HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2355

PERIOD COVERED:  0000Z (UTC) 04/20/99 - 0000Z (UTC) 04/21/99

Daily Status Report as of 111/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed STIS/CCD/MA1/MA2 7301 (Studies of the Characteristics of
the Interstellar Medium in the Carina Nebula)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used
to make observations of the star HD93205 which is located in the Carina
Nebula.  It is proposed to carry out high-resolution ultraviolet
spectroscopic observations of interstellar lines in the spectra of OB stars
in the Carina Nebula, which will provide unique data on the interstellar
medium associated with star cluster formation.  A wavelength calibration
image was also taken.  The observations were completed as planned, and no
anomalies were noted.

   1.2 Completed Two Sets of STIS/CCD 7949 (CCD Dark and Bias Monitor --
Cont. to June 99)

       The Space Telescope Imaging Spectrograph (CCD) was used to conduct a
CCD dark calibration and a bias monitoring program.  It was also scheduled
to track the growth of hot pixels on the CCD in general and within the
various target acquisition apertures specifically.  The observations were
executed as scheduled, and no anomalies were noted.

   1.3 Completed WF/PC-2 6356 (SNAPSHOT Survey of Ultraluminous Infrared
Galaxies)

       The WF/PC-2 was used to make observations of galaxy Gal-143347 as
part of a survey of ultraluminous infrared galaxies.  The nature of
ultraluminous infrared galaxies has generated considerable controversy.
The two main issues are: {1} are they powered by violent bursts of star
formation or by hidden quasars?  {2} are interactions and mergers
invariably involved?  The observations were executed as scheduled, and no
anomalies were noted.

   1.4 Completed Two Sets of WF/PC-2 7713 (WF/P-2 Cycle 7 Supplemental
Darks pt3/3)

       The WF/PC-2 was used to make supplemental dark calibration images.
This dark calibration program obtains 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 anomalies were noted.

   1.5 Completed WF/PC-2 7374 (Probing Low Density Cluster Environments at
Moderate-to-High Redshifts)

       The WF/PC-2 was used to make observations of the galactic cluster
Gal-Clus-0723.  Recent HST WF/PC-2 images of rich clusters at
moderate-to-high redshifts have revealed that morphological information is
a crucial ingredient in understanding the physical processes responsible
for the evolution of the galaxy population in clusters.  The observations
were executed as scheduled, and no anomalies were noted.

   1.6 Completed STIS/CCD 8091 (POMS Test Proposal: STIS Non-Scripted
Parallel Proposal Continuation)

       The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude, non-scripted, parallel observations.  The observations
were completed as planned, and no anomalies were noted.

   1.7 Completed STIS/CCD/MA1/MA2 7269 (The 1997/98 Eclipse of VV Cephei)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used
to make ultraviolet spectrographic observations of the long-period
eclipsing binary star HD208816 (a.k.a., VV-Cephei).  This eclipse will
provide an unprecedented opportunity to obtain spatially resolved
information about the density, ionization and velocity structure in the
outer atmosphere of the M supergiant primary.  A wave length calibration
observation was also taken.  The observations were completed as scheduled,
and no anomalies were noted.

   1.8 Completed STIS/CCC/MA1/MA2 7436 (A Complete Sample of Hot Post-AGB
Stars in Globular Clusters)
>[3|
       The Space Telescope Imaging Spectrograph (CCD/MA1/MA2) was used to
make observations of the globular cluster NGC-2808-UI.  Recent observations
with the Ultraviolet Imaging Telescope have provided a complete sample of
the hot post asymptotic giant branch {post-AGB} population in fourteen
globular clusters.  A wavelength calibration image was also taken.  The
observations were completed as planned, and no anomalies were reported.

   1.9 Completed WF/PC-2 7619 (WF/PC-2 Cycle 7 Decontamination)

       The WF/PC-2 was used to conduct a Cycle 7 decontamination procedure.
Ultraviolet-blocking contaminants were removed, and hot pixels cured, by
warming the CCDs to +20C for 6 hours.  A variety of internal images were
taken before and after the decontamination in order to verify its success
and to monitor the instrument health.  The procedures were conducted as
scheduled, and no problems were reported.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 5
                                        Successful : 5

                          Scheduled Reacquisitions : 4
                                        Successful : 4

   2.2 FHST Updates:

                              Scheduled : 15
                             Successful : 15

   2.3 Operations Notes:

       Using ROP SR-1, the SSR EDAC error counter was cleared three times.

       At 110/130301Z, as documented in HSTAR 7105, Gyro-3, which had been
in the shadow mode, failed.  The motor current decreased from 212 ma to 0.0
ma.  The new operational gyro configuration is 1,5,2.  The PSEA was
reconfigured to the same three gyro set at 110/2102Z.  At 110/2103Z, the
safemode recovery macro was updated to reflect the new gyro confuguration.
Finally, at 110/210711Z, Gyro-3 was turned off.  Science operations were
not affected by these events.

       The SAMS backup facility was successfully checked out at 110/1745Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH