroidal parent bodies which probably did not affect the material now present in cometary nuclei. Production of meteoritic organic matter apparently involved the following sequence of events: Molecule formation by a variety of reaction pathways in dense interstellar clouds; Condensation of those molecules onto refractory interstellar grains; Irradiation of organic-rich interstellar-grain mantles producing a range of molecular fragments and free radicals; Inclusion of those interstellar grains into the protosolar nebula with probable heating of at least some grain mantles during passage through the shock wave bounding the solar accretion disc; Agglomeration of residual interstellar grains and locally produced nebular condensates into asteroid-sized planetesimals; Heating of planetesimals by decay of extinct radionuclides; Melting of ice to produce liquid water within asteroidal bodies; Reaction of interstellar molecules, fragments and radicals with each other and with the aqueous environment, possibly catalysed by mineral grains; Loss of water and other volatiles to space yielding a partially hydrated lithology containing a complex suite of organic molecules; Heating of some of this organic matter to generate a kerogen-like complex; Mixing of heated and unheated material to yield the meteoritic material now observed. Properties of meteoritic organic matter believed to be consistent with this scenario include: Systematic decrease of abundance with increasing C number in homologous series of characterisable molecules; Complete structural diversity within homologous series; Predominance of branched-chain isomers; Considerable isotopic variability among characterisable molecules and within kerogen-like material; Substantial deuterium enrichment in all organic fractions; Some fractions significantly enriched in nitrogen-15; Modest excesses of L-enantiomers in some racemisation-resistant molecules but no general enantiomeric preference. Despite much speculation about the possible role of Fischer-Tropsch catalytic hydrogenation of CO in production of organic molecules in the solar nebula, no convincing evidence for such material has been found in meteorites. A similarity between some meteoritic organics and those produced by Miller-Urey discharge synthesis may reflect involvement of common intermediates rather than the operation of electric discharges in the early solar system. Meteoritic organic matter constitutes a useful, but not exact, guide to what we shall find with in situ analytical and sample-return missions to cometary nuclei.

Compatibility of molten salts with advanced solar dynamic receiver materials

NASA Technical Reports Server (NTRS)

Jaworske, D. A.; Perry, W. D.

1989-01-01

Metal-coated graphite fibers are being considered as a thermal conductivity enhancement filler material for molten salts in solar dynamic thermal energy storage systems. The successful metal coating chosen for this application must exhibit acceptable wettability and must be compatible with the molten salt environment. Contact angle values between molten lithium fluoride and several metal, metal fluoride, and metal oxide substrates have been determined at 892 C using a modification of the Wilhelmy plate technique. Reproducible contact angles with repeated exposure to the molten LiF indicated compatibility.

Molecular solution processing of metal chalcogenide thin film solar cells

NASA Astrophysics Data System (ADS)

Yang, Wenbing

The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (CISS) and kesterite Cu2ZnSn(S,Se) 4 organized in chronological order. Chalcopyrite CISS is a very promising material. It has been demonstrated to achieve the highest efficiency among thin film solar cells. Scaled-up industry production at present has reached the giga-watt per year level. The process however mainly relies on vacuum systems which account for a significant percentage of the manufacturing cost. In the first section of this dissertation, hydrazine based solution processed CISS has been explored. The focus of the research involves the procedures to fabricate devices from solution. The topics covered in Chapter 2 include: precursor solution synthesis with a focus on understanding the solution chemistry, CISS absorber formation from precursor, properties modification toward favorable device performance, and device structure innovation toward tandem device. For photovoltaics to have a significant impact toward meeting energy demands, the annual production capability needs to be on TW-level. On such a level, raw materials supply of rare elements (indium for CIS or tellurium for CdTe) will be the bottleneck limiting the scalability. Replacing indium with zinc and tin, earth abundant kesterite CZTS exhibits great potential to reach the goal of TW-level with no limitations on raw material availability. Chapter 3 shows pioneering work towards solution processing of CZTS film at low temperature. The solution processed devices show performances which rival vacuum-based techniques and is partially attributed to the ease in controlling composition and CZTS phase through this technique. Based on this platform, comprehensive characterization on CZTS devices is carried out including solar cells and transistors. Especially defects properties are exploited in Chapter 4 targeting to identify the limiting factors for further improvement on CZTS solar cells efficiency. Finally, molecular structures and precursor solution stability have been explored, potentially to provide a universal approach to process multinary compounds.

Near Earth Asteroid Scout Solar Sail Thrust and Torque Model

NASA Technical Reports Server (NTRS)

Heaton, Andy; Ahmad, Naeem; Miller, Kyle

2017-01-01

The Near Earth Asteroid (NEA) Scout is a solar sail mission whose objective is to scout at least one Near Earth Asteroid to help prepare for human missions to Near Earth Asteroids. NEA Scout will launch as a secondary payload on the first SLS-Orion mission. NEA Scout will perform a small trim maneuver shortly after deploy from the spent SLS upper stage using a cold gas propulsion system, but from that point on will depend entirely on the solar sail for thrust. As such, it is important to accurately characterize the thrust of the sail in order to achieve mission success. Additionally, the solar sail creates a relatively large solar disturbance torque that must be mitigated. For early mission design studies a flat plate model of the solar sail with a fixed center of pressure was adequate, but as mission concepts and the sail design matured, greater fidelity was required. Here we discuss the progress to a three-dimensional sail model that includes the effects of tension and thermal deformation that has been derived from a large structural Finite Element Model (FEM) developed by the Langley Research Center. We have found that the deformed sail membrane affects torque relatively much more than thrust; a flat plate model could potentially model thrust well enough to close mission design studies, but a three-dimensional solar sail is essential to control system design. The three-dimensional solar sail model revealed that thermal deformations of unshielded booms would create unacceptably large solar disturbance torques. The original large FEM model was used in control and mission simulations, but was resulted in simulations with prohibitive run times. This led us to adapt the Generalized Sail Model (GSM) of Rios-Reyes. A design reference sail model has been baselined for NEA Scout and has been used to design the mission and control system for the sailcraft. Additionally, since NEA Scout uses reaction wheels for attitude pointing and control, the solar torque model is essentially to successfully design the NEA Scout momentum management control system. We have also updated the estimate of diffusivity used for the aluminized sail material based on optical testing of wrinkled sail material. The model presented here represents the current state of the art of NASA's ability to model solar sail thrust and torque.

Chondrulelike objects in short-period comet 81P/Wild 2.

PubMed

Nakamura, Tomoki; Noguchi, Takaaki; Tsuchiyama, Akira; Ushikubo, Takayuki; Kita, Noriko T; Valley, John W; Zolensky, Michael E; Kakazu, Yuki; Sakamoto, Kanako; Mashio, Etsuko; Uesugi, Kentaro; Nakano, Tsukasa

2008-09-19

The Stardust spacecraft returned cometary samples that contain crystalline material, but the origin of the material is not yet well understood. We found four crystalline particles from comet 81P/Wild 2 that were apparently formed by flash-melting at a high temperature and are texturally, mineralogically, and compositionally similar to chondrules. Chondrules are submillimeter particles that dominate chondrites and are believed to have formed in the inner solar nebula. The comet particles show oxygen isotope compositions similar to chondrules in carbonaceous chondrites that compose the middle-to-outer asteroid belt. The presence of the chondrulelike objects in the comet suggests that chondrules have been transported out to the cold outer solar nebula and spread widely over the early solar system.

The "Rust" Challenge: On the Correlations between Electronic Structure, Excited State Dynamics, and Photoelectrochemical Performance of Hematite Photoanodes for Solar Water Splitting.

PubMed

Grave, Daniel A; Yatom, Natav; Ellis, David S; Toroker, Maytal Caspary; Rothschild, Avner

2018-03-05

In recent years, hematite's potential as a photoanode material for solar hydrogen production has ignited a renewed interest in its physical and interfacial properties, which continues to be an active field of research. Research on hematite photoanodes provides new insights on the correlations between electronic structure, transport properties, excited state dynamics, and charge transfer phenomena, and expands our knowledge on solar cell materials into correlated electron systems. This research news article presents a snapshot of selected theoretical and experimental developments linking the electronic structure to the photoelectrochemical performance, with particular focus on optoelectronic properties and charge carrier dynamics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Life Cycle Analysis for the Feasibility of Photovoltaic System Application in Indonesia

NASA Astrophysics Data System (ADS)

Yudha, H. M.; Dewi, T.; Risma, P.; Oktarina, Y.

2018-03-01

Electricity has become the basic need for everyone, from industry to domestic. Today electricity source still depends heavily on fossil fuels that soon will be diminished from the earth in around 50 years. This condition demands us to find the renewable energy to support our everyday life. One of the famous renewable energy sources is from solar, harnessed by energy conversion device named solar cells. Countries like Indonesia are gifted with an abundance of sunlight all the yearlong. The application of solar cells with its photovoltaic (PV) technology harnesses the sunlight and converts it into electricity. Although this technology is emerging very fast, it still has some limitation due to the current PV technology, economic feasibility, and its environmental impacts. Life cycle assessment is the method to analyze and evaluate the sustainability of PV system and its environmental impact. This paper presents literature study of PV system from the cradle to grave, it begins with the material choices (from the first generation and the possibility of the fourth generation), manufacturing process, implementation, and ends it with the after-life effect of PV modules. The result of this study will be the insights look of the PV system application in Indonesia, from the best option of material choice, the best method of application, the energy payback time, and finally the possible after life recycle of PV materials.

Achieving high performance polymer tandem solar cells via novel materials design

NASA Astrophysics Data System (ADS)

Dou, Letian

Organic photovoltaic (OPV) devices show great promise in low-cost, flexible, lightweight, and large-area energy-generation applications. Nonetheless, most of the materials designed today always suffer from the inherent disadvantage of not having a broad absorption range, and relatively low mobility, which limit the utilization of the full solar spectrum. Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption bands. However, for polymer solar cells, the performance of tandem devices lags behind single-layer solar cells mainly due to the lack of suitable low-bandgap polymers (near-IR absorbing polymers). In this dissertation, in order to achieve high performance, we focus on design and synthesis of novel low bandgap polymers specifically for tandem solar cells. In Chapter 3, I demonstrate highly efficient single junction and tandem polymer solar cells featuring a spectrally matched low-bandgap conjugated polymer (PBDTT-DPP: bandgap, ˜1.44 eV). The polymer has a backbone based on alternating benzodithiophene and diketopyrrolopyrrole units. A single-layer device based on the polymer provides a power conversion efficiency of ˜6%. When the polymer is applied to tandem solar cells, a power conversion efficiency of 8.62% is achieved, which was the highest certified efficiency for a polymer solar cell. To further improve this material system, in Chapter 4, I show that the reduction of the bandgap and the enhancement of the charge transport properties of the low bandgap polymer PBDTT-DPP can be accomplished simultaneously by substituting the sulfur atoms on the DPP unit with selenium atoms. The newly designed polymer PBDTT-SeDPP (Eg = 1.38 eV) shows excellent photovoltaic performance in single junction devices with PCEs over 7% and photo-response up to 900 nm. Tandem polymer solar cells based on PBDTT-SeDPP are also demonstrated with a 9.5% PCE, which are more than 10% enhancement over those based on PBDTT-DPP. Finally, in Chapter 5, I demonstrate a new polymer system based on alternating dithienopyran and benzothiadiazole units with a bandgap of 1.38 eV, high mobility, deep highest occupied molecular orbital. As a result, a single-junction device shows high external quantum efficiency of >60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions, which is the first certified polymer solar cell efficiency over 10%.

High Rate Production of Clean Water Based on the Combined Photo-Electro-Thermal Effect of Graphene Architecture.

PubMed

Cui, Linfan; Zhang, Panpan; Xiao, Yukun; Liang, Yuan; Liang, Hanxue; Cheng, Zhihua; Qu, Liangti

2018-05-01

The use of abundant solar energy for regeneration and desalination of water is a promising strategy to address the challenge of a global shortage of clean water. Progress has been made to develop photothermal materials to improve the solar steam generation performance. However, the mass production rate of water is still low. Herein, by a rational combination of photo-electro-thermal effect on an all-graphene hybrid architecture, solar energy can not only be absorbed fully and transferred into heat, but also converted into electric power to further heat up the graphene skeleton frame for a much enhanced generation of water vapor. As a result, the unique graphene evaporator reaches a record high water production rate of 2.01-2.61 kg m -2 h -1 under solar illumination of 1 kW m -2 even without system optimization. Several square meters of the graphene evaporators will provide a daily water supply that is enough for tens of people. The combination of photo-electro-thermal effect on graphene materials offers a new strategy to build a fast and scalable solar steam generation system, which makes an important step towards a solution for the scarcity of clean water. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wind, Sun and Water: Complexities of Alternative Energy Development in Rural Northern Peru

ERIC Educational Resources Information Center

Love, Thomas; Garwood, Anna

2011-01-01

Drawing on recent research with NGO-driven projects in rural Cajamarca, Peru, we examine the paradoxes of relying on wind, solar and micro-hydro generation of electricity for rural community development. In spite of cost, vagaries of these energy resources and limited material benefits, especially with wind and solar systems, villagers are eagerly…

AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack

NASA Technical Reports Server (NTRS)

Dinetta, L. C.; Hannon, M. H.; Cummings, J. R.; Mcneeley, J. B.; Barnett, Allen M.

1990-01-01

Free-standing, transparent, tunable bandgap AlxGa1-xAs top solar cells have been fabricated for mechanical attachment in a four terminal tandem stack solar cell. Evaluation of the device results has demonstrated 1.80 eV top solar cells with efficiencies of 18 percent (100 X, and AM0) which would yield stack efficiencies of 31 percent (100 X, AM0) with a silicon bottom cell. When fully developed, the AlxGa1-xAs/Si mechanically-stacked two-junction solar cell concentrator system can provide efficiencies of 36 percent (AM0, 100 X). AlxGa1-xAs top solar cells with bandgaps from 1.66 eV to 2.08 eV have been fabricated. Liquid phase epitaxy (LPE) growth techniques have been used and LPE has been found to yield superior AlxGa1-xAs material when compared to molecular beam epitaxy and metal-organic chemical vapor deposition. It is projected that stack assembly technology will be readily applicable to any mechanically stacked multijunction (MSMJ) system. Development of a wide bandgap top solar cell is the only feasible method for obtaining stack efficiencies greater than 40 percent at AM0. System efficiencies of greater than 40 percent can be realized when the AlGaAs top solar cell is used in a three solar cell mechanical stack.

Solar-heating and hot water system--St. Louis, Missouri

NASA Technical Reports Server (NTRS)

1981-01-01

Sunlight supplies about half heat energy needs of small office. System includes six tilt-adjustable commercial collectors and 1,000 gallon energy storage tank. Report contains description of system and components, drawings and photographs, manufacturer's data, and related material.

Isotopic evolution of the protoplanetary disk and the building blocks of Earth and the Moon.

PubMed

Schiller, Martin; Bizzarro, Martin; Fernandes, Vera Assis

2018-03-21

Nucleosynthetic isotope variability among Solar System objects is often used to probe the genetic relationship between meteorite groups and the rocky planets (Mercury, Venus, Earth and Mars), which, in turn, may provide insights into the building blocks of the Earth-Moon system. Using this approach, it has been inferred that no primitive meteorite matches the terrestrial composition and the protoplanetary disk material from which Earth and the Moon accreted is therefore largely unconstrained. This conclusion, however, is based on the assumption that the observed nucleosynthetic variability of inner-Solar-System objects predominantly reflects spatial heterogeneity. Here we use the isotopic composition of the refractory element calcium to show that the nucleosynthetic variability in the inner Solar System primarily reflects a rapid change in the mass-independent calcium isotope composition of protoplanetary disk solids associated with early mass accretion to the proto-Sun. We measure the mass-independent 48 Ca/ 44 Ca ratios of samples originating from the parent bodies of ureilite and angrite meteorites, as well as from Vesta, Mars and Earth, and find that they are positively correlated with the masses of their parent asteroids and planets, which are a proxy of their accretion timescales. This correlation implies a secular evolution of the bulk calcium isotope composition of the protoplanetary disk in the terrestrial planet-forming region. Individual chondrules from ordinary chondrites formed within one million years of the collapse of the proto-Sun reveal the full range of inner-Solar-System mass-independent 48 Ca/ 44 Ca ratios, indicating a rapid change in the composition of the material of the protoplanetary disk. We infer that this secular evolution reflects admixing of pristine outer-Solar-System material into the thermally processed inner protoplanetary disk associated with the accretion of mass to the proto-Sun. The identical calcium isotope composition of Earth and the Moon reported here is a prediction of our model if the Moon-forming impact involved protoplanets or precursors that completed their accretion near the end of the protoplanetary disk's lifetime.

Isotopic evolution of the protoplanetary disk and the building blocks of Earth and the Moon

NASA Astrophysics Data System (ADS)

Schiller, Martin; Bizzarro, Martin; Fernandes, Vera Assis

2018-03-01

Nucleosynthetic isotope variability among Solar System objects is often used to probe the genetic relationship between meteorite groups and the rocky planets (Mercury, Venus, Earth and Mars), which, in turn, may provide insights into the building blocks of the Earth–Moon system. Using this approach, it has been inferred that no primitive meteorite matches the terrestrial composition and the protoplanetary disk material from which Earth and the Moon accreted is therefore largely unconstrained. This conclusion, however, is based on the assumption that the observed nucleosynthetic variability of inner-Solar-System objects predominantly reflects spatial heterogeneity. Here we use the isotopic composition of the refractory element calcium to show that the nucleosynthetic variability in the inner Solar System primarily reflects a rapid change in the mass-independent calcium isotope composition of protoplanetary disk solids associated with early mass accretion to the proto-Sun. We measure the mass-independent 48Ca/44Ca ratios of samples originating from the parent bodies of ureilite and angrite meteorites, as well as from Vesta, Mars and Earth, and find that they are positively correlated with the masses of their parent asteroids and planets, which are a proxy of their accretion timescales. This correlation implies a secular evolution of the bulk calcium isotope composition of the protoplanetary disk in the terrestrial planet-forming region. Individual chondrules from ordinary chondrites formed within one million years of the collapse of the proto-Sun reveal the full range of inner-Solar-System mass-independent 48Ca/44Ca ratios, indicating a rapid change in the composition of the material of the protoplanetary disk. We infer that this secular evolution reflects admixing of pristine outer-Solar-System material into the thermally processed inner protoplanetary disk associated with the accretion of mass to the proto-Sun. The identical calcium isotope composition of Earth and the Moon reported here is a prediction of our model if the Moon-forming impact involved protoplanets or precursors that completed their accretion near the end of the protoplanetary disk’s lifetime.

The Development of Solar Sail Propulsion for NASA Science Missions to the Inner Solar System

NASA Technical Reports Server (NTRS)

Montgomery, Edward E, IV; Johnson, Charles Les

2004-01-01

This paper examines recent assessments of the technology challenges facing solar sails, identifies the systems and technologies needing development, and the approach employed by NASA's In-space Propulsion Program in NASA to achieve near term products that move this important technology from low technology readiness level (TRL) toward the goal of application to science missions in near earth space and beyond. The status of on-going efforts to design, build, and test ground demonstrators of alternate approaches to structures (inflatable versus rigid), membrane materials, optical shape sensing, and attitude control will be presented along with planned future investments.

Comet 81P/wild 2 under a microscope

USGS Publications Warehouse

Brownlee, D.; Tsou, P.; Aleon, J.; O'D, Alexander; Araki, T.; Bajt, S.; Baratta, G.A.; Bastien, R.; Bland, P.; Bleuet, P.; Borg, J.; Bradley, J.P.; Brearley, A.; Brenker, F.; Brennan, S.; Bridges, J.C.; Browning, N.D.; Brucato, J.R.; Bullock, E.; Burchell, M.J.; Busemann, H.; Butterworth, Anna L.; Chaussidon, M.; Cheuvront, A.; Chi, M.; Cintala, M.J.; Clark, B. C.; Clemett, S.J.; Cody, G.; Colangeli, L.; Cooper, G.; Cordier, P.; Daghlian, C.; Dai, Z.; D'Hendecourt, L.; Djouadi, Z.; Dominguez, G.; Duxbury, T.; Dworkin, J.P.; Ebel, D.S.; Economou, T.E.; Fakra, S.; Fairey, S.A.J.; Fallon, S.; Ferrini, G.; Ferroir, T.; Fleckenstein, H.; Floss, C.; Flynn, G.; Franchi, I.A.; Fries, M.; Gainsforth, Z.; Gallien, J.-P.; Genge, M.; Gilles, M.K.; Gillet, P.; Gilmour, J.; Glavin, D.P.; Gounelle, M.; Grady, M.M.; Graham, G.A.; Grant, P.G.; Green, S.F.; Grossemy, F.; Grossman, L.; Grossman, J.N.; Guan, Y.; Hagiya, K.; Harvey, R.; Heck, P.; Herzog, G.F.; Hoppe, P.; Horz, F.; Huth, J.; Hutcheon, I.D.; Ignatyev, K.; Ishii, H.; Ito, M.; Jacob, D.; Jacobsen, C.; Jacobsen, S.; Jones, S.; Joswiak, D.; Jurewicz, A.; Kearsley, A.T.; Keller, L.P.; Khodja, H.; Kilcoyne, A.L.D.; Kissel, J.; Krot, A.; Langenhorst, F.; Lanzirotti, A.; Le, L.; Leshin, L.A.; Leitner, J.; Lemelle, L.; Leroux, H.; Liu, M.-C.; Luening, K.; Lyon, I.; MacPherson, G.; Marcus, M.A.; Marhas, K.; Marty, B.; Matrajt, G.; McKeegan, K.; Meibom, A.; Mennella, V.; Messenger, K.; Messenger, S.; Mikouchi, T.; Mostefaoui, S.; Nakamura, T.; Nakano, T.; Newville, M.; Nittler, L.R.; Ohnishi, I.; Ohsumi, K.; Okudaira, K.; Papanastassiou, D.A.; Palma, R.; Palumbo, M.E.; Pepin, R.O.; Perkins, D.; Perronnet, M.; Pianetta, P.; Rao, W.; Rietmeijer, F.J.M.; Robert, F.; Rost, D.; Rotundi, A.; Ryan, R.; Sandford, S.A.; Schwandt, C.S.; See, T.H.; Schlutter, D.; Sheffield-Parker, J.; Simionovici, A.; Simon, S.; Sitnitsky, I.; Snead, C.J.; Spencer, M.K.; Stadermann, F.J.; Steele, A.; Stephan, T.

2006-01-01

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.

Organic matter in carbonaceous meteorites: past, present and future research.

PubMed

Sephton, Mark A

2005-12-15

Carbonaceous meteorites are fragments of ancient asteroids that have remained relatively unprocessed since the formation of the Solar System. These carbon-rich objects provide a record of prebiotic chemical evolution and a window on the early Solar System. Many compound classes are present reflecting a rich organic chemical environment during the formation of the planets. Recent theories suggest that similar extraterrestrial organic mixtures may have acted as the starting materials for life on Earth.

The spectroscopic characterization of newly developed emissive materials and the effects of environment on their photophysical properties

NASA Astrophysics Data System (ADS)

McNamara, Louis Edward, III

The development of new materials capable of efficient charge transfer and energy storage has become increasingly important in many areas of modern chemical research. This is especially true for the development of emissive optoelectronic devices and in the field of solar to electric energy conversion. The characterization of the photophysical properties of new molecular systems for these applications has become critical in the design and development of these materials. Many molecular building blocks have been developed and understanding the properties of these molecules at a fundamental level is essential for their successful implementation and future engineering. This dissertation focuses on the characterization of some of these newly-developed molecular systems. The spectroscopic studies focus on the characterization of newly-developed molecules based on perylene and indolizine derivatives for solar to electric energy conversion, thienopyrazine derivatives for near infrared (NIR) emissive applications, an SCS pincer complex for blue emissive materials and a fluorescent probe for medical applications. The effects of noncovalent interactions are also investigated on these systems and a benchmark biological molecule trimethylamine N-oxide (TMAO).

Solar-Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2001-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Solar-Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Solar Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Space station solar concentrator materials research

NASA Technical Reports Server (NTRS)

Gulino, Daniel A.

1988-01-01

The Space Station will represent the first time that a solar dynamic power system will be used to generate electrical power in space. In a system such as this, sunlight is collected and focused by a solar concentrator onto the receiver of a heat engine which converts the energy into electricity. The concentrator must be capable of collecting and focusing as much of the incident sunlight as possible, and it must also withstand the atomic oxygen bombardment which occurs in low Earth orbit (LEO). This has led to the development of a system of thin film coatings applied to the concentrator facet surface in a chamber designed especially for this purpose. The system of thin film coatings employed gives both the necessary degree of reflectance and the required protection from the LEO atomic oxygen environment.

Development of an innovative solar absorber

NASA Astrophysics Data System (ADS)

Goodchild, Gavin

Solar thermal systems have great potential to replace or reduce the dependence of conventional fossil fuel based heating technologies required for space and water heating. Specifically solar domestic hot water systems can contribute 50-75% of the annual thermal load. To date residential users have been slow to purchase and install systems, primarily due to the large monetary investment required to purchase and install a system. Recent innovations in materials design and manufacturing techniques, offer opportunities for the development of absorber plate designs that have the potential to reduce cost, increase efficiency and reduce payback periods. Consequently, this design study was conducted in conjunction with industrial partners to develop an improved absorber based on roll bond manufacturing that can be produced at reduced cost with comparable or greater thermal efficiency.

Embedding solar cell materials with on-board integrated energy storage for load-leveling and dark power delivery (Presentation Recording)

NASA Astrophysics Data System (ADS)

Pint, Cary L.; Westover, Andrew S.; Cohn, Adam P.; Erwin, William R.; Share, Keith; Metke, Thomas; Bardhan, Rizia

2015-10-01

This work will discuss our recent advances focused on integrating high power energy storage directly into the native materials of both conventional photovoltaics (PV) and dye-sensitized solar cells (DSSCs). In the first case (PV), we demonstrate the ability to etch high surface-area porous silicon charge storage interfaces directly into the backside of a conventional polycrystalline silicon photovoltaic device exhibiting over 14% efficiency. These high surface area materials are then coupled with solid-state ionic liquid-polymer electrolytes to produce solid-state fully integrated devices where the PV device can directly inject charge into an on-board supercapacitor that can be separately discharged under dark conditions with a Coulombic efficiency of 84%. In a similar manner, we further demonstrate that surface engineered silicon materials can be utilized to replace Pt counterelectrodes in conventional DSSC energy conversion devices. As the silicon counterelectrodes rely strictly on surface Faradaic chemical reactions with the electrolyte on one side of the wafer electrode, we demonstrate double-sided processing of electrodes that enables dual-function of the material for simultaneous energy storage and conversion, each on opposing sides. In both of these devices, we demonstrate the ability to produce an all-silicon coupled energy conversion and storage system through the common ability to convert unused silicon in solar cells into high power silicon-based supercapacitors. Beyond the proof-of-concept design and performance of this integrated solar-storage system, this talk will conclude with a brief discussion of the hurdles and challenges that we envision for this emerging area both from a fundamental and technological viewpoint.

High throughput parallel backside contacting and periodic texturing for high-efficiency solar cells

DOEpatents

Daniel, Claus; Blue, Craig A.; Ott, Ronald D.

2014-08-19

Disclosed are configurations of long-range ordered features of solar cell materials, and methods for forming same. Some features include electrical access openings through a backing layer to a photovoltaic material in the solar cell. Some features include textured features disposed adjacent a surface of a solar cell material. Typically the long-range ordered features are formed by ablating the solar cell material with a laser interference pattern from at least two laser beams.

Low cost solar array project. Task 1: Silicon material, gaseous melt replenishment system

NASA Technical Reports Server (NTRS)

Jewett, D. N.; Bates, H. E.; Hill, D. M.

1979-01-01

A system to combine silicon formation, by hydrogen reduction of trichlorosilane, with the capability to replenish a crystal growth system is described. A variety of process parameters to allow sizing and specification of gas handling system components was estimated.

Experimental study of efficiency of solar panel by phase change material cooling

NASA Astrophysics Data System (ADS)

Wei, Nicholas Tan Jian; Nan, Wong Jian; Guiping, Cheng

2017-07-01

The dependence of efficiency of photovoltaic panels on their temperature during operation is a major concern for developers and users. In this paper, a phase change material (PCM) cooling system was designed for a 60W mono-crystalline solar panel. Tealights candle was selected as the cooling medium. The solar irradiance was recorded using Kipp & Zonen CMP3 pyranometer and Meteon data logger. Temperature distribution on the surface of solar panel, output voltage and output current of solar panel were measured. The average irradiance throughout data collection was found to be 705W/m2 and highest irradiance was 1100 W/m2. The average solar panel temperature was 43.6°C and a maximum temperature of 53°C was at the center of solar panel. Results showed that average power output and efficiency of the solar panel were 44.4W and 15%, respectively. It was found that the higher the solar irradiance, the lower the efficiency of solar panel and the higher the temperature and power output of solar panel. This is due to the fact that high irradiance results in high power input and high solar panel temperature. But high PV panel temperature reduces its power output. Therefore, the increase of power input outweighs that of power output, which leads to the decrease of efficiency of solar panel with the increase of solar irradiance. Compared with solar panel without cooling, the power output and efficiency of solar panel did not increase with PCM cooling. It indicates that Tealights candle as PCM cooling is not efficient in improving the efficiency of solar panel in this study.

Extraterrestrial organic matter: a review

NASA Technical Reports Server (NTRS)

Irvine, W. M.

1998-01-01

We review the nature of the widespread organic material present in the Milky Way Galaxy and in the Solar System. Attention is given to the links between these environments and between primitive Solar System objects and the early Earth, indicating the preservation of organic material as an interstellar cloud collapsed to form the Solar System and as the Earth accreted such material from asteroids, comets and interplanetary dust particles. In the interstellar medium of the Milky Way Galaxy more than 100 molecular species, the bulk of them organic, have been securely identified, primarily through spectroscopy at the highest radio frequencies. There is considerable evidence for significantly heavier organic molecules, particularly polycyclic aromatics, although precise identification of individual species has not yet been obtained. The so-called diffuse interstellar bands are probably important in this context. The low temperature kinetics in interstellar clouds leads to very large isotopic fractionation, particularly for hydrogen, and this signature is present in organic components preserved in carbonaceous chondritic meteorites. Outer belt asteroids are the probable parent bodies of the carbonaceous chondrites, which may contain as much as 5% organic material, including a rich variety of amino acids, purines, pyrimidines, and other species of potential prebiotic interest. Richer in volatiles and hence less thermally processed are the comets, whose organic matter is abundant and poorly characterized. Cometary volatiles, observed after sublimation into the coma, include many species also present in the interstellar medium. There is evidence that most of the Earth's volatiles may have been supplied by a 'late' bombardment of comets and carbonaceous meteorites, scattered into the inner Solar System following the formation of the giant planets. How much in the way of intact organic molecules of potential prebiotic interest survived delivery to the Earth has become an increasingly debated topic over the last several years. The principal source for such intact organics was probably accretion of interplanetary dust particles of cometary origin.

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

DOE PAGES

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit; ...

2017-06-12

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two geneticallymore » distinct nebular reservoirs that coexisted and remained spatially separated between ~1 My and ~3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ~20 Earth masses within <1 My, followed by a more protracted growth to ~50 Earth masses until at least ~3–4 My after Solar System formation. Furthermore, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.« less

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

NASA Astrophysics Data System (ADS)

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit; Kleine, Thorsten

2017-06-01

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ˜1 My and ˜3-4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ˜20 Earth masses within <1 My, followed by a more protracted growth to ˜50 Earth masses until at least ˜3-4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

PubMed Central

Kruijer, Thomas S.; Burkhardt, Christoph; Kleine, Thorsten

2017-01-01

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ∼1 My and ∼3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ∼20 Earth masses within <1 My, followed by a more protracted growth to ∼50 Earth masses until at least ∼3–4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation. PMID:28607079

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two geneticallymore » distinct nebular reservoirs that coexisted and remained spatially separated between ~1 My and ~3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ~20 Earth masses within <1 My, followed by a more protracted growth to ~50 Earth masses until at least ~3–4 My after Solar System formation. Furthermore, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.« less

Age of Jupiter inferred from the distinct genetics and formation times of meteorites.

PubMed

Kruijer, Thomas S; Burkhardt, Christoph; Budde, Gerrit; Kleine, Thorsten

2017-06-27

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ∼1 My and ∼3-4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter's core grew to ∼20 Earth masses within <1 My, followed by a more protracted growth to ∼50 Earth masses until at least ∼3-4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.

Kinetic isotopic fractionation and the origin of HDO and CH3D in the solar system

NASA Technical Reports Server (NTRS)

Yung, Yuk L.; Wen, Jun-Shan; Friedl, Randall R.; Pinto, Joseph P.; Bayes, Kyle D.

1988-01-01

It is suggested that photochemical enrichment processes driven by stellar UV emissions could result in a large deuterium fractionation of water and methane relative to H2 in the primitive solar nebula. These enrichment processes could have profoundly influenced the isotopic content of water in the terrestrial planets, if a large fraction of their volatiles had been added by impacts of meteorites and comets formed in the outer parts of the solar nebula. Efficient mixing could have exposed the material in the interior of the solar nebula to starlight.

Ternary Oxides in the TiO2-ZnO System as Efficient Electron-Transport Layers for Perovskite Solar Cells with Efficiency over 15.

PubMed

Yin, Xiong; Xu, Zhongzhong; Guo, Yanjun; Xu, Peng; He, Meng

2016-11-02

Perovskite solar cells, which utilize organometal-halide perovskites as light-harvesting materials, have attracted great attention due to their high power conversion efficiency (PCE) and potentially low cost in fabrication. A compact layer of TiO 2 or ZnO is generally applied as electron-transport layer (ETL) in a typical perovskite solar cell. In this study, we explored ternary oxides in the TiO 2 -ZnO system to find new materials for the ETL. Compact layers of titanium zinc oxides were readily prepared on the conducting substrate via spray pyrolysis method. The optical band gap, valence band maximum and conduction band minimum of the ternary oxides varied significantly with the ratio of Ti to Zn, surprisingly, in a nonmonotonic way. When a zinc-rich ternary oxide was applied as ETL for the device, a PCE of 15.10% was achieved, comparable to that of the device using conventional TiO 2 ETL. Interestingly, the perovskite layer deposited on the zinc-rich ternary oxide is stable, in sharp contrast with that fabricated on a ZnO layer, which will turn into PbI 2 readily when heated. These results indicate that potentially new materials with better performance can be found for ETL of perovskite solar cells in ternary oxides, which deserve more exploration.

