Space Telescope Science Institute   4.4.3 Optical Performance  4.5.2 MAMA Overflow of the 16 Bit Buffer

4.5 SBC Operations and Limitations


4.5.1 SBC Scheduling Policies


The STIS MAMA control electronics are subject to resets due to cosmic-ray upsets. Therefore, STIS MAMAs were operated only during the contiguous orbits of each day that are free of the South Atlantic Anomaly (SAA). Even though the design of the ACS MAMA control electronics in the SBC was modified so that they would not be susceptible to cosmic-ray hits, the background count rate still exceeds the bright object limits for the SBC during SAA passage. Consequently, the SBC will in general only be scheduled for use during SAA-free orbits.


 4.4.3 Optical Performance  4.5.2 MAMA Overflow of the 16 Bit Buffer
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