HUBBLE SPACE TELESCOPE

                        DAILY REPORT #2476

PERIOD COVERED:  0000Z (UTC) 10/11/99 - 0000Z (UTC) 10/12/99

Daily Status Report as of 285/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed 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.

    1.2 Completed Three Sets of WF/PC-2 8442 (WF/PC-2 Cycle 8 Standard Darks)

        The WF/PC-2 was used to make a series of Cycle 8 standard dark 
calibration observations.  This dark calibration program obtains dark 
frames every week in order to provide data for the ongoing calibration of 
the CCD dark current rate, and to monitor and characterize the evolution of 
hot pixels.  The observations were executed as scheduled, and no anomalies 
were noted.

    1.3 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.

    1.4 Completed WF/PC-2 7466 (From Globular Clusters to Tidal Dwarfs: 
Structure Formation in Tidal Tails.)

        The WF/PC-2 was used to make observations of the globular clusters 
(et al.) within the tidal tail of galactic merger NGC-3256.  By modeling 
these systems with N-body hydrodynamic codes, can we identify the physical 
circumstances and formation histories which can produce tidal dwarfs, star 
clusters, and other structures in tidal tails?  The observations were 
completed as planned, and no anomalies were reported.

    1.5 Completed STIS/CCD 8549 (POMS Test Proposal: STIS non-scripted 
parallel proposal continuation III)

        The Space Telescope Imaging Spectrograph (CCD) was used to make low 
galactic latitude observations as part of a non-scripted POMS Test 
Proposal. The observations were completed as scheduled, and no problems 
were reported.

    1.6 Completed STIS/CCD 8313 (Imaging the Host Galaxies of High Redshift 
Type Ia Supernovae)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations of 970 and its host galaxy.  The propose is to obtain 
snapshot, unfiltered STIS images of distant galaxies of known redshift 
which have hosted supernovae {SNe} of Type IA found via the Supernova 
Cosmology Project.  The observations were completed as scheduled, and no 
anomalies were reported.

    1.7 Completed Two Sets of WF/PC-2/STIS/CCD 8169 (HST-Galileo Io Campaign)

        Both the WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) 
were used to make observations of Jupiter's moon Io.  Io plays a central 
role in the Jovian system, yet the mechanisms that couple its volcanoes, 
the tenuous atmosphere, the escaping corona and the plasma torus remain 
elusive.  In 1999 there is the unique opportunity to combine HST 
observations with the Galileo close flybys of Io.  The observations were 
completed as planned, and no problems were reported.

    1.8 Completed Three Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) 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.

    1.9 Completed Three Sets of WF/PC-2 8457 (UV Earthflats)

        The WF/PC-2 was used to make a ultraviolet Earth flat calibration 
image.  This is to improve the quality of pipeline the ultraviolet 
flatfields.  The observations were completed as scheduled, and no problems 
were reported.

    1.10 Completed Two Sets of WF/PC-2 8443 (WF/PC-2 Cycle-8 Supplemental 
Darks pt1/3)

        The WF/PC-2 was used to obtain three dark frames every day to 
provide data for monitoring and characterizing the evolution of hot 
pixels.  The observations were completed as planned, and no problems were 
reported.

    1.11 Completed STIS/CCD/MA1 8171 (HST Far-UV Imaging and Spectra of 
Jupiter's Aurora During the Galileo Extended Mission)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
make far-ultraviolet spectrographic observations of the northern aurora on 
the planet Jupiter as part of the extended Galileo Mission.  Observations 
were also made of the moon Europa.  This is to study the nature of the 
satellite auroral footprints in Jupiter's atmosphere.  The observations 
were completed as planned, and no problems were reported.

    1.12 Completed WF/PC-2 8222 (An Emission Line Survey of the Crab Nebula)

        The WF/PC-2 was used to conduct an emission line survey of the Crab 
Nebula (a.k.a., M-1) in the light of emission from O I, S II, and O III, 
and in a single continuum band.  In addition to our specific scientific 
objectives, this survey will provide a data set that is essential to all 
future studies of the structure, dynamics, and evolution of the Crab.  The 
observations were executed as scheduled, and no anomalies were reported.

    1.13 Completed STIS/CCD 8104 (Constraints on the Evolution of Powerful 
Radio Galaxies)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
observations 3C277.1.  Recent work has identified the GHz Peaked Spectrum 
and Compact Steep Spectrum radio sources as the most likely candidates for 
the progenitors of the large-scale powerful classical double sources.  Both 
a wavelength calibration image and a CCD flat calibration image were also 
taken.  The observations were completed as planned, and no anomalies were 
reported.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:

                             Scheduled Acquisitions:  4
                                         Successful:  4

                          Scheduled Re-acquisitions: 10
                                         Successful: 10

    2.2 FHST Updates:

                               Scheduled: 10
                              Successful: 10

    2.3 Operations Notes:

        Received after yesterday's report had been transmitted: The gyro 1 
motor current shifted from approximately 145ma to approximately 162ma at 
281/1656Z.  The step function occurred about four minutes after the 
completion of a guide star acquisition, and was accompanied by an 
approximate 35/arc/sec/hr shift in the vehicle rate bias, as seen in the 
control law observer.  Vehicle bias measures were executed and a new bias 
was uplinked at 281/2120Z.  No unusual bias trends have been observed since 
this event, although a small (2.4%) decrease in heater duty cycle was noted 
over the 12-hour period following the event.  It is thought that the 
probable cause is a lubrication patch.  The contractor has been notified.

        The SSR EDAC error counter was cleared twice per ROP SR-1.

       At 284/100534Z, a STIS status buffer message was received indicating 
that an MIE second event threshold had been exceeded.  HSTAR 7307 was 
written.  The STIS flight software error counter was reset at 284/1134Z per 
ROP NS-12.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/DMH