ALBERT

Description: The new genus Lianus of subfamily Doryctinae (Hymenoptera: Braconidae) is described and illustrated. The differences from other genera of Doryctinae are discussed. Both included species originate from the Atlantic forest at Campos do Jordão, São Paulo State, Brazil.

Description: The Pterophoridae (Ochyroticinae, Deuterocopinae, Pterophorinae (Tribus: Platyptiliini, Exelastini, Oxyptilini)) species of the Neotropical fauna are reviewed. The species are redescribed. Moths are illustrated in colour for the first time, their genitalia are illustrated in line drawings. The examination of type specimens revealed the presence of four new synonyms: Platyptilia juanvinas Gielis, 1999, is a junior synonym of Platyptilia gravior Meyrick, 1932; Platyptilia jonesi Gielis, 1996, is a junior synonym of Platyptilia semnopis Meyrick, 1931; Oxyptilus maleficus Meyrick, 1926, is a junior synonym of Leptodeuterocopus neales (Walsingham, 1915); Lioptilus parvus Walsingham, 1880, is a junior synonym of Lioptilodes albistriolatus (Zeller, 1871). During the study of much new material 40 new species were discovered: Leptodeuterocopus tungurahue, L. angulatus, L. panamaensis, L. duchicela, Sochchora mulinus, Melanoptilia nigra, Platyptilia spicula, Stenoptilodes maculatus, S. agricultura, S. heppneri, S. medius, S. altiaustralis, Postplatyptilia nebuloarbustum, P. antillae, P. caribica, P. uruguayensis, P. pluvia, P. seitetazas, P. transversus, P. carchi, P. boletus, P, ugartei, P. drechseli, P. corticis, P. zongoensis, P. vorbecki, Amblyptilia landryi, A. kosteri, Lioptilodes altivolans, L. arequipa, L. yungas, L. salarius, L. cocodrilo, Michaelophorus margaritae, M. bahiaensis, Geina integumentum, Capperia browni, Buckleria brasilia, Megalorhipida paraiso, M. dubiosa. In the larger genera the species are arranged in groups. For a distinct group of species a new genus: Melanoptilia is proposed. A comprehensive checklist of the species has been made. To facilitate identification a key is presented to the genus level.

Description: A bibliography of the family Braconidae/Hymenoptera: Ichneumonidae is given for the period 1964-2003. It is an addition to Shenefelt's bibliography (1965), which covers the period 1785-1963. In total 10,436 references are listed.

Description: The European species of the genus Helorus Latreille, 1802, are keyed and illustrated, with special reference to their distribution in The Netherlands. Three of the four European species are newly reported for The Netherlands. The description of a new species from Sulawesi (Indonesia) is added: H. celebensis spec. nov.

Description: Two new genera of Entedoninae are described from Afrotropical region. The genus Janicharis gen. nov. (type species: J. africana spec. nov.) is described from Cameroon, Nigeria and Madagascar. The genus Hakuna gen. nov. (type species: H. matata spec. nov.) is described from Uganda. Both genera have a rather characteristic habitus and a peculiar propodeum bearing large anterolateral strips. A new, but yet unnamed, species of the genus Trisecodes Delvare & LaSalle, 2000, is recorded from Cameroon. This is the fi rst Afrotropical record of this genus, originally described from the Neotropical region.

Description: In total 32 new species of Tenthredinidae are described from Vietnam and 18 new species from Indonesia: Nesoselandria albotonkinensis spec. nov., N. albeotegularissima spec. nov., N. devriesiana spec. nov., Anapeptamena achterbergiana spec. nov., Neostromboceros nigrogiganteus spec. nov., N. gracilioides spec. nov., N. alboclypeatus spec. nov., N. daoensis spec. nov., N. phuongensis spec. nov., Abusarbidea bicoloristigmata spec. nov., Eusunoxa alboapicalis spec. nov., Neopoppia tonkinometallica spec. nov., Abeleses vietnamensis spec. nov., A. metallotonkinensis spec. nov., Heptamelus tonkinensis spec. nov., Athlophorus devriesi spec. nov., Rhopographus vietnamensis spec. nov., Xenapatidea hematothoracica spec. nov., X. devriesi spec. nov., Allantidea achterbergiana spec. nov., Neothrinax nigrotonkinensis spec. nov., Indotaxonus flavissimus spec. nov., Darjilingia vietnamensis spec. nov., D. tonkinensis spec. nov., D. hoangliensis spec. nov., Ferna achterbergi spec. nov., Monophadnus bicoloritonkinensis spec. nov., Eutomostethus phongdiensis spec. nov., Eutomostethus albotegularissimus spec. nov., Tenthredo octomaculatus spec. nov., T. tricoloritonkinensis spec. nov. and T. danangiensis spec. nov. from Vietnam. Neostromboceros pleuronotatus spec. nov., N. albopedissimus spec. nov., N. flavopedis spec. nov., N. rubroguinealis spec. nov., N. rubromalayensis spec. nov., Eusunoxa malaya spec. nov., Emphytus danumiensis spec. nov., Hemibeleses sulawesiensis spec. nov., Neopoppia irregulata spec. nov., Tenthredo nigrosabahensis spec. nov., T. djampangensis spec. nov., Neothrinax kaindiensis spec. nov., N. excavata spec. nov., N. gedehensis spec. nov., Abeleses metallojavanus spec. nov., Caliroa nigrojavana spec. nov., Nesoselandria sulawesiensis spec. nov. and Athlophorus achterbergianus spec. nov. from Indonesia. Monophadnus glaucus Enderlein, 1919; Monophadnus sumatranus Enderlein, 1919; Amonophadnus nigripennis Benson, 1935; Amonophadnus nigrojavanus Haris, 2002; Corporaalinus azureus Forsius, 1925; Corporaalinus cyanescens Forsius, 1925; and Corporaalinus jacobsoni Forsius, 1929, are proposed as new synonyms of Monophadnus rivalis Konow, 1906. An identification key is added for the known Tenthredinidae of Borneo, Sumatra, Java, Sulawesi and New Guinea.

Description: Two new host records for Exasticolus fuscicornis (Cameron, 1887)(Hymenoptera: Braconidae: Homolobinae)are presented with detailed larvae morphology and other biological information.

Description: Thirty species belonging to 16 genera of the family Braconidae (Hymenoptera) are reported from Greenland. Seven are new species described and illustrated below: Dacnusa groenlandica spec. nov.; Aphidius tarsalis spec. nov.; Praon brevistigma spec. nov.; Blacus (B.) groenlandicus spec. nov.; Cotesia crassifemorata spec. nov.; C. fascifemorata spec. nov. and Microplitis lugubroides spec. nov.

Description: The little-known monotypic genus Paracyphocrania Redtenbacher, 1908 (Phasmatinae: Phasmatini) is reviewed and now comprises two species: P. lativentris Redtenbacher, 1908, and P. tecticollis (Redtenbacher, 1908) comb. nov., which are redescribed and illustrated. A neotype is designated for P. lativentris which is newly recorded from Sulawesi.

Description: Vestalaria vinnula spec.nov. (holotype male, southern Vietnam, Lam Dong province, Blao, 1962) is described in both sexes and compared with other species of Vestalaria May, 1935 (= the Vestalis smaragdina - group), which is ranked as valid genus.

Description: A new species of the genus Artocella van Achterberg is described from Spain. On the basis of its substantial sexual dimorphisim, the differences between the two previously known species of this Turanian-Mediterranean genus, which had each been described from specimens of only one (and differing) sex, are reassessed.

Description: Dasypoda intermedia spec. nov. from Iran is described. Its description fills a gap of our knowledge of the East Mediterranean fauna of the genus Dasypoda. The West Mediterranean Dasypoda species are well known but the eastern species lack convincing records. Moreover, D. intermedia spec. nov. is a very interesting species from a phylogenetic point of view. It shares some characters common to subgenera Dasypoda s. str. and Megadasypoda Michez, 2004, which provide further evidence for the close relationship of both subgenera.

Description: Thirty-one species of the family Platystictidae of the Philippines are revised, i.e. all species recognised, excluding the species of the Drepanosticta halterata-group. The following new taxa are described: 16 species in Drepanosticta Laidlaw: D. acuta spec. nov., D. aurita spec. nov., D. centrosaurus spec. nov., D. clados spec. nov., D. flavomaculata spec. nov., D. furcata spec. nov., D. hermes spec. nov., D. krios spec. nov., D. luzonica spec. nov., D. malleus spec. nov., D. myzouris spec. nov., D. paruatia spec. nov., D. pistor spec. nov., D. quadricornu spec. nov., D. rhamphis spec. nov., D. trachelocele spec. nov., two in Protosticta Selys, viz. P. lepteca spec. nov. and P. plicata spec. nov., and three in Sulcosticta gen. nov., viz. S. striata spec. nov., S. pallida spec. nov. and S. viticula spec. nov. The status of eleven previously described nominal taxa is established. One, D. septima Needham & Gyger, is doubtfully considered a synonym of D. mylitta Cowley. Based on a preliminary phylogenetic analysis, the species of Drepanosticta are divided into informal species groups. Most species of the Philippines have affinities to species of Sulawesi, the Moluccas and New Guinea. Several species confined to Palawan have sister-group relationships with species from Borneo. The affinities of various other species confined to the Sulu archipelago, are unsettled as yet. The species of Platystictidae here assigned to Protosticta Selys are presumably not closely related to the type species, P. simplicinervis Selys from Sulawesi. However, a better placement has to await a more detailed phylogenetic study of the family. For three species the new genus Sulcosticta gen. nov. is erected. These species are closely allied based on the structure of the appendages, but should have been assigned to different genera if based on the present generic definitions. Many species here described have small distributional ranges, a common phenomenon in Platystictidae. Since most forests in the Philippines are heavily under threat or have already disappeared in the last fifty years, several taxa described in this paper should be considered under threat of immediate extinction.

