HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2455

PERIOD COVERED:  0000Z (UTC) 09/10/99 - 0000Z (UTC) 09/13/99

Daily Status Report as of 256/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Seven 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.  

   1.2 Completed Six 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.  

   1.3 Completed Three 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.  The observations were
executed as scheduled, and no anomalies were reported.  

   1.4 Completed STIS/CCD/MA1 8287 (A Search For Transparent Lines of Sight
With Intergalactic He-II Absorption Towards 26 Bright z > 2.9 Quasars)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
He-II absorption line observations of quasar HS1140+350.  The aim is to
identify more suitable bright objects for detailed studies of intergalactic
He-II absorption at a redshift of Z <2.9 and >3.2 .  A wavelength calibration
observation was also taken.  The observations were executed as scheduled, and
no anomalies were noted.  

   1.5 Completed STIS/CCD 8313 (Imaging the Host Galaxies of High Redshift Type
Ia Supernovae)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of 9569 and its host galaxy.  The propose is to obtain snapshot,
unfiltered STIS images of distant galaxies of known redshift which have hosted
supernovae {SNe} of Type IA found via the Supernova Cosmology Project.  The
observations were completed as scheduled, and no anomalies were reported.  

   1.6 Completed Five 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.  

   1.7 Completed WF/PC-2 7304 (High Resolution Imaging and Spectroscopy of Cool
Hypergiants Near the Top of the HR Diagram)

       The WF/PC-2 was used to make high resolution images of the cool,
hypergiant, variable star IRC+10420.  A few highly unstable, very massive stars
lie on or near the empirical upper luminosity boundary in the HR diagram. 
These include the Luminous Blue Variables, the cool hypergiants and other even
rarer objects, all related by the violent mass loss phenomena responsible for
the upper boundary.  A wave length calibration image was also taken.  The
observations were executed as scheduled, and no anomalies were noted.  

   1.8 Completed Seven 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.  

   1.9 Completed Four Sets of WF/PC-2 7469 (Internal Velocity Distribution in
Globular Clusters)

       The WF/PC-2 was used to make observations of the globular cluster
NGC-6752, NGC-7078 and NGC-6752 in order to study the internal velocity
distribution in its cores and as a function of distance from the cluster
center, and thus also infer its mass distribution.  The observations were
executed as scheduled, and no anomalies were noted.  

   1.10 Completed STIS/CCD/MA1 8219 (A Definitive Census of the Cataclysmic
Variable Population in 47 Tuc)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
deep, far-ultraviolet, time-resolved observations of the cataclysmic variable
population in the globular cluster 47 Tuc (a.k.a., NGC-104).  A wavelength
calibration image was also taken.  The observations were executed as scheduled,
and no anomalies were noted.  

   1.11 Completed Three Sets of 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. 

   1.12 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.  

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

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

   1.14 Completed STIS/CCD/MA2 8218 (Exploring Triton in the Act of Global
Change)

       The Space Telescope Imaging Spectrograph (CCD and MA2) was used to make
ultraviolet observations of the moon Triton.  Triton appears to be undergoing
the start of a long-awaited, and perhaps fundamental, global seasonal change. 
The HST is required for this work owing to Triton's small {0.13"} apparent
diameter and the need for ultraviolet observations.  The observations were
completed as planned, and no problems were reported.  

   1.15 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 Both low
and 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 described in HSTAR 7250 and 2.1, the
acquisition for the third iteration of this proposal failed, affecting one
observation.  Otherwise, the observations were completed as scheduled, and no
further anomalies were reported.  

   1.16 Completed FGS 8309 (A Link Between Massive Binary Stars and Non-thermal
Radio Emission)

       The Fine Guidance Sensors were used to make astrometric observations of
the massive Wolf-Rayet binary star WR98 and several nearby reference stars. 
Non-thermal radio emission in Wolf-Rayet stars is explained in terms of
synchrotron emission from shocks in the stellar wind.  The observations were
executed as scheduled, and no anomalies were noted.  

   1.17 Completed WF/PC-2 8301 (A Snapshot Survey of X-ray Selected Central
Cluster Galaxies)

       The WF/PC-2 was used to make snapshot survey observations of the x-ray,
central cluster galaxy Z2701.  Central cluster galaxies are the most massive
stellar systems known and have been used as standard candles for many decades. 
The observations were executed as scheduled, and no anomalies were noted. 

   1.18 Completed STIS/CCD 8418 (CCD Sensitivity Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
observations of standard source AGK+81D266 as part of a CCD
sensitivity-monitoring program in Cycle-8.  The sensitivity of each CCD grating
mode is monitored to detect any change due to contamination or other causes.  A
wavelength calibration image aand a CCD flat were also taken.  The observations
were completed as planned, and no anomalies were reported.  

   1.19 Completed FGS 8319 (Masses and Distances of Pre-Main Sequence Binaries)

       The Fine Guidance Sensors were used to make astrometric observations of
the pre-main sequence binary star system DF-Tau.  Observations were also made
of several reference stars.  Our goal is to measure the masses of low mass
young stars.  This will enable a calibration of theoretical calculations of
stellar evolution to the main sequence.  The observations were completed as
planned and no problems were reported.  

   1.20 Completed STIS/MA1 8424 (MAMA Sensitivity and Focus Monitor C8)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
observations of object AGK+81D266 in order to measure the sensitivity and to
focus monitor C8.  This also is to monitor sensitivity of each MAMA grating
mode to detect any change due to contamination or other causes, and to monitor
the STIS focus in a spectroscopic mode.  A wavelength calibration was also
taken.  The observations were completed as planned, and no anomalies were
reported.  

   1.21 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 MRC2156-24.  The role of associated
absorption systems and dust obscuration close to the central engines of AGN is
not understood.  A wavelength calibration image was also taken.  The
observations were completed as planned, and no anomalies were reported.   

   1.22 Completed STIS/MA1 8103 (A Global Picture of White Dwarfs in
Cataclysmic Variables)

       The Space Telescope Imaging Spectrograph (MA1) was used to make
ultraviolet spectrographic observations of the white dwarf star that is located
in the cataclysmic variable star system known as HE2350-390.  A wavelength
calibration image was also taken.  The observations were executed as scheduled,
and no problems were reported.  

   1.23 Completed STIS/CCD/MA2 7316 (Saturn's Satellites: Alteration of the
Surface by Ion Irradiation on Enceladus and Tethys)

       The Space Telescope Imaging Spectrograph (CCD and MA2) was used to make
observations of Saturn’s moon Tethys.  Saturn's medium-sized icy satellites
display a diverse range of surface alteration caused by one or more external
processes.  A wavelength calibration image was also taken.  The observations
were completed as planned, and no anomalies were noted.  

   1.24 Completed WF/PC-2 8194 (Evolution of high-redshift Seyfert Galaxies)

       The WF/PC-2 was to be used to make observations of the high-redshifted
Seyfert galaxy Gal-105312 in order to study its evolution.  As described in
HSTAR 7250 and 2.1, the acquisition for this proposal failed, affecting two
observations.

   1.25 Completed STIS/CCD 8271 (A Snapshot Survey of LMC Planetary Nebulae: A
Study of Nebular and Late Stellar Evolution)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
medium-resolution slitless spectroscopy snapshot images of the planetary nebula
LMC-SMP-028 that is located in the Large Magellanic Cloud to study the parallel
evolution of the nebula and its central star.  The observations were completed
as planned, and no problems were reported.  

   1.26 Completed STIS/CCD/MA1 8546 (The First Comprehensive High Spectral
Resolution Study of Stellar Coronae: The 1999 Chandra, HST, EUVE, SAX and VLA
Capella Campaign)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
observations of the stellar corona on the star Capella.  This is the first
comprehensive high spectral resolution study of stellar coronae: The 1999
Chandra, HST, EUVE, SAX and VLA Capella Campaign.  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: 21
                                        Successful: 20

       The acquisition at 255/0642Z failed the attitude vector test and
defaulted to RGA control.  HSTAR 7250 was written.  The proposals detailed in
1.15 and 1.24 were affected.

                         Scheduled Re-acquisitions: 22
                                        Successful: 22

   2.2 FHST Updates: 

                              Scheduled: 57
                             Successful: 57

   2.3 Operations Notes: 

       The SSR EDAC error counter was cleared eight times per ROP SR-1.

       The STIS MCE-1 reset at 253/131754Z while the low voltage was on and
while outside any SAA interval.  The STIS flight software error counter was
reset at 253/1317Z as directed by ROP NS-12.  The MAMA-1 was recovered via
normal SMS commanding at 253/1838Z, the time of a high voltage turn-on.

       The NSSC-1 status buffer was dumped at 254/0052 per ROP NS-3.

       ESTR-2 was re-conditioned at 254/0411Z in accordance with ROP RD-7.

3.0 SIGNIFICANT FORTHCOMING EVENTS: 

       Continuation of normal science observations and calibrations.

/DMH