NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
AXAF-I Low Intensity-Low Temperature (LILT) Testing of the Development Verification Test (DVT) Solar PanelThe planned orbit of the AXAF-I spacecraft will subject the spacecraft to both short, less than 30 minutes for solar and less than 2 hours for lunar, and long earth eclipses and lunar eclipses with combined conjunctive duration of up to 3 to 4 hours. Lack of proper Electrical Power System (EPS) conditioning prior to eclipse may cause loss of mission. To avoid this problem, for short eclipses, it is necessary to off-point the solar array prior to or at the beginning of the eclipse to reduce the battery state of charge (SOC). This yields less overcharge during the high charge currents at sun entry. For long lunar eclipses, solar array pointing and load scheduling must be tailored for the profile of the eclipse. The battery SOC, loads, and solar array current-voltage (I-V) must be known or predictable to maintain the bus voltage within acceptable range. To address engineering concerns about the electrical performance of the AXAF-I solar array under Low Intensity and Low Temperature (LILT) conditions, Marshall Space Flight Center (MSFC) engineers undertook special testing of the AXAF-I Development Verification Test (DVT) solar panel in September-November 1997. In the test the DVT test panel was installed in a thermal vacuum chamber with a large view window with a mechanical "flapper door". The DVT test panel was "flash" tested with a Large Area Pulse Solar Simulator (LAPSS) at various fractional sun intensities and panel (solar cell) temperatures. The testing was unique with regards to the large size of the test article and type of testing performed. The test setup, results, and lessons learned from the testing will be presented.
Document ID
19990095040
Document Type
Conference Paper
Authors
Alexander, Doug (NASA Marshall Space Flight Center Huntsville, AL United States)
Edge, Ted (NASA Marshall Space Flight Center Huntsville, AL United States)
Willowby, Doug (NASA Marshall Space Flight Center Huntsville, AL United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1998
Subject Category
Energy Production and Conversion
Meeting Information
Intersociety Energy Conversion Engineering Conference (IECEC)(Colorado Springs, CO)
Funding Number(s)
CONTRACT_GRANT: NAS8-37710
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.