Photoelectric sun sensing unit similar to those flown on the OSO series satellites. The OSO satellites consisted of a circular bus that rotated at 30 rpm and an upper sail-like section that carried solar cells and additional instruments. (see OSO-1; Catalogue # A19820270000). Signals from this sail-mounted sun sensor were fed to a servo-feedback mechanism to keep the upper portion instruments and solar cells pointed on the center of the sun within +/- 1 minute of arc. This device was transferred to NASM by NASA (GSFC) in 1988.
Transferred from the National Aeronautics and Space Administration