HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2451

PERIOD COVERED:  0000Z (UTC) 09/03/99 - 0000Z (UTC) 09/07/99

Daily Status Report as of 250/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Seven Sets of WF/PC-2 8443 (WF/PC-2 Cycle-8 Supplemental Darks
pt1/3)

       The WF/PC-2 was used to obtain 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 problems were reported.  

   1.2 Completed Six Sets of STIS/CCD 8408 (STIS CCD Dark Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD
bias calibration observation.  This is to monitor the darks for the STIS CCD. 
The observations were executed as scheduled, and no anomalies were reported.  

   1.3 Completed WF/PC-2 8243 (SINS: The Supernova Intensive Study - Cycle 8)

       The WF/PC-2 was used to make observations of supernova LMC-SN1987. 
Supernovae reveal the last stages of stellar evolution, create the chemical
history of the Universe, energize the interstellar gas, and occupy the center
of attention for the extragalactic distance scale and cosmology.  A wavelength
calibration image was also taken.  The observations were completed as planned,
and no problems were reported.  

   1.4 Completed STIS/CCD/MA1/MA2 8188 (Snapshot Spectroscopic Diagnostic
Survey of the Symbiotic Stars)

       The Space Telescope imaging Spectrograph (CCD, MA1 and MA2) was used to
make ultraviolet observations of star V741-Per as part of a snapshot
spectroscopic diagnostic survey of symbiotic stars.  Using these data we will
be able to establish meaningful statistical limits on the nature of hot
component sources of ionization and fundamental wind parameters, which are
vital steps toward understanding the accretion hydrodynamics and the
evolutionary status of symbiotic systems.  A wavelength calibration image was
also taken.  The observations were executed as scheduled, and no anomalies were
noted.  

   1.5 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 to be used to make observations of the quasar BR2237-060
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.  As reported in the previous
report and HSTAR 7244, the acquisition for this proposal failed, and the take
data flag remained down.

   1.6 Completed Four Sets of STIS/CCD 8409 (STIS CCD Bias Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD
bias calibration observation.  This is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up high-S/N
superbiases and to track the evolution of hot columns.  As reported in the
previous report and HSTAR 7244, the acquisition for the first iteration of this
proposal failed, and the take data flag remained down.  Otherwise, the
observations were executed as scheduled, and no further anomalies were
reported.  

   1.7 Completed STIS/CCD 8470 (POMS Test Proposal: STIS Non-Scripted Parallel
Proposal Continuation V)

       The Space Telescope Imaging Spectrograph (CCD) was to be used to make
high galactic latitude observations taken in parallel with the prime science
observations as part of a POMS proposal.  As reported in the previous report
and HSTAR 7244, the acquisition for this proposal failed, and the take data
flag remained down.

   1.8 Completed Five 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.  As reported in the previous report and HSTAR 7244, the
acquisition for the first iteration of this proposal failed, and the take data
flag remained down.  Otherwise, the observations were completed as scheduled,
and no further anomalies were reported.  

   1.9 Completed Two Sets of STIS/CCD 7579 (Coronographic Imaging &
Spectroscopy of Beta Pictoris)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
coronographic imaging and spectrographic analysis of the star HD290600-2 and
HD50241 (a.k.a., Beta Pictoris).  The program aims to obtain STIS/G430L spectra
of the central region of the Beta Pic disk.  The observations were executed as
scheduled, and no anomalies were noted.  

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

   1.11 Completed STIS/CCD/MA1 7437 (Understanding High-Redshift and Starburst
Galaxies: A UV Spectroscopic Survey of O-Stars in the SMC)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was  used to make
ultraviolet spectrographic observations of galaxy NGC-346.  The data from this
survey, of importance in many areas of astrophysics, will immediately be made
public as no proprietary period is requested.  A wavelength calibration image
was also taken.  The observations were executed as scheduled, and no anomalies
were noted.  

   1.12 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.  

