HUBBLE SPACE TELESCOPE

                       DAILY REPORT #1681

PERIOD COVERED:  0000Z (UTC) 07/23/96 - 0000Z (UTC) 07/24/96

Daily Status Report as of 206/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed FOS/RD 6595 (Does Pluto Have a Haze Layer?)

       The Faint Object Spectrograph (Red Side) was used to make =
spectrographic observations of the planet Pluto in order to determine if =
the planet has a haze layer.  These observations were made during a =
series of stellar occultations.  The objective is to study the physical =
structure of the atmosphere at kilometer-level spatial resolution.  =
During this proposal there occurred a status buffer message at =
205/024015Z that described an FOS target aquisition failure which had =
been scheduled at 205/023522Z.  Aperture mapping had not found a target.  =
This happened about 30 minutes into a three-hour observation.  HSTAR 5661 =
was written.  Otherwise, the observation completed as scheduled, and no =
further anomalies were noted. 

   1.2 Completed WF/PC-2 6187 (WF/PC-2 Cycle 5 Calibration: Earth Flat)

       The WF/PC-2 was used to make Earth streak flat calibration images. =
 These streak flats will be used to produce flat fields, to map the OTA =
illumination pattern and, in combination with other data, to produce new =
superflats.  The observations were completed as planned, and no problems =
were reported.

   1.3 Completed WF/PC-2 6431 (Determination of the Extragalactric =
Distance Scale)

       The WF/PC-2 was used to make observations of the galaxy NGC-4535 =
to be used in measuring the periods of Cepheid variable stars within this =
galaxy.  This will allow for a more accurate estimate of the distances to =
these galaxies through the period-luminosity relation for the Cepheid =
stars.  The observations were executed as scheduled, and no anomalies =
were noted.

   1.4 Completed Two Sets of FOS/BL 6166 (FOS Cycle 5: Location of =
Spectra and Wavelength Calibration)

       The Faint Object Spectrograph (Blue Side) was used to make =
wavelength calibration images to measure the stability of the FOS Blue =
Side wavelength scale and spectral locations.  A Taled calibration =
observations was also taken.  The observations were completed as planned, =
and no anomalies were reported.

   1.5 Completed Two Sets of GHRS/2 6213 (GHRS Aperture Offsets- Cycle 5)

   The High Resolution Spectrograph (Side Two) was used to make =
calibration images of the star HD155763 in order to determine the offsets =
of the instruments focal plain apertures.  The purpose of this calibration=
 program is to measure the relative wavelength offsets between the Large =
Science Aperture and Small Science Aperture with various gratings.  A =
wavelength calibration image was also taken.  The observations were =
completed as scheduled, and no anomalies were reported.

   1.6 Completed FOS/RD 6204 (FOS Cycle 5 Internal/External Offset)

       The Faint Object Spectrograph (Red Side) was used to make =
spectrographic calibration images of the object NGC-6833 in order to =
measure the spectrograph's internal and external offsets.  The internal =
lamp was intermingled with the external observations.  The observations =
were completed as planned, and no problems were reported.

   1.7 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 =
spiral galaxy NGC-5879 in order to study its central bulge.  The aim is =
to investigate the core properties, correlation's 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.

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions: 

                            Scheduled Acquisitions : 5
                                        Successful : 5

                          Scheduled Reacquisitions : 7
                                        Successful : 7

   2.2 FHST Updates: 

                              Scheduled : 2
                             Successful : 2

   2.3 Operations Notes: 

       Operations personnel have ensured that all STR playbacks have been =
collected using manually scheduled TDRSS services.

       In preparation for the simulation being conducted today, HST =
operations transferred to the SAMS back-up facility at 206/0245Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS: 

        GSFC Internal Simulation #8 (EVAs 3/4) will be conducted today =
from 8:00 a.m. until approximately 8:00 p.m.

/DMH