Sunday 15 August 1999 7.00am EST
|The following is an overview of the events that occurred over the last 24 hours
Offline System (OFLS) scheduling of mission loads. - Started performing maneuvers and test observations controlled from onboard Real Time Sequences (RTS) derived in the OFLS instead of real time ground commands. This load was to control the Chandra until about midnight Sunday. During maneuvers experienced problems acquiring FID lights and stars. During one maneuver Chandra did not acquire scheduled guide stars, and as designed dropped into bright start hold mode, by locking onto bright stars in the Aspect Camera field of view. As expected, on-board mission Stored Command Sequences (SCS) were also terminated. Further analysis indicated that the logic in the On Board Computer (OBC) needs to be corrected to allow the Aspect Camera to release and reacquire guide stars based on maneuver requirements. Activities are underway to correct these problems, and re-enter the OFLS mission scheduling within 24 hours. In the meantime, Chandra activities are being be performed via real time commands.
ACIS focusing activities are in progress. As part of this activity the Science Instrument Module (SIM) underwent successful movements in the focus direction. This is the first time this mechanism was exercised since launch. Movement of the SIM Translation mechanism is planned in a few days.
Activities for next 24 hours
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