Chandra Operations CXO Status Report Friday 10 May 2002

During the last week, Chandra completed the observing schedule as planned.

A software patch was approved to increase two glitch counters to mitigate unintended EPHIN hardware failure flag state changes. State changes in April and last December led to loss of science time due to SCS 107 executions. The cause has been traced to a subtle timing interaction. Uplink of the patch is expected next week.

Chandra will pass through a 15 minute lunar eclipse on 11 May. Due to the short duration and small change in solar array illumination, no actions on-board are required. A 3 degree F temperature drop in the solar arrays is predicted, and comparisons will be made with the actual performance using dump data following the eclipse.

The observing schedule for the next week is shown below and includes an observation of Mrk 279 coordinated with Hubble Space Telescope.

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G349.7+0.2             ACIS-S       May 12
NGC6397                ACIS-S       May 13
XRF020427              ACIS-S
Radiation Belts                     May 14
0858-771               ACIS-S
1343-601               ACIS-S
SNR 1987A              ACIS-S
0903-573               ACIS-S       May 15
NGC6397                ACIS-S
G21.5-0.9              ACIS-I
LBQS 2350-0045A        ACIS-S       May 16
G21.5-0.9              ACIS-S
PSS 1605+4405          ACIS-S
Q0740+380              ACIS-S
Radiation Belts                     May 17
NGC 2782               ACIS-S
RXJ1552.2+2013         ACIS-S
Mrk279                 ACIS-S/HETG  May 18
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All spacecraft subsystems continued to operate nominally.