Concentration of solar radiation by white painted transparent plates.

PubMed

Smestad, G; Hamill, P

1982-04-01

A simple flat-plate solar concentrator is described in this paper. The device is composed of a white painted transparent plate with a photovoltaic cell fixed to an unpainted area on the bottom of the plate. Light scattering off the white material is either lost or directed to the solar cell. Experimental concentrations of up to 1.9 times the incident solar flux have been achieved using white clays. These values are close to those predicted by theory for the experimental parameters investigated. A theory of the device operation is developed. Using this theory suggestions are made for optimizing the concentrator system. For reasonable choices of cell and plate size and reflectivities of 80% concentrations of over 2x are possible. The concentrator has the advantage over other systems in that the concentration is independent of incidence angle and the concentrator is easy to produce. The device needs no tracking system and will concentrate on a cloudy day.

Development of an integrated heat pipe-thermal storage system for a solar receiver

NASA Technical Reports Server (NTRS)

Keddy, E. S.; Sena, J. T.; Merrigan, M. A.; Heidenreich, G.; Johnson, S.

1987-01-01

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

The Moon as a Recorder of Organic Evolution in the Early Solar System: A Lunar Regolith Analog Study

PubMed Central

Court, Richard W.; Crawford, Ian A.; Jones, Adrian P.; Joy, Katherine H.; Sephton, Mark A.

2015-01-01

Abstract The organic record of Earth older than ∼3.8 Ga has been effectively erased. Some insight is provided to us by meteorites as well as remote and direct observations of asteroids and comets left over from the formation of the Solar System. These primitive objects provide a record of early chemical evolution and a sample of material that has been delivered to Earth's surface throughout the past 4.5 billion years. Yet an effective chronicle of organic evolution on all Solar System objects, including that on planetary surfaces, is more difficult to find. Fortunately, early Earth would not have been the only recipient of organic matter–containing objects in the early Solar System. For example, a recently proposed model suggests the possibility that volatiles, including organic material, remain archived in buried paleoregolith deposits intercalated with lava flows on the Moon. Where asteroids and comets allow the study of processes before planet formation, the lunar record could extend that chronicle to early biological evolution on the planets. In this study, we use selected free and polymeric organic materials to assess the hypothesis that organic matter can survive the effects of heating in the lunar regolith by overlying lava flows. Results indicate that the presence of lunar regolith simulant appears to promote polymerization and, therefore, preservation of organic matter. Once polymerized, the mineral-hosted newly formed organic network is relatively protected from further thermal degradation. Our findings reveal the thermal conditions under which preservation of organic matter on the Moon is viable. Key Words: Moon—Regolith—Organic preservation—Biomarkers. Astrobiology 15, 154–168. PMID:25615648

Extraterrestrial fiberglass production using solar energy. [lunar plants or space manufacturing facilities

NASA Technical Reports Server (NTRS)

Ho, D.; Sobon, L. E.

1979-01-01

A conceptual design is presented for fiberglass production systems in both lunar and space environments. The raw material, of lunar origin, will be plagioclase concentrate, high silica content slag, and calcium oxide. Glass will be melted by solar energy. The multifurnace in the lunar plant and the spinning cylinder in the space plant are unique design features. Furnace design appears to be the most critical element in optimizing system performance. A conservative estimate of the total power generated by solar concentrators is 1880 kW; the mass of both plants is 120 tons. The systems will reproduce about 90 times their total mass in fiberglass in 1 year. A new design concept would be necessary if glass rods were produced in space.

Primitive Fine-Grained Matrix in the Unequilbrated Enstatite Chondrites

NASA Technical Reports Server (NTRS)

Weisberg, M. K.; Zolensky, M. E.; Kimura, M.; Ebel, D. S.

2014-01-01

Enstatite chondrites (EC) have important implications for constraining conditions in the early solar system and for understanding the evolution of the Earth and other inner planets. They are among the most reduced solar system materials as reflected in their mineral compositions and assemblage. They are the only chondrites with oxygen as well as Cr, Ti, Ni and Zn stable isotope compositions similar to the earth and moon and most are completely dry, lacking any evidence of hydrous alteration; the only exception are EC clasts in the Kaidun breccia which have hydrous minerals. Thus, ECs likely formed within the snow line and are good candidates to be building blocks of the inner planets. Our goals are to provide a more detailed characterization the fine-grained matrix in E3 chondrites, understand its origin and relationship to chondrules, decipher the relationship between EH and EL chondrites and compare E3 matrix to matrices in C and O chondrites as well as other fine-grained solar system materials. Is E3 matrix the dust remaining from chondrule formation or a product of parent body processing or both?

The Air Force concentrating photovoltaic array program

NASA Technical Reports Server (NTRS)

Geis, Jack W.

1987-01-01

A summary is given of Air Force solar concentrator projects beginning with the Rockwell International study program in 1977. The Satellite Materials Hardening Programs (SMATH) explored and developed techniques for hardening planar solar cell array power systems to the combined nuclear and laser radiation threat environments. A portion of program dollars was devoted to developing a preliminary design for a hardened solar concentrator. The results of the Survivable Concentrating Photovoltaic Array (SCOPA) program, and the design, fabrication and flight qualification of a hardened concentrator panel are discussed.

Development of an all-metal thick film cost effective metallization system for solar cells

NASA Technical Reports Server (NTRS)

Ross, B.; Parker, J.

1983-01-01

Improved thick film solar cell contacts for the high volume production of low cost silicon solar arrays are needed. All metal screenable pastes made from economical base metals and suitable for application to low to high conductivity silicon were examined. Silver fluoride containing copper pastes and fluorocarbon containing copper pastes were discussed. The effect of hydrogen on the adhesion of metals to silicon was investigated. A cost analysis of various paste materials is provided.

Delivery of Volatiles to Habitable Planets in Extrasolar Planetary Systems

NASA Technical Reports Server (NTRS)

Chambers, John E.; Kress, Monika E.; Bell, K. Robbins; Cash, Michele; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

The Earth can support life because: (1) its orbit lies in the Sun's habitable zone', and (2) it contains enough volatile material (e.g. water and organics) for life to flourish. However, it seems likely that the Earth was drier when it formed because it accreted in a part of the Sun's protoplanetary nebula that was too hot for volatiles to condense. If this is correct, water and organics must have been delivered to the habitable zone, after dissipation of the solar nebula, from a 'wet zone' in the asteroid belt or the outer solar system, where the nebula was cool enough for volatiles to condense. Material from the wet zone would have been delivered to the Earth by Jupiter and Saturn. Gravitational perturbations from these giant planets made much of the wet zone unstable, scattering volatile-rich planetesimals and protoplanets across the Solar System. Some of these objects ultimately collided with the inner Planets which themselves lie in a stable part of the Solar System. Giant planets are now being discovered orbiting other sunlike stars. To date, these planets have orbits and masses very different from Jupiter and Saturn, such that few if any of these systems is likely to have terrestrial planets in the star's habitable zone. However, new discoveries are anticipated due to improved detector sensitivity and the increase in the timespan of observations. Here we present numerical experiments examining the range of giant-planet characteristics that: (1) allow stable terrestrial Planets to exist in a star's habitable zone, and (2) make a large part of the star's wet zone weakly unstable, thus delivering volatiles to the terrestrial planets over an extended period of time after the dissipation of the solar nebula.

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

NASA Technical Reports Server (NTRS)

Hopkins, R. H.; Davis, J. R.; Rai-Choudhury, P.; Blais, P. D.; Mccormick, J. R.

1976-01-01

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.

Beeswax as phase change material to improve solar panel’s performance

NASA Astrophysics Data System (ADS)

Thaib, R.; Rizal, S.; Riza, M.; Mahlia, T. M. I.; Rizal, T. A.

2018-02-01

One of the main obstacles faced during the operation of photovoltaic (PV) panels was overheating due to excessive solar radiation and high ambient temperatures. In this research, investigates the use of beeswax phase change materials (PCM) to maintain the temperature of the panels close to ambient. Solar panels used in this study has 839 mm length, 537 mm wide, and 50 mm thick, with maximum output power at 50 W. During the study, there were two solar panels was evaluated, one without phase change material while the other one was using beeswax phase change material. Solar panels were mounted at 15° slope. Variables observed was the temperature of solar panel’s surface, output voltage and current that produced by PV panels, wind speed around solar panels, and solar radiation. The observation was started at 07:00 am and ended at 06:00 pm. The research shows that maximum temperature of solar panels surface without phase change material is ranging between 46-49 °C, and electrical efficiency is about 7.2-8.8%. Meanwhile, for solar panels with beeswax phase change material, the maximum temperature solar panels surface is relatively low ranging between 33-34 °C, and its electrical efficiency seems to increase about 9.1-9.3%.

Photovoltaic module encapsulation design and materials selection, volume 1

NASA Technical Reports Server (NTRS)

Cuddihy, E.; Carroll, W.; Coulbert, C.; Gupta, A.; Liang, R. H.

1982-01-01

Encapsulation material system requirements, material selection criteria, and the status and properties of encapsulation materials and processes available are presented. Technical and economic goals established for photovoltaic modules and encapsulation systems and their status are described. Available encapsulation technology and data are presented to facilitate design and material selection for silicon flat plate photovoltaic modules, using the best materials available and processes optimized for specific power applications and geographic sites. The operational and environmental loads that encapsulation system functional requirements and candidate design concepts and materials that are identified to have the best potential to meet the cost and performance goals for the flat plate solar array project are described. Available data on encapsulant material properties, fabrication processing, and module life and durability characteristics are presented.

Japanese Exploration to Solar System Small Bodies: Rewriting a Planetary Formation Theory with Astromaterial Connection (Invited)

NASA Astrophysics Data System (ADS)

Yano, H.

2013-12-01

Three decades ago, Japan's deep space exploration started with Sakigake and Suisei, twin flyby probes to P/Halley. Since then, the Solar System small bodies have been one of focused destinations to the Japanese solar system studies even today. Only one year after the Halley armada launch, the very first meeting was held for an asteroid sample return mission at ISAS, which after 25 years, materialized as the successful Earth return of Hayabusa , an engineering verification mission for sample return from surfaces of an NEO for the first time in the history. Launched in 2003 and returned in 2010, Hayabusa became the first to visit a sub-km, rubble-pile potentially hazardous asteroid in near Earth space. Its returned samples solved S-type asteroid - ordinary chondrite paradox by proving space weathering evidences in sub-micron scale. Between the Halley missions and Hayabusa, SOCCER concept by M-V rocket was jointly studied between ISAS and NASA; yet it was not realized due to insufficient delta-V for intact capture by decelerating flyby/encounter velocity to a cometary coma. The SOCCER later became reality as Stardust, NASA Discovery mission for cometary coma dust sample return in1999-2006. Japan has collected the second largest collection of the Antarctic meteorites and micrometeorites of the world and asteromaterial scientists are eager to collaborate with space missions. Also Japan enjoyed a long history of collaborations between professional astronomers and high-end amateur observers in the area of observational studies of asteroids, comets and meteors. Having these academic foundations, Japan has an emphasis on programmatic approach to sample returns of Solar System small bodies in future prospects. The immediate follow-on to Hayabusa is Hayabusa-2 mission to sample return with an artificial impactor from 1999 JU3, a C-type NEO in 2014-2020. Following successful demonstration of deep space solar sail technique by IKAROS in 2010-2013, the solar power sail is a deep space probe with hybrid propulsion of solar photon sail and ion engine system that will enable Japan to reach out deep interplanetary space beyond the main asteroid belt. Since 2002, Japanese scientists and engineers have been investigating the solar power sail mission to Jupiter Trojans and interdisciplinary cruising science, such as infrared observation of zodiacal light due to cosmic dust, which at the same time hit a large cross section of the solar sail membrane dust detector, concentrating inside the main asteroid belt. Now the mission design has extended from cruising and fly-by only to rendezvous and sample return options from Jupiter Trojan asteroids. Major scientific goal of Jupiter Trojan exploration is to constrain its origin between two competing hypothesis such as remnants of building blocks the Jovian system as the classic model and the second generation captured EKBOs as the planetary migration models, in which several theories are in deep discussion. Also important is to better understand mixing process of material and structure of the early Solar System just beyond snow line. The current plan involves its launch and both solar photon and IES accelerations combined with Earth and Jupiter gravity assists in 2020's, detailed rendezvous investigation of a few 10-km sized D-type asteroid among Jupiter Trojans in early 2030's and an optional sample return of its surface materials to the Earth in late 2030's.

Materials and systems for unassisted photoelectrochemical solar fuels production (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lee, Jae Sung

2016-10-01

About 400 semiconductor solids are known to have photocatalytic activity for water splitting. Yet there is no single material that could satisfy all the requirements for desired photocatalysts: i) suitable band gap energy (1.7 eV< Eg < 2.3 eV) for high efficiency, ii) proper band position for reduction and/or oxidation of water, iii) long-term stability in aqueous solutions, iv) low cost, v) high crystallinity, and vi) high conductivity. Hence, in the selection of photocatalytic materials, we better start from intrinsically stable materials made of earth-abundant elements. The band bap energy is also the primary consideration to absorb ample amount of solar energy of wide wavelength spectrum. It sets the limit of theoretically maximum efficiency and it could also be extended by band engineering techniques. Upon selection of the candidate materials, we can also modify the materials for full utilization their potentials. The main path of efficiency loss in PEC water splitting process is recombination of photoelectrons and holes. We discuss the material designs including i) p-n heterojunction photoanodes for effective electron-hole separation, ii) electron highway to facilitate interparticle electron transfer, iii) metal or anion doping to improve conductivity of the semiconductor and to extend the range of light absorption, iv) one-dimensional nanomaterials to secure a short hole diffusion distance and vectoral electron transfer, and v) loading co-catalysts for facile charge separation. High efficiency has been demonstrated for all these examples due to efficient electron-hole separation. Finally, total systems for unassisted solar fuel production are demonstrated.

The feasibility of solar reflector production from lunar materials for solar power in space

NASA Technical Reports Server (NTRS)

1990-01-01

Science Applications International Corporation (SAIC) investigated the feasibility of producing solar reflectors from indigenous lunar materials for solar power production on the moon. First, lunar construction materials and production processes were reviewed, and candidate materials for reflector production were identified. At the same time, lunar environmental conditions were reviewed for their effect on production of concentrators. Next, conceptual designs and fabrication methods were proposed and studied for production of dish concentrators and heliostats. Finally, fabrication testing was performed on small-scale models using earth analogs of lunar materials. Findings from this initial investigation indicate that production of concentrators from lunar materials may be an attractive approach for solar energy production on the moon. Further design and testing are required to determine the best techniques and approaches to optimize this concept. Four materials were identified as having high potential for solar reflector manufacture. These baseline materials were foamed glass, concrete with glass-fiber reinforcement, a glass-fiber/glass-melt composite, and an iron-glass sintered material.

Cosmochemical evidence for astrophysical processes during the formation of our solar system.

PubMed

MacPherson, Glenn J; Boss, Alan

2011-11-29

Through the laboratory study of ancient solar system materials such as meteorites and comet dust, we can recognize evidence for the same star-formation processes in our own solar system as those that we can observe now through telescopes in nearby star-forming regions. High temperature grains formed in the innermost region of the solar system ended up much farther out in the solar system, not only the asteroid belt but even in the comet accretion region, suggesting a huge and efficient process of mass transport. Bi-polar outflows, turbulent diffusion, and marginal gravitational instability are the likely mechanisms for this transport. The presence of short-lived radionuclides in the early solar system, especially (60)Fe, (26)Al, and (41)Ca, requires a nearby supernova shortly before our solar system was formed, suggesting that the Sun was formed in a massive star-forming region similar to Orion or Carina. Solar system formation may have been "triggered" by ionizing radiation originating from massive O and B stars at the center of an expanding HII bubble, one of which may have later provided the supernova source for the short-lived radionuclides. Alternatively, a supernova shock wave may have simultaneously triggered the collapse and injected the short-lived radionuclides. Because the Sun formed in a region where many other stars were forming more or less contemporaneously, the bi-polar outflows from all such stars enriched the local region in interstellar silicate and oxide dust. This may explain several observed anomalies in the meteorite record: a near absence of detectable (no extreme isotopic properties) presolar silicate grains and a dichotomy in the isotope record between (26)Al and nucleosynthetic (nonradiogenic) anomalies.

Cosmochemical evidence for astrophysical processes during the formation of our solar system

PubMed Central

MacPherson, Glenn J.; Boss, Alan

2011-01-01

Through the laboratory study of ancient solar system materials such as meteorites and comet dust, we can recognize evidence for the same star-formation processes in our own solar system as those that we can observe now through telescopes in nearby star-forming regions. High temperature grains formed in the innermost region of the solar system ended up much farther out in the solar system, not only the asteroid belt but even in the comet accretion region, suggesting a huge and efficient process of mass transport. Bi-polar outflows, turbulent diffusion, and marginal gravitational instability are the likely mechanisms for this transport. The presence of short-lived radionuclides in the early solar system, especially 60Fe, 26Al, and 41Ca, requires a nearby supernova shortly before our solar system was formed, suggesting that the Sun was formed in a massive star-forming region similar to Orion or Carina. Solar system formation may have been “triggered” by ionizing radiation originating from massive O and B stars at the center of an expanding HII bubble, one of which may have later provided the supernova source for the short-lived radionuclides. Alternatively, a supernova shock wave may have simultaneously triggered the collapse and injected the short-lived radionuclides. Because the Sun formed in a region where many other stars were forming more or less contemporaneously, the bi-polar outflows from all such stars enriched the local region in interstellar silicate and oxide dust. This may explain several observed anomalies in the meteorite record: a near absence of detectable (no extreme isotopic properties) presolar silicate grains and a dichotomy in the isotope record between 26Al and nucleosynthetic (nonradiogenic) anomalies. PMID:22106251

Chasing Manxes: Long-Period Comets Without Tails

NASA Astrophysics Data System (ADS)

Stephens, Haynes; Meech, Karen Jean; Kleyna, Jan; Keane, Jacqueline; Hainaut, Olivier; Yang, Bin; Wainscoat, Richard J.; Micheli, Marco; Bhatt, Bhuwan; Sahu, Devendra

2017-10-01

A Manx is a minor body on a long-period comet orbit that is inactive or minimally active at small perihelion distances (where water would be expected to be strongly sublimating), resulting in the lack of a significant tail. These objects are being discovered at a rate of about a dozen per year from large all-sky surveys, and the Pan-STARRS1 telescope in Hawai'i is the most prolific at discovering these weakly active objects. Manxes are theorized to be planetesimals that formed in the inner solar system, perhaps some even in the Earth-forming region, that were subsequently ejected out into the Oort cloud due to the migration of Jupiter and Saturn as the Solar System evolved. We use spectral reflectivities obtained with the Gemini North 8m telescope and ESO's Very Large Telescope to determine the surface composition of these objects. The observed Manxes exhibit a wide variety of surface properties, from primitive materials (i.e. C-, P- or D-types) to anhydrous materials (i.e. S-types). The relative numbers of objects with surface materials that are consistent with relatively dry, rocky inner solar system material may be used to constrain dynamical solar system formation models which make different predictions about the amount and sources of material that gets ejected to the Oort cloud. To date, we have observed 27 Manxes from 2013-2017. Here, we present preliminary results from this survey of spectral reflectivities for various Manxes. In addition, for some of the objects, we have sufficient heliocentric photometry to model the activity in terms of water-ice sublimation and can obtain estimates of the amount of near-surface water in comparison to comets. This work is supported in part by an NSF award AST-1617015, and is based in part on observations obtained at the Gemini Observatory acquired through the Gemini Observatory Archive (GN2015A-FT18, GN2016A-Q15, GN2016A-FT22, GN2016B-Q19, GN-2016B-FT-24, GN-2017A-Q-14) and the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 098.C-0303 and 099.C-0787.

Determining Possible Building Blocks of the Earth and Mars

NASA Technical Reports Server (NTRS)

Burbine, T. H.; OBrien, K. M.

2004-01-01

One of the fundamental questions concerning planetary formation is exactly what material did the planets form from? All the planets in our solar system are believed to have formed out of material from the solar nebula. Chondritic meteorites appear to sample this primitive material. Chondritic meteorites are generally classified into 13 major groups, which have a variety of compositions. Detailed studies of possible building blocks of the terrestrial planets require samples that can be used to estimate the bulk chemistry of these bodies. This study will focus on trying to determine possible building blocks of Earth and Mars since samples of these two planets can be studied in detail in the laboratory.

Design of the Heat Receiver for the U.S./Russia Solar Dynamic Power Joint Flight Demonstration

NASA Technical Reports Server (NTRS)

Strumpf, Hal J.; Krystkowiak, Christopher; Klucher, Beth A.

1996-01-01

A joint U.S./Russia program is being conducted to develop, fabricate, launch, and operate a solar dynamic demonstration system on Space Station Mir. The goal of the program is to demonstrate and confirm that solar dynamic power systems are viable for future space applications such as the International Space Station Alpha The major components of the system include a heat receiver, a closed Brayton cycle power conversion unit, a power conditioning and control unit, a concentrator, a radiator, a thermal control system, and a Space Shuttle Carrier. This paper discusses the design of the heat receiver component. The receiver comprises a cylindrical cavity, the walls of which are lined with a series of tubes running the length of the cavity. The engine working fluid, a mixture of xenon and helium, is heated by the concentrated sunlight incident on these tubes. The receiver incorporates integral thermal storage, using a eutectic mixture of lithium fluoride and calcium difluoride as the thermal storage solid-to-liquid phase change materiaL This thermal storage is required to enable power production during eclipse. The phase change material is contained in a series of individual containment canisters.

Nanocomposites for enhancing current collection in organic solar cells

NASA Astrophysics Data System (ADS)

Peterson, Eric David

The enhancement of charge collection in organic photovoltaics by using nanocomposite materials is investigated. Two such approaches are detailed in this thesis. Chapter 1 addresses the addition of metal nanorods to the PEDOT layer of an organic solar cell in an attempt to focus incident light for better absorption by the polymer layer. Composites designed to facilitate charge transfer from nanoparticles to the polymer/fullerene system are the focus of the second chapter. Chapter 3 details a refinement to the research presented in chapter 2, adding fullerenes to the mix and creating ternary systems and providing an analytical framework for evaluating these systems. The material choices are expanded in chapter 4; we investigate a new, lower band gap conjugated polymer (PCPDTBT) as well as core-shell nanoparticles and how they interact in the system. Results are reported and further avenues of research are suggested.

