Tuesday 14 September 1999 11.00am EST
|During the last 24 hours the ACIS bakeout completed nominally. The focal plane was kept warm (approx 31 deg C) for 4 hours before being cooled to -100 deg C. The SIM was moved to allow calibration source measurements to be made with ACIS after the bakeout and then translated back to have ACIS-S at the focal point for radiation belt entry. Initial analysis of real-time data readout from ACIS after the bakeout did not show improvement in the energy resolution of the front-illuminated chips. Data from the back-illuminated chips continued to indicate no change in performance since launch.
Following the radiation belt exit at 2.30PM 9/14, the next load will perform a long (200Ks) observation of HR1099 with ACIS-S and HETG, portions of which will be coordinated with Hubble.
Analysis of the grating anomaly has concluded and indicates that a time delay in the daily load needed to be increased to allow time for the flight software to complete commanding. This change has been incorporated into the next load.
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