HUBBLE SPACE TELESCOPE

   DAILY REPORT #2872

PERIOD COVERED:  0000Z (UTC) 05/14/01 - 0000Z (UTC) 05/15/01

Daily Status Report as of 135/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Three Sets of STIS/CCD 8845 (Spectroscopic Flats C9)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
CCD flats in the spectroscopic mode.  The observations completed with no 
reported problems.

    1.2 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies)

        The WF/PC-2 was used to perform snapshot images of a representative 
subset of the central cluster galaxies from an X-ray selected cluster 
sample that would provide important constraints on the formation and 
evolution of dust in cluster cores that cannot be obtained from 
ground-based observations.  The observations completed as planned.

    1.3 Completed Twelve Sets of STIS/CCD 9248 (Probing the Large Scale 
Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  The 
observations completed nominally.

    1.4 Completed Three Sets of STIS/CCD 8864 (CCD Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks for the CCD.  The proposal completed nominally.

    1.5 Completed Four Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

        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 proposal completed with no reported problems.

    1.6 Completed Two Sets of WF/PC-2 8599 (A Census of Nuclear Star 
Clusters in Late-Type Spiral Galaxies)

        The WF/PC-2 was used to conduct an I-band snapshot survey of a 
well-defined sample of nearby, face-on spiral galaxies of type Scd or 
later.  The proposal completed nominally.

    1.7 Completed Two Sets of WF/PC-2 8812 (Cycle 9 Internal Monitor)

        The WF/PC-2 was used to obtain routine internal monitors for WFPC2 
in order to monitor the health of the cameras.  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.  There were no reported problems.

    1.8 Completed STIS/MA1 8658 (Atmospheric Escape and the D/H Ratio in 
Mars' Atmosphere)

        The Space Telescope Imaging Spectrograph (MA1) was used to observe 
the highly extended upper atmosphere and the UV airglow of Mars that have 
not been studied by any in situ spacecraft since Mariner 9 in 1972.  At the 
same time, one of the main elements of NASA's space science program today 
is the study of Mars and how it has evolved over time to a hostile 
environment, compared with the favorable conditions on the Earth.  The 
availability of long aperture spatially resolved UV spectra with STIS makes 
it possible to obtain unique information on the extended upper atmosphere 
of Mars by mapping the H and O dayglow emissions with altitude above the 
limb.  It is  proposed to make these observations just before Mars 
opposition near the end of HST cycle 9.  Initial modeling indicates that we 
will have sufficient angular resolution and sensitivity to measure the 
scale heights of the suprathermal atom populations of H and O atoms.  We 
also propose to determine accurate values for the D and H columns, and the 
D/H ratio, in the upper atmosphere of Mars.  The present-day D/H ratio 
gives vital information leading to understanding the evolution of Mars' 
atmosphere, the historic escape of water into space, and potentially the 
remaining water abundance on Mars.  The observations completed with no 
problems.

    1.9 Completed Two Sets of STIS/CCD 8865 (Bias Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used 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 track the evolution of hot 
columns.  The proposal completed with no anomalous activity.

    1.10 Completed STIS/CCD 8667 (Nuclear Stellar Disks in Early Galaxies: 
Black Hole Masses and Disk/Bar/Bulge Evolution)

        The Space Telescope Imaging Spectrograph (CCD) was used to image of 
an additional four E/SO galaxies to: {1} test whether the unusual 
M_bh/M_bulge ratio is typical of these nuclear disk galaxies and {2} search 
for additional ring/bar structures will help determine the source of the 
accreted material and the time sequence of the disk/bar/bulge/Black Hole 
fueling connection.  The observations completed with no reported anomalies.