An Experimental Study on the Effect of Using Fresnel Lenses on the Performance of Solar Stills

NASA Astrophysics Data System (ADS)

Abdelsalam, Tarek I.; Abdel-Mesih, Bahy

The global water concern is mainly about the scarcity of fresh water resources despite the abundance of saline and brackish water in oceans, seas, and underground. Solar desalination offers a worthy solution to produce fresh water by using solar radiation, which also lessens the energy concern by offering a renewable source of energy to alter the consumption of fossil fuels and other non-renewable resources. One of the solar desalination technologies is the solar still system, which is a portable unit capable of producing distilled water by evaporating brackish or saline water by using solar thermal energy. The steam is then condensed on the inside of the glass cover and collected as fresh water. Solar stills are easy to manufacture and install using local materials and workmanship, which suits underprivileged remote communities that face difficulties in finding clean potable water, while locating near a source of saline water. However, efficiency and productivity of solar stills are still feeble when compared to other traditional desalination techniques. As an attempt to overcome these issues, an upgraded system is proposed and tested experimentally to augment the incoming solar radiation falling on the top glass surface of the still by concentrating extra solar radiation to preheat the flowing feedwater to the solar still system. The results of the experimental study showed that the integration of linear Fresnel lenses has approximately tripled the productivity of distilled water and improved efficiency of a solar still, by about 68.76 %, when compared to a conventional non-concentrating solar still.

Vacuum ultraviolet radiation and thermal cycling effects on atomic oxygen protective photovoltaic array blanket materials

NASA Technical Reports Server (NTRS)

Brady, J.; Banks, B.

1990-01-01

The importance of synergistic environmental exposure is demonstrated through the evaluation of DuPont 93-1 in simulated LEO environment. Changes in optical properties, surface condition, and mass loss data are described. The qualitative results indicate the necessity for exposure of materials to a series of simulated LEO environments in order to properly determine synergistic effects and demonstrate the overall LEO durability of candidate materials. It is shown that synergistic effects may occur with vacuum thermal cycling combined with VUV radiation followed by atomic oxygen exposure. Testing the durability of candidate solar array blanket materials in a test sequence with necessary synergistic effects makes it possible to determine the appropriate material for providing structural support and maintaining the proper operating temperature for solar cells in the SSF Photovaltaic Power System.

Highly efficient multiple-layer CdS quantum dot sensitized III-V solar cells.

PubMed

Lin, Chien-Chung; Han, Hau-Vei; Chen, Hsin-Chu; Chen, Kuo-Ju; Tsai, Yu-Lin; Lin, Wein-Yi; Kuo, Hao-Chung; Yu, Peichen

2014-02-01

In this review, the concept of utilization of solar spectrum in order to increase the solar cell efficiency is discussed. Among the three mechanisms, down-shifting effect is investigated in detail. Organic dye, rare-earth minerals and quantum dots are three most popular down-shift materials. While the enhancement of solar cell efficiency was not clearly observed in the past, the advances in quantum dot fabrication have brought strong response out of the hybrid platform of a quantum dot solar cell. A multiple layer structure, including PDMS as the isolation layer, is proposed and demonstrated. With the help of pulse spray system, precise control can be achieved and the optimized concentration can be found.

A global renewable mix with proven technologies and common materials

NASA Astrophysics Data System (ADS)

Ballabrera, J.; Garcia-Olivares, A.; Garcia-Ladona, E.; Turiel, A.

2012-04-01

A global alternative mix to fossil fuels is proposed, based on proven renewable energy technologies that do not use scarce materials. Taking into account the availability of materials, the resulting mix consists of a combination of onshore and offshore wind turbines, concentrating solar power stations, hydroelectricity and wave power devices attached to the offshore turbines. Solar photovoltaic power could contribute to the mix if its dependence on scarce materials is solved. Material requirements are studied for the generation, power transport and for some future transport systems. The order of magnitude of copper, aluminium, neodymium, lithium, nickel, zinc and platinum that might be required for the proposed solution is obtained and compared with available reserves. While the proposed global alternative to fossil fuels seems technically feasible, lithium, nickel and platinum could become limiting materials for future vehicles fleet if no global recycling system were implemented and rechargeable zinc-air batteries could not be developed. As much as 60% of the current copper reserves would have to be employed in the implementation of the proposed solution. Altogether, the availability of materials may become a long-term physical constraint, preventing the continuation of the usual exponential growth of energy consumption.

Optical system design of solar-blind UV target receiver with large FOV

NASA Astrophysics Data System (ADS)

Chen, Yu; Huo, Furong; Zheng, Liqin

2014-11-01

Ultraviolet (UV) radiation of 200nm-300nm waveband from the sun is absorbed by atmosphere, which is often referred to the solar-blind region of the solar spectrum. Solar-blind characteristics of this waveband have important application value in forest-fire prevention, UV security communication, UV corona detection and other aspects. Especially in military fields such as missile warning, the application of solar-blind waveband has developed very rapidly, which is receiving more and more attention recently. In this paper, ZEMAX software is used to design an optical system of solar-blind UV target receiver with waveband 240nm-280nm, with which UV target signal can be detected. The optional materials are very few for UV optical systems to choose from, in which only CaF2 and JGS1 are commonly used. Various aberrations are not easy to be corrected. So it is very difficult to design a good UV system. Besides, doublet or triplet cannot be used in UV optical system considering possible cracking for different thermal expansion coefficients of different materials. So the doublet in initial structure is separated for this reason. During the optimization process, an aspheric surface is used to correct the aberrations. But this surface is removed before the design is finished to save production cost and enhance the precision of fabrication and test, which still keeps the image quality meeting the usage requirements. What we care for is the converging condition for different field of view from the far object on image plane. So this is an energy system. Spot diagram is taken as the evaluation criterion of image quality. The system is composed of 6 lenses with field of view (FOV) 31 degrees. In the final design results, the root mean square (RMS) radius for marginal FOV is less than 6.3 microns, while the value is only 4 microns for zero FOV. Point Spread Function and diffraction encircled energy diagram within the maximum FOV confirms the good performance of system further.

Solar energy system performance evaluation: Seasonal report for Decade 80 House, Tucson, Arizona

NASA Technical Reports Server (NTRS)

1980-01-01

The operational and thermal performance of the Decade 80 solar energy system is described. The system was designed by Cooper Development Association, Inc. with space heating and space cooling to a one-story, single family residence located in Tucson, Arizona. The Decade 80 House was designed and built in the mid-70's to be a showplace/workshop for solar energy utilization. Superior construction techniques, the use of quality materials and a full time maintenance staff have served to make the entire system an outstanding example of the application of solar energy for residential purposes. The luxury of a full time, on-site maintenance person is perhaps the single most important aspect of this program. While most installations cannot support this level of maintenance, it was very useful in keeping all subsystems operating in top form and allowing for a full season data collection to be obtained. Several conclusions were drawn from the long term monitoring effort, among which are: (1) flat plate collectors will support cooling; (2) definite energy savings can be realized; and (3) more frequent periodic maintenance may be required on solar energy systems that are not custom built.

The carbon budget in the outer solar nebula.

PubMed

Simonelli, D P; Pollack, J B; McKay, C P; Reynolds, R T; Summers, A L

1989-01-01

Detailed models of the internal structures of Pluto and Charon, assuming rock and water ice as the only constituents, indicate that the mean silicate mass fraction of this two-body system is on the order of 0.7; thus the Pluto/Charon system is significantly "rockier" than the satellites of the giant planets (silicate mass fraction approximately 0.55). This compositional contrast reflects different formation mechanisms: it is likely that Pluto and Charon formed directly from the solar nebula, while the circumplanetary nebulae that produced the giant planet satellites were derived from envelopes that surrounded the forming giant planets (envelopes in which icy planetesimals dissolved more readily than rocky planetesimals). Simple cosmic abundance calculations, and the assumption that the Pluto/Charon system formed directly from solar nebula condensates, strongly suggest that the majority of the carbon in the outer solar nebula was in the form of carbon monoxide; these results are consistent with (1) inheritance from the dense molecular clouds in the interstellar medium (where CH4/CO < 10(-2) in the gas phase) and/or (2) of the Lewis and Prinn kinetic inhibition model of solar nebula chemistry. Theoretical predictions of the C/H enhancements in the atmospheres of the giant planets, when compared to the actual observed enhancements, suggest that 10%, or slightly more, of the carbon in the outer solar nebula was in the form of condensed materials (although the amount of condensed C may have dropped slightly with increasing heliocentric distance). Strict compositional limits computed for the Pluto/Charon system using the densities of CH4 and CO ices indicate that these pure ices are at best minor components in the interiors of these bodies, and imply that CH4 and CO ices were not the dominant C-bearing solids in the outer nebula. Clathrate-hydrates could not have appropriated enough CH4 or CO to be the major form of condensed carbon, although such clathrates may be necessary to explain the presence of methane on Pluto after its formation from a CO-rich nebula. Laboratory studies of carbonaceous chondrites, and spacecraft observations of Comet Halley, strongly suggest that of the remaining possibilities, organic material, rather than elemental carbon, is the most likely candidate for the dominant C-bearing solid in the outer solar nebula. We conclude that the majority of the carbon in the outer solar nebula was in gaseous CO; 10% to a few tens of percent of the C was in condensed organic materials; and at least a trace amount of carbon was in methane gas.

Materials, Structures and Manufacturing: An Integrated Approach to Develop Expandable Structures

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Zander, Martin E.; Sleight, Daid W.; Connell, John; Holloway, Nancy; Palmieri, Frank

2012-01-01

Membrane dominated space structures are lightweight and package efficiently for launch; however, they must be expanded (deployed) in-orbit to achieve the desired geometry. These expandable structural systems include solar sails, solar power arrays, antennas, and numerous other large aperture devices that are used to collect, reflect and/or transmit electromagnetic radiation. In this work, an integrated approach to development of thin-film damage tolerant membranes is explored using advanced manufacturing. Bio-inspired hierarchical structures were printed on films using additive manufacturing to achieve improved tear resistance and to facilitate membrane deployment. High precision, robust expandable structures can be realized using materials that are both space durable and processable using additive manufacturing. Test results show this initial work produced higher tear resistance than neat film of equivalent mass. Future research and development opportunities for expandable structural systems designed using an integrated approach to structural design, manufacturing, and materials selection are discussed.

Silicon dendritic web material

NASA Technical Reports Server (NTRS)

Meier, D. L.; Campbell, R. B.; Sienkiewicz, L. J.; Rai-Choudhury, P.

1982-01-01

The development of a low cost and reliable contact system for solar cells and the fabrication of several solar cell modules using ultrasonic bonding for the interconnection of cells and ethylene vinyl acetate as the potting material for module encapsulation are examined. The cells in the modules were made from dendritic web silicon. To reduce cost, the electroplated layer of silver was replaced with an electroplated layer of copper. The modules that were fabricated used the evaporated Ti, Pd, Ag and electroplated Cu (TiPdAg/Cu) system. Adherence of Ni to Si is improved if a nickel silicide can be formed by heat treatment. The effectiveness of Ni as a diffusion barrier to Cu and the ease with which nickel silicide is formed is discussed. The fabrication of three modules using dendritic web silicon and employing ultrasonic bonding for interconnecting calls and ethylene vinyl acetate as the potting material is examined.

Silicon dendritic web material

NASA Astrophysics Data System (ADS)

Meier, D. L.; Campbell, R. B.; Sienkiewicz, L. J.; Rai-Choudhury, P.

1982-03-01

The development of a low cost and reliable contact system for solar cells and the fabrication of several solar cell modules using ultrasonic bonding for the interconnection of cells and ethylene vinyl acetate as the potting material for module encapsulation are examined. The cells in the modules were made from dendritic web silicon. To reduce cost, the electroplated layer of silver was replaced with an electroplated layer of copper. The modules that were fabricated used the evaporated Ti, Pd, Ag and electroplated Cu (TiPdAg/Cu) system. Adherence of Ni to Si is improved if a nickel silicide can be formed by heat treatment. The effectiveness of Ni as a diffusion barrier to Cu and the ease with which nickel silicide is formed is discussed. The fabrication of three modules using dendritic web silicon and employing ultrasonic bonding for interconnecting calls and ethylene vinyl acetate as the potting material is examined.

Algorithm applying a modified BRDF function in Λ-ridge concentrator of solar radiation

NASA Astrophysics Data System (ADS)

Plachta, Kamil

2015-05-01

This paper presents an algorithm that uses the modified BRDF function. It allows the calculation of the parameters of Λ-ridge concentrator system. The concentrator directs reflected solar radiation on photovoltaic surface, increasing its efficiency. The efficiency of the concentrator depends on the surface characteristics of the material which it is made of, the angle of the photovoltaic panel and the resolution of the tracking system. It shows a method of modeling the surface by using the BRDF function and describes its basic parameters, e.g. roughness and the components of the reflected stream. A cost calculation of chosen models with presented in this article BRDF function modification has been made. The author's own simulation program allows to choose the appropriate material for construction of a Λ-ridge concentrator, generate micro surface of the material, and simulate the shape and components of the reflected stream.

Modeling the microstructure of surface by applying BRDF function

NASA Astrophysics Data System (ADS)

Plachta, Kamil

2017-06-01

The paper presents the modeling of surface microstructure using a bidirectional reflectance distribution function. This function contains full information about the reflectance properties of the flat surfaces - it is possible to determine the share of the specular, directional and diffuse components in the reflected luminous stream. The software is based on the authorial algorithm that uses selected elements of this function models, which allows to determine the share of each component. Basing on obtained data, the surface microstructure of each material can be modeled, which allows to determine the properties of this materials. The concentrator directs the reflected solar radiation onto the photovoltaic surface, increasing, at the same time, the value of the incident luminous stream. The paper presents an analysis of selected materials that can be used to construct the solar concentrator system. The use of concentrator increases the power output of the photovoltaic system by up to 17% as compared to the standard solution.

Twisted Fields

NASA Image and Video Library

2017-12-08

OHO captured this image of a CME from the side – but the structure looks much different from the classic light bulb CME. The filament of material bursting off the sun has a helical magnetic structure, which is unraveling like a piece of yarn during the eruption. Credit: ESA/NASA/SOHO..---..CME WEEK: What To See in CME Images Two main types of explosions occur on the sun: solar flares and coronal mass ejections. Unlike the energy and x-rays produced in a solar flare – which can reach Earth at the speed of light in eight minutes – coronal mass ejections are giant, expanding clouds of solar material that take one to three days to reach Earth. Once at Earth, these ejections, also called CMEs, can impact satellites in space or interfere with radio communications. During CME WEEK from Sept. 22 to 26, 2014, we explore different aspects of these giant eruptions that surge out from the star we live with. When a coronal mass ejection blasts off the sun, scientists rely on instruments called coronagraphs to track their progress. Coronagraphs block out the bright light of the sun, so that the much fainter material in the solar atmosphere -- including CMEs -- can be seen in the surrounding space. CMEs appear in these images as expanding shells of material from the sun's atmosphere -- sometimes a core of colder, solar material (called a filament) from near the sun's surface moves in the center. But mapping out such three-dimensional components from a two-dimensional image isn't easy. Watch the slideshow to find out how scientists interpret what they see in CME pictures. The images in the slideshow are from the three sets of coronagraphs NASA currently has in space. One is on the joint European Space Agency and NASA Solar and Heliospheric Observatory, or SOHO. SOHO launched in 1995, and sits between Earth and the sun about a million miles away from Earth. The other two coronagraphs are on the two spacecraft of the NASA Solar Terrestrial Relations Observatory, or STEREO, mission, which launched in 2006. The two STEREO spacecraft are both currently viewing the far side of the sun. Together these instruments help scientists create a three-dimensional model of any CME as its journey unfolds through interplanetary space. Such information can show why a given characteristic of a CME close to the sun might lead to a given effect near Earth, or any other planet in the solar system...NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Activities of Combined TiO2 Semiconductor Nanocatalysts Under Solar Light on the Reduction of CO2.

PubMed

Liu, Hongfang; Dao, Anh Quang; Fu, Chaoyang

2016-04-01

The materials based on TiO2 semiconductors are a promising option for electro-photocatalytic systems working as solar energy low-carbon fuels exchanger. These materials' structures are modified by doping metals and metal oxides, by metal sulfides sensitization, or by graphene supported membrane, enhancing their catalytic activity. The basic phenomenon of CO2 reduction to CH4 on Pd modified TiO2 under UV irradiation could be enhanced by Pd, or RuO2 co-doped TiO2. Sensitization with metal sulfide QDs is effective by moving of photo-excited electron from QDs to TiO2 particles. Based on characteristics of the catalysts various combinations of catalysts are proposed in order to creat catalyst systems with good CO2 reduction efficiency. From this critical review of the CO2 reduction to organic compounds by converting solar light and CO2 to storable fuels it is clear that more studies are still attractive and needed.

Dopant-Free Tetrakis-Triphenylamine Hole Transporting Material for Efficient Tin-Based Perovskite Solar Cells.

PubMed

Ke, Weijun; Priyanka, Pragya; Vegiraju, Sureshraju; Stoumpos, Constantinos C; Spanopoulos, Ioannis; Soe, Chan Myae Myae; Marks, Tobin J; Chen, Ming-Chou; Kanatzidis, Mercouri G

2018-01-10

Developing dopant-free hole transporting layers (HTLs) is critical in achieving high-performance and robust state-of-the-art perovskite photovoltaics, especially for the air-sensitive tin-based perovskite systems. The commonly used HTLs require hygroscopic dopants and additives for optimal performance, which adds extra cost to manufacturing and limits long-term device stability. Here we demonstrate the use of a novel tetrakis-triphenylamine (TPE) small molecule prepared by a facile synthetic route as a superior dopant-free HTL for lead-free tin-based perovskite solar cells. The best-performing tin iodide perovskite cells employing the novel mixed-cation ethylenediammonium/formamidinium with the dopant-free TPE HTL achieve a power conversion efficiency as high as 7.23%, ascribed to the HTL's suitable band alignment and excellent hole extraction/collection properties. This efficiency is one of the highest reported so far for tin halide perovskite systems, highlighting potential application of TPE HTL material in low-cost high-performance tin-based perovskite solar cells.

The mini-CIDEX GC/IMS: Analysis of cometary ice and dust

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Carle, Glenn C.; Humphry, Donald E.; Shao, Maxine; Takeuchi, Nori

1995-01-01

Comets are recognized as among the most scientifically important objects in the solar system. They are presumed relics of the early primitive material in the solar nebula and are believed to have provided a general enrichment of volatiles to the inner solar system. The Cometary Coma Chemical Composition (C4) Mission, a proposed Discovery-Class Mission, will analyze materials released into the coma, providing information leading to the understanding of the chemical composition and make-up of the cometary nucleus. As one of two scientific instruments in the C4 spacecraft, an advanced and streamlined version of the Cometary Ice and Dust Experiment (CIDEX), a mini-CIDEX, will employ an X-Ray Fluorescence (XRF) spectrometer to determine bulk elemental composition of cometary dust grains and a Gas Chromatograph/Ion Mobility Spectrometer (GC/IMS) for determination of the molecular composition of dust and ices following stepwise pyrolysis and combustion. A description of the mini-CIDEX IMS will be provided as well as data from analyses conducted using the mini-CIDEX breadboard instrument.

Snowy CME

NASA Image and Video Library

2017-12-08

A solar flare associated with the coronal mass ejection seen in this image generated a flurry of fast-moving solar protons. As each one hits the CCD camera on SOHO, it produces a brief snow-like speckle in the image. Credit: NASA/SOHO CME WEEK: What To See in CME Images Two main types of explosions occur on the sun: solar flares and coronal mass ejections. Unlike the energy and x-rays produced in a solar flare – which can reach Earth at the speed of light in eight minutes – coronal mass ejections are giant, expanding clouds of solar material that take one to three days to reach Earth. Once at Earth, these ejections, also called CMEs, can impact satellites in space or interfere with radio communications. During CME WEEK from Sept. 22 to 26, 2014, we explore different aspects of these giant eruptions that surge out from the star we live with. When a coronal mass ejection blasts off the sun, scientists rely on instruments called coronagraphs to track their progress. Coronagraphs block out the bright light of the sun, so that the much fainter material in the solar atmosphere -- including CMEs -- can be seen in the surrounding space. CMEs appear in these images as expanding shells of material from the sun's atmosphere -- sometimes a core of colder, solar material (called a filament) from near the sun's surface moves in the center. But mapping out such three-dimensional components from a two-dimensional image isn't easy. Watch the slideshow to find out how scientists interpret what they see in CME pictures. The images in the slideshow are from the three sets of coronagraphs NASA currently has in space. One is on the joint European Space Agency and NASA Solar and Heliospheric Observatory, or SOHO. SOHO launched in 1995, and sits between Earth and the sun about a million miles away from Earth. The other two coronagraphs are on the two spacecraft of the NASA Solar Terrestrial Relations Observatory, or STEREO, mission, which launched in 2006. The two STEREO spacecraft are both currently viewing the far side of the sun. Together these instruments help scientists create a three-dimensional model of any CME as its journey unfolds through interplanetary space. Such information can show why a given characteristic of a CME close to the sun might lead to a given effect near Earth, or any other planet in the solar system...NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Materials Challenges in Space Exploration

NASA Technical Reports Server (NTRS)

Bhat, Biliyar N.

2005-01-01

United States civil space program administered by National Aeronautics and Space Administration has a new strategic direction to explore the solar system. This new 'vision for space exploration' encompasses a broad range of human and robotic missions, including the Moon. Mars and destinations beyond. These missions require advanced systems and capabilities that will accelerate the development of many critical technologies, including advanced materials and structural concepts. Specifically, it is planned to develop high-performance materials for vehicle structures, propulsion systems, and space suits; structural concepts for modular assembly for space infrastructure: lightweight deployable and inflatable structures for large space systems and crew habitats; and highly integrated structural systems and advanced thermal management systems for reducing launch mass and volume. This paper will present several materials challenges in advanced space systems-high performance structural and thermal materials, space durable materials, radiation protection materials, and nano-structural materials. Finally, the paper will take a look at the possibility of utilizing materials in situ, i.e., processing materials on the surface of the Moon and Mars.

Primary reflector for solar energy collection systems

NASA Technical Reports Server (NTRS)

Miller, C. G. (Inventor); Stephens, J. B.

1978-01-01

A fixed, linear, ground-based primary reflector is disclosed which has an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material. The device reflects solar energy to a movably supported collector that is kept at the concentrated line focus of the reflector primary. The primary reflector may be constructed by a process utilizing well-known freeway paving machinery.

Primary reflector for solar energy collection systems and method of making same

NASA Technical Reports Server (NTRS)

Miller, C. G.; Stephens, J. B. (Inventor)

1979-01-01

Solar energy is reflected to a movably supported collector that is kept at the concentrated line focus of the reflector primary by a fixed, linear, ground-based primary reflector having an extended curved sawtooth contoured surface covered with a metalized polymeric reflecting material. The primary reflector was constructed by a process utilizing well-known freeway paving machinery.

The utilization of nonterrestrial materials. [resources for solar power satellite construction

NASA Technical Reports Server (NTRS)

1981-01-01

The development of research and technology programs on the user of nonterrestrial materials for space applications was considered with emphasis on the space power satellite system as a model of large space systems for which the use of nonterrestrial materials may be economically viable. Sample topics discussed include the mining of raw materials and the conversion of raw materials into useful products. These topics were considered against a background of the comparative costs of using terrestrial materials. Exploratory activities involved in the preparation of a nonterrestrial materials utilization program, and the human factors involved were also addressed. Several recommendations from the workshop are now incorporated in NASA activities.

Rocky Planetary Debris Around Young WDs

NASA Astrophysics Data System (ADS)

Gaensicke, B.

2014-04-01

The vast majority of all known planet host stars, including the Sun, will eventually evolve into red giants and finally end their lives as white dwarfs: extremely dense Earth-sized stellar embers. Only close-in planets will be devoured during the red-giant phase. In the solar system, Mars, the asteroid belt, and all the giant planets will escape evaporation, and the same is true for many of the known exo-planets. It is hence certain that a significant fraction of the known white dwarfs were once host stars to planets, and it is very likely that many of them still have remnants of planetary systems. The detection of metals in the atmospheres of white dwarfs is the unmistakable signpost of such evolved planetary systems. The strong surface gravity of white dwarfs causes metals to sink out of the atmosphere on time-scales much shorter than their cooling ages, leading unavoidably to pristine H/He atmospheres. Therefore any metals detected in the atmosphere of a white dwarf imply recent or ongoing accretion of planetary debris. In fact, planetary debris is also detected as circumstellar dust and gas around a number of white dwarfs. These debris disks are formed from the tidal disruption of asteroids or Kuiper belt-like objects, stirred up by left-over planets, and are subsequently accreted onto the white dwarf, imprinting their abundance pattern into its atmosphere. Determining the photospheric abundances of debris-polluted white dwarfs is hence entirely analogue to the use of meteorites, "rocks that fell from the sky", for measuring the abundances of planetary material in the solar system. I will briefly review this new field of exo-planet science, and then focus on the results of a large, unbiased COS snapshot survey of relatively young ( 20-100Myr) white dwarfs that we carried out in Cycle 18/19. * At least 30% of all white dwarfs in our sample are accreting planetary debris, and that fraction may be as high as 50%. * In most cases where debris pollution is detected, the low C/Si ratio demonstrates that the planetary material is of rocky nature. * None of the 9 systems where we measure the C/O ratio shows evidence for carbon-dominated chemistry, implying that "carbon planets" are not common. * In the most polluted white dwarfs, we measure the debris abundances of up to 11 elements, enabling a detailed comparison between the chemistry of exo-planetary material with that of solar system meteorites. We find that the exo-planetary debris shares many characteristics of solar-system material, i.e. a wide spread in the relative abundances of Mg, Fe, Si, and O, a constant Al/Ca ratio, and evidence for differentiation in the form of Fe over-abundances All of the above is suggestive that thermal and collisional processing of planetary material in those systems might have been similar to that in the solar system.

Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)

NASA Astrophysics Data System (ADS)

Biver, Nicolas; Bockelée-Morvan, Dominique; Moreno, Raphaël; Crovisier, Jacques; Colom, Pierre; Lis, Dariusz C.; Sandqvist, Aage; Boissier, Jérémie; Despois, Didier; Milam, Stefanie N.

2015-10-01

The presence of numerous complex organic molecules (COMs; defined as those containing six or more atoms) around protostars shows that star formation is accompanied by an increase of molecular complexity. These COMs may be part of the material from which planetesimals and, ultimately, planets formed. Comets represent some of the oldest and most primitive material in the solar system, including ices, and are thus our best window into the volatile composition of the solar protoplanetary disk. Molecules identified to be present in cometary ices include water, simple hydrocarbons, oxygen, sulfur, and nitrogen-bearing species, as well as a few COMs, such as ethylene glycol and glycine. We report the detection of 21 molecules in comet C/2014 Q2 (Lovejoy), including the first identification of ethyl alcohol (ethanol, C2H5OH) and the simplest monosaccharide sugar glycolaldehyde (CH2OHCHO) in a comet. The abundances of ethanol and glycolaldehyde, respectively 5 and 0.8% relative to methanol (0.12 and 0.02% relative to water), are somewhat higher than the values measured in solar- type protostars. Overall, the high abundance of COMs in cometary ices supports the formation through grain-surface reactions in the solar system protoplanetary disk.

Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)

PubMed Central

Biver, Nicolas; Bockelée-Morvan, Dominique; Moreno, Raphaël; Crovisier, Jacques; Colom, Pierre; Lis, Dariusz C.; Sandqvist, Aage; Boissier, Jérémie; Despois, Didier; Milam, Stefanie N.

2015-01-01

The presence of numerous complex organic molecules (COMs; defined as those containing six or more atoms) around protostars shows that star formation is accompanied by an increase of molecular complexity. These COMs may be part of the material from which planetesimals and, ultimately, planets formed. Comets represent some of the oldest and most primitive material in the solar system, including ices, and are thus our best window into the volatile composition of the solar protoplanetary disk. Molecules identified to be present in cometary ices include water, simple hydrocarbons, oxygen, sulfur, and nitrogen-bearing species, as well as a few COMs, such as ethylene glycol and glycine. We report the detection of 21 molecules in comet C/2014 Q2 (Lovejoy), including the first identification of ethyl alcohol (ethanol, C2H5OH) and the simplest monosaccharide sugar glycolaldehyde (CH2OHCHO) in a comet. The abundances of ethanol and glycolaldehyde, respectively 5 and 0.8% relative to methanol (0.12 and 0.02% relative to water), are somewhat higher than the values measured in solar-type protostars. Overall, the high abundance of COMs in cometary ices supports the formation through grain-surface reactions in the solar system protoplanetary disk. PMID:26601319

Space manufacturing III; Proceedings of the Fourth Conference, Princeton University, Princeton, N.J., May 14-17, 1979

NASA Technical Reports Server (NTRS)

Grey, J. (Editor); Krop, C.

1979-01-01

Papers are presented on the various technological, political, economic, environmental and social aspects of large manufacturing facilities in space. Specific topics include the potential global market for satellite solar power stations in 2025, the electrostatic separation of lunar soil, methods for extraterrestrial materials processing, the socio-political status of efforts toward the development of space manufacturing facilities, the financing of space industrialization, the optimization of space manufacturing systems, the design and project status of Mass Driver Two, and the use of laser-boosted lighter-than-air-vehicles as heavy-lift launch vehicles. Attention is also given to systems integration in the development of controlled ecological life support systems, the design of a space manufacturing facility to use lunar materials, high performance solar sails, the environmental effects of the satellite power system reference design, the guidance, trajectory and capture of lunar materials ejected from the moon by mass driver, the relative design merits of zero-gravity and one-gravity space environments, consciousness alteration in space and the prospecting and retrieval of asteroids.

Jupiter: Cosmic Jekyll and Hyde.

PubMed

Grazier, Kevin R

2016-01-01

It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to shield or intercept Earth-bound comets originating in the outer Solar System is poor, and that the importance of jovian planets on the formation of life is not that they act as shields, but rather that they deliver life-enabling volatiles to the terrestrial planets.

Membrane-Based Absorption Refrigeration Systems: Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

BEETIT Project: UFL is improving a refrigeration system that uses low quality heat to provide the energy needed to drive cooling. This system, known as absorption refrigeration system (ARS), typically consists of large coils that transfer heat. Unfortunately, these large heat exchanger coils are responsible for bulkiness and high cost of ARS. UFL is using new materials as well as system design innovations to develop nanoengineered membranes to allow for enhanced heat exchange that reduces bulkiness. UFL’s design allows for compact, cheaper and more reliable use of ARS that use solar or waste heat.

Satellite thermal storage systems using metallic phase-change materials

NASA Astrophysics Data System (ADS)

Lauf, R. J.; Hamby, C.

Solar (thermal) dynamic power systems for satellites require a heat storage system capable of operating the engine during eclipse. A system is described in which the phase-change material (PCM) is a metal rather than the more conventional fluoride salts. Thermal storage modules consisting of germanium contained in graphite have good thermal conductivity, low parasitic mass, and are physically and chemically stable. The result is described for thermal cycle testing of graphite capsules containing germanium and several germanium- and silicon-based alloys, as well as some initial tests of the compatibility of graphite with Nb-1 percent Zr structural materials.

Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sano, Naoko, E-mail: naoko.sano@ncl.ac.uk; Barlow, Anders J.; Cumpson, Peter J.

The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars andmore » Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.« less

Technology for large space systems: A special bibliography with indexes (supplement 03)

NASA Technical Reports Server (NTRS)

1980-01-01

A bibliography containing 217 abstracts addressing the technology for large space systems is presented. State of the art and advanced concepts concerning interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments are represented.

Recent advances in polymer solar cells: realization of high device performance by incorporating water/alcohol-soluble conjugated polymers as electrode buffer layer.

PubMed

He, Zhicai; Wu, Hongbin; Cao, Yong

2014-02-01

This Progress Report highlights recent advances in polymer solar cells with special attention focused on the recent rapid-growing progress in methods that use a thin layer of alcohol/water-soluble conjugated polymers as key component to obtain optimized device performance, but also discusses novel materials and device architectures made by major prestigious institutions in this field. We anticipate that due to drastic improvements in efficiency and easy utilization, this method opens up new opportunities for PSCs from various material systems to improve towards 10% efficiency, and many novel device structures will emerge as suitable architectures for developing the ideal roll-to-roll type processing of polymer-based solar cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of Space Environmental Effects on Candidate Solar Sail Material

NASA Technical Reports Server (NTRS)

Edwards, David; Hubbs, Whitney; Stanaland, Tesia; Munafo, Paul M. (Technical Monitor)

2002-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two if the sunfacing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. The Space Environmental Effects Team, at MSFC, is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to radiation environments simulating orbital environments. This paper describes the results of three candidate materials after exposure to a simulated Geosynchronous Transfer Orbit (GTO). This is the first known characterization of solar sail material exposed to space simulated radiation environments. The technique of radiation dose versus material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.

Toward an Urban Political Ecology of Energy Justice: The Case of Rooftop Solar in Tucson, AZ

NASA Astrophysics Data System (ADS)

Franklin, Remington Santiago

A central challenge of the twenty-first century is to transition to a low-carbon energy system to reduce the risks of climate change. For Pima County, Arizona, where electricity accounts for the majority of greenhouse gas emissions, this requires rapid deployment of grid-tied renewable energy resources. In light of this challenge, photovoltaic solar has emerged as an important solution, providing the top source of new US electric generating capacity installed in 2016. However, there is still no consensus about the optimal scale for solar (centralized power plants, or small, decentralized systems) and the socio-economic implications for low income households. This thesis explores the implications of rooftop solar for energy justice through empirical research about a southern Arizona electric utility rate case. Utilities argue that existing rate structures shift costs from solar owners to lower-income ratepayers, while critics say the utility's proposed rate changes are unjust and that rooftop solar benefits all ratepayers. Drawing on my empirical data and an urban political ecology (UPE) approach, I analyze competing narratives that speak to three types of justice: distributive, procedural, and recognition. While dominant justice claims revolve around the distribution of costs through rates, competing narratives emphasize procedural and recognition (in)justice. Focusing on political economy, power relations, and the materiality of the grid, I reframe the utility's cost shift argument as a strategic narrative and explain why this justice claim is ultimately validated. I propose that UPE can further an energy justice analysis by understanding procedural and recognition injustice as systemic products of rate of return regulation and the material configuration of the electric grid.