HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2323

PERIOD COVERED:  0000Z (UTC) 03/05/99 - 0000Z (UTC) 03/08/99

Daily Status Report as of 067/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Four Sets of STIS 8393 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation IV)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
POMS, non-scripted, low galactic latitude observations made in parallel
with the prime science observations.  During the final iteration of this
proposal, the re-acquisition failure described in 2.1 and HSTAR 7039
occurred, affecting two observations.  Otherwise, the observations were
executed as scheduled, and no further anomalies were noted.

   1.2 Completed Eight 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.
During the seventh iteration of this proposal, the re-acquisition failure
described in 2.1 and HSTAR 7039 occurred, affecting one observation.
Otherwise, the observations were completed as planned, and no further
anomalies were noted.

   1.3 Completed WF/PC-2 6738 (Super Star Clusters and H II Regions in
Nuclear Rings)

       The WF/PC-2 was used to make observations of the super star clusters
and the H-II regions in the nuclear ring in galaxy NGC-1512.  Together with
our ultraviolet data, new WF/PC-2 images will enable us to determine the
H-II region and cluster luminosity functions within nuclear rings, measure
cluster radii, derive age and mass estimates for the clusters by comparison
with evolutionary synthesis models, and study the structure and evolution
of nuclear rings.  The observations were completed as scheduled, and no
anomalies were reported.

   1.4 Completed Two Sets of STIS/CCD 7912 (STIS Parallel Archive Proposal
- Nearby Galaxies - Imaging and Spectroscopy)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
parallel observations of nearby galaxies.  This survey will be useful to
study the star formation histories, chemical be placed immediately into the
Hubble Data Archive.  The observations were completed as scheduled, and no
problems were reported.

   1.5 Completed Fifteen Sets of 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.  During the eighth
iteration of this proposal, the acquisition default to fine lock backup on
one FGS only, described in 2.1, occurred possibly affecting six
observations.  During the tenth iteration, a re-acquisition failure (at
065/184633Z) occurred (described in HSTAR 7037 and 2.1), affecting four
observations.  During the eleventh iteration, other re-acquisition failures
(at 065/220004Z and at 065/233701Z) occurred (described in HSTAR 7038 and
2.1), affecting four observations.  Otherwise, the observations were
completed as planned, and no further anomalies were noted.

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

       The WF/PC-2 was used to make observations of GAL-201736 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.

   1.7 Completed WF/PC-2 7373 (Sher 25 in NGC 3603: A Galactic Counterpart
of SN 1987 A's Progenitor)

       The WF/PC-2 was used to make observations of the Supergiant
progenitor star Sher-25 of Super Nova SN-1987A which is located in giant
H-II region of NGC-3603.  The detailed structure of Sher 25's circumstellar
nebula will be compared to wind-interaction models in order to determine
its mass loss history and the dominant type of instability responsible for
the fragmentation of the ring.  The observations were executed as
scheduled, and no anomalies were noted.

   1.8 Completed Six Sets of STIS/CCD 7948 (CCD Dark and Bias Monitor --
Cont. to Dec. 98)

       The Space Telescope Imaging Spectrograph (CCD) was used to measure
CCD dark current and bias rates for the two supported amplifier settings
{GAIN=1 and GAIN=4} in order to gather data for making superdarks and
superbiases.  The data will be used 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.

   1.9 Completed Three Sets of WF/PC-2 6967 (Blue Continuum Snapshots of
3CR Radio - Continued Galaxies)

       The WF/PC-2 was used to make observations of the radio galaxies
3C232, 3C114.0 and 3C105.0.  Radio galaxies are an important class of
extragalactic objects: they represent one of the most energetic
astrophysical phenomena and they may be used as probes of their
environments.  They are unique probes of the early Universe.  The
observations were completed as planned, and no problems were reported.

   1.10 Completed WF/PC-2 7465 (White Dwarf Distance and Precision Age for
Globular Clusters)

       The WF/PC-2 was used to make observations of white dwarf star
WD1240+754 which is located in globular cluster 47-Tuc.  The observed
cooling sequences for the clusters is to be fit to the corresponding FCSs
(Fiducial Cooling Sequences) to determine accurate cluster distance moduli
and absolute ages.  The observations were executed as scheduled, and no
anomalies were noted.

   1.11 Completed STIS/CCD/MA1 8043 (Physical Properties of H-I and H-II
Regions)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was to be
used to make observations of the early-type star HD3827 in order to study
its H-I and H-II regions.  The acquisition and re-acquisition failures
described in 2.1, 2.2, and HSTAR 7035 occurred during this proposal, and
the take data flag remained down.

   1.12 Completed Three 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 some low galactic
latitude archive observations.  The program will be used to take parallel
images of random areas of the sky.  The acquisition and re-acquisition
failures described in 2.1, 2.2, and HSTAR 7035 occurred during the first
iteration of this proposal, and the take data flag remained down.
Otherwise, the observations were executed as scheduled, and no further
anomalies were noted.

   1.13 Completed 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.

   1.14 Completed Three Sets of WF/PC-2 7506 (NGC 1705: A Benchmark for
Galaxy Evolution)

       The WF/PC-2 was used to make observations of the irregular  galaxy
NGC-1705 whose stellar content cannot be resolved from ground to obtain
information to be used as a benchmark of galaxy evolution.  For this galaxy
there is direct observational evidence for the presence of a galactic wind,
a phenomenon predicted by most chemical evolution models for this type of
galaxy.  During the first iteration of this proposal, the acquisition
default to fine lock backup on one FGS only, described in 2.1, occurred
possibly affecting ten observations.  During the second iteration, a
re-acquisition failure (at 065/184633Z) occurred (described in HSTAR 7037
and 2.1), affecting eight observations.  During the third iteration, other
re-acquisition failures (at 065/220004Z and at 065/233701Z) occurred
(described in HSTAR 7038 and 2.1), affecting three observations.
Otherwise, the observations were executed as scheduled, and no further
anomalies were noted.

   1.15 Completed WF/PC-2 6699 (The Globular Cluster System of the Dwarf
Elliptical System Galaxies NGC-185 and NGC 205)

       The WF/PC-2 was used to make observations of the globular cluster
system around the nucleus of dwarf galaxy NGC-205.  The propose is to carry
out a general reconnaissance of the properties of the globular clusters.
The observations were completed as planned, and no anomalies were reported.

   1.16 Completed STIS/CCD 7332 (Improved Hubble Constant
from the 0957+561 Gravitational Lens)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of the gravitational lens system 0957+561 in order to improve
the value of the know Hubble Constant.  The image was made to be at least
one magnitude deeper than previous HST data in order to detect more faint
lensed structures.  The observations were executed as scheduled, and no
anomalies were noted.

   1.17 Completed WF/PC-2 8061 (POMS Test Proposal: WF-II Backup Parallel
Archive Proposal)

       This is a POMS test proposal designed to simulate scientific plans.
The proposal was executed as planned, and no anomalies were reported.

   1.18 Completed STIS/CCD 7615 (Determination of the Mass Function of a
Globular Cluster Through Gravitational Microlensing)

       The Space Telescope Imaging Spectrograph (CCD) was 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.

   1.19 Completed WF/PC-2 7505 (The Hubble Diagram for Distant Supernovae
Measuring Cosmic Deceleration and Global Curvature)

       The WF/PC-2 was used to make observations of Super Nova SN1999A1 in
order to produce a precise Hubble diagram from measuring cosmic
deceleration and global curvature.  HST can make an essential contribution
by providing photometry with substantially higher precision and better
temporal coverage than can be obtained from the ground.  The observations
were completed as planned, and no anomalies were reported.

   1.20 Completed WF/PC-2  6791 (The Collisional Debris of NGC 4438)

       The WF/PC-2 was used to make observations of the collisional debris
in galaxy NGC-4435.  This system is the nearest example of a recent and
close high-velocity collision between two large galaxies, and offers a
unique opportunity to learn about the physical processes in high-velocity
collisions which can transform cluster galaxies.  The observations were
completed as planned, and no anomalies were reported.

   1.21 Completed STIS/CCD/MA1 7576 (Lyman-Alpha Absorption in Low-Z QSO's)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make observations of the Lyman-Alpha absorption in the low-Z quasar
PKS0405-12.  A luminous early-type galaxy 40" from the sight line is
present at this redshift {projected distance = 78/h kpc}.  A wavelength
calibration image was also taken.  The observations were completed as
planned, and no problems were reported.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 16
                                        Successful : 15

       See the explanation for acquisition failure under 2.2.  Proposals
described in 1.11 and 1.12 were affected.

       When FGS-1 did not acquire fine lock, the acquisition at 064/201621Z
defaulted to fine lock on FGS-3 only.  HSTAR 7034 was written.  The
proposals described in 1.5 and 1.14 may have been affected.

                          Scheduled Reacquisitions : 28
                                        Successful : 22

       See the explanation for two of the re-acquisiton failures under 2.2.
Proposals described in 1.11 and 1.12 were affected.

       Per HSTAR 7037, the re-acquisition scheduled at 065/184633Z failed
when the scan step limit being exceeded.  The proposals described in 1.5
and 1.14 were affected.

       The re-acquisitions scheduled at 065/220004Z and at 065/233701Z
failed when the scan step limit was exceeded.  HSTAR 7038 was written.  The
proposals described in 1.5 and 1.14 were affected.

       The re-acquisition scheduled at 066/075010Z failed when the scan
step limit was exceeded.  HSTAR 7039 was written.  The proposals described
in 1.1 and 1.2 were affected.

   2.2 FHST Updates:

                              Scheduled : 39
                             Successful : 36

       As described in HSTAR 7035, following an good FHST map at 064/1635Z,
the roll delay update at 064/163820Z failed, as did the two following full
maneuver updates.  When the acquisition at 064/170843Z failed (due to the
search radius limit being exceeded), a subsequent map showed significant
errors and an attitude reference update was performed.  The re-acquisition
at 064/184602Z also failed when the search radius limit was exceeded.

   2.3 Operations Notes:

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

       The STIS flight software error counter was cleared at 064/1837Z per
ROP NS-12.

       Per ROP NS-3, the NSSC-1 status buffer was dumped at 064/2157Z.

       A PRD online update was performed at 065/0500Z per an operations
request.

       The NICMOS FPA temperature sensor for detector two was enabled at
065/1226Z.  The sensor for detector one was enabled at 066/1045Z.

       The Gyro-3 drift rate bias trend for the last week shows a decrease
since the last report.  The rate of change is 6.88 arcseconds/hour/day (was
25.29), but analyses indicate the trend is dominated by a step shift in the
bias over the last two days, and is therefore not considered sufficiently
stable to recommand return to a four-gyro configuration at this time.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and
calibrations.

/DMH