HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2108

PERIOD COVERED:  0000Z (UTC) 04/22/98 - 0000Z (UTC) 04/23/98

Daily Status Report as of 113/0000Z

1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED:

   1.1 Completed Two Sets of WF/PC-2 7712 (WF/PC-2 Cycle 7 Supplemental
Darks pt2/3)

       The WF/PC-2 was used to make a series of Cycle 7 supplemental
calibration darks.  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 executed as scheduled, and no
anomalies were noted.

   1.2 Completed STIS/CCD 7926 (CCD Dark and Bias Monitor -- Continued)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
several dark and bias calibration observations.  This is to measure CCD
dark current and bias rates for the two supported amplifier settings {gain
= 1 and gain = 4} in order to gather data for making superdarks and
superbiases.  These observations will also 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 with no
anomalies.

   1.3 Completed FOC/96/WF/PC-2/NIC/1/2/3/STIS/CCD 7591 (1997 Spring
Heptathlon)

       The Faint Object Camera (f/96), the WF/PC-2, the Near Infrared
Camera (Cameras One, Two, and Three), and the Space Telescope Infrared
Spectrograph were used to make calibration observations as part of the
Spring Heptathlon.  This test is a continuation of the focal plane
monitoring program.  The goal is to measure relative positions of the SIs
to within 50 milli-arcseconds, to verify the focal plane plate scale, and
by repetition, to assess stability of the focal plane and FGSs.  The
observations were executed as scheduled, and no anomalies were noted.

   1.4 Completed Two Sets of NIC/2 7330 (The Fueling of Active Nucleii: A
NICMOS Snapshot Survey)

       The Near Infrared Camera (Camera Two) was used to probe the dark
matter distribution of NGC-3627 and NGC-2903 far from the center by
observing intervening absorption from the MgII doublet (lambda 2800) in the
spectrum of one background QSO located in a geometrically optimal position.
HST observations are required because this feature is in a wavelength range
not accessible from the ground, and the QSO magnitudes and expected
strength of absorption make IUE observations unfeasible.  The proposal
completed as expected.

   1.5 Completed STIS/CCD 7803 (Daily Darks to Update Acquisition Bad Pixel
Table Part III)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
daily dark calibration updates.  These daily darks are intended to identify
hot pixels for update to the acquisition on-board FSW hot pixel table.
Daily hot pixel lists can also be used for science data analysis.  The
observations were completed as planned, and no anomalies were reported.

   1.6 Completed NIC/1/2/3 7505 (The Hubble Diagram for Distant Supernovae
Measuring Cosmic Deceleration and Global Curvature)

       The Near Infrared Cmaera (Cameras One, Two and Three) was used to
make observations of Super Nova SN1998E in order to produce a precise
Hubble diagram from measuring cosmic deceleration and global curvature.
HST can make an essential contribution by providing photometry with
substantially higher precision and better temporal coverage than can be
obtained from the ground.  The observations were completed as planned, and
no anomalies were reported.

   1.7 Completed Three Sets of STIS/CCD 7908 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal)

       The Space Telescope Imaging Spectrograph (CCD) was used to make
calibration observations as part of the POMS Test Proposal.  This was a
STIS non-scripted parallel proposal.  The observations were completed as
planned, and no problems were reported.

   1.8 Completed NIC/1/2/3 7218 (Nearby Starburst Galaxies)

       The Near Infrared Camera (Cameras One, Two and Three) was used to
make observations of the nearby starbursting galaxy M-82.  This proposal
encompasses a study of both the stars and interstellar material in
starburst nuclei which will test ideas about the triggering of starbursts
and whether starbursts propagate outwards in a nucleus.  As described in
2.1, one of the re-acquisitions for this proposal defaulted to fine lock
backup on one FGS only.  Otherwise, the observations were completed as
planned, and no anomalies were reported.

   1.9 Completed Three Sets of WF/PC-2 7909 (POMS Test Proposal: WF II
Parallel Archive Proposal)

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

   1.10 Completed STIS/CCD 7635 (STIS CCD Hot Pixel Annealing)

       The Space Telescope Imaging Spectrograph (CCD) was used to test the
hot pixel annealing procedure.  The effectiveness of the CCD hot pixel
annealing process is assessed by measuring the dark current behavior before
and after annealing and by searching for any window contamination effects.
The observations were completed as planned, and no problems were reported.

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions:

                            Scheduled Acquisitions : 4
                                        Successful : 4

       The acquisition at 113/041048Z defaulted to fine lock backup on
FGS-3 only when FGS-1 experienced a walkdown failure.  HSTAR 6446 was
written.  Three proposals which will be dwscribed in tomorrow's report may
have been affected: WF/PC-2 7909, NICMOS 7596, and STIS 7510.

                          Scheduled Reacquisitions : 11
                                        Successful : 11

       The re-acquisition at 112/123216Z defaulted to fine lock backup on
FGS-1 only when the FGS-3 scan step limit was exceeded.  HSTAR 6445 was
written.  The proposal described in 1.8 may have been affected.

   2.2 FHST Updates:

                              Scheduled : 6
                             Successful : 6

   2.3 Operations Notes:

       The NSSC-1 status buffer was dumped at 112/1401Z using ROP NS-3.

       Per ROP SR-1, the SSR correctable EDAC error counter was cleared on
two occasions.

       The Battery 3 capacity check test continues.  Discharge was
terminated nominally at 15 Volts by the special hardware limit test at
112/1254Z.  Engineering data recording for the test was stopped at
112/1311Z, and was subsequently played back.  Recharge was started at
112/1432Z, the normal orbit day entry.  The charge acceptance behavior is
typical relative to that of other batteries.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

       Continuation of normal science observations and calibrations.

/DMH