HUBBLE SPACE TELESCOPE

       DAILY REPORT #3097

PERIOD COVERED:  0000Z (UTC) 04/17/02 - 0000Z (UTC) 04/18/02

Daily Status Report as of 108/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

The following scheduled proposals did not execute properly (the take data 
flag remained down) due to the Gyro #3 problem described in yesterday's report:

         WF/PC-2 8950 (SM3B Cool Down, Contamination Monitor, and Focus Check)
         STIS/CCD 9077 (Survey of the LMC Planetary Nebulae)
         Three Sets of WF/PC-2 8937 (Cycle 9 Supplemental Darks pt2/3)
         STIS/CCD 8904 (Bias Monitor-Part 2)
         Two Sets of STIS/CCD 8902 (Dark Monitor-Part 2)
         Five Sets ACS/WFC 9018 (Flat Field Stability)
         STIS/MA2 9573 (NUV-MAMA Daily Dark Monitor)
         STISMA1/MA2 8965 (MAMA Darks)
         STIS/CCD 8906 (Hot Pixel Annealing)
         STIS/MA1 8922 (FUV-MAMA Cycle 10 Flats)

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The following proposals partially executed once FGS control was achieved:

    1.1 WF/PC-2 8950 (SM3B Cool Down, Contamination Monitor, and Focus Check)

        The WF/PC-2 was used to monitor the planned cooldown to -88C, 
followed by UV monitors, focus checks, as well as decons and associated 
monitors.  Fine lock was achieved approximately three hours into this 
15-hour proposal.

    1.2 ACS/WFC 9018 (Flat Field Stability)

        The Advanced Camera for Surveys (WFC) was used to assess the 
stability and uniformity of the low-frequency flat fields {L-flat} of the 
WFC detector by using multiple pointing observations of the globular 
clusters 47 Tucanae {NGC104}, thus imaging moderately dense stellar 
fields.  By placing the same star over different portions of the detectors 
and measuring relative changes in its brightness it will be possible to 
determine local variations in the response of the detectors.  Fine lock was 
achieved approximately two hours into this three-and-one-half-hour proposal.

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2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 5
    Successful: 1
  Scheduled Re-acquisitions: 9
    Successful: 2

        Following the Gyro #3 problems, Gyro #1 was powered on at 
107/1013Z.  The gyro configuration was changed at 107/1349Z to reflect 
active gyros #3, #4, #2, #1 with gyro #3 in the shadow mode.  Fine attitude 
control was established via an attitude reference update at 107/1710Z with 
the first successful re-acquisition at 107/1713Z.  A subsequent 
re-acquisition at 107/1750Z was also successful.  Then, at 108/0749Z, there 
was a successful acquisition.

    2.2 FHST Updates:
    Scheduled: 3
    Successful: 3

    2.3 Operations Notes:

       See 2.1 for events relating to the recovery from the Gyro #3 problem.

        The 486 engineering status buffer limit for SESBSLD was updated 
eleven times per ROP DF-18A.

        Using ROP NS-3, the NSSC-1 status buffer was dumped at 107/1009Z.

        The Battery #3 Capacity Test began at 107/1124Z and is proceeding 
nominally.

        Per HSTAR 8614, at 107/171406Z, during the first successful 
re-acquisition, a measurement of the V1 (roll) error while guiding was 
made.  This measured value (QSFGSENB0) was -2188.939 a-s was saved, since 
the error null bias is not calculated for a re-acquisition.

        At 107/173750Z, QDVTHEJ1 (Observer Rate Bias Estimate 2) flagged 
out-of-limits with a value of -3.70619e-10 and QDVTHEJ2 (Observer Rate Bias 
Estimate 3) flagged out-of-limits with a value of 1.1934e-9.  HSTAR 8613 
was written.

        The following operations requests were completed during the day:

                 16671-0 - ARU/PRT @ 107/0904z
                 16672-1 - Gyro 1 Power On @ 107/1013z
                 16674-0 - ARU/PRT @ 107/1233z
                 16673-0 - Gyro 3 Reconfiguration @ 107/1349z
                 16667-0 - HLGBU from LBBias Maps @ 107/1710z
                 16675-0 - R/T Map @ 107/1755z
                 16678-0 - ARU/PRT @ 107/1913z
                 16679-0 - R/T Map @ 107/1929z
                 16681-0 - R/T Map @ 107/2111z
                 16624-0 - Reset NCS Min/Max buffer @ 107/2112z
                 16682-0 - ARU/PRT @ 107/2237z
                 16684-0 - ARU/PRT @ 108/0109z
                 16685-0 - HLGBU from LBBias Maps @ 108/0121z
                 16686-0 - ARU/PRT @ 108/0216z
                 16687-0 - R/T Map @ 107/0345z
                 16691-0 - ARU/PRT @ 108/0435z
                 16689-0 - R/T Map @ 108/0513z
                 16680-1 - Mask -E SPA from TRSWCC stack @ 108/0523z
                 16662-0 - Battery 3 Reconditioning (thru step 30) @ 108/0524z
                 16690-2 - HLGBU from LBBias Maps @ 108/0528z
                 16666-0 - Recorder Management for Battery Reconditioning
                         (Completed Continuous Engineering Record Mode) @ 
108/0538z
                 16692-0 - HLGBU from LBBias Maps @ 108/0713z
                 16693-0 - ARU/PRT @ 108/0714z

        The following operations notes were completed:

                 989-0 - Gyro 3 Reconfiguration Limits
                 990-1 - Reset Safing Limits for Gyro Reconfiguration
                 991-0 - Ignore ACS STB 290 due to Event Flag2 being set
                 911-0 - Limit Management During WFPC2 Decontamination (M001)

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        The NICMOS recovery-is scheduled to begin tomorrow at approximately 
109/0705Z.

        Continuation of Servicing Mission Orbital Verification and the 
gradual resumption of normal science observations and calibrations.

/CAW