Optimizing the efficiency of command load inspection for the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Telescope

The Chandra X-ray Observatory (CXO), launched in July of 1999, contains two focal-plane imaging detectors and two gratings spectrometers. Keeping these instruments operating at an optimal performance level is the responsibility of the Chandra X-ray Center, located in Cambridge, MA. Each week a new set of command loads is generated to be uploaded to the spacecraft for use in the following week. The command loads contain all of the necessary instructions for the observatory to execute a week's worth of science observations and spacecraft maintenance activities. Ensuring that these loads do not compromise the performance of the observatory or its health and safety in any way is a complex procedure. It requires a coordinated review and subsequent approval of the loads from a team of scientists and engineers representing each instrument on the spacecraft. Reviewing the command loads can be quite a daunting task; but with the help of automated scripts and command load interpretation into "human-readable" form, we have been able to streamline the command load review process as well as improve our ability to identify errors in commanding. We present here a detailed review of those scripts utilized in the inspection of command loads for the ACIS instrument. This work was supported by NASA contract NAS8-39073.