HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2391

PERIOD COVERED:  0000Z (UTC) 06/10/99 - 0000Z (UTC) 06/11/99

Daily Status Report as of 162/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

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

   1.3 Completed WF/PC-2 6354 (Measuring Luminosity Evolution in Z = 0.3
Field Galaxies)

       The WF/PC-2 was used to make snapshot observations of the galactic
cluster Gal-Cluster-0173 located at a distance of Z = 0.3.  The targets
were drawn from a much larger pool of galaxies for which the internal
kinematics have been measured from an extensive ground based program.  The
observations were executed as scheduled, and no anomalies were noted.

   1.4 Completed Four 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 described in 2.1 and HSTAR 7164, the
aquisition for the third iteration of this proposal defaulted to fine lock
back-up on one FGS only.  Otherwise, the observations were completed as
scheduled, and no further anomalies were reported.

   1.5 Completed WF/PC-2 7431 (Snapshot Survey of Microlensed Source Stars)

       The WF/PC-2 was used to make snapshot survey images of microlensed
source star MACHO-95-5.  Gravitational microlensing surveys have revealed
an excess of lensing events over theoretical predictions toward both the
Large Magellanic Cloud and the Galactic Bulge.  The observations were
completed as planned, 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 WF/PC-2 8200 (Globular Cluster Systems in Three Giant Coma
Ellipticals)

       The WF/PC-2 was used to make observations of the giant Coma
elliptical galaxy NGC-4926 in order to study its globular clusters.  What
we know about the Coma ellipticals so far present serious challenges to
virtually every one of the current formation scenarios for globular cluster
systems.  As described in 2.1 and HSTAR 7164, the aquisition for this
proposal defaulted to fine lock back-up on one FGS only.  Otherwise, the
observations were executed as scheduled, and no further anomalies were
noted.

   1.8 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.

   1.9 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 V853-Oph.  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.

   1.10 Completed 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/MA2 7950 (Cycle 7 MAMA Dark Measurements)

       The Space Telescope Imaging Spectrograph (MA1) was used to make a
dark calibration image.  This is to establish if the detectors are
performing nominally, that no internal movement of the MCP has taken place,
and establish dark level in orbit for a given operating temperature.  These
darks will be used in later image reduction and also trended over
instrument life time as indicators of detector degradation or damage.  The
observations were completed as planned, and no problems were reported.

   1.12 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.

   1.13 Completed WF/PC-2 7622 (WF/PC-2 Cycle 7 Internal Monitor)

       The WF/PC-2 was used to make a set of Cycle 7 internal monitoring
calibration measurements.  A variety of internal exposures are obtained in
order to provide a monitor of the integrity of the CCD camera electronics
in both bays {gain 7 and gain 15}, a test for quantum efficiency in the
CCDs, and a monitor for possible buildup of contaminants on the CCD
windows.  A bias calibration and an internal flat calibration image were
also taken.  The observations were executed as scheduled, and no anomalies
were noted.

   1.14 Completed STIS/CCD/MA1/MA2 7773 (Simultaneous Multiwavelength
Observations of the Dwarf Nova Oscillations of SS Cygni)

       The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used
to make simultaneous multiwavelength observations oscillations of the dwarf
nova SS-Cygni.  We attempted a multiwavelength campaign using RXTE, EUVE,
HST, and ground-based optical telescopes to characterize the dwarf nova
oscillations of SS Cygni.  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 : 5
                                        Successful : 5

       Per HSTAR 7164, the acquisition at 161/093500Z defaulted to fine
lock back-up on FGS-1 only.  The proposals described in 1.4 and 1.7 may
have been affected.

                          Scheduled Reacquisitions : 10
                                        Successful : 10

   2.2 FHST Updates:

                              Scheduled : 14
                             Successful : 14

   2.3 Operations Notes:

       Operations transferred to CCS string "A" at 161/1132Z and remains
there this morning.

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

       The CCS 48-hour engineering data test completed on CCS string "B" at
161/1044Z.

       Science data for the STIS instrument was re-transmitted at 162/0155Z
per ROP SR-1.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH