HUBBLE SPACE TELESCOPE

       DAILY REPORT #2941

PERIOD COVERED:  0000Z (UTC) 08/21/01 - 0000Z (UTC) 08/22/01

Daily Status Report as of 234/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Two Sets of WF/PC-2 9042 (An Archive To Detect The 
Progenitors Of Massive, Core-Collapse Supernovae)

         The WF/PC-s was used to search for supernovae which have massive 
star progenitors.  The already extensive HST archive and high-resolution 
ground-based images of galaxies within ~20 Mpc enables us to resolve and 
quantify their individual bright stellar content.  As massive, evolved 
stars are the most luminous single objects in a galaxy, the progenitors of 
core-collapse supernovae should be directly detectable on pre-explosion 
images.  One Type II progenitor has been observed this year, and the 
investigators have proposed a short, companion WFPC2 proposal to confirm 
this candidate and identify a second.  The observations completed nominally.

    1.2 Completed WF/PC-2 8941 (Cycle 10 UV Earthflats)

        The WF/PC-2 was used to monitor flat field stability by obtaining 
sequences of earth streak flats to improve the quality of pipeline flat 
fields for the WFPC2 UV filter set.  The proposal had no problems.

    1.3 Completed Two Sets of STIS/CCD 8841 (Hot Pixel Annealing C9)

        The Space Telescope Imaging Spectrograph (CCD) was used to improve 
the effectiveness of the CCD hot pixel annealing process.  This is assessed 
by measuring the dark current behavior before and after annealing and by 
searching for any window contamination effects.  In addition CTE 
performance is examined by looking for traps in a low signal level 
flat.  The observations completed with no reported problems.

    1.4 Completed Two Sets of WF/PC-2 9124 (Mid-UV SNAPSHOT Survey of 
Nearby Irregulars: Galaxy Structure and Evolution Benchmark)

        The WF/PC-2 was used to investigate the relation between star 
formation and the global physical characteristics of galaxies to interpret 
the morphologies of distant galaxies in terms of their evolutionary 
status.  Distant galaxies are primarily observed in their rest frame 
mid-ultraviolet.  They resemble nearby late-type galaxies, but are they 
really physically similar classes of objects?  It is proposed to address 
this question through a SNAPSHOT survey in the 2 mid-UV filter F300W of 98 
nearby late-type, irregular and peculiar galaxies.  No problems were reported.

    1.5 Completed Two 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 STIS/CCD/MA1 8306 (Lyman Alpha Clouds toward PKS1302-102)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
conduct high spectral resolution observations of the low-redshift quasar 
PKS1302-102, whose line of sight comprises ~20 Lyman Alpha absorbers with 
HI column densities in excess of 10^14 cm^- 2.  The observations completed 
nominally.

    1.7 Completed Four Sets of 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.  As described in 2.1 and HSTAR 8311, the 
acquisition for the third iteration of this proposal defaulted to fine lock 
backup on one FGS only, possibly affecting two observations.  Otherwise, 
the observations completed with no other anomalous activity.

    1.8 Completed WF/PC-2 9101 (Toward Understanding the Bipolar Geometries 
of Preplanetary Nebulae with High-Velocity Polar Flows)

        The WF/PC-2 was used to image 17 preplanetary nebula for comparison 
with high-resolution spectral-line images {being obtained with 
VLA/MERLIN/ATCA}, enabling us to understand the fast outflow and how its 
hydrodynamical interaction with the AGB wind produces a bipolar nebula.  No 
problems were reported.

    1.9 Completed STIS/MA1 8843 (Cycle 9 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA1) was used to perform 
the routine monitoring of the MAMA detector dark noise.  The proposal 
completed nominally.

    1.10 Completed STIS/CCD 9077 (Survey of the LMC Planetary Nebulae)

        The Space telescope Imaging Spectrograph (CCD) was used to perform 
a snapshot survey of all known LMC planetary nebulae {PNe} in order to 
study the co-evolution of the nebulae and their central stars, and to probe 
the chemical enrichment history of the LMC.  There were no reported problems.

    1.11 Completed 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.  As described in 2.1 and HSTAR 8311, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
two observations.  Otherwise, the proposal completed with no further 
anomalous activity.

    1.12 Completed FGS/1 9169 (An Interferometric Harvest of Double 
Degenerates)

        Fine Guidance Sensor #1R was used to observe the white dwarf mass 
and age distributions that hold clues to the star formation history of our 
Galaxy and the age of the disk.  As described in 2.1 and HSTAR 8311, the 
acquisition for this proposal defaulted to fine lock backup on one FGS 
only, possibly affecting all observations.  Otherwise, no other problems 
were reported.

    1.13 Completed STIS/CCD 9066 (Closing in on the Hydrogen Reionization 
Edge of the Universe)

        The Space Telescope Imaging Spectrograph (CCD) was used in parallel 
constrain the Hydrogen reionization edge in emission that marks the 
transition from a neutral to a fully ionized IGM at a predicted 
redshifts.  As described in 2.1 and HSTAR 8313, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
eight observations.  Otherwise, the proposal completed uneventfully.

    1.14 Completed WF/PC-2 9138 (Host Galaxies of Gravitationally Lensed 
Quasars)

        The WF/PC-2 was used to perform imaging studies of quasar host 
galaxies at high redshift that are biased toward detecting luminous 
hosts.  Gravitational lensing combined with optical and near-IR imaging 
enhances their detectivity and has nearly doubled the number of known hosts 
at z>1.  Lens studies have successfully imaged hosts with lower 
luminosities at farther distances beneath a larger fraction of quasars than 
imaging of non- lensed quasars.  We propose deep WFPC2 follow-up imaging of 
five lensed systems in the F555W and F814W filters, which offer unique 
opportunities for detailed studies of faint, high-redshift, quasar 
hosts.  As described in 2.1 and HSTAR 8313, the acquisition for this 
proposal defaulted to fine lock backup on one FGS only, possibly affecting 
twelve observations.  Otherwise, the proposal completed as planned.

    1.15 Completed STIS/CCD 9187 (A Lyman Limit Snapshot Survey: The Search 
for Candidate D/H Absorbers)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
D/H in gas clouds seen against background QSOs.  This provides a unique and 
fundamental cosmological probe of the baryonic density parameter.  To date, 
most of the QSO absorption line D/H constraints have been derived at high 
redshift.  In this proposal the proposers investigate a lower redshift 
range, because there are two potentially crucial advantages to be gained by 
carrying out D/H measurements at intermediate redshift.  First, the 
background of HI forest lines is lower and contamination of the DI feature 
is significantly reduced.  Second, a far larger sample of very bright QSOs 
exists.  There were no reported problems.

    1.16 Completed Two 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.

    1.17 Completed STIS/CCD 9148 (Light Echos and the Nature of Type Ia 
Supernovae)

        The Space Telescope Imaging Spectrograph (CCD) was used to take 
STIS snapshot images of a subset of 43 well observed Type Ia supernovae 
{SNIa}, most of which have been discovered in late type galaxies over the 
last 40 years to make a systematic search for light echos around SN 
Ia.  STIS will also observe a sample of 10 SN II and SN Ib/c, which are 
believed to be the result of massive star core collapse and, therefore, to 
be thin-disk population objects, in order to make an empirical calibration 
of the accuracy of our method for determining scale heights.  The SN Ia 
sample will provide a direct as well as accurate estimate of the scale 
height of SN Ia which is an important clue to the progenitors of these 
events.  The proposal completed nominally.

    1.18 Completed STIS/CCD 9285 (POMS Test Proposal: STIS Non-scripted 
Parallel Proposal Continuation III)

        The Space Telescope Imaging Spectrograph (CCD) was used to make low 
galactic latitude, non-scripted parallel observations as part of a POMS 
test proposal.  The observations were completed as planned, and no 
anomalies were reported.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  9
Successful:  9

        Per HSTAR 8311, the acquisition at 233/144504Z defaulted to fine 
lock backup on FGS-3 only when the scan step limit was exceeded on 
FGS-2.  The proposals detailed in 1.7, 1.11, and 1.12 may have been affected.

        Per HSTAR 8313, the acquisition at 233/155451Z defaulted to fine 
lock backup on FGS-3 only when the scan step limit was exceeded on 
FGS-2.  The proposals detailed in 1.13 and 1.14 may have been affected.
  Scheduled Re-acquisitions:  5
Successful:  5

    2.2 FHST Updates:
Scheduled: 19
Successful: 19

    2.3 Operations Notes:

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

        Flight software 2.0B RAM installation was performed at 
233/1732Z.  This installation, together with related installations to 
follow, changes the Diode Buss Controller commanding post-SM3B and fixes 
the Magnetic Torquer Electronics echo check timing.

        The STIS MCE-2 reset at 233/225044Z while the low voltage was on 
and while outside any SAA interval.  The STIS flight software error counter 
was reset at 233/2250Z per ROP NS-12.  MAMA-2 was recovered via normal SMSM 
commanding at 234/0210Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Installation of 2.0B EEPROM and 2.0C RAM flight software today.

        Continuation of normal science observations and calibrations.

/CAW