NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsModular Stirling Radioisotope GeneratorHigh-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and similar to the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). However, the reliability should be significantly increased compared to ASRG.Document ID20160005725Acquisition SourceGlenn Research CenterDocument TypeTechnical Memorandum (TM)AuthorsSchmitz, Paul C.*(Power Computing Solutions, Inc. Avon, OH, United States)*Mason, Lee S.*(NASA Glenn Research Center Cleveland, OH United States)*Schifer, Nicholas A.*(NASA Glenn Research Center Cleveland, OH United States)*Date AcquiredMay 3, 2016Publication DateApril 1, 2016Subject CategoryEnergy Production And ConversionReport/Patent NumberNASA/TM-2016-218911AIAA Paper 2015-3809E-19167GRC-E-DAA-TN25959Meeting InformationMeeting: International Energy Conversion Engineering Conference (IECEC)Location: Orlando, FLCountry: United StatesStart Date: July 27, 2015End Date: July 31, 2015Sponsors:American Inst. of Aeronautics and AstronauticsFunding Number(s)WBS: WBS 138494.04.18.01.01.01CONTRACT_GRANT: NNC12BA01BDistribution LimitsPublicCopyrightPublic Use Permitted.KeywordsModulesElectric GeneratorsStirling CycleAvailable DownloadsNameType20160005725.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
 No Fear Act | Freedom of Information Act | Office of the Inspector General | Agency Financial ReportsNASA Web Privacy Policy and Important Notices | NASA Guidelines for Quality of InformationDisclaimers, Copyright, Terms of Use | Accessibility | NASA OCIO | USA.gov | NASA.govContact Us | Site MapSTI LogoNASA Official: JoAnne R. Calhoun Site Curator: STI Compliance and Distribution Services Last Modified: September 12, 2024