HUBBLE SPACE TELESCOPE

       DAILY REPORT #3093

PERIOD COVERED:  0000Z (UTC) 04/11/02 - 0000Z (UTC) 04/12/02

Daily Status Report as of 102/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Four Sets of STIS/CCD 8902 (Dark Monitor-Part 2)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks.  No problems were reported.

    1.2 Completed Two Sets of ACS/WFC/HRC 8947 (Weekly Test)

        The Advanced Camera for Surveys (WFC and HRC) was used to perform 
basic tests to monitor, the read noise, the development of hot pixels and 
test for any source of noise in ACS CCD detectors.  This program will be 
executed at least once a day for the entire lifetime of ACS.  There were no 
problems reported.

    1.3 Completed Twenty-five Sets of ACS/WFC 8948 (CTE Test)

        The Advanced Camera for Surveys (WFC) was used to measure the 
baseline charge transfer efficiency {CTE} performance of the HRC and WFC 
detectors, emulating the CTE ground calibration testing.  Also, a  similar 
program will perform periodic measurements in order to track the change in 
the CTE as damage due to radiation exposure accumulates.   All observations 
were successful.

    1.4 Completed STIS/CCD 9131 (Imaging the Host Galaxies of High Redshift 
Type Ia Supernovae)

        The Space Telescope Imaging Spectrograph (CCD) was used to complete 
the snapshot survey of distant galaxies of known redshift which hosted 
supernovae {SNe} of Type Ia found via the Supernova Cosmology Project 
{SCP}.  No problems were seen.

    1.5 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.

    1.6 Completed STIS/CCD 9176 (LMC Eclipsing Binaries with Cepheid 
Components: The Key to the Extragalactic Distance Scale)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
determine the distance to the LMC and to observe the Cepheid P-L that form 
the backbone of the Cosmic Distance Scale and the determination of 
H_degrees.  Unfortunately, in spite of concerted efforts of many 
investigators, the zero point of the Cepheid P-L law and the LMC distance 
remain controversial and uncertain to ~10-15, using eclipsing binaries 
{EBs} as "standard candles'' to include two recently discovered LMC 
eclipsing binaries {EBs} with Cepheid components.  These observations of 
these extraordinary systems hold the key to determining simultaneously the 
Cepheid P-L zero point and the LMC distance, and to provide a direct test 
of the Baade-Wesselink parallax method.  There were no reported problems.

    1.7 Completed STIS/CCD 8904 (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 in order to build up high-S/N superbiases and track the evolution 
of hot columns.  The proposal completed with no anomalous activity.

    1.8 Completed Two Sets of WF/PC-2 9091 (Evolution of Star Forming 
Environments in H II Regions)

        The WF/PC-2 was used to look for evaporating gaseous globules and 
silhouette disks in two young clusters and along one molecular cloud 
wall.  The proposal completed nominally.

    1.9 Completed ACS/HRC/WFC 9292 (The Nature of Galaxies at z > 4)

        The Advanced Camera for Surveys (HRC and WFC) was used to further 
look into recent discoveries of a number of galaxies and quasars at 
redshifts greater than 5 that has identified the z>5-6 epoch as key to 
understanding the earliest formation phases for galaxies.  However, 
establishing the characteristics and properties of these earliest galaxies 
is proving to be a particularly difficult.  They are faint, with I{AB} 
magnitudes around 26-27.  Thus, substantial investments of time are needed 
to obtain high S/N images, while ground-based spectroscopy, even with 8-10 
m class telescopes, has provided little more than redshifts.  Establishing 
the physical properties of these galaxies will be a challenge for the 
foreseeable future.  However, there is a subset of this high redshift 
population that is amenable to more detailed study.  These are sources that 
have been strongly lensed by low redshift clusters.  No problems were reported.

    1.10 Completed STIS/CCD 9070 (A Census of Nuclear Star Clusters in 
Late-Type Spiral Galaxies: II. Spectroscopy and Stellar Populations)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate spiral galaxies that have a prominent star cluster in their 
dynamical center.  Statistics for cluster frequency, size, and luminosity 
remain incomplete.  The proposal completed as planned.

    1.11 Completed Three Sets of WF/PC-2 8937 (Cycle 9 Supplemental Darks 
pt2/3)

        The WF/PC-2 was used obtain three dark frames every day to provide 
data for monitoring and characterizing the evolution of hot pixels.  No 
problems were encountered.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  4
    Successful:  4

  Scheduled Re-acquisitions: 10
    Successful: 10

    2.2 FHST Updates:
    Scheduled: 10
    Successful: 10

    2.3 Operations Notes:

        The NICMOS Cryo Cooler cool down continues and is now in the range 
of the expected endpoints.  As of yesterday morning, the NICMOS Outlet 
Temperature (MNPNCOLT) was 78.73K (expected end point 76K), the NCC TA 
Inlet Temperature (MNPTAILT) was 67.49K (expected end point 68K), the CLI 
Temperature (MNPLINTT) was 70.07K (expected end point 71K), and the NICMOS 
Inlet Temperature (MNRNCILT) was 62.92K (expected endpoint 63K).

        The CCS engineering status buffer limits were adjusted at 101/2218Z 
per ROP DF18A.

        Per an operations note, the limit adjustment CCL was updated on all 
CCS strings by 101/2225Z.

        Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 102/0346Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of Servicing Mission Orbital Verification and the 
gradual resumption of normal science observations and calibrations.

/CAW