   1.13 Completed WF/PC-2 8436 (POMS Test Proposal: WFII Backup Parallel
Archive Proposal II)

       The WF/PC-2 was used to make archive observations parallel to the prime
science observations as part of a POMS test proposal.  This is a POMS test
proposal designed to simulate scientific plans.  The observations were
completed as planned, and no anomalies were reported. 

   1.14 Completed WF/PC-2 8134 (Is the IMF Universal at Low Stellar Masses?)

       The WF/PC-2 was used to make observations of the NGC-330.  Only the HST
can provide the resolution and limiting magnitude required to reach the
low-mass end of the IMF at extragalactic distances.  The observations were
executed as scheduled, and no problems were reported.  

   1.15 Completed WF/PC-2 8251 (The Second-Parameter Effect in Metal- Rich,
Globular Clusters: A Snapshot Study of NGC 6441)

       The WF/PC-2 was used to observe the newly-discovered hot horizontal
branch (HB) populations in the metal-rich globular cluster (GC) NGC 6441
providing an unique opportunity for unraveling the second-parameter effect. 
While it has long been known that at least one parameter besides the
metallicity, Fe/H, determines the HB morphology of GCs, our ignorance as to the
nature of this second parameter {or parameters} has been a major stumbling
block in understanding the formation history and age of the GC system.  The
proposal completed nominally with no reported problems.

   1.16 Completed Five Sets of WF/PC-2 6825 (Quantitative Measures of the
Evolution of the Cluster Galaxy Population)

       The WF/PC-2 was used to make observations of galaxies MS1621+26D,
MS1621+26A, MS1621+26E, MS1621+26B and MS1612+26C.  The goal of this proposal
is to understand the differential evolution of cluster and field galaxies over
the redshift range 0.3 < Z < 0.6.  A wave length calibration image was also
taken.  The observations were executed as scheduled, and no anomalies were
noted.  

   1.17 Completed Two Sets of WF/PC-2/STIS/CCD 8196 (High Spatial Resolution
UV/Optical Spectroscopy of H-II Regions in the Magellanic Clouds)

       Both the WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to make high signal/noise, ultraviolet and optical observations of the
H-II region in the Large Magellanic Cloud known as SMC/N12A.  This is to make
definitive measurements of the abundances of C and N, and to study the
temperature, density, and ionization structures of the nebulae.  A wavelength
calibration image was also taken.  The observations were executed as scheduled,
and no anomalies were noted.  

   1.18 Completed 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 a unique sample
of the faint blue compact galaxy SA68-1067 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.

   1.19 Completed Two Sets of STIS/CCD 8202 (Bright Quasar Close Lensing
Search)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of HCLQ0041-0 and HCLQ0731+4as part of a second generation survey
to search for bright lensing quasars.  With the restored PSF, new images will
be considerably more sensitive to the presence of both close separation and
faint lens components, and because STIS reaches two magnitudes fainter the PC,
the new snapshot images will have much greater dynamic range.  The observations
were executed as scheduled, and no anomalies were noted.  

   1.20 Completed STIS/CCD/MA1 8316 (The Lyman-Alpha Absorption Cross-Section
of Nearby Galaxies)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to study
the Lyman-Alpha absorption cross-section of nearby galaxy SBS1127+57.  The high
resolution of the spectra will allow us to accurately determine the velocity of
the gas, which can be compared to the systemic velocity of the galaxy, and to
the velocity field determined from 21 cm H-I emission measurements, when
available, enabling us to determine if or how the gas is kinematically tied to
the galaxy.  A wavelength calibration image was also taken.  The observations
were executed as scheduled, and no anomalies were noted.  

   1.21 Completed STIS/CCD/MA1 8241 (A Snapshot Survey of Interstellar
Absorption Lines)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
high resolution Echelle spectrographic observations of the standard ultraviolet
star HD198781 as part of a snapshot survey of interstellar absorption lines.  A
wavelength calibration image was also taken.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.22 Completed STIS/CCD 7310 (The Interaction of Accretion Disks with
Protostellar Binaries)

       The Space Telescope Imaging Spectrograph (CCD) was used to study the
interaction of the accretion disk with the protostellar binary system DD-Tau. 
This should determine how the accretion disk interacts with stars in young
binary systems and will measure the rates that mass accumulates onto each
component of the pair.  A wavelength calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were noted.  

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

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of the radio-loud quasar MRCO413-21.  The role of associated
absorption systems and dust obscuration close to the central engines of AGN is
not understood.  A wavelength calibration was also taken.  The observations
were completed as planned, and no anomalies were reported.   

   1.24 Completed WF/PC-2 8442 (WF/PC-2 Cycle 8 Standard Darks)

       The WF/PC-2 was used to make a series of Cycle 8 standard dark
calibration observations.  This dark calibration program obtains dark frames
every week in order to provide data for the ongoing calibration of the CCD dark
current rate, and to monitor and characterize the evolution of hot pixels.  The
observations were executed as scheduled, and no anomalies were noted.  

   1.25 Completed Eight Sets of WF/PC-2 8457 (UV Earthflats)

       The WF/PC-2 was used to make a ultraviolet Earth flat calibration
image.  This is to improve the quality of pipeline the ultraviolet flatfields. 
The observations were completed as scheduled, and no problems were reported.  

   1.26 Completed Three Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)

       The Space Telescope Imaging Spectrograph (MA1) was used to make a
routine Cycle-8 MAMA dark noise calibration measurement.  This proposal will
provide the primary means of checking on the health of the MAMA detectors. 
This is done through frequent monitoring of the background count rate.  The
observations were completed as planned, and no problems were reported.  

   1.27 Completed Seven Sets of WF/PC-2/STIS/CCD 8414 (STIS Sparse Field CTE
test {Cycle 8))

       Both the WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to conduct CTE measurements using the "sparse field test", along both the
serial and parallel axes.  This program needs special commanding to provide {a}
off-center MSM positionings of some slits, and {b} the ability to read out with
any amplifier {A, B, C, or D}.  All exposures are internals.  The observations
were completed as planned, and no anomalies were reported.  

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions: 

                            Scheduled Acquisitions: 24
                                        Successful: 24

                         Scheduled Re-acquisitions: 35
                                        Successful: 30

       These re-acquisition failures are related to the primary guide star
acquisition failure mentioned in the previous report and HSTAR 7244.  The
proposals detailed in 1.5, 1.6, 1.7, and 1.8 were affected by these failures.

   2.2 FHST Updates: 

                              Scheduled: 52
                             Successful: 52

   2.3 Operations Notes: 

       Operations continue on CCS “A” string.  The CCM monitor was re-cycled at
247/1143Z.  Master and command capabilities were temporarily lost on both “A”
and “B” strings at 249/1950Z.

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

       Per an operations note, the K-based recharge ratio for sun/orbit time
was adjusted for the period from day 246 until day 250.

       As described in HSTAR 7245, the battery 4 and main bus voltage flagged
out-of-limits marginally low for three seconds.  The occurrences were at the
end of orbit night when no vehicle maneuvers were in progress.

       The STIS MCE-1 reset at 246/114058Z while in a SAA boundary and while
the low voltage was on.  ROP NS-12 was utilized at 246/1259Z to reset the STIS
flight software error counter.  MAMA-1 was recovered at 246/2201Z via nominal
SMS commanding.

       ROP NS-12 was used at 246/1552Z and at 246/2243Z to reset the STIS
flight software error counter after previous EMC retries.

       A real-time map was performed at 246/1629Z, using ROP PO-8.  At the same
time, a fine attitude determination was calculated, using the same ROP.

       TTRs were written at 246/1732Z, at 247/0300Z and at 247/1016Z.  The
first was for a data dropout; the second and third, for the temporary loss of
ODM/GCMR capability.

       The NICMOS FPA temperature sensor for detector 3 was enabled at
247/2258Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS: 

       Continuation of normal science observations and calibrations.

/DMH