Description: In this part the remaining 78 species of the genus Pepsis, belonging to ten species-groups, are described and figured, and their phylogenetics and biogeography are discussed. 14 of the species are described as new: P. achterbergi spec. nov., P. adonta spec. nov., P. boharti spec. nov., P. caliente spec. nov., P. dayi spec. nov., P. esmeralda spec. nov., P. ianthoides spec. nov., P. jamaicensis spec. nov., P. krombeini spec. nov., P. martini spec. nov., P. multichroma spec. nov., P. nanoides spec. nov., P. wahisi spec. nov., and P. willinki spec. nov. Three species-names, P. infuscata Spinola, 1841, P. lampas Lucas, 1895, and P. thoreyi Dahlbom, 1845, are recalled from synonymy. The following 293 names are newly synonymized (the valid names are listed first): P. atalanta Mocsáry, 1885 = P. nitens Mocsáry, 1894, P. mocsaryi Lucas, 1895; P. inclyta Lepeletier, 1845 = P. mutabilis Lepeletier, 1845, P. vagabunda Lepeletier, 1845, P. cupripennis Taschenberg, 1869, P. violaceipennis Mocsáry, 1885, P. clotho Mocsáry, 1888, P. spengeli Mocsáry, 1888, P. sickmanni Mocsáry, 1888, P. nireus Mocsáry, 1894, P. atrovirens Lucas, 1895, P. cerastes Lucas, 1895, P. pygidialis Brèthes, 1908, P. guaranitica Brèthes, 1908, P. parca Lucas, 1919, P. atahualpa Banks, 1946, opimicornis, Haupt, 1952, atropos, Haupt, 1952, azurea Haupt, 1952; crassicornis Mocsáry, 1885 = P. sappho Brèthes, 1908, P. nitocris Brèthes, 1908, P. vivida Brèthes, 1908, P. arechavaletai Brèthes, 1908, P. lynchii Brèthes, 1908, P. operosa Brèthes, 1908, P. ataraqua Banks, 1946, P. splendida Haupt, 1952; P. sommeri Dahlbom, 1845 = P. azteca Cameron, 1893; P. xanthocera Dahlbom, 1843 = P. nigrescens Smith, 1855, P. fulgidipennis Mocsáry, 1885, P. juno Brèthes, 1908, P. ismare Banks, 1946, P. nigroprasina Haupt, 1952; P. seifferti Lucas, 1895 = P. cornuta Lucas, 1895, P. moebiusi Lucas, 1895, P. stygia Lucas, 1895; P. luteicornis Fabricius, 1804 = P. strenua Erichson, 1848, P. tinctipennis Smith, 1873, P. citreicornis Mocsáry, 1894, P. venosa Banks, 1945, P. alector Banks, 1946; P. asteria Mocsáry, 1894 = P. luridicornis Brèthes, 1926; P. convexa Lucas, 1895 = P. humeralis Brèthes, 1914; P. helvolicornis Lucas, 1895 = P. bahiae Brèthes, 1914; P. vitripennis Smith, 1855 = P. obscura Lepeletier, 1845, P. amabilis Mocsáry, 1885, P. centralis Cameron, 1893, P. margarete Lucas, 1895, P. venezuelae Kaye, 1913, P. aeneipennis Banks, 1946, P. helenae Haupt, 1952, P. coeruleoviridis Haupt, 1952; P. fumipennis Smith, 1855 = P. pallidicornis Mocsáry, 1885; P. amyntas Mocsáry, 1885 = P. vicina Lucas, 1895, P. clarinervis Brèthes, 1908, P. amyntoides Lucas, 1919, P. eurydice Lucas, 1919; P. dimidiata Fabricius, 1804 = P. vittigera Lucas, 1897, P. argentina Brèthes, 1908, P. sanctaeannae Brèthes, 1908, P. virgo Brèthes, 1908, P. externa Brèthes, 1908, P. transversa Brèthes, 1908, P. cordubensis Brèthes, 1908, P. banghaasi Lucas, 1919; P. menechma Lepeletier, 1845 = P. elegans Lepeletier, 1845, P. dubitata Cresson, 1867, P. prismatica Smith, 1855, P. advena Mocsáry, 1885, cinctipennis Mocsáry, 1885, P. guatemalensis Cameron, 1893, P. nestor Mocsáry, 1894, P. nigricornis Mocsáry, 1894, P. auranticornis Lucas, 1895, P. fruhstorferi Lucas, 1895, P. concolor Lucas, 1895, P. cerberus Lucas, 1895, P. euchroma Lucas, 1895, P. nigrocincta Lucas, 1895, P. mordax Lucas, 1895, P. inermis Fox, 1898, P. roberti Brèthes, 1908, P. janira Brèthes, 1908, P. cultrata Brèthes, 1908, P. novitia Banks, 1921; P. decipiens Lucas, 1895 = P. similis Lucas, 1895; P. minarum Brèthes, 1914 = P. pulchra Brèthes, 1914; P. basifusca Lucas, 1895 = P. angustimarginata Viereck, 1908; P. chrysoptera Burmeister, 1872 = P. exigua Lucas, 1895, P. smaragdinula Lucas, 1895, P. nebulosa Lucas, 1895, P. karschi Lucas, 1895, P. anisitsii Brèthes, 1908, P. indistincta Brèthes, 1908, P. dimidiatipennis Brèthes, 1908, P. chloroptera Brèthes, 1908, P. culta Brèthes, 1908, P. recta Brèthes, 1908, P. tornowii Brèthes, 1908, P. schrottkyi Brèthes, 1908, P. itinerata Brèthes, 1908, P. miniata Brèthes, 1908, P. spegazzinii Brèthes, 1908, P. paulistana Brèthes, 1914, P. chloe Brèthes, 1914, P. coronaria Brèthes, 1914, P. semilucana Haupt, 1952, P. bruneipes Haupt, 1952, P. brachynotus Haupt, 1952, P. diagonalis Haupt, 1952, P. discrepans Haupt, 1952; P. elongata Lepeletier, 1845 = P. purpurascens Smith, 1855, P. fuscipennis Smith, 1873, P. longula Banks, 1946; P. australis Saussure, 1867 = P. centaurus Lucas, 1897; P. cyanescens Lepeletier, 1845 = P. micans Mocsáry, 1885, P. jucunda Mocsáry, 1885, P. balloui Banks, 1946, P. diversa Haupt, 1952; P. lampas Lucas, 1895 = P. venturii Schrottky, 1902; P. nitida Lepeletier, 1845 = P. lucidula Smith, 1855, P. vaualba Smith, 1855, P. pruinosa Mocsáry, 1894, P. cylindrica Lucas, 1895, P. andina Brèthes, 1908, P. dilatata Brèthes, 1908, P. holmbergi Brèthes, 1908, P. concava Brèthes, 1908, P. ephebus Brèthes, 1908, P. vaga Brèthes, 1908, P. fuscobasalis Brèthes, 1908, P. cordata Brèthes, 1914, P. impatiens Brèthes, 1914, P. tricolor Brèthes, 1914, P. joergenseni Brèthes, 1914, P. cleone Brèthes, 1914, P. dorsata Brèthes, 1914, P. aretheas Brèthes, 1914, P. lassonis Lucas, 1819, P. consors Banks, 1946, P. interrupta Banks, 1946, P. analis Haupt, 1952; P. seladonica Dahlbom, 1843 = P. deuteroleuca Smith, 1855, P. kohli Lucas, 1895, P. venezolana Brèthes, 1908, P. burmeisteri Brèthes, 1908; P. cybele Banks, 1945 = P. weberi Banks, 1946; P. thoreyi Dahlbom, 1845 = P. lurida Lucas, 1895, P. euterpe Brèthes, 1908; P. flavescens Lucas, 1895 = P. periphetes Lucas, 1895, P. limbatella Brèthes, 1908, P. discoidalis Brèthes, 1914, P. limbatica Brèthes, 1914, P. militaris Brèthes, 1914, P. cavillatrix Haupt, 1952, P. arcuata Haupt, 1952, P. recterugosa Haupt, 1952, P. adversatrix Haupt, 1952; P. nigricans Lucas, 1895 = P. troglodytes Brèthes, 1908; P. montezuma Smith, 1855 = P. quitonensis Packard, 1869, P. sibylla Mocsáry, 1885, P. circe Mocsáry, 1885, P. occidentalis Cameron, 1893, P. peruanus Lucas, 1895, P. fulva Lucas, 1895, P. nessus Lucas, 1895, P. fusca Lucas, 1895, P. andicola Cameron, 1903, P. chilloensis Cameron, 1903, P. patagonica Brèthes, 1908, P. fasciculata Brèthes, 1908, P. pisoensis Strand, 1911, P. pacifica Brèthes, 1914, P. huascar Banks, 1946; P. completa Smith, 1855 = P. quichua Brèthes, 1908, P. comes Banks, 1946; P. smaragdina Dahlbom, 1843 = P. thunbergi Dahlbom, 1843, P. lara Mocsáry, 1888, P. satrapes Lucas, 1895, P. nupta Lucas, 1895, P. erynnis Lucas, 1895, P. fraterna Lucas, 1895, P. diabolus Lucas, 1895, P. mystica Lucas, 1895, P. thalia Brèthes, 1908, P. brasiliensis Brèthes, 1908, P. pallida Brèthes, 1908, P. iheringi Brèthes, 1908, P. dromeda Brèthes, 1908, P. sepultrix Lucas, 1919, P. strickeri Lucas, 1919; P. discolor Taschenberg, 1869 = P. sinnis Lucas, 1895, P. jujuyensis Brèthes, 1908, P. modesta Brèthes, 1908, P. comparata Brèthes, 1908, P. neutra Brèthes, 1908, P. terebrans Brèthes, 1908, P. procera Haupt, 1952, P. plaumanni Haupt, 1952, P. ogloblini Haupt, 1952, P. deletrix Haupt, 1952; P. limbata Guérin, 1831 = P. richteri Brèthes, 1908, P. polita Brèthes, 1908, P. limbella Haupt, 1952, P. artemis Haupt, 1952; P. basalis Mocsáry, 1885 = P. erdmanni Lucas, 1895, P. basinigra Haupt, 1952; P. infuscata Spinola, 1841 = P. niobe Mocsáry, 1885, P. sagana Mocsáry, 1894, P. incerta Banks, 1946; P. hyalinipennis Mocsáry, 1885 = P. subruficornis Haupt, 1952; P. festiva Fabricius, 1804 = P. pulchella Lepeletier, 1845, P. solitaria Smith, 1879, P. gallardoi Brèthes, 1908, P. hora Brèthes, 1914, P. amok Lucas, 1919, P. riojaneirensis Lucas, 1919; P. gracilis Lepeletier, 1845 = P. diana Mocsáry, 1885, P. hecate Mocsáry, 1885, P. spathulifera Lucas, 1895, P. sphinx Lucas, 1895, P. ierensis Banks, 1945, P. alceste Banks, 1946, P. scalaris Haupt, 1952; P. mildei Stål, 1857 = P. charon Mocsáry, 1885, P. cyanoptera Lucas, 1895, P. dryas Lucas, 1919; P. filiola Brèthes, 1914 = P. denserugosa Haupt, 1952; P. ruficornis Fabricius, 1804 = P. saphirus Palisot de Beauvois, 1805, P. violacea Mocsáry, 1885, P. hexamita Lucas, 1895, P. omniviolacea Haupt, 1952; P. brunneicornis Lucas, 1895 = P. glabripennis Lucas, 1895; P. purpurea Smith, 1873 = P. pan Mocsáry, 1885, P. parthenope Mocsáry, 1885, P. sagax Lucas, 1895, P. clypeata Brèthes, 1914, P. consimilis Banks, 1946, P. laconia Banks, 1946; P. viridisetosa Spinola, 1841 = P. eximia Smith, 1873; P. viridis Lepeletier, 1845 = P. errans Lepeletier, 1845, P. chlorotica Mocsáry, 1885, P. excelsa Lucas, 1895, P. selene Lucas, 1895, P. fimbriata Lucas, 1895, P. calypso Brèthes, 1908, P. fluminensis Brèthes, 1908, P. argentinicus Strand, 1910, P. mimetica Brèthes, 1914, P. garbei Brèthes, 1914, P. erecta Brèthes, 1914, P. tandilensis Brèthes, 1914, P. meridionalis Brèthes, 1914, P. minor Lucas, 1919, P. basifulgens Lucas, 1919, P. nebulosipennis Lucas, 1919, P. purpurea Lucas, 1919, P. koerberi Lucas, 1919, P. inimicissima Lucas, 1919, P. debilitans Lucas, 1919, P. itapaca Banks, 1946; P. aciculata Taschenberg, 1869 = P. nero Lucas, 1895; P. atripennis Fabricius, 1804 = P. flavilis Brèthes, 1908; P. ianthina Erichson, 1848 = P. fulvicornis Mocsáry, 1885, P. sirene Lucas, 1895, P. balboae Lucas, 1919, P. herodes Lucas, 1919, P. curti Lucas, 1919; P. nana Mocsáry, 1885 = P. mapiriensis Lucas, 1919, P. vinciens Lucas, 1919, P. ilione Banks, 1946, P. moesta Banks, 1946, P. orestes Banks, 1946, P. amautas Banks, 1946, P. inaequalis Haupt, 1952; P. hirtiventris Banks, 1946 = P. viridaurea Haupt, 1952, P. aequalis Haupt, 1952; P. auriguttata Burmeister, 1872 = P. aurimacula Mocsáry, 1885, P. flavicornis Mocsáry, 1894, P. guttata Lucas, 1895, P. incendiaria Lucas, 1895, P. pubiventris Lucas, 1895, P. planifrons Lucas, 1895, P. lestes Lucas, 1895, P. villosa Brèthes, 1908; P. sabina Mocsáry, 1885 = P. astioles Banks, 1946; and P. purpureipes Packard, 1869 = P. chlorana Mocsáry, 1885, P. antennalis Cameron, 1893, P. sulcifrons Cameron, 1903, P. carinata Brèthes, 1914, P. equatoriana Brèthes, 1914, P. angusta Banks, 1946. Keys to all forms are given. The mimicry-groups of P. atripennis Fabricius, 1804, and P. completa Smith, 1855, are defined and described and a comparative account of mimicry based on all four mimicrygroups in Pepsis is given. Lists of excluded species (with their current taxonomic placement and depository where ascertained), unplaced names, and a nomen nudum are given.

Description: This computer program, SOLINS, was developed to aid engineers and solar system designers in the accurate modeling of the average hourly solar insolation on a surface of arbitrary orientation. The program can be used to study insolation problems specific to residential and commercial applications where the amount of space available for solar collectors is limited by shadowing problems, energy output requirements, and costs. For tandem rack arrays, SOLINS will accommodate the use of augmentation reflectors built into the support structure to increase insolation values at the collector surface. As the use of flat plate solar collectors becomes more prevalent in the building industry, the engineer and designer must have the capability to conduct extensive sensitivity analyses on the orientation and location of solar collectors. SOLINS should prove to be a valuable aid in this area of engineering. SOLINS uses a modified version of the National Bureau of Standards model to calculate the direct, diffuse, and reflected components of total insolation on a tilted surface with a given azimuthal orientation. The model is based on the work of Liu and Jordan with corrections by Kusuda and Ishii to account for early morning and late afternoon errors. The model uses a parametric description of the average day solar climate to generate monthly average day profiles by hour of the insolation level on the collector surface. The model includes accommodation of user specified ground and landscape reflectivities at the collector site. For roof or ground mounted, tilted arrays, SOLINS will calculate insolation including the effects of shadowing and augmentation reflectors. The user provides SOLINS with data describing the array design, array orientation, the month, the solar climate parameter, the ground reflectance, and printout control specifications. For the specified array and environmental conditions, SOLINS outputs the hourly insolation the array will receive during an average day during the month specified, along with the total insolation the collector surface will receive over an average 24-hour period. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 computer with a central memory requirement of approximately 46K of 8 bit bytes. The SOLINS routines were developed in 1979.

Description: OFFSET is a ray tracing computer code for optical analysis of a solar collector. The code models the flux distributions within the receiver cavity produced by reflections from the solar collector. It was developed to model the offset solar collector of the solar dynamic electric power system being developed for Space Station Freedom. OFFSET has been used to improve the understanding of the collector-receiver interface and to guide the efforts of NASA contractors also researching the optical components of the power system. The collector for Space Station Freedom consists of 19 hexagonal panels each containing 24 triangular, reflective facets. Current research is geared toward optimizing flux distribution inside the receiver via changes in collector design and receiver orientation. OFFSET offers many options for experimenting with the design of the system. The offset parabolic collector model configuration is determined by an input file of facet corner coordinates. The user may choose other configurations by changing this file, but to simulate collectors that have other than 19 groups of 24 triangular facets would require modification of the FORTRAN code. Each of the roughly 500 facets in the assembled collector may be independently aimed to smooth out, or tailor, the flux distribution on the receiver's wall. OFFSET simulates the effects of design changes such as in receiver aperture location, tilt angle, and collector facet contour. Unique features of OFFSET include: 1) equations developed to pseudo-randomly select ray originating sources on the Sun which appear evenly distributed and include solar limb darkening; 2) Cone-optics technique used to add surface specular error to the ray originating sources to determine the apparent ray sources of the reflected sun; 3) choice of facet reflective surface contour -- spherical, ideal parabolic, or toroidal; 4) Gaussian distributions of radial and tangential components of surface slope error added to the surface normals at the ten nodal points on each facet; and 5) color contour plots of receiver incident flux distribution generated by PATRAN processing of FORTRAN computer code output. OFFSET output includes a file of input data for confirmation, a PATRAN results file containing the values necessary to plot the flux distribution at the receiver surface, a PATRAN results file containing the intensity distribution on a 40 x 40 cm area of the receiver aperture plane, a data file containing calculated information on the system configuration, a file including the X-Y coordinates of the target points of each collector facet on the aperture opening, and twelve P/PLOT input data files to allow X-Y plotting of various results data. OFFSET is written in FORTRAN (70%) for the IBM VM operating system. The code contains PATRAN statements (12%) and P/PLOT statements (18%) for generating plots. Once the program has been run on VM (or an equivalent system), the PATRAN and P/PLOT files may be transferred to a DEC VAX (or equivalent system) with access to PATRAN for PATRAN post processing. OFFSET was written in 1988 and last updated in 1989. PATRAN is a registered trademark of PDA Engineering. IBM is a registered trademark of International Business Machines Corporation. DEC VAX is a registered trademark of Digital Equipment Corporation.

Description: The solar array module plasma interactions experiment is a space shuttle experiment designed to investigate and quantify the high voltage plasma interactions. One of the objectives of the experiment is to test the performance of the Advanced Photovoltaic Solar Array (APSA). The material properties of array blanket are also studied as electric insulators for APSA arrays in high voltage conditions. Three twelve cell prototype coupons of silicon cells were constructed and tested in a space simulation chamber.

Description: The Simplified Calculation of Solar Flux Distribution on the Side Wall of Cylindrical Cavity Solar Receivers program employs a simple solar flux calculation algorithm for a cylindrical cavity type solar receiver. Applications of this program include the study of solar energy, heat transfer, and space power-solar dynamics engineering. The aperture plate of the receiver is assumed to be located in the focal plane of a paraboloidal concentrator, and the geometry is assumed to be axisymmetric. The concentrator slope error is assumed to be the only surface error; it is assumed that there are no pointing or misalignment errors. Using cone optics, the contour error method is utilized to handle the slope error of the concentrator. The flux distribution on the side wall is calculated by integration of the energy incident from cones emanating from all the differential elements on the concentrator. The calculations are done for any set of dimensions and properties of the receiver and the concentrator, and account for any spillover on the aperture plate. The results of this algorithm compared excellently with those predicted by more complicated programs. Because of the utilization of axial symmetry and overall simplification, it is extremely fast. It can be easily extended to other axi-symmetric receiver geometries. The program was written in Fortran 77, compiled using a Ryan McFarland compiler, and run on an IBM PC-AT with a math coprocessor. It requires 60K of memory and has been implemented under MS-DOS 3.2.1. The program was developed in 1988.

Description: The Indian National Satellite (INSAT) 2A and 2B have deployment mechanisms for deploying the solar array, two C/S band antenna reflectors and a coilable lattice boom with sail. The mechanisms have worked flawlessly on both satellites. The configuration details, precautions taken during the design phase, the test philosophy, and some of the critical analysis activities are discussed.

Description: Current and projected technology is assessed for photovoltaic power for a lunar base. The following topics are discussed: requirements for power during the lunar day and night; solar cell efficiencies, specific power, temperature sensitivity, and availability; storage options for the lunar night; array and system integration; the potential for in situ production of photovoltaic arrays and storage medium.

Description: Eagle-Picher currently has several advanced nickel-hydrogen (NiH2) cell component and battery designs under development including common pressure vessel (CPV), single pressure vessel (SPV), and dependent pressure vessel (DPV) designs. A CPV NiH2 battery, utilizing low-cost 64 mm (2.5 in.) cell diameter technology, has been designed and built for multiple smallsat programs, including the TUBSAT B spacecraft which is currently scheduled (24 Nov. 93) for launch aboard a Russian Proton rocket. An advanced 90 mm (3.5 in.) NiH2 cell design is currently being manufactured for the Space Station Freedom program. Prototype 254 mm (10 in.) diameter SPV batteries are currently under construction and initial boilerplate testing has shown excellent results. NiH2 cycle life testing is being continued at Eagle-Picher and IPV cells have currently completed more than 89,000 accelerated LEO cycles at 15% DOD, 49,000 real-time LEO cycles at 30 percent DOD, 37,800 cycles under a real-time LEO profile, 30 eclipse seasons in accelerated GEO, and 6 eclipse seasons in real-time GEO testing at 75 percent DOD maximum. Nickel-metal hydride battery development is continuing for both aerospace and electric vehicle applications. Eagle-Picher has also developed an extensive range of battery evaluation, test, and analysis (BETA) measurement and control equipment and software, based on Hewlett-Packard computerized data acquisition/control hardware.

Description: Tests to establish current-voltage characteristics at selected temperatures for 9 a-h Super Nickel-Cadmium cells were conducted at Hughes Industrial Electronics Company's Electron Dynamics Division (HIEC/EDD) under sponsorship of NASA/GSFC through their prime spacecraft contractors Fairchild Space (SMEX/SAMPEX) and TRW (TOMSEP). Curves were constructed using techniques established by Webster, Ford, et al, at NASA/GSFC in the late 1960's - early 1970's time period for conventional nickel cadmium cells used on OAO and OSO aircraft. The NASA/GSFC techniques were slightly modified by HIEC/EDD to fit the Super Ni-Cd situation.

Description: The question of the best approach for battery charge control is addressed from two points of view: from the battery point-of-view; and from the spacecraft/mission point-of-view. In terms of performance, more aggressive charging can result in higher discharge voltage and capacity; however, aggressive charging usually implies more overcharge at higher rates and a concomitant higher end of charge temperature (higher stress, shorter life). In terms of life, benign charging can result in lower discharge voltage and capacity (poorer performance). Additionally, benign, or low stress charging, usually implies less overcharge at lower rates with lower end of charge temperature (lower stress, longer life). A discussion of these topics is presented in viewgraph form.

Description: Recently, we have succeeded in fabricating diffused junction p(sup +)n(Cd,S) InP solar cells with measured AMO, 25 C open circuit voltage (V(sub OC)) of 887.6 mV, which, to the best of our knowledge, is higher than previously reported V(sub OC) values for any InP homojunction solar cells. The experiment-based projected achievable efficiency of these cells using LEC grown substrates is 21.3 percent. The maximum AMO, 25 C internal losses due to date on bare cells is, however, only 13.2 percent. This is because of large external and internal losses due to non-optimized front grid design, antireflection (AR) coating and emitter thickness. This paper summarizes recent advances in the technology of fabrication of p(sup +)n InP diffused structures and solar cells, resulted from a study undertaken in an effort to increase the cell efficiency. The topics discussed in this paper include advances in: (1) the formation on thin p(sup +) InP:Cd emitter layers, (2) electroplated front contacts, (3) surface passivation and (4) the design of a new native oxide/Al2O3/MgF2 tree layer AR coating using a chemically-grown P-rich passivating oxide as a first layer. Based on the high radiation resistance and the excellent post-irradiation annealing and recovery demonstrated in the early tests done to date, as well as the projected high efficiency and low-cost high-volume fabricability, these cells show a very good potential for space photovoltaic applications.

Description: SAMPIE, the Solar Array Module Plasma Interactions Experiment, flew in the Space Shuttle Columbia payload bay as part of the Office of Aeronautics and Space Technology-2 (OAST-2) mission on STS-62, March, 1994. SAMPIE biased samples of solar arrays and space power materials to varying potentials with respect to the surrounding space plasma, and recorded the plasma currents collected and the arcs which occurred, along with a set of plasma diagnostics data. A large set of high quality data was obtained on the behavior of solar arrays and space power materials in the space environment. This paper is the first report on the data SAMPIE telemetered to the ground during the mission. It will be seen that the flight data promise to help determine arcing thresholds, snapover potentials, and floating potentials for arrays and spacecraft in LEO.

Description: It has been found useful in the past to use the concept of 'equivalent fluence' to compare the radiation response of different solar cell technologies. Results are usually given in terms of an equivalent 1 MeV electron or an equivalent 10 MeV proton fluence. To specify cell response in a complex space-radiation environment in terms of an equivalent fluence, it is necessary to measure damage coefficients for a number of representative electron and proton energies. However, at the last Photovoltaic Specialist Conference we showed that nonionizing energy loss (NIEL) could be used to correlate damage coefficients for protons, using measurements for GaAs as an example. This correlation means that damage coefficients for all proton energies except near threshold can be predicted from a measurement made at one particular energy. NIEL is the exact equivalent for displacement damage of linear energy transfer (LET) for ionization energy loss. The use of NIEL in this way leads naturally to the concept of 10 MeV equivalent proton fluence. The situation for electron damage is more complex, however. It is shown that the concept of 'displacement damage dose' gives a more general way of unifying damage coefficients. It follows that 1 MeV electron equivalent fluence is a special case of a more general quantity for unifying electron damage coefficients which we call the 'effective 1 MeV electron equivalent dose'.

Description: Radiation damage results from two-terminal monolithic InP/Ga(0.47)In(0.53)As tandem solar cells subject to 1 MeV electron irradiation are presented. Efficiencies greater than 22 percent have been measured by the National Renewable Energy Laboratory from 2x2 sq cm cells at 1 sun, AMO (25 C). The short circuit current density, open circuit voltage and fill factor are found to tolerate the same amount of radiation at low fluences. At high fluence levels, slight differences are observed. Decreasing the base amount of radiation at the Ga(0.47)In(0.53)As bottomcell improved the radiation resistance of J(sub sc) dramatically. This is turn, extended the series current flow through the subcell substantially up to a fluence of 3x10(exp 15) cm(exp -2) compared to 3x10(exp 14) cm(exp -2), as observed previously. The degradation of the maximum power output form tandem device is comparable to that from shallow homojunction (SHJ) InP solar cells, and the mechanism responsible for such degradation is explained in terms of the radiation response of the component cells. Annealing studies revealed that the recovery of the tandem cell response is dictated by the annealing characteristics exhibited by SHJ InP solar cells.

Description: An analysis of InP/GaAs tandem solar cell structure has been undertaken to allow for maximum AMO conversion efficiencies (space applications) while still taking into account both the theoretical and technological limitations. The dependence of intrinsic and extrinsic parameters such as diffusion lengths and generation-recombination (GR) lifetimes on N/P and P/N devices performances are clearly demonstrated. We also report for the first time the improvement attainable through the use of a new patterned tunnel junction as the inter cell ohmic interconnect. Such a design minimizes the light absorption in the interconnect region and leads to a noticeable increase in the cell efficiency. Our computations predict 27 percent AMO efficiency for N/P tandems with ideality factor gamma = 2 (GR lifetimes approximately equal 1 micron), and 36 percent for gamma = 1 (GR lifetimes approximately equals 100 microns). The method of optimization and the values of the physical and optical parameters are discussed.

Description: Progress is reported with respect to the development of thin film amorphous (alpha-Si) terrestrial solar cells for space applications. Such devices promise to result in very lightweight, low cost, flexible arrays with superior end of life (EOL) performance. Each alpha-Si cell consists of a tandem arrangement of three very thin p-i-n junctions vapor deposited between film electrodes. The thickness of this entire stack is approximately 2.0 microns, resulting in a device of negligible weight, but one that must be mechanically supported for handling and fabrication into arrays. The stack is therefore presently deposited onto a large area (12 by 13 in), rigid, glass superstrate, 40 mil thick, and preliminary space qualification testing of modules so configured is underway. At the same time, a more advanced version is under development in which the thin film stack is transferred from the glass onto a thin (2.0 mil) polymer substrate to create large arrays that are truly flexible and significantly lighter than either the glassed alpha-Si version or present conventional crystalline technologies. In this paper the key processes for such effective transfer are described. In addition, both glassed (rigid) and unglassed (flexible) alpha-Si cells are studied when integrated with various advanced structures to form lightweight systems. EOL predictions are generated for the case of a 1000 W array in a standard, 10 year geosynchronous (GEO) orbit. Specific powers (W/kg), power densities (W/sq m) and total array costs ($/sq ft) are compared.

Description: This paper describes ultra-lightweight, high performance, thin, light trapping GaAs solar cells for advanced space power systems. The device designs can achieve 24.5 percent efficiency at AMO and 1X conditions, corresponding to a power density of 330 W/m2. A significant breakthrough lies in the potential for a specific power of 2906 W/kg because the entire device is less than 1.5 microns thick. This represents a 440 percent improvement over conventional 4-mil silicon solar cells. In addition to being lightweight, this thin device design can result in increased radiation tolerance. The attachment of the cover glass support to the front surface has been demonstrated by both silicone and electrostatic bonding techniques. Device parameters of 1.002 volts open-circuit voltage, 80 percent fill factor, and a short-circuit current of 24.3 mA/sq cm have been obtained. This demonstrates a conversion efficiency of 14.4 percent resulting in a specific power of 2240 W/kg. Additionally, this new technology offers an alternative approach for enabling multi-bandgap solar cells and high output space solar power devices. The thin device structure can be applied to any 3-5 based solar cell application, yielding both an increase in specific power and radiation tolerance.

Description: Indium phosphide (InP) P-on-N one-sun solar cells were epitaxially grown using a metalorganic chemical vapor deposition process on germanium (Ge) wafers. The motivation for this work is to replace expensive InP wafers, which are fragile and must be thick and therefore heavy, with less expensive Ge wafers, which are stronger, allowing use of thinner, lighter weight wafers. An intermediate InxGs1-xP grading layer starting as In(0.49)Ga(0.51) at the GaAs-coated Ge wafer surface and ending as InP at the top of the grading layer (backside of the InP cell) was used to attempt to bend some of the threading dislocations generated by lattice-mismatch between the Ge wafer and InP cell so they would be harmlessly confined in this grading layer. The best InP/Ge cell was independently measured by NASA-Lewis with a one-sun 25 C AMO efficiently measured by NASA-Lewis with a one-circuit photocurrent 22.6 mA/sq cm. We believe this is the first published report of an InP cell grown on a Ge wafer. Why get excited over a 9 percent InP/Ge cell? If we look at the cell weight and efficiency, a 9 percent InP cell on an 8 mil Ge wafer has about the same cell power density, 118 W/kg (BOL), as the best InP cell ever made, a 19 percent InP cell on an 18 mil InP wafer, because of the lighter Ge wafer weight. As cell panel materials become lighter, the cell weight becomes more important, and the advantage of lightweight cells to the panel power density becomes more important. In addition, although InP/Ge cells have a low beginning-of-life (BOL) efficiency due to dislocation defects, the InP/Ge cells are very radiation hard (end-of-life power similar to beginning-of-life). We have irradiated an InP/Ge cell with alpha particles to an equivalent fluence of 1.6 x 10(exp 16) 1 MeV electrons/sq cm and the efficiency is still 83 percent of its BOL value. At this fluence level, the power output of these InP/Ge cells matches the GaAs/Ge cell data tabulated in the JPL handbook. Data are presented indicating InP/Ge has more power output than GaAs/Ge cells at fluences in excess of this value.

Description: InP on Si solar cells combine the low-cost and high-strength of Si with the high efficiency and radiation tolerance of InP. The main obstacle in the growth of single crystal InP-on-Si is the high residual strain and high dislocation density of the heteroepitaxial InP films. The dislocations result from the large differences in lattice constant and thermal expansion mismatch of InP and Si. Adjusting the size and geometry of the growth area is one possible method of addressing this problem. In this work, we conducted a material quality study of liquid phase epitaxy overgrowth layers on selective area InP grown by a proprietary vapor phase epitaxy technique on Si. The relationship between growth area and dislocation density was quantified using etch pit density measurements. Material quality of the InP on Si improved both with reduced growth area and increased aspect ratio (length/width) of the selective area. Areas with etch pit density as low as 1.6 x 10(exp 4) sq cm were obtained. Assuming dislocation density is an order of magnitude greater than etch pit density, solar cells made with this material could achieve the maximum theoretical efficiency of 23% at AMO. Etch pit density dependence on the orientation of the selective areas on the substrate was also studied.

Description: The current space PV (photovoltaic) technology development program of ESA is described. The program is closely coupled to the European space mission scenario for the next 10 year period and has as its main objective to make the most effective use of the limited resources available for technology in the present economical climate. This requires a well-balanced approach between concentration on very few options and keeping the competition alive if more than one promising technology exists. The paper describes ESA's main activities in the areas of solar array technology, solar cell technology, solar cell assembly technology, and special test and verification activities including the in-orbit demonstration of new technologies.

Description: Funding for the terrestrial photovoltaic's program is $78 million in 1994. This is more than double the minimum level reached in 1989 and runs counter to the general trend of decreasing budgets for Department of Energy (DOE) programs. During the past five years, the program has expanded its mission from research and development to also address manufacturing technology and commercialization assistance. These new activities are directed toward revitalizing the market to reinstate the rapid rate of sales growth needed to attract investment. The program is approaching balance among efforts in each of the three areas. This translates to a reduction in some of the R & D activities of most relevance to the space power community. On the other hand, some of the advancements in manufacturing may finally bring thin-film technologies to reality for space arrays. This talk will describe the status and direction of DOE program with an eye toward highlighting its impact on technology of interest for space.

Description: We report on the development and performance of deep-junction (approximately 0.25 micron), graded-emitter-doped, n(sup +)-p InP solar cells grown by metallorganic chemical vapor deposition (MOCVD). A novel, diffusion-transport process for obtaining lightly-doped p-type base regions of the solar cell is described. The I-V data and external quantum-efficiency response of these cells are presented. The best active-area AMO efficiency for these deep-junction cells on (100)-oriented InP substrates is 16.8 percent, with a J(sub SC) of 31.8 mA/sq cm, a V(sub OC) of 0.843 V, and a fill-factor of 0.85. By comparison, the best cell efficiency on the (111)B-oriented InP substrates was 15.0 percent. These efficiency values for deep-junction cells are encouraging and compare favorably with performance of thin-emitter (0.03 micron) epitaxial cells as well as that of deep-emitter diffused cells. The cell performance and breakdown voltage characteristics of a batch of 20 cells on each of the orientations are presented, indicating the superior breakdown voltage properties and other characteristics of InP cells on the (111)B orientation. Spectral response, dark I-V data, and photoluminescence (PL) measurements on the InP cells are presented with an analysis on the variation in J(sub SC) and V(sub OC) of the cells. It is observed, under open-circuit conditions, that lower-V(sub OC) cells exhibit higher band-edge PL intensity for both the (100) and (111)B orientations. This anomalous behavior suggests that radiative recombination in the heavily-doped n(sup +)-InP emitter may be detrimental to achieving higher V(sub OC) in n(sup +)-p InP solar cells.

Description: Solar cells have been used to convert sunlight to electrical energy for many years and also offer great potential for non-solar energy conversion applications. Their greatly improved performance under monochromatic light compared to sunlight, makes them suitable as photovoltaic (PV) receivers in laser power beaming applications. Laser beamed power to a PV array receiver could provide power to satellites, an orbital transfer vehicle, or a lunar base. Gallium arsenide (GaAs) and indium phosphide (InP) solar cells have calculated efficiencies of more than 50 percent under continuous illumination at the optimum wavelength. Currently high power free-electron lasers are being developed which operate in pulsed conditions. Understanding cell behavior under a laser pulse is important in the selection of the solar cell material and the laser. An experiment by NAsA lewis and JPL at the AVLIS laser facility in Livermore, CA presented experimental data on cell performance under pulsed laser illumination. Reference 5 contains an overview of technical issues concerning the use of solar cells for laser power conversion, written before the experiments were performed. As the experimental results showed, the actual effects of pulsed operation are more complicated. Reference 6 discusses simulations of the output of GaAs concentrator solar cells under pulsed laser illumination. The present paper continues this work, and compares the output of Si and GaAs solar cells.

Description: InP-based multijunction tandem solar cells show great promise for the conversion efficiency (eta) and high radiation resistance. InP and its related ternary and quanternary compound semiconductors such as InGaAs and InGaAsP offer desirable combinations for energy bandgap values which are very suitable for multijunction tandem solar cell applications. The monolithically integrated InP/In(0.53)Ga(0.47)As tandem solar cells are expected to reach efficiencies above 30 percent. Wanlass, et.al., have reported AMO efficiencies as high as 20.1% for two terminal cells fabricated using atmospheric-pressure metalorganic vapor phase epitaxy (APMOVPE). The main limitations in their technique are first related to the degradation of the intercell ohmic contact (IOC), in this case the In(0.53)Ga(0.47)As tunnel junction during the growth of the top InP subcell structure, and second to the current matching, often limited by the In(0.53)Ga(0.47)As bottom subcell. Chemical beam epitaxy (CBE) has been shown to allow the growth of high quality materials with reproducible complex compositional and doping profiles. The main advantage of CBE compared to metalorganic chemical vapor deposition (MOCVD), the most popular technique for InP-based photovoltaic device fabrication, is the ability to grow high purity epilayers at much lower temperatures (450 C - 530 C). In a recent report it was shown that cost-wise CBE is a breakthrough technology for photovoltaic (PV) solar energy progress in the energy conversion efficiency of InP-based solar cells fabricated using chemical beam epitaxy. This communication summarizes our recent results on PV devices and demonstrates the strength of this new technology.

Description: This is an overview of the Ballistic Missile Defense Organization (BMDO) Photovoltaic Program. Areas discussed are: (1) BMDO advanced Solar Array program; (2) Brilliant Eyes type satellites; (3) Electric propulsion; (4) Contractor Solar arrays; (5) Iofee Concentrator and Cell development; (6) Entech linear mini-dome concentrator; and (7) Flight test update/plans.

Description: The Goddard Space Flight Center (GSFC) develops and operates a wide variety of spacecraft for conducting NASA's communications, space science, and earth science missions. Some are 'in house' spacecraft for which the GSFC builds the spacecraft and performs all solar array design, analysis, integration, and test. Others are 'out of house' spacecraft for which an aerospace contractor builds the spacecraft and develops the solar array under direction from GSFC. The experience of developing flight solar arrays for numerous GSFC 'in house' and 'out of house' spacecraft has resulted in an understanding of solar array requirements for many different applications. This presentation will review those solar array requirements that are common to most GSFC spacecraft. Solar array technologies will be discussed that are currently under development and that could be useful to future GSFC spacecraft.

Description: Energy conversion efficiency is an important parameter for solar cells, and well reported in the literature. However, solar cells heat up in sunlight, and the efficiency decreases. The temperature coefficient of the conversion efficiency is thus also extremely important, especially in mission modeling, but is much less well reported. It is of value to have a table which compiles into a single document values of temperature coefficients reported in the literature. In addition to modeling performance of solar cells in Earth orbit, where operating temperatures may range from about 20 C to as high as 85 C, it is of interest to model solar cells for several other recently proposed missions. These include use for the surface of Mars, for solar electric propulsion missions that may range from Venus to the Asteroid belt, and for laser-photovoltaic power that may involve laser intensities equivalent several suns. For all of these applications, variations in operating temperature away from the nominal test conditions result in significant changes in operating performance. In general the efficiency change with temperature is non-linear, however, in the range from negative 100 C through room temperature to a few hundred degrees C, efficiency is usually quite well modeled as a linear function of temperature (except for a few unusual cell types, such as amorphous silicon, and for extremely low bandgap cells, such as InGaAs).

Description: In future space missions, free electron lasers (FEL) may be used to illuminate photovoltaic array receivers to provide remote power. Both the radio-frequency (RF) and induction FEL provide FEL produce pulsed rather than continuous output. In this work we investigate cell response to pulsed laser light which simulates the RF FEL format. The results indicate that if the pulse repetition is high, cell efficiencies are only slightly reduced compared to constant illumination at the same wavelength. The frequency response of the cells is weak, with both voltage and current outputs essentially dc in nature. Comparison with previous experiments indicates that the RF FEL pulse format yields more efficient photovoltaic conversion than does an induction FEL pulse format.

Description: Concentrator arrays offer a number of generic benefits for space (i.e. high array efficiency, protection from space radiation effects, minimized plasma interactions, etc.). The line-focus refractive concept, however, also offers two very important advantages: (1) relaxation of precise array tracking requirements to only a single axis and (2) low-cost mass production of the lens material. The linear refractive concentrator can be designed to provide an essentially flat response over a wide range of longitudinal errors for satellites having only single-axis tracking capability. New panel designs emphasize light weight, high stiffness, storability, and ease of manufacturing and assembly. This paper addresses the current status of the concentrator program with special emphasis on the design implications, and flexibility, of using a linear refractive concentrator lens as well as details recent fabrication of prototype hardware.

Description: In 1993 two ESA solar power generators were successfully retrieved from space: EURECA with its 10 panel rigid array in August, after 11 months in a 500 km orbit, and one of the two flexible Hubble Space Telescope (HST) arrays in December, after almost 4 years in a 600 km orbit. Both solar generators are undergoing separate post-flight investigation programs (PFIP). These programs cover investigations of all solar array (SA) components and mechanisms. Since both programs have much in common, most of the component and material investigations are the same. Extremely valuable information on numerous essential subjects, such as atomic oxygen, radiation, meteoroid and space debris environment resulting damage, low cycle fatigue, material degradation, etc. are expected to be obtained for both types of arrays. We will also be able to explain and understand the anomalies experienced on both solar arrays in orbit. The paper will outline both post-flight investigation programs and will concentrate on reporting the first results and findings.

Description: Solar cells at potentials positive with respect to a surrounding plasma collect electrons. Current is collected by the exposed high voltage surfaces: the interconnects and the sides of the solar cells. This current is a drain on the array power that can be significant for high-voltage arrays. In addition, this current influences the current balance that determines the floating potential of the spacecraft. One of the objectives of the Air Force (PL/GPS) PASP Plus experiment is an improved understanding of parasitic current collection. As part of the PASP Plus program, we are using computer modeling to improve our understanding of the physical processes that control parasitic current collection.

Description: A 4000 hour experiment, conducted in late 1992 through mid 1993, confirmed earlier results on the ultraviolet damage effects in covered solar cells of various types being used, or proposed for use, in INTELSAT programs. Two different UV test systems were used to identify systematic errors and to study the effects of UV source-bulb age on degradation rate. After correction for contamination and UV source-bulb aging, the extrapolated degradation rates for irradiated and unirradiated INTELSAT-5, -6 single AR(SAR) coated cells and INTELSAT-7, -7A, -8 double layer AR(DAR) coated cells in both the 1993 tests confirm the following hypotheses resulting from the 1992 experiment. (a) Irradiated cells display significantly more UV degradation than do the unirradiated cells for tests exceeding 2000 hours. The new data indicates that degradation effects from electron irradiation are proportional to t(exp 2) (the square of the UV hours), at least for times less than or equal to 3000 hours. (b) This difference does not depend upon entire reflective coating, cell resistivity, or manufacturer within the sensitivity and reproducibility of the experiment. (c) There is a clear difference in degradation rate between single AR coated cells (TiO(x)) and double layer AR coated cells (SiO(x) and Al2O3?). At 100,000 hours (11.4 years) the DAR coated cells display more degradation than do the SAR coated cells, even though at 1,000 hours the DAR cells display less degradation. (d) UV degradation rates, to modern covered silicon solar cells, at the beginning of bulb life drop from approximately 2 times the average rate to near zero after 2000 hours (average end-of-life for the xenon short-arc lamps used in the tests). The effects of 1 MeV electron irradiation (10(exp 15) e(-)/sq cm) prior to UV exposure are clearly indicated in the plot of percent change in cell open circuit voltage (Voc) versus percent change in short circuit current (Isc) during the UV test and post-test cleanup of the cells. Clearly, extended UV testing produces a permanent photo-induced redegradation of previously irradiated cells. However, this photo-induced redegradation may be caused by the long-wavelength light, not the UV light.

Description: 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.

Description: The Advanced Photovoltaic Experiment (APEX) was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space solar cells. In addition to the cells, it was equipped with an absolute cavity radiometer to measure solar intensity, a spectroradiometer to measure the spectral content of this radiation, and a sun angle sensor. Data from the solar cells and various sensors was obtained on a daily basis during the first eleven months of the 69 month flight. We compare pre-flight and post-flight laboratory measurements with on-orbit calibration data. Pre-flight and post-flight calibration data for the cavity radiometers as well as on-orbit data demonstrated the accuracy and durability of the Eppley Labs instrument flown on APEX.

Description: At the last SPRAT conference, the Naval Research Laboratory (NRL) presented results from two experiments. One studied n+p diffused junction (DJ) InP solar cells, and the other studied n+p shallow homojunction (SHJ) InP mesa diodes grown by metalorganic chemical vapor deposition (MOCVD). The former work showed that a DJ solar cell in which the maximum power P(sub max) had been degraded by nearly 80 percent under irradiation recovered completely under short circuit illumination at 450K. The recovery was accompanied by the removal of all but one of the radiation-induced defect levels. The latter work, on the other hand, showed that the radiation-induced defects in the SHJ diodes did not anneal until the temperature reached 650K. These results suggest that an irradiated DJ solar cell, under illumination, will anneal at a temperature 200K lower than an irradiated SHJ cell. This is an unexpected result considering the similarity of the devices. The goal of the present research is to explain this different behavior. This paper investigates two points which arose from the previous studies. The first point is that the DJ cells were annealed under illumination while the SHJ diodes were annealed without bias. The second point investigated here is that the emitters of the DJ and SHJ devices were significantly different.

Description: The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys is reported. A number of different device structures were irradiated with 1.0 MeV protons. The cells were annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters or fluences below 1(exp 14) cm(exp -2); fluences above 1(exp 14) cm(exp -2) require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed in dark I-V measurements. The current mechanisms were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

Description: The superior radiation resistance of InP over other solar cell materials such as Si or GaAs has prompted the development of InP cells for space applications. The early research on radiation effects in InP was performed by Yamaguchi and co-workers who showed that, in diffused p-InP junctions, radiation-induced defects were readily annealed both thermally and by injection, which was accompanied by significant cell recovery. More recent research efforts have been made using p-InP grown by metalorganic chemical vapor deposition (MOCVD). While similar deep level transient spectroscopy (DLTS) results were found for radiation induced defects in these cells and in diffused junctions, significant differences existed in the annealing characteristics. After injection annealing at room temperature, Yamaguchi noticed an almost complete recovery of the photovoltaic parameters, while the MOCVD samples showed only minimal annealing. In searching for an explanation of the different annealing behavior of diffused junctions and those grown by MOCVD, several possibilities have been considered. One possibility is the difference in the emitter structure. The diffused junctions have S-doped graded emitters with widths of approximately 0.3 micrometers, while the MOCVD emitters are often doped with Si and have widths of approximately 300A (0.03 micrometers). The difference in the emitter thickness can have important effects, e.g. a larger fraction of the total photocurrent is generated in the n-type material for thicker emitters. Therefore the properties of the n-InP material may explain the difference in the observed overall annealing behavior of the cells.

Description: The highest AMO efficiency (19.1 percent) InP solar cell consisted of an n+pp+ structure epitaxially grown on a p+ InP substrate. However, the high cost and relative fragility of InP served as motivation for research efforts directed at heteroepitaxial growth of InP on more viable substrates. The highest AMO efficiency (13.7 percent) for this type of cell was achieved using a GaAs substrate. Considering only cost and fracture toughness, Si would be the preferred substrate. The fact that Si is a donor in InP introduces complexities which are necessary in order to avoid the formation of an efficiency limiting counterdiode. One method used to overcome this problem lies in employing an n+p+ tunnel junction in contact with the cell's p region. A simpler method consists of using an n+ substrate and processing the cell in the p+ nn+ configuration. This eliminates the need for a tunnel junction. Unfortunately, the p/n configuration has received relatively little attention the best cell with this geometry having achieved an efficiency of 17 percent. Irradiation of these homoepitaxial cells, with 1 Mev electrons, showed that they were slightly more radiation resistant than diffused junction n/p cells. Additional p/n InP cells have been processed by some activity aimed at diffusion. Currently, there has been some activity aimed at producing heteroepitaxial p+nn+ InP cells using n+ Ge substrates. Since, like Si, Ge is an n-dopant in InP, use of this configuration obviates the need for a tunnel junction. Obviously, before attempting to process heteroepitaxial cells, one must produce a reasonably good homoepitaxial cell. In the present case we focus our attention on homoepitaxially on an n+ Ge substrate.

Description: This document presents in viewgraph format information on bipolar battery development at Johnson Controls, Incorporated. The organization structure, goals, progress to date, future plans, and battery parameters and electrical properties are given.

Description: This paper presents in viewgraph format an overview of NASDA's evaluation of commercial nickel metal-hydride (Ni-MH) cells and the development and testing of Ni-MH cells for use in space. The commercial cells are concluded to be feasible and suitable for use in LEO; for GEO, the durability for overcharge is needed because long-term charge retention is required. For the aerospace Ni-MH cell design, two activation procedures are applied to evaluate the effect of the difference in the amount of overcharge protection and precharge. Specific energy of the Ni-MH cell is nearly accomplished at 50 Wh/kg. Initial characteristics indicate the effect derived from precharge. Thirty-five amp-hour class Ni-MH cells have good performance for LEO cycle of 25 and 40 percent DOD up to 3000 cycles as similar to commercial cells. The effect of the difference in the amount of overcharge protection will appear in life test.

Description: To perform heat flow measurements on batteries, it is necessary to consider the following requirements: establish thermal neutral potential; identify inefficient charging; understand self discharge mechanisms; and provide accurate voltage/temperature data. A discussion is provided in viewgraph format.

Description: The TELSTAR 4 communication satellites being manufactured by Martin Marietta Astro Space (Astro Space) for AT&T are three axis stabilized spacecraft scheduled to be launched on expendable vehicles such as the Atlas or Ariane rockets. Typically, these spacecraft consist of a box that holds the electronics and supports the antenna reflectors and the solar array wings. The wings and reflectors are folded against the sides of the box during launch and the spacecraft is spun for attitude control in that phase; they are then deployed after achieving the final orbit. The launch phase and transfer orbits required to achieve the final geosynchronous orbit typically take 4 to 5 days during which time the power required for command, telemetry, attitude control, heaters, etc., is provided by two 50 AH nickel hydrogen batteries augmented by the exposed outboard solar panels. In the past, this situation has presented no problem since there was a considerable excess of power available from the array. In the case of large high powered spacecraft such as TELSTAR 4, however, the design power levels in transfer orbit approach the time-averaged power available from the exposed surface area of the solar arrays, resulting in a very tight power margin. To compound the difficulty, the array output of the spinning spacecraft in transfer orbit is shaped like a full wave rectified sine function and provides very low charging rates to the batteries during portions of the rotation. In view of the typically low charging efficiency of alkaline nickel batteries at low rates, it was decided to measure the efficiency during a simulation of the TELSTAR 4 conditions at the expected power levels and temperatures on three nickel hydrogen cells of similar design. The unique feature of nickel hydrogen cells that makes the continuous measurement of efficiency possible is that hydrogen is one of the active materials and thus, cell pressure is a direct measure of the state of charge or available capacity. The pressure is measured with a calibrated strain gage mounted on the outside of the pressurized cell.

Description: The topics are presented in viewgraph form and cycle life vs. depth of discharge data for the following are presented: data as of three years ago; Air Force/Crane-Fuhr-Smithrick; Ken Fuhr's Data; Air Force/Crane Data; Eagle-Pitcher Data; Steve Schiffer's Data; John Smithrick's Data; temperature effects; and E-P, Yardney, and Hughes 26% Data. Other topics covered include the following: LeRC cycling tests of Yardney Space Station Cells; general statements; general observations; two different models of cycle life vs. depth of discharge; and other degradation modes.

Description: The thermoneutral potential of a nickel cadmium or nickel hydrogen cell is the potential at which the cell charge or discharge process puts out zero heat, and thus is the potential corresponding to the enthalpy change of the charge/discharge reaction, delta H. A relatively straightforward method for obtaining the thermoneutral potential E(sub tn), is based on the measured potential and temperature derivative of the cell reactions, which are related to the free energy change delta G, and entropy change delta S, respectively. Particularly in the nickel hydrogen cell, the pressure of hydrogen can often vary over an order of magnitude or more during the course of a charge or discharge. In a nickel cadmium cell, although significant changes in oxygen pressure can occur during charge or discharge, since oxygen does not enter into the charge/discharge reaction, these pressure changes are related to the heat generated from oxygen evolution and recombination. However, the entropy changes due to changes in hydrogen pressure relative to the 1 atm standard state must be included to apply this method to the nickel hydrogen cell.

Description: An overview of the NiH2 cell development is given. The NiH2 SAFT system is an electrochemical (single or dual) stack (IPV). The stack is mounted in an hydroformed Inconel 718 vessel operating at high pressure, equipped with 'rabbit ears' ceramic brazed electrical feedthroughs. The cell design is described: positive electrode, negative electrode, and stack configuration. Overviews of low earth orbit and geostationary earth orbit cyclings are provided. DPA results are also provided. The cycling and DPA results demonstrate that SAFT NiH2 is characterized by high reliability and very stable performances.

Description: The NASA-Goddard procedure for destructive physical analysis (DPA) of nickel-cadmium cells contains a method for analysis of residual charged nickel as NiOOH in the positive plates at complete cell discharge, also known as nickel precharge. In the method, the Ni(III) is treated with an excess of an Fe(II) reducing agent and then back titrated with permanganate. The Ni(III) content is the difference between Fe(II) equivalents and permanganate equivalents. Problems have arisen in analysis at NAVSURFWARCENDIV, Crane because for many types of cells, particularly AA-size and some 'space-qualified' cells, zero or negative Ni(III) contents are recorded for which the manufacturer claims 3-5 percent precharge. Our approach to this problem was to reexamine the procedure for the source of error, and correct it or develop an alternative method.

Description: A new procedure is described which was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

Description: The Aerospace Cell Test History Database was developed to provide project engineers and scientists ready access to the data obtained from testing of aerospace cell designs at Naval Surface Warfare Center, Crane Division. The database is intended for use by all aerospace engineers and scientists involved in the design of power systems for satellites. Specifically, the database will provide a tool for project engineers to review the progress of their test at Crane and to have ready access to data for evaluation. Additionally, the database will provide a history of test results that designers can draw upon to answer questions about cell performance under certain test conditions and aid in selection of a cell for a satellite battery. Viewgraphs are included.

Description: This document presents in viewgraph format the design and development of silver zinc (AgZn) batteries for the solid rocket booster (SRB) and external tank (ET) range safety subsystems. Various engineering techniques, including composite separator systems, new electrode processing techniques, and new restraint techniques, were used to meet difficult requirements.

Description: The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

Description: The topics are presented in viewgraph form and include the following: cell/battery history, operational strategy, and spacecraft data.

Description: The following topics are discussed: the Electrical Power Subsystem; the Eclipse Energy Requirements; the NiH2 CPV battery; and the battery pressure transducer. The discussion is presented in viewgraph format.

Description: The following topics are discussed: NiCd charge control; GSFC TCVL control; program specific TCVL's; and v/t changes with time/temperature/cycling. The discussion is presented in viewgraph format.

Description: The present status of the USAF NiCd cell qualification program, which is underway at the Naval Surface Warfare Center-Crane Division, is summarized. The following topics are discussed: overview; background; purpose; stress tests; results for super Ni-Cd; results for SAFT cells; GPS stress test; GPS simulated orbit; and results for gates cells. The discussion is presented in viewgraph format.

Description: The Upper Atmosphere Research Satellite (UARS), designed, built, integrated, tested, and operated by NASA and Martin Marietta is a low-Earth orbiting, Earth-observing spacecraft which was launched via Space Shuttle Discovery on September 12, 1991 and deployed three days later. The Modular Power Subsystem (MPS) onboard the satellite is equipped with three NASA Standard 50 Ampere-hour (Ah) nickel-cadmium (NiCd) batteries. McDonnell Douglas Electronics Systems Company fabricated the MPS, and batteries from Gates Aerospace Batteries cells. Nominal battery performance was achieved for the first four months of spacecraft operation. First evidence of anomalous battery performance was observed in January 1992, after the first maximum beta angle (low Depth of Discharge) period. Since then, the Flight Operations Team (FOT), under the direction of Goddard Space Flight Center's UARS Project and Space Power Application Branch, has monitored and managed battery performance by adjusting solar array offset angle, conducting periodic deep discharge, and controlling battery recharge ratio. This paper covers a brief overview of the UARS, the FOT's operational battery management, and the observed spacecraft battery performance.

Description: The topics discussed are presented in viewgraph form and include Air Force nickel hydrogen standardization goals, philosophy, project outline, cell level standardization, battery level standardization, and schedule.

Description: The following are discussed: NiH2 battery mission and environment; NiH2 cell heat dissipation; Nodal software; model development general philosophy; NiH2 battery model development; and NiH2 experimental developments.

Description: A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for appropriate pore size distributions, and the maintenance of both convective electrolyte and gas flow paths through the stack, if the recirculating stack nickel hydrogen cell design is to work properly.

Description: Viewgraphs on the battery study for the Mars Environmental Survey (MESUR) Pathfinder are presented. Topics covered include: MESUR pathfinder introduction; power subsystem concept; battery technology selection; mission battery performance; cell/battery baseline design; charge methodology; and proposed testing.

Description: Viewgraphs on advanced energy storage for space applications are presented. Topics covered include: categories of space missions using batteries; battery challenges; properties of SOA and advanced primary batteries; lithium primary cell applications; advanced rechargeable battery applications; present limitations of advanced battery technologies; and status of Li-TiS2, Ni-MH, and Na-NiCl2 cell technologies.

Description: Space Station Freedom will feature six large solar arrays, called solar array wings, built by Lockheed Missiles & Space Company under contract to Rockwell International, Rocketdyne Division. Solar cells are mounted on flexible substrate panels which are hinged together to form a 'blanket.' Each wing is comprised of two blankets supported by a central mast, producing approximately 32 kW of power at beginning-of-life. During launch, the blankets are fan-folded and compressed to 1.5 percent of their deployed length into containment boxes. This paper describes the main containment box mechanisms designed to protect, deploy, and retract the solar array blankets: the latch, blanket restraint, tension, and guidewire mechanisms.

Description: The silver-zinc (AgZn) battery system has been unique in its ability to safely satisfy high power demand applications with low mass and volume. However, a new generation of defense, aerospace, and commercial applications will impose even higher power demands. These new power demands can be satisfied by the development of a bipolar battery design. In this configuration the power consuming, interelectrode current conductors are eliminated while the current is then conducted via the large cross-section electrode substrate. Negative and positive active materials are applied to opposite sides of a solid silver foil substrate. In addition to reducing the weight and volume required for a specified power level, the output voltage performance is also improved as follows. Reduced weight through: elimination of the plastic cell container; elimination of plate leads and intercell connector; and elimination of internal plate current collector. Increased voltage through: elimination of resistance of current collector; elimination of resistance of plate lead; and elimination of resistance of intercell connector. EPI worked previously on development of a secondary bipolar silver zinc battery. This development demonstrated the electrical capability of the system and manufacturing techniques. One difficulty with this development was mechanical problems with the seals. However, recent improvements in plastics and adhesives should eliminate the major problem of maintaining a seal around the periphery of the bipolar module. The seal problem is not as significant for a primary battery application or for a requirement for only a few discharge cycles. A second difficulty encountered was with activation (introducing electrolyte into the cell) and with venting gas from the cell without loss of electrolyte. During previous work, the following projections for energy density were made from test data for a high power system which demonstrated in excess of 50 discharge/charge cycles. Projected system power = 100 kilowatts; discharge time = 30 seconds; discharge current density = 1.75 amps/sq in.; system weight = 86 lbs (9.7 WH/lb); and system volume = 1071 cu. in. (.78 WH/cu. in.). EPI is currently working on a development program to produce a bipolar silver-zinc battery design for NASA. The potential application would be to power electromechanical actuators for space launch vehicles.

Description: Gates Aerospace Batteries is conducting two long term test programs to fully characterize the NiMH cell technology for aerospace applications. The first program analyzes the effects of long term storage upon cell performance. The second program analyzes cycle life testing and preliminary production lot testing. This paper summarizes these approaches to testing the NiMH couple and culminates with initial storage and testing recommendations. Long term storage presents challenges to deter the adverse condition of capacity fade in NiMH cells. Elevated but stabilized pressures and elevated but stabilized end-of-charge voltages also appear to be a characteristic phenomenon of long term storage modes. However, the performance degradation is dependent upon specific characteristics of the metal-hydride alloy. To date, there is no objective evidence with which to recommend the proper method for storage and handling of NiMH cells upon shipment. This is particularly critical due to limited data points that indicate open circuit storage at room temperature for 60 to 90 days will result in irrecoverable capacity loss. Accordingly a test plan was developed to determine what method of mid-term to long-term storage will prevent irrecoverable capacity loss. The explicit assumption is that trickle charging at some rate above the self-discharge rate will prevent the irreversible chemical changes to the negative electrode that result in the irrecoverable capacity loss. Another premise is that lower storage temperatures, typically 0 C for aerospace customers, will impede any negative chemical reactions. Three different trickle charge rates are expected to yield a fairly flat response with respect to recoverable capacity versus baseline cells in two different modes of open circuit. Specific attributes monitored include: end-of-charge voltage, end-of-charge pressure, mid-point discharge voltage, capacity, and end-of-discharge pressure. Cycle life testing and preliminary production lot testing continue to dominate the overall technology development effort at GAB. The cell life test program reflects continuing improvements in baseline cell designs. Performance improvements include lower and more stable charge voltages and pressures. The continuing review of production lot testing assures conformance to the design criteria and expectations. This is especially critical during this period of transferring technology from research and development status to production.

Description: This is a follow-up of studies of the NASA standard 50 AH cell presented at the NASA battery workshop each of the last two years. This is a dynamic study. Data trends continue to be developed and analyzed for their utility in judging NiCd performance. The trends and parameters presented here may bear relevance to many designs of conventional NiCd batteries, not just the 50 AH and 60 AH sizes.

Description: The topics covered are presented in viewgraph form and include the following: development schedule; main specification; cell design; production flow; acceptance test (1); acceptance test (2); cell weight; 20 C performance; capacity; overcharge pressure; end of charge voltage; -5 C performance; ETS-VI simulation cycle test; and battery storage.

Description: Several recently manufactured 50 and 60 ampere hour aerospace NiCd battery cell lots, produced by Gates Aerospace Batteries, are prone to premature on orbit performance degradation. The failure mechanism is cadmium migration, and the consequent development of soft shorts. A Martin Marietta Astronautics satellite program instituted an orbital management strategy for a set of these batteries that reduced the rate of degradation and brought the system to stable operation. This strategy involves: (1) minimizing the accumulated battery overcharge; (2) regular discharge exercises; and (3) periodic battery reconditioning. Because of changes in the NiCd cell manufacturing process, the actual performance of subsequent lots of NiCd cells is open to question. Future NiCd based power system designs should therefore allow for fine control of charge parameters, and an on orbit battery reconditioning capability. To minimize risk, it is much better to perform a full life test to qualify the cells before launch, rather than in parallel with orbital operations. If there are any changes in the manufacturing process of cells, it is extremely important to maintain very strong cognizance of secondary subcontractors, recognizing that the cell and battery manufacturing discipline is easily atrophied.

Description: Nickel-hydrogen cell reversal characteristics are being studied as part of a TRW program directed towards development of a high current battery cell bypass switch. The following are discussed: cell bypass switch; nickel-hydrogen cell reversal characteristics; and nickel-hydrogen cell chemistry: discharge/reversal and overdischarge (reversal) with nickel and hydrogen precharge.

Description: Various Ni/H2 cell designs manufactured for INTELSAT Programs during the past decade have been characterized electrically as a function of temperature. The resulting data for these INTELSAT V, VI, VII and VIIA cells are assembled in a manner which allows ready comparison of performance. Also included is a detailed description of each design.

Description: Testing for the Space Station Freedom Nickel Hydrogen Cell Test Program began in 1990 at Crave Division, Naval Surface Warfare Center. The program has included receipt inspection, random vibration, acceptance, characterization, and life cycle testing of Ni-H2 cells in accordance with the NASA LeRC Interagency Order C-31001-J. A total of 400 Ni-H2 cells have been received at NAVSURFWARCENDIV Crane from three separate manufacturers; Yardney Technical Products (Yardney), Eagle Picher Industries (Eagle Picher), and Gates Energy Products (Gates). Of those, 308 cells distributed among 39 packs have undergone life cycle testing under a test regime simulating low earth orbit conditions. As of 30 September 1993, there are 252 cells assembled into 32 packs still on life cycle test. Since the beginning of the program, failed cells have been detected in all phases of testing. The failures include the following; seven 65 AmpHr and 81 AmpHr Yardney cells were found to be leaking KOH on receipt, one 65 AmpHr Eagle Picher cell failed the acceptance test, one 65 AmpHr Gates cell failed during the characterization test, and six 65 AmpHr Gates cells failed the random vibration test. Of the 39 life cycle packs, testing on seven packs, 56 cells, has been suspended because of low end of discharge voltages. All of the failed life cycle packs were cycled at 60% depth of discharge.

Description: A summary of NASA Aerospace Flight Battery Systems Program Activities is presented. The NASA Aerospace Flight Battery Systems Program represents a unified NASA wide effort with the overall objective of providing NASA with the policy and posture which will increase the safety, performance, and reliability of space power systems. The specific objectives of the program are to: enhance cell/battery safety and reliability; maintain current battery technology; increase fundamental understanding of primary and secondary cells; provide a means to bring forth advanced technology for flight use; assist flight programs in minimizing battery technology related flight risks; and ensure that safe, reliable batteries are available for NASA's future missions.

Description: A test program was conducted to characterize five space-quality nickel-hydrogen (NiH2) battery cells. A subset of those tests was also done on five commercial nickel-cadmium (NiCd) cells, for correlation to the characteristics of an Energy Storage Unit Simulator. The test program implemented the recommendations of a 1991 study, as reported to IECEC-92. The findings of the tests are summarized, and expected impacts on the performance of the electrical power system (EPS) of a large space-based radar (SBR) surveillance satellite are derived. The main characteristics examined and compared were terminal voltage (average and transient) and capacity through discharge, equivalent series resistance, derived inductance and capacitance, charge return efficiency, and inter-pulse charge effectiveness.

Description: A solar photovoltaic power system was designed and built at the NASA Lewis Research Center as part of the NASA/NSF Antarctic Space Analog Program. The system was installed at a remote field camp at Lake Hoare in the Dry Valleys and provided a six-person field team with the power to run personal computers and printers, lab equipment, lightning, and a small microwave oven. The system consists of three silicon photovoltaic sub-arrays delivering 1.5 kW peak power, three lead-acid gel battery modules supplying 2.4 kWh, and electrical distribution system which delivers 120 Vac and 12 Vdc to the user. The system was modularized for each of deployment and operation. Previously the camp has been powered by diesel generators, which have proven to be both noisy and polluting. The NSF, in an effort to reduce their dependence on diesel fuel from both and environmental and cost standpoint is interested in the use of alternate forms of energy, such as solar power. Such a power system will also provide NASA with important data on system level deployment and operation in a remote location by a minimally trained crew, as well as validate initial integration concepts.

Description: This paper presents the work performed to develop a multiring composite material flywheel and improvements of a magnetically suspended energy storage system. The flywheel is constructed of filament would graphite/epoxy and is interference assembled for better stress distribution to obtain higher speeds. The stationary stack in the center of the disk supports the flywheel with two magnetic bearings and provides power transfer to the flywheel with a motor/generator. The system operates under a 10(exp -4) torr environment and has been demonstrated to 20,000 rpm with a total stored energy of 15.9 Wh. When this flywheel cycles between its design speeds (45,000 to 90,000 rpm), it will deliver 242 Wh and have a usable specific energy density of 42.6 Wh/kg.

Description: A flywheel for energy storage using autostable high-T(sub c) superconducting magnetic bearings has been built. The rotating disk has a total weight of 2.8 kg. The maximum speed is 9240 rpm. A process that allows accelerated, reliable and reproducible production of melt-textured superconducting material used for the bearings has been developed. In order to define optimum configurations for radial and axial bearings, interaction forces in three dimensions and vertical and horizontal stiffness have been measured between superconductors and permanent magnets in different geometries and various shapes. Static as well as dynamic measurements have been performed. Results are being reported and compared to theoretical models.

Description: Presented in viewgraph format are results and accomplishments on the development of lithium/thionyl chloride bipolar batteries. Results include the development of manufacturing capability for producing large quantities of uniform cathodes and bipolar plates; the development of assembly, sealing, and activation procedures for fabrication of battery modules containing up to 150 cells in bipolar configuration; and the successful demonstration of a 10.7 kW 150-cell module with constant power pulse discharge, 20 second pulse, and 10 percent duty cycle.

Description: Polycrystalline thin film solar cells fabricated on light-weight, flexible substrates are very attractive for space applications. In this work CulnSe2 (CIS) based thin film devices were processed on metallic foil substrates using the selenization technique. CIS deposition method involved reaction of electron-bean evaporated Cu-In precursor layers with a selenizing atmosphere at around 400 C. Several metallic foils such as Mo, Ti, Al, Ni, and Cu were evaluated as possible substrates for these devices. Solar cells with AM1.5 efficiencies of 9.0-9.34 percent and good mechanical integrity were demonstrated on Mo and Ti foils. Monolithic integration of these devices was also demonstrated up to 4 in x 4 in size.

Description: The Large Area Pulsed Solar Simulator (LAPSS) has been installed at JPL. It is primarily intended to be used to illuminate and measure the electrical performance of photovoltaic devices. The simulator, originally manufactured by Spectrolab, Sylmar, CA, occupies an area measuring about 3 m wide x 12 m long. The data acquisition and data processing subsystems have been modernized. Tests on the LAPSS performance resulted in better than plus or minus 2 percent uniformity of irradiance at the test plane and better than plus or minus 0.3 percent measurement repeatability after warm-up. Glass absorption filters reduce the ultraviolet light emitted from the xenon flash lamps. This results in a close match to three different standard airmass zero and airmass 1.5 spectral irradiances. The 2-ms light pulse prevents heating of the device under test, resulting in more reliable temperature measurements. Overall, excellent electrical performance measurements have been made of many different types and sizes of photovoltaic devices. Since the original printing of this publication, in 1993, the LAPSS has been operational and new capabilities have been added. This revision includes a new section relating to the installation of a method to measure the I-V curve of a solar cell or array exhibiting a large effective capacitance. Another new section has been added relating to new capabilities for plotting single and multiple I-V curves, and for archiving the I-V data and test parameters. Finally, a section has been added regarding the data acquisition electronics calibration.

Description: SAMPIE is an in-space technology experiment that flew on STS-62. Its intent is to investigate the potentially damaging effects of space plasma (gases) on different types, sizes, and shapes of solar cells, solar modules, and spacecraft materials.

Description: The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

Description: The 1994 solar cell calibration balloon flight was completed on August 6, 1994. All objectives of the flight program were met. Thirty-seven modules were carried to an altitude of 119,000 ft (36.6 km). Data telemetered from the modules was corrected to 28 C and to 1 AU. The calibrated cells have been returned to the 6 participants and can now be used as reference standards in simulator testing of cells and arrays.

Description: Ever since Viking 1 and 2 landed on the surface of Mars in the summer of 1976, man has yearned to go back. But before man steps foot upon the surface of Mars, unmanned missions such as the Martian Soft Lander and Martian Subsurface Penetrator will precede him. Alternative renewable power sources must be developed to supply the next generation of surface exploratory spacecraft, since RTG's, solar cells, and long-life batteries all have their significant drawbacks. One such alternative is to take advantage of the unique Martian atmospheric conditions by designing a small scale, Martian wind power generator, capable of surviving impact and fulfilling the long term (2-5 years), low-level power requirements (1-2 Watts) of an unmanned surface probe. After investigation of several wind machines, a tornado vortex generator was chosen based upon its capability of theoretically augmenting and increasing the available power that may be extracted from average Martian wind speeds of approximately 7.5 m/s. The Martian Tornado Vortex Wind Generator stands 1 meter high and has a diameter of 0.5 m. Martian winds enter the base and shroud of the Tornado Vortex Generator at 7.5 m/s and are increased to an exit velocity of 13.657 m/s due to the vortex that is created. This results in a rapid pressure drop of 4.56 kg/s(exp 2) m across the vortex core which aids in producing a net power output of 1.1765 Watts. The report contains the necessary analysis and requirements needed to feasibly operate a low-level powered, unmanned, Martian surface probe.

Description: In recently years, Ga(0.5)In((0.5)P/GaAs cells have drawn increased attention both because of their high efficiencies and because they are well suited for space applications. They can be grown and processed as two-junction devices with roughly twice the voltage and half the current of GaAs cells. They have low temperature coefficients, and have good potential for radiation hardness. We have previously reported the effects of electron irradiation on test cells which were not optimally designed for space. From those results we estimated that an optimally designed cell could achieve 20 percent after irradiation with 10(exp 15) cm(exp -2) 1 MeV electrons. Modeling studies predicted that slightly higher efficiencies may be achievable. Record efficiencies for EOL performance of other types of cells are significantly lower. Even the best Si and InP cells have BOL efficiencies lower than the EOL efficiency we report here. Good GaAs cells have an EOL efficiency of 16 percent. The InP/Ga(0.5)In(0.5)As two-junction, two-terminal device has a BOL efficiency as high as 22.2 percent, but radiation results for these cells were limited. In this study we use the previous modeling and irradiation results to design a set of Ga(0.5)In(0.5)P/GaAs cells that will demonstrate the importance of the design parameters and result in high-efficiency devices. We report record AMO efficiencies: a BOL efficiency of 25.7 percent for a device optimized for BOL performance and two of different designs with EOL efficiencies of 19.6 percent (at 10(exp 15) cm(exp -2) 1MeV electrons). We vary the bottom-cell base doping and the top-cell thickness to show the effects of these two important design parameters. We get an unexpected result indicating that the dopant added to the bottom-cell base also increases the degradation of the top cell.

Description: This report documents the work performed by Rockwell International's Rocketdyne Division on NASA Contract No. NAS3-25808 (Task Order No. 16) entitled 'Mars Power System Definition Study'. This work was performed for NASA's Lewis Research Center (LeRC). The report is divided into two volumes as follows: Volume 1 - Study Results; and Volume 2 - Appendices. The results of the power system characterization studies, operations studies, and technology evaluations are summarized in Volume 1. The appendices include complete, standalone technology development plans for each candidate power system that was investigated.

Description: A preliminary top level study was completed to define power system concepts applicable to Mars surface applications. This effort included definition of power system requirements and selection of power systems with the potential for high commonality. These power systems included dynamic isotope, Proton Exchange Membrane (PEM) regenerative fuel cell, sodium sulfur battery, photovoltaic, and reactor concepts. Design influencing factors were identified. Characterization studies were then done for each concept to determine system performance, size/volume, and mass. Operations studies were done to determine emplacement/deployment maintenance/servicing, and startup/shutdown requirements. Technology development roadmaps were written for each candidate power system (included in Volume 2). Example power system architectures were defined and compared on a mass basis. The dynamic isotope power system and nuclear reactor power system architectures had significantly lower total masses than the photovoltaic system architectures. Integrated development and deployment time phasing plans were completed for an example DIPS and reactor architecture option to determine the development strategies required to meet the mission scenario requirements.

Description: Polycrystalline, thin-film photovoltaics represent one of the few (if not the only) renewable power sources which has the potential to satisfy the demanding technical requirements for future space applications. The demand in space is for deployable, flexible arrays with high power-to-weight ratios and long-term stability (15-20 years). In addition, there is also the demand that these arrays be produced by scalable, low-cost, high yield, processes. An approach to significantly reduce costs and increase reliability is to interconnect individual cells series via monolithic integration. Both CIS and CdTe semiconductor films are optimum absorber materials for thin-film n-p heterojunction solar cells, having band gaps between 0.9-1.5 ev and demonstrated small area efficiencies, with cadmium sulfide window layers, above 16.5 percent. Both CIS and CdTe polycrystalline thin-film cells have been produced on a laboratory scale by a variety of physical and chemical deposition methods, including evaporation, sputtering, and electrodeposition. Translating laboratory processes which yield these high efficiency, small area cells into the design of a manufacturing process capable of producing 1-sq ft modules, however, requires a quantitative understanding of each individual step in the process and its (each step) effect on overall module performance. With a proper quantification and understanding of material transport and reactivity for each individual step, manufacturing process can be designed that is not 'reactor-specific' and can be controlled intelligently with the design parameters of the process. The objective of this paper is to present an overview of the current efforts at MMC to develop large-scale manufacturing processes for both CIS and CdTe thin-film polycrystalline modules. CIS cells/modules are fabricated in a 'substrate configuration' by physical vapor deposition techniques and CdTe cells/modules are fabricated in a 'superstrate configuration' by wet chemical methods. Both laser and mechanical scribing operations are used to monolithically integrate (series interconnect) the individual cells into modules. Results will be presented at the cell and module development levels with a brief description of the test methods used to qualify these devices for space applications. The approach and development efforts are directed towards large-scale manufacturability of established thin-film, polycrystalline processing methods for large area modules with less emphasis on maximizing small area efficiencies.

Description: The primary purpose of this study was to measure the effects of inflow-produced heat turbulence on heat transfer in Stirling machine cylinders. A secondary purpose was to provide new experimental information on heat transfer in gas springs without inflow. The apparatus for the experiment consisted of a varying-volume piston-cylinder space connected to a fixed volume space by an orifice. The orifice size could be varied to adjust the level of inflow-produced turbulence, or the orifice plate could be removed completely so as to merge the two spaces into a single gas spring space. Speed, cycle mean pressure, overall volume ratio, and varying volume space clearance ratio could also be adjusted. Volume, pressure in both spaces, and local heat flux at two locations were measured. The pressure and volume measurements were used to calculate area averaged heat flux, heat transfer hysteresis loss, and other heat transfer-related effects. Experiments in the one space arrangement extended the range of previous gas spring tests to lower volume ratio and higher nondimensional speed. The tests corroborated previous results and showed that analytic models for heat transfer and loss based on volume ratio approaching 1 were valid for volume ratios ranging from 1 to 2, a range covering most gas springs in Stirling machines. Data from experiments in the two space arrangement were first analyzed based on lumping the two spaces together and examining total loss and averaged heat transfer as a function of overall nondimensional parameter. Heat transfer and loss were found to be significantly increased by inflow-produced turbulence. These increases could be modeled by appropriate adjustment of empirical coefficients in an existing semi-analytic model. An attempt was made to use an inverse, parameter optimization procedure to find the heat transfer in each of the two spaces. This procedure was successful in retrieving this information from simulated pressure-volume data with artificially generated noise, but it failed with the actual experimental data. This is evidence that the models used in the parameter optimization procedure (and to generate the simulated data) were not correct. Data from the surface heat flux sensors indicated that the primary shortcoming of these models was that they assumed turbulence levels to be constant over the cycle. Sensor data in the varying volume space showed a large increase in heat flux, probably due to turbulence, during the expansion stroke.

Description: The Long Duration Exposure Facility (LDEF) was composed of many separate experiments, some of which contained solar cells. These solar cells were distributed at various positions on the LDEF and, therefore, were exposed to the space environment with an orientational dependence. This report will address the space environmental effects on solar cells and solar cell assemblies (SCA's), including electrical interconnects and associated insulation blankets where flown in conjunction with solar cells.