HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2343

PERIOD COVERED:  0000Z (UTC) 04/02/99 - 0000Z (UTC) 04/05/99

Daily Status Report as of 095/0000Z

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 Two 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 observations were executed as
scheduled, and no anomalies were noted.

   1.3 Completed Thirteen 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.  The observations
were completed as planned, and no anomalies were noted.

   1.4 Completed 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.

   1.5 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.
The observations were completed as planned, and no anomalies were noted.

   1.6 Completed STIS/CCD/MA1 6461 (High-Resolution Next Bright Galactic Nova)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
make high resolution images of the bright galactic nova U-Scorpii after it
erupted to search for fluorescence and reflection light echoes from, and
small-scale structure in, the nova circumstellar gas and dust ejecta.  The
observations were executed as scheduled, and no anomalies were noted.

   1.7 Completed STIS/CCD/MA1/MA2 7757 (Time-Resolved Spectrophotometry of
the Smallest Mass Function Binary Star)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used
to make time resolved spectrographic observations of the x-ray, small mass,
contact binary star KZ-TrA (a.k.a., The 7s Pulsar).  The optical
counterpart of this star exhibits optical pulsations with the same period
as the X-ray pulsations.  The observations were executed as scheduled, and
no anomalies were noted.

   1.8 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-1046 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.

   1.9 Completed WF/PC-2 7447 (The Cosmological Evolution of Quasar Host
Galaxies)

       The WF/PC-2 was used to make observations of the host galaxy which
surrounds quasar A012058+11 in order to study its cosmological evolution.
The observations were executed as scheduled, and no anomalies were
reported.

   1.10 Completed WF/PC-2 7497 (WF/PC-2 Observations of Astrophysically
Important Visual Binaries)

       The WF/PC-2 was used to make observations of the visual binary
variable star system G107-70.  This system is a famous metal-deficient G
dwarf for which accurate masses will lead to the star's helium content with
cosmological implications.  The observations were completed as planned, and
no anomalies were reported.

   1.11 Completed WF/PC-2 6363 (The Environments and Host Galaxies of
BL-Lac Objects)

       The WF/PC-2 was used to make snapshot survey observations of BL-Lac
object QS01215+30 in order to study its environment and its host galaxy.
The goal is to investigate systematic trends in host galaxy type, unusual
morphological features, nearby companion galaxies, etc.  The observations
were executed as scheduled, and no anomalies were noted.

   1.12 Completed Four Sets of WF/PC-2 7335 (Deep Survey for CVs and
Compact Binaries in the Collapsed Core Cluster NGC-6397)

       The WF/PC-2 was used to make deep survey observations cataclysmic
variables and compact binaries in the collapsed core of globular cluster
NGC-6397.  The ultimate test for the total number and characteristics of
cataclysmic variables {CVs} and compact binaries in the core of a globular
cluster can best be conducted on this close collapsed core cluster.  The
observations were completed as planned, and no problems were reported.

   1.13 Completed Two Sets of STIS/CCD 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.  The observations were executed as
scheduled, and no anomalies were noted.

   1.14 Completed STIS/CCD 8080 (STIS Spectroscopic CCD Flatfielding --
Revised)

       The Space Telescope Imaging Spectrograph (CCD) was used to make CCD
flat fielding calibration observations in the spectroscopic mode.  The
observations were completed as planned, and no anomalies were reported.

   1.15 Completed WF/PC-2 7266 (High-Resolution IR and Optical Imaging of
the Fields Around a Large Sample of Z > 4.5 Quasars)

       The WF/PC-2 was used to make observations of the quasar BR1033-032
in order to make high-resolution infrared and optical imaging of the fields
around the quasars.  This object appears to be very primitive and may
represent early stages in the galaxy formation process.  The observations
were completed as planned, and no anomalies were reported.

   1.16 Completed STIS/CCD 7672 (STIS CCD Sensitivity Monitor)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of standard star AGK+81D266 in order to monitor the
sensitivity of each CCD grating mode to detect any change due to
contamination or other causes.  The observations were completed as
scheduled, and no anomalies were noted.

   1.17 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.

   1.18 Completed WF/PC-2 6359 (Core Properties of the Bulges of Spiral
Galaxies)

       The WF/PC-2 was used to make snapshot survey observations of the
spiral galaxy NGC-5566 in order to study its central bulge.  The aim is to
investigate the core properties, correlations with global galactic
properties, and the frequency of occurrence of multiple and/or miscentered
nuclei.  The observations were completed as scheduled, and no anomalies
were noted.

   1.19 Completed WF/PC-2 6438 (Dust Structure in Backlit Galaxies)

       The WF/PC-2 was used to make observations of the Backlit Galaxy
NGC-3314 in order to study its dust structure.  This effect is produced by
a pair of overlapping galaxies which offer an unusually direct way to
measure the extinction within the disk of spiral galaxies.  The
observations were completed as planned, and no problems were reported.

   1.20 Completed STIS/MA1 7345 (Origin and Physical Conditions in the
Local Lyman-Alpha Forest)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of Markarian galaxy Mark-1383 in order to study the origin and
physical conditions in the local Lyman-Alpha forest.  A wavelength
calibration image was also taken.  The observations were executed as
scheduled, and no anomalies were noted.

2.0 FLIGHT OPERATIONS SUMMARY

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 17
                                        Successful : 17

                          Scheduled Reacquisitions : 26
                                        Successful : 26

   2.2 FHST Updates:

                              Scheduled : 39
                             Successful : 38

       Per HSTAR 7083, the roll delay update scheduled for 094/051015Z failed.

   2.3 Operations Notes:

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

       A TTR was written when 65 seconds of realtime data was lost,
beginning at 092/1733Z, due to a late acquisition.

       As described in HSTAR 7084, the ground received indications that the
data playback at 094/143427Z was not correctly received.  As a result, a
backup ESTR record was commanded to cover the expected data loss.
Subsequently, it was confirmed that the indications of non-receipt were
erroneous.

       The CCS "A" SAC server was recycled at 094/1900Z.

       An operations request was executed at 094/1912Z to enable the NICMOS
FPA temperature sensor for detector 3.

       HSTAR 7085 documents a STIS EMC retry at 095/023432Z when the
mechanism initially failed to move.  Per ROP NS-12, the STIS flight
software error counter was reset at 095/0251Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH