NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsMegawatt solar power systems for lunar surface operationsLunar surface operations require habitation, transportation, life support, scientific, and manufacturing systems, all of which require some form of power. As an alternative to nuclear power, the development of a modular one megawatt solar power system is studied, examining both photovoltaic and dynamic cycle conversion methods, along with energy storage, heat rejection, and power backup subsystems. For photovoltaic power conversion, two systems are examined. First, a substantial increase in photovoltaic conversion efficiency is realized with the use of new GaAs/GaSb tandem photovoltaic cells, offering an impressive overall array efficiency of 23.5 percent. Since these new cells are still in the experimental phase of development, a currently available GaAs cell providing 18 percent efficiency is examined as an alternate to the experimental cells. Both Brayton and Stirling cycles, powered by linear parabolic solar concentrators, are examined for dynamic cycle power conversion. The Brayton cycle is studied in depth since it is already well developed and can provide high power levels fairly efficiently in a compact, low mass system. The dynamic conversion system requires large scale waste heat rejection capability. To provide this heat rejection, a comparison is made between a heat pipe/radiative fin system using advanced composites, and a potentially less massive liquid droplet radiator system. To supply power through the lunar night, both a low temperature alkaline fuel cell system and an experimental high temperature monolithic solid-oxide fuel cell system are considered. The reactants for the fuel cells are stored cryogenically in order to avoid the high tankage mass required by conventional gaseous storage. In addition, it is proposed that the propellant tanks from a spent, prototype lunar excursion vehicle be used for this purpose, therefore resulting in a significant overall reduction in effective storage system mass.Document ID19900017075Acquisition SourceLegacy CDMSDocument TypeContractor Report (CR)AuthorsAdams, Brian*(Washington Univ. Seattle, WA, United States)*Alhadeff, Sam*(Washington Univ. Seattle, WA, United States)*Beard, Shawn*(Washington Univ. Seattle, WA, United States)*Carlile, David*(Washington Univ. Seattle, WA, United States)*Cook, David*(Washington Univ. Seattle, WA, United States)*Douglas, Craig*(Washington Univ. Seattle, WA, United States)*Garcia, Don*(Washington Univ. Seattle, WA, United States)*Gillespie, David*(Washington Univ. Seattle, WA, United States)*Golingo, Raymond*(Washington Univ. Seattle, WA, United States)*Gonzalez, Drew*(Washington Univ. Seattle, WA, United States)*Date AcquiredSeptember 6, 2013Publication DateJune 21, 1990Subject CategoryEnergy Production And ConversionReport/Patent NumberAA-420NASA-CR-186509AA-421NAS 1.26:186509Accession Number90N26391Funding Number(s)CONTRACT_GRANT: NGT-21-002-800Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19900017075.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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