Operations CXO Status Report

Friday 20 December 2002 9.00am EST

During the last week Chandra completed the observing schedule as planned. During a real-time pass on 19 Dec the ACIS Digital Processing Assembly (DPA-A) was seen in an unexpected powered-off state. Assessment of the real-time telemetry indicated behavior consistent with a similar DPA turn-off in October 2000. In that case fault-tree analysis concluded the event was due to a single event upset. The DPA was powered back on and the required software patches reloaded during a real-time pass at 1am on Dec 20. Since the power-off and power-on occurred within the radiation belt zone, no science was lost due to the event. Further engineering analysis will be performed. A real-time procedure was completed on Dec 19 to disable an aberration adjustment made in the OBC software. The adjustment has been disabled to accommodate the accuracy requirements of a series of observation of the Crab nebular that will be occulted by Saturn's moon Titan on Jan 5. Of note last week was the conduct of the Chandra User's Committee meeting on Dec 17-18. The mission planning team completed work on the 2-week schedule to span the holiday period. The schedule of observations is shown below and includes the occultation observation of Titan.

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MACS-J2243.3-0935       ACIS-I       Dec 23
MR2251-178              HRC-S/LETG
NGC 1365                ACIS-S       Dec 24
MACS-J0329.6-0211       ACIS-I
Z03521+0028             ACIS-S
Radiation Belts                      Dec 25
NGC 1265                ACIS-S
MACSJ2228.5+2036        ACIS-I       Dec 26
3C 438                  ACIS-S       Dec 27
Radiation Belts                      Dec 28
A665                    ACIS-I
1E0953.8+6918           ACIS-S
RCS1620+2929            ACIS-S       Dec 28
AX J1532.3+2401         ACIS-S       Dec 29
NGC5953                 ACIS-S
M87                     ACIS-S
4U 1145-619             ACIS-S
0506-68.0               ACIS-S
Radiation Belts                      Dec 30
SNR1987A                ACIS-S
MYCN 18                 ACIS-S       Dec 31
DEM L50                 ACIS-S       Jan 1
EIS0954-2023/22         ACIS-S
LBSQ1009-0252           ACIS-S
PC 1015+4752            ACIS-S
2MASS093844+005716      ACIS-S
Radiation Belts                      Jan 2
3C215                   ACIS-S
SDSS J141234.68-003500  ACIS-S       Jan 3
NGC 5845                ACIS-S
GRB021201               ACIS-I
NGC2623                 ACIS-S
MACS-J0744.8+3927       ACIS-I
RX J045707.4+452751     ACIS-S       Jan 4
RXJ0439.0+0715          ACIS-I
Radiation Belts
Titan                   ACIS-S/HETG  Jan 5

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All spacecraft subsystems continued to operate nominally.

The next report is planned for January 3 following the holiday. A Happy Holiday and New Year to everyone from the entire Chandra Team!

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