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Pre-Flight Dark Forward Electrical Testing of the Mir Cooperative Solar ArrayThe Mir Cooperative Solar Array (MCSA) was developed jointly by the United States (US) and Russia to provide approximately 6 kW of photovoltaic power to the Russian space station Mir. After final assembly in Russia, the MCSA was shipped to the NASA Kennedy Space Center (KSC) in the summer of 1995 and launched to Mir in November 1995. Program managers were concerned of the potential for MCSA damage during the transatlantic shipment and the associated handling operations. To address this concern, NASA Lewis Research Center (LERC) developed an innovative dark-forward electrical test program to assess the gross electrical condition of each generator following shipment from Russia. The use of dark test techniques, which allow the array to remain in the stowed configuration, greatly simplifies the checkout of large area solar arrays. MCSA dark electrical testing was successfully performed at KSC in July 1995 following transatlantic shipment. Data from this testing enabled engineers to quantify the effects of potential MCSA physical damage that would degrade on-orbit electrical performance. In this paper, an overview of the principles and heritage of photovoltaic array dark testing is given. The specific MCSA dark test program is also described including the hardware, software, testing procedures and test results. The current-voltage (4) response of both solar cell circuitry and by-pass diode circuitry was obtained. To guide the development of dark test hardware, software and procedures, a dedicated FORTRAN computer code was developed to predict the dark 4 responses of generators with a variety of feasible damage modes. By comparing the actual test data with the predictions, the physical condition of the generator could be inferred. Based on this data analysis, no electrical short-circuits or open-circuits were detected. This suggested the MCSA did not sustain physical damage that affected electrical performance during handling and shipment from Russia to the US. Good agreement between the test data and computational predictions indicated MCSA electrical performance was amenable to accurate analysis and was well understood.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Kerslake, Thomas W.
(NASA Lewis Research Center Cleveland, OH United States)
Scheiman, David A.
(NYMA, Inc. Brook Park, OH United States)
Hoffman, David J.
(NASA Lewis Research Center Cleveland, OH United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1997
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
NAS 1.15:107496
Meeting Information
Meeting: Intersociety Energy Conversion Engineering
Location: Honolulu, HI
Country: United States
Start Date: July 27, 1997
End Date: August 1, 1997
Sponsors: American Inst. of Aeronautics and Astronautics, American Inst. of Chemical Engineers, Society of Automotive Engineers, Inc., Institute of Electrical and Electronics Engineers, American Nuclear Society, American Society of Mechanical Engineers
Accession Number
Funding Number(s)
PROJECT: RTOP 478-12-10
Distribution Limits
Work of the US Gov. Public Use Permitted.
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