HUBBLE SPACE TELESCOPE

   DAILY REPORT #2541

PERIOD COVERED:  0000Z (UTC) 01/17/00 - 0000Z (UTC) 01/18/00

Daily Status Report as of 018/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD 8411 (STIS CCD Spectroscopic Flats C-8)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
CCD flats in the spectroscopic mode.  The observations were completed as 
scheduled, and no anomalies were reported.

    1.2 Completed Two Sets of FGS 8522 (Adjusting FGS2r's AMA for Optimal 
Interferometric Performance)

        The FGS2R was used to obtain S-curves at selected locations within 
the FGS2R FOV.  These data will be will be used to adjust the AMA so as to 
align the HST pupil onto the interferometer's Koesters prisms.  The final 
AMA position will be set to produce an acceptable set of s-curves across 
the FGS2r FOV.  The proposal completed with no reported problems.

    1.3 Completed Two Sets of STIS/CCD 8408 (STIS CCD Dark Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to make a 
CCD bias calibration observation.  This is to monitor the darks for the 
STIS CCD.  The observations were executed as scheduled, and no anomalies 
were reported.

    1.4 Completed Three Sets of WF/PC-2 8491 (Transition to Hold, Decon and 
Cool Down Procedure)

        This program covers the transition from Protect Safe Mode to Hold 
Mode, then performs a Protect Decontamination. This is followed by a series 
of UV monitors and focus checks at -43C, then a special decon to take the 
instrument to -88C.  The program completed nominally.

    1.5 Completed STIS/CCD 8409 (STIS CCD Bias Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to make a 
CCD bias calibration observation.  This is to monitor the bias in the 1x1, 
1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up 
high-S/N superbiases and to track the evolution of hot columns.  The 
observations were executed as scheduled, and no anomalies were reported.

    1.6 Completed STIS/CCD 8412 (STIS CCD Imaging Flats C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate the flat-field stability of the unit over a monthly period.  A 
bias calibration observation was also taken.  The observations were 
executed as scheduled, and no anomalies were noted.

    1.7 Completed STIS/MA1/MA2 8426 (Cycle 8 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to 
make a routine Cycle-8 MAMA dark noise calibration measurement.  This 
proposal will provide the primary means of checking on the health of the 
MAMA detectors.  This is done through frequent monitoring of the background 
count rate.  The observations were completed as planned, and no problems 
were reported.

    1.8 Completed STIS/CCD/MA1 8107 (What is the Nature of the Cold Medium 
in Cooling Flow Clusters?)

        The Space Telescope Imaging Spectrograph (CCD/MA1) was used to 
observe X-ray spectra of cooling flow clusters of galaxies in an attempt to 
discover the presence of large columns of "cold'' absorbing material.  The 
proposal completed with no reported problems.

    1.9 Completed STIS/MA2 8509 (NUV MAMA Darks)

        The Space Telescope Imaging Spectrograph (MA2) was used to 
determine the health of the FUV MAMA detector by monitoring the background 
count rate.  The observations completed with no reported problems.

    1.10 Completed STIS/CCD 8511 (Full-field Sensitivity and Geometry)

        The Space Telescope Imaging Telescope (CCD) was used to measure the 
geometric distortion for each STIS detector, using the same field as 
previously used for measuring the MAMA geometric distortion in cycle 
7.  These exposures will also serve to measure the image location for each 
of the MAMA imaging modes, with respect to the CCD frame, In order to fix 
the detector coordinates for the STIS MAMA imaging modes with respect to 
the CCD coordinates, and hence to the FGS system.  The proposal completed 
nominally.

    1.11 Completed FGS 8334 (HD 98800: An Opportunity to Measure True 
Masses for Low-Mass PMS Stars)

        The Fine Guidance Sensors were used to make astrometric 
observations of the low mass pre-main sequence (PMS) star HD98800 in order 
to measure its true mass.  HD 98800 became interesting when IRAS found it 
to have a large infrared excess, indicating a substantial dust disk.  The 
observations were executed as scheduled, and no anomalies were noted.

    1.12 Completed WF/PC-22 8498 (Internal Monitor - Post-TEC Turn On)

        The WF/PC-2 was used to obtain routine internal observations in 
order to monitor basic instrument health, and optical alignment (K-spots, 
INTFLATS, VISFLATS, UVFLATS, bias,
Darks).  The observations completed nominally.

    1.13 Completed STIS/CCD 8202 (Bright Quasar Close Lensing Search)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations of HCLQ1651+4+5 as part of a second generation survey to 
search for bright lensing quasars.  With the restored PSF, new images will 
be considerably more sensitive to the presence of both close separation and 
faint lens components, and because STIS reaches two magnitudes fainter the 
PC, the new snapshot images will have much greater dynamic range.  The 
observations were executed as scheduled, and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 8
Successful: 8

  Scheduled Re-acquisitions: 3
Successful: 3

    2.2 FHST Updates:
Scheduled: 23
Successful: 23

    2.3 Operations Notes:

        Servicing Mission Observatory Verification (SMOV) activities 
dominate the observations currently being performed.

        Using ROP SR-1A, the SSR EDAC error counter was reset once.

        Per HSTAR 7475, on five occasions, beginning at 017/122358Z and 
lasting for approximately nine minutes, Coarse Sun Sensor  (CSS) #2 
position parameter (GAPXASS2) flagged out-of-limits low with a value of 
-5.04001.  There was no CCS #2 sun presence at the time.

        With ROP DF-07A as a guide, the ephemeris tables were uplinked at 
018/0007Z.

        The acquisition at 018/030811Z defaulted to fine lock backup on 
FGS-1 only when the scan step limit was exceeded.  HSTAR 7476 was 
written.  STIS/CCD/MA1 proposal 8511, occurring during the period of the 
next report, may have been affected.

        The STIS EMC experienced a re-try at 108/034146Z.  Per ROP NS-12, 
the STIS flight software error counter was reset at 018/0501Z.

        At 018/060928Z, various coarse sun sensor parameters (GAPCASS1, 
GAPXASS2, GAPCBSS1, and GAPXBSS2) flagged out-of-limits with values of 5.04 
and -5.04.  Limits are 5.0 and -5.0.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of SMOV and normal science observations and calibrations.

/CAW