HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2376

PERIOD COVERED:  0000Z (UTC) 05/19/99 - 0000Z (UTC) 05/20/99

Daily Status Report as of 140/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed STIS/CCD 8042 (UV Imaging and Spectroscopy of High
Excitation Herbig-Haro Objects)

       The Space Telescope Imaging Spectrograph (CCD) was to be used to
make ultraviolet images and spectrographic observations of the high
excitation Herbig-Haro object HD-163296.  A wavelength calibration image
was also to be taken.  As described in yesterday's report and HSTAR 7135, a
re-acquisition for this proposal failed, and the take data flag remained
down.

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

       The Space Telescope Imaging Spectrograph (CCD) was to be 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.  As described
in yesterday's report and HSTAR 7135, a re-acquisition for this proposal
failed, and the take data flag remained down.

   1.3 Completed STIS/CCD/MA1 7272 (Helium Absorption by Protogalactic Gas)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of PKS1935-69.  These observations will provide
substantially improved S/N and substantially reduced geocoronal
contamination compared with extant GHRS spectra, providing a much more
secure measure of both discrete cloud and diffuse IGM contributions to the
He-II opacity in this sightline.  A wavelength calibration image was also
taken.  The observations were completed as planned, and no problems were
reported.

   1.4 Completed Two Sets of WF/PC-2 8441 (WF/PC-2 Decontaminations and
Associated Observations Pt. 1/2)

       The WF/PC-2 was used to make its monthly decontamination operations.
Also included are instrument monitors tied to decons: photometric stability
check, focus monitor, pre- and post-decon internals {bias, internal flats,
k-spots, & darks}, and ultraviolet throughput checks.  The observations
were executed as scheduled, and no anomalies were noted.

   1.5 Completed Three Sets of WF/PC-2 7624 (WF/PC-2 Cycle 7 UV Flats)

       The WF/PC-2 was used to make a set of ultraviolet calibration flat
images.  The ultraviolet flat fields will be obtained with the
cal-channel's ultraviolet lamp {UVFLAT} using the UV filter set {F122M,
F170W, F160BW, F185W, and F336W}.  During the second iteration of this
proposal, the loss of lock reported in HSTAR 7136 and 2.1 occurred.
Otherwise, the observations were executed as scheduled, and no further
anomalies were noted.

   1.6 Completed STIS/CCD/MA1 7577 (Slitless Spectroscopy of the Nuclear
Starburst of NGC-5236)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of NGC-5236. These observations are  to address five basic
questions about the nature of starbursts: {1} What kind of star cluster -
open cluster or globular cluster - is formed in a starburst? {2} How is the
evolution of a starburst system influenced by metallacity, especially in
the case of a super-solar metallicity? {3} Does the birth and evolution of
one star cluster trigger star formation in its environs? {4} Is there a
physical and/or evolutionary link between a circum-nuclear starburst and
the nucleus? {5} For barred spirals, what is the connection between a
starburst and a spiral bar?  During this proposal, the loss of lock
reported in HSTAR 7136 and 2.1 occurred.  Otherwise, the observations were
completed as planned, and no further anomalies were reported.

   1.7 Completed Two Sets of WF/PC-2 7281 (Snapshot Survey of the B2 Sample
of Radio Galaxies)

       The WF/PC-2 was used to make snapshot survey observations of the B2
sample radio galaxies B2+1658+30 and B2+0755+37.  This program is aimed to
answer the following key questions: How common are extended nuclear disks?
What is their orientation and morphology?  How common are optical jets?
The observations were executed as scheduled, and no anomalies were noted.

   1.8 Completed Two Sets of STIS/CCD 8406 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation V)

        The Space Telescope Imaging Spectrograph (CCD) was used to make
high galactic latitude observations taken in parallel with the prime
science observations as part of a POMS proposal.  This is a STIS
non-scripted parallel Condition V proposal.  The observations were
completed as scheduled, and no anomalies were reported.

   1.9 Completed WF/PC-2/STIS/CCD 7615 (Determination of the Mass Function
of a Globular Cluster Through Gravitational Microlensing)

       The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to make gravitational microlensing observations of the large globular
cluster NGC-6656 located in Sagittarius in order to study its mass
function.  Gravitational microlensing offers a unique and direct method of
determining the masses of stars and other compact objects down to planetary
masses.  A bias and dark calibration observations were also taken.  The
observations were completed as planned, and no problems were reported.

   1.10 Completed STIS/CCD 8261 (Nuclear Structure & Merger-Starburst
Relation in the Ultraluminous IR Galaxy NGC 6240: II. Kinematics)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of the nuclear structure and merger starburst relation in the
ultraluminous infrared galaxy NGC-6240-BH.   This galaxy has tidal tails
and a double nucleus.  The observations were completed as planned, and no
anomalies were reported.

   1.11 Completed WF/PC-2 7621 (WF/PC-2 Cycle 7 Supplemental Darks PT1/3)

       The WF/PC-2 was used to make supplemental dark calibration images.
This set of calibrations is intended to obtain three dark frames every day
to provide data for monitoring and characterizing the evolution of hot
pixels.  The observations were executed as scheduled, and no anomalies were
noted.

   1.12 Completed WF/PC-2 7282 (A Continuing Snapshot Survey for Compact
Stellar Groups and Clusters around Wolf-Rayet Stars)

       The WF/PC-2 was used to make observations of the Wolf-Rayet star
WR81 as part of a continuing snapshot survey of compact stellar groups and
clusters.  The newly imaged clusters allow us to accurately determine the
distances, luminosities, and ages of the WR members.  The observations were
executed as scheduled, and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 10
                                        Successful : 10

       According to HSTAR 7136, there was a loss of lock at 139/120749Z
which temporarily took down the take data flag.  The proposals described in
1.5 and 1.6 were affected by this event.

       At 140/065556Z, the scheduled acquisition defaulted to fine lock
back-up on FGS-3 only when the scan step limit was exceeded on FGS-2.  The
take data flag did not go up until 140/070530Z.  HSTAR 7137 was written.
Two proposals (STIS 7295 and WF/PC-2 7621), occurring during the period of
the next report, may have been affected.

                          Scheduled Reacquisitions : 4
                                        Successful : 4

   2.2 FHST Updates:

                              Scheduled : 26
                             Successful : 26

   2.3 Operations Notes:

       The operations team continues to reside in the SAMS back-up
facility, utilizing the PRS ground system.

       The SSR EDAC error counter was cleared three times, using ROP SR-1.

       The STIS MCE-1 reset at 140/0703Z while the high voltage was on and
while outside an SAA interval.  STIS proposal 7295, occurring during the
period of the next report, was affected.  The STIS flight software error
counter was reset at 140/0733Z.  The MAMA-1 was recovered by normal SMS
commanding at 140/0807Z

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH