HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2378

PERIOD COVERED:  0000Z (UTC) 05/21/99 - 0000Z (UTC) 05/24/99

Daily Status Report as of 144/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Six 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.

   1.2 Completed Seven Sets of 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 seventh iteration of this proposal was affected by the
acquisition failure described in 2.1 and HSTAR 7141.  Otherwise, the
observations were executed as scheduled, and no further anomalies were
noted.

   1.3 Completed Two Sets of 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 stars
WR143 and WR49 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.

   1.4 Completed Two Sets of WF/PC-2 7470 (A Snapshot Survey of Galactic
Globular Clusters)

       The WF/PC-2 was used to make snapshot survey observations of the
crowded center of the galactic globular clusters NGC-5986 and NGC-6325.
The resulting color-magnitude diagram will include all stars down to about
one magnitude below the main-sequence turnoff.  The observations were
completed as scheduled, and no problems were reported.

   1.5 Completed Fifteen 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 both
high and low 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.

   1.6 Completed WF/PC-2 7504 (Calibration of Nearby Type Ia Supernovae as
Standard Candles: The Next Three-Year Step)

       The WF/PC-2 was used to make observations of parent galaxy NGC-4527
in order to determining its Cepheid distance.  This is to continue the
calibration of the Type 1a supernova as standard candles.  The observations
were completed as planned, and no porblems were reported.

   1.7 Completed Six Sets of WF/PC-2 8053 (WF/PC-2 Cycle-7 Earth Flats --
Part II)

       The WF/PC-2 was used to take Earth flat calibration images.  This
proposal obtains sequences of Earth streak flats to construct high quality
flat fields for the WF/PC-2 filter set.  The observations were executed as
scheduled, and no anomalies were noted.

   1.8 Completed STIS/CCD/MA1 7270 (The Origin of Highly Ionized Gas in the
Milky Way and Its Relationship To Large Galactic Structures)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make spectrographic observations of the star HD-177989 in order to study
the origin of highly ionized gas in the Milky Way and its relationship to
large galactic structures.  A wavelength calibration image was also taken.
The observations were completed as scheduled, and no anomalies were
reported.

   1.9 Completed Three Sets of WF/PC-2 8059 (POMS Test Proposal: WF-2
Targeted Parallel Archive Proposal)

       The WF/PC-2 was used to make observations in parallel with the prime
science observations.  The parallel opportunities available with WF/PC-2 in
the neighborhood of bright galaxies are treated in a slightly different way
from the normal pure parallels.  Local group galaxies offer the opportunity
for a closer look at young stellar populations.  The observations were
completed as planned, and no anomalies were reported.

   1.10 Completed Six 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+1441+26, B2+1827+32, B2+1457+29, B2+1521+28,
B2+1450+28 and B2+1447+27.  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.

   1.11 Completed WF/PC-2 6556 (Rest-Frame Ultraviolet Imaging of Normal
Galaxies at High Redshifts)

       The WF/PC-2 was used to make observation of Field-1344 in order to
study the rest-frame of ultraviolet imaging of normal galaxies at high
redshifts.  This is to study the evolution of normal galaxies over the last
two-thirds of the age of the Universe through HST imaging of fields from
our deep redshift surveys.  The observations were executed as scheduled,
and no anomalies were noted.

   1.12 Completed STIS/CCD 8172 (STIS Deep DLA Imaging Survey II)

       The Space Telescope Imaging Spectrograph (CCD) was used to make deep
observations of quasar/alpha galaxy PKS0582-25.  The HST imaging, together
with ground-based spectroscopy, will unify absorption-line studies and
faint galaxy imaging studies, providing a comprehensive picture of the
history of assembly, star formation, gas consumption, and chemical
enrichment in the Damped Lyman-Alpha galaxies.  The observations were
executed as scheduled, and no anomalies were noted.

   1.13 Completed FOC/96 7923 (FOC F/96 Turnon)

       The Faint Object Camera (f/96) was used to take an internal flat and
a dark to ensure that the 30-day limit for the FOC is not exceeded.  The
observations were executed as scheduled, and no anomalies were noted.

   1.14 Completed S/C 5582 (FOC/48 Monthly Activation (Camera Section
Only): Cycle 4)

        This proposal was executed as scheduled, and no anomalies were noted.

   1.15 Completed Two Sets of STIS/CCD/MA1 7740 (Spin-Cycle Variations of
the UV Emission Lines of Intermediate Polars)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was to be
used to used to make observations of the variable star AO-Psc.  The
intermediate polars are a prime opportunity for observing the interaction
of an accretion flow with a strong magnetic fields.  A wavelength
calibration image was also to be taken.  As documented in 2.1 and HSTARs
7140 and 7041, each of the acquisitions and the re-acquisitions for both
iterations of this proposal failed.  The take data remained down, affecting
25 observations in each iteration.

   1.16 Completed Six Sets of WF/PC-2 8090 (POMS Test Proposal: WF-II
Parallel Archive Proposal Continuation)

       The WF/PC-2 was used in the parallel mode to make both low and highv
galactic latitude archive observations.  The program will be used to take
parallel images of random areas of the sky.  As documented 2.1 and in
HSTARs 7140 and 7041, each of the acquisitions and/or the re-acquisitions
for the first and fourth iterations of this proposal failed.  The take data
remained down, affecting nine observations in each iteration.  Otherwise,
the observations were executed as scheduled, and no further anomalies were
noted.

   1.17 Completed STIS/CCD/MA1/MA2 7673 (STIS MAMA Sensitivity and Focus
Monitor)

       The Space Telescope Imaging Spectrograph (CCD/MA1/MA2) was used to
make observations of standard star BD+28D4211 in order to perform a MAMA
sensitivity and focus monitoring program.  This is to monitor sensitivity
of each MAMA grating mode to detect any change due to contamination or
other causes.  A wavelength calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were noted.

   1.18 Completed STIS/CCD/MA2 8225 (Absorption and Obscuration in
Radio-Loud Quasars)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of the radio-loud quasar MRC2255-28.  The role of
associated absorption systems and dust obscuration close to the central
engines of AGN is not understood.  The observations were completed as
planned, and no anomalies were reported.

   1.19 Completed WF/PC-2 7378 (Narrow Band Imaging of Jets and Bipolar
Outflows From Symbiotic Stars)

       The WF/PC-2 was used to make observations of the symbiotic star
PK315+09D1 to make narrow band imaging of its jets and bipolar outflows.
With these HST observations we have the unique opportunity to follow in
real-time the spatial evolution of the outflows {on a time basis of very
few years}, and therefore to derive 3-D dynamical models of their
structure.  The observations were completed as scheduled, and no problems
were reported.

   1.20 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.

   1.21 Completed Four Sets of WF/PC-2 7339 (Sizes and Structures of Faint
Blue Compact Galaxies that are New Candidates for Proto-Spheroidal Galaxies)

       The WF/PC-2 was used to obtain two-band WFPC-2 images of the faint
blue compact galaxies SA68-8846, SA68-6597, SA68-9640 and SA68-5935 at
redshifts up to z ~ 0.7, that are excellent new candidates for being
spheroidal galaxies, caught in the act of undergoing a major star-forming
event.  The observations completed with no reported anomalies.

   1.22 Completed STIS/CCD/MA2 7433 (UV Spectral Dating of Galaxies)

       The Space Telescope Imaging Spectrograph (MA2) was used to make
ultraviolet spectrographic observations of HD2454 to calculate a highly
accurate library of UV stellar spectra that can be used to estimate the age
and metallicity of galaxies of intermediate age {between 1 and 8 Gyrs}.
The critical step in this effort is to test the model spectra against
high-quality UV spectra of real stars.  A wave length calibration image was
also taken.  The observations were executed as scheduled, and no anomalies
were noted.

   1.23 Completed STIS/CCD/MA1 7296 (A STIS Probe of Unique ISM
Lines-of-Sight Having Measured H and He Ionization Fractions)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
probe the interstellar medium around object  2RE2156-5 in the far
ultraviolet.  A wave length calibration image was also taken.  The
observations were completed as planned, and no anomalies were reported.

    1.24 Completed Two Sets of STIS/CCD 8226 (Discerning the Origins of
Blue Stragglers: Masses and Rotation Rates)

       The Space Telescope Imaging Spectrograph (CCD) was used to study the
blue stragglers in globular cluster NGC-6752 and NGC-105.  Conventional
wisdom holds that the masses of Blue Straggler Stars in globular clusters
are significantly larger than the turnoff mass.  A wavelength calibration
observation was also taken.  The observations were executed as scheduled,
and no anomalies were noted.

   1.25 Completed STIS/CCD 8470 (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 VI proposal.  The observations were completed as
scheduled, and no anomalies were reported.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 27
                                        Successful : 25

       Per HSTAR 7140, the acquisition at 142/020119Z failed when the scan
step limit was exceed on FGS-3.  The subsequent three re-acqusitions also
failed.  The proposals described in 1.15 and 1.16 were affected.

       HSTAR 7141 documents the acquisition at 143/021814Z which failed due
to a large FGS attitude vector.  The prior full maneuver update had been
successful and the FHST map had good attitude errors.  The subsequent three
re-acquisitions also failed.  The proposals described in 1.2, 1.15, and
1.16 were affected.

                          Scheduled Reacquisitions : 22
                                        Successful : 16

       See explanations included under 2.1.

   2.2 FHST Updates:

                              Scheduled : 61
                             Successful : 61

   2.3 Operations Notes:

       HST operations personnel remain in the SAMS back-up facility using
the PRS ground system.

       Using ROP SR-1, the SSR EDAC error counter was cleared 11 times.

       The STIS flight software error counter was reset at 142/0245Z and at
143/0450Z per ROP NS-12.

       At 143/192348Z, 10 FGS-3 mnemonics flagged out-of-limits momentarily
while the HST was transversing the level 1 South Atlantic Anomaly region.
All three FGSs were in default with the HST under gyro control at the time
of the upset.  HSTAR 7142 was written.

       At 144/005928Z, the voltages on both batteries 2 and 4 flagged low
after entering orbit day and also immediately after a spacecraft slew.
HSTAR 7143 was written.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH