HUBBLE SPACE TELESCOPE

       DAILY REPORT #3083

PERIOD COVERED:  0000Z (UTC) 03/28/02 - 0000Z (UTC) 03/29/02

Daily Status Report as of 088/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed ACS/WFC/HRC 8947 (Weekly Test)

        The Advanced Camera for Surveys (WFC and HRC) was used to perform 
basic tests to monitor, the read noise, the development of hot pixels and 
test for any source of noise in ACS CCD detectors.  This program will be 
executed at least once a day for the entire lifetime of ACS.  There were no 
problems reported.

    1.2 Completed Twelve Sets of NICMOS/1/2/3 8945 (Cooling System Monitoring)

        The Near Infrared Camera and Multi-Object Camera (NIC1, NIC2 and 
NIC3 was used 1}.to measure NICMOS detector performance during the 
cool-down and steady state operation of the NCS. 2}. to demonstrate 
stability {+/-0.1K} of the NICMOS detector temperature at the optimal 
science operating temperature. and 3}.to demonstrate repeatability {+/-0.1 
K} of NICMOS detector temperature following changes from the optimal 
science operating temperature.  No problems were encountered.

    1.3 Completed 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.  No problems were noted.

    1.4 Completed Three Sets of WF/PC-2 8698 (Identification of the 
Galaxy's Missing Mass)

        The WF/PC-2 was used to observe the nature of dark matter that is 
one of the key astrophysical questions of the day.  The existence of dark 
matter and its dynamical dominance in the outer parts of our Galaxy and 
spiral galaxies with flat rotation curves is well established.  The MACHO 
project has identified ~half of the Milky Way's dark matter with stellar 
objects of ~0.5 M_sun, probably white dwarfs.  But the location of the 
microlensing in the halo is disputed.  Several have detected two candidate 
halo white dwarfs of L/L_sun ~ 10^-5 in the Hubble Deep Field with 25 +/- 5 
mas/year proper motions.  The observations completed with no reported problems.

    1.5 Completed Two Sets of STIS/CCD 8963 (CCD Bias)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
CCD read noise from multiple bias frames obtained in common science modes: 
amplifier D, gains 1 and 4 electrons/DN, and binning factors of 1x1, 1x2, 
2x1, and 2x2.  The read noise measurements before and after NCC turn-on are 
then compared, and standard calibration reference files for use in pipeline 
reduction of SMOV3B data are constructed.  The proposal had no reported 
problems.

    1.6 Completed ACS/WFC/HRC 9031 (CCD Hot Pixel Annealing)

        The Advanced Camera for Surveys (WFC and HRC) was used to perform 
hot pixel annealing, which will be done once per month.  The CCD TECs will 
be turned off and heaters will be activated to bring the WFC detector 
temperature to about +10C.  The HRC temperature will reach about 30C.  This 
state will be held for approximately 24 hours, after which the heaters are 
turned off, the TECs turned on, and the CCDs returned to normal operating 
condition.  To assess the effectiveness of this procedure, a bias and two 
dark images will be taken before and after the annealing procedure for both 
WFC and HRC.  There were no reported problems.

    1.7 Completed STIS/CCD 8964 (CCD Darks)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
dark frames twice daily, as in a corresponding calibration 
program.  Standard calibration reference darks are constructed and hot 
pixel lists are updated for use in pipeline reduction of SMOV3B data.  All 
observations completed without incident.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  4
    Successful:  4

        Per HSTAR 8584, following a successful re-acquisition at 
087/181114Z, a loss-of-lock occurred at 087/181352Z.  No observations were 
affected.
  Scheduled Re-acquisitions: 10
    Successful: 10

    2.2 FHST Updates:
    Scheduled:  5
    Successful:  5

    2.3 Operations Notes:

        The NICMOS Cryo Cooler (NCC) cooldown continues nominally.

        SI C&DH errors were reset three times per ROP NS-5.

        The following Operations Notes were executed during this 
operational day;
Adjust ACS Error Counter Limit @087/1446z
Equipment Shelf by FHST Temp Limit Change @087/1448z
NICMOS Safing Status Buffer Messages @087/1910z
3 Gyro Configurations Limit Changes @087/2057z
Reset NICMOS MEB Radiator 2 Default Limit @087/2059z
3 Gyro Configurations Limit Changes @087/2343z
Turn Off ACS HRC/SBC Corrector Status limit @088/0350z
NICMOS Bad Mode Count OFF while NICMOS is safed @088/0359z

        Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 087/1013Z.

        The FHST 21 Shelf Temperature (ESHLF21T) flagged out-of-limits high 
at 087/122400Z with a value of 13.06189 degC (the limit is 13.0 
degC).  HSTAR 8583 was written.

        As directed by an operations request, the ACS Coarse Corrector 
Alignment -- Part 3 was performed at 087/1446Z.

        Per an operations request, Gyro 1 was powered off at 
087/192058Z.  Commanding to change the gyro configuration in the PSEA went 
smoothly, completing its reconfiguration at 087/192854Z. Final commanding 
to adjust gyro safemode test limits finished at 087/011418Z.  Attitude 
errors from a Real Time Fine Attitude Determination showed approximately 11 
arc-seconds of error (RSS) an hour after the gyro reconfiguration, well 
within the nominal errors.  A second map showed slightly higher errors (~46 
arc-seconds), not unexpected, and an ARU/PRT was scheduled to buy back 
additional margin to ensure the success of the Guide Star Acquisition.  The 
following FHST Updates and Guide Star Acquisition were successful.  SAC has 
fully reconfigured their software to match the current on-orbit 
configuration.  These updated configuration files have been transported to 
all of the CCS operational strings.

        NICMOS was safed at 087/1910Z to help the NCS cooldown process.

        At 087/1910, using an operations request, STIS and ACS high voltage 
turn-ons (via SMS commanding, were inhibited until a sufficiently low 
temperature is reached during the NCC cooldown.

        A TTR was generated when a GCMR was not acknowledged by WSGT at 
087/2302Z.

        ROP DF-18A was utilized to change an engineering status buffer 
limit System Monitor=11) at 088/0341Z.

        Per HSTAR 8585, the Zone 3B temperature (OTCZ3BT) began 
intermittently flagging out-of-limits low at 088/070758Z with a value of 
17.8714 degC.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

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

/CAW