    1.11 Completed STIS/CCD/MA2 8672 (Establishing the Gaseous Phases of 
Galaxies Following the Epoch of Star Formation)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used in 
an ambitious program designed to: {1} establish if high ionization, 
metal-rich halos/coronae were in place as early as z~1, which would imply 
that extended, early-epoch, galactic halos result from reprocessed galactic 
gas and that the kinematics are mechanically driven; {2} obtain the first 
comparison of the relative kinematics of low and high ionization species in 
z~1 galaxies, covering a wide range of N{HI} environments and MgII 
kinematic spreads up to ~400 km/s; {3} discriminate between single-phase 
and multi-phase ionization, and therefore spatial, absorbing structures 
{eg. MgII clouds embedded in diffuse high ionization halos}; and {4} place 
constraints on the gas-phase metallicites in early-epoch galaxies.  The 
observations complete with no reported problems.

    1.12 Completed WF/PC-2 9244 (POMS Test Proposal: WFII Parallel Archive 
Proposal Continuation)

        The WF/PC-2 was used to perform a generic target version of the 
Archival Pure Parallel program.  The program will be used to take parallel 
images of random areas of the sky, following the recommendations of the 
Parallels Working Group.  The observations completed with no anomalous 
activity.

    1.13 Completed STIS/CCD/MA1 8582 (UV Detectability of Bright Quasars in 
the Sloan Fields)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
examine the He II Ly alpha absorption at 304{1+z} Angstrom which is a far 
more sensitive tracer of the intergalactic medium {IGM} than its H I 
counterpart.  The recent detections of such absorption in four quasars, 
albeit with limited data quality and a small sample size, demonstrate the 
great potential of such a probe.  There were no reported problems.

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

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

    1.15 Completed WF/PC-2 8591 (The Smallest Nuclear Black Holes)

        The WF/PC-2 was used to observe small nuclear black holes which are 
the last major unexplored part of BH parameter space, searching for the 
smallest BHs that HST can possibly find.  The proposal completed with no 
reported anomalies.

    1.16 Completed FOC/96 7923 (FOC F/96 Turn-on)

        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.

    1.17 Completed STIS/CCD 8840 (Read Noise Monitor)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the read noise of all the amplifiers on the STIS CCD using pairs of bias 
frames.  Full frame and binned observations are made in both Gain 1 and 
Gain 4, with binning factors of 1 x 1, 1 x 2, 2 x 1 and 2 x 2.  All 
exposures are internals.  The observations completed with no reported problems.

    1.18 Completed WF/PC-2 9149 (The Nature Of The Most Luminous Star- 
Forming Galaxies In The Redshift Range 0.4 To 1.5)

      The WF/PC-2 was used to perform additional ISO deep surveys that have 
previously uncovered a population of galaxies which are making stars at the 
fantastic rate of > 100 M_odotyr^-1 in the redshift range from 0.4 to 
1.5.  However this population evolves rapidly and luminous star-forming 
galaxies are 5 to 10 times more numerous at z=1 than today.  Combination of 
ISO data with radio {VLA}, sub-mm {SCUBA} and optical data shows that they 
contribute a major fraction {30-50$ representing only a few percent of the 
field galaxy population.  HST imaging of a small subsample of these 
galaxies indicates that most of them are disks showing disrupted 
morphologies or possessing companions, emphasizing the role of merging in 
their star formation history.  The proposal completed without incident.

    1.19 Completed WF/PC-2 8824 (Decontaminations and Associated 
Observations Pt. 3/4)

        The WF/PC-2 was used for the monthly WFPC2 decons.  Also included 
are instrument monitors tied to decons: photometric stability check, focus 
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, 
UV throughput check, VISFLAT sweep, and internal UV flat check.  There were 
no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  7
Successful:  7

  Scheduled Re-acquisitions: 11
Successful: 11

    2.2 FHST Updates:
Scheduled:  5
Successful:  5

    2.3 Operations Notes:

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

        As directed by ROP DF-07A, the ephemeris table was uplinked at 
135/1017Z.

        The STIS MCE-2 reset at 135/033950Z while the low voltage was on 
and while outside any SAA interval.  The STIS flight software error counter 
was cleared at 135/0446Z per ROP NS-12.  MAMA-2 was recovered via normal 
SMS commanding at 135/0418Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW