Fig. 8-17. SAS-3 Major Frames of Data Showing Flagged Data at the Beginning and End of a Data Pass

When more data are available than required by the attitude determination software, data segments are often filled with every nth available data point, thereby reducing the size of the arrays which must be allocated in core for processing. Alternatively, when the volume of data is great enough to prohibit retaining all results in core, the telemetry processor can write its results to an intermediate storage device so the attitude determination software can read and process only the data needed for a particular function (e.g., star camera data, Sun and magnetometer data, slit star sensor data, or infrared Earth horizon sensor data). This method was used for SAS-3 and HEAO-1.

* For examples of time-checking schemes, see Lerner, et a/, [1974J, Williams, el al, [1974], or Cheuvront and Eiserike [1975].


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14. U.S. Senate, Soviet Space Programs, 1966-70, Staff Report for the Committee on Aeronautical and Space Sciences, 92nd Congress, Document No. 92-51, Dec. 1971.

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