HUBBLE SPACE TELESCOPE

       DAILY REPORT #3101

PERIOD COVERED:  0000Z (UTC) 04/23/02 - 0000Z (UTC) 04/24/02

Daily Status Report as of 114/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD 9139 (Variability in the UV Spectrum of 3C 279: 
Testing Models for the Gamma-Ray Emission in Blazars)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
determine whether gamma- rays are produced on the scale of the broad line 
region, using multi-epoch UV snapshots of 3C 279 to find and characterize 
its LyAlpha variability.  This will validate the mirror model for 
generating the intense gamma-ray emission from blazars.  3C 279 is the 
best-studied blazar from radio to gamma-ray wavelengths, showing frequent 
large flares over days to months.  Variability in the UV continuum and 
LyAlpha will directly reveal any coupling between the jet ionizing flux and 
the broad-line region emission, providing clues to the physics and 
energetics of all radio-loud AGN.  All observations completed without 
reported incident.

    1.2 Completed Three Sets of ACS/WFC 9575 (Default {Archival} Pure 
Parallel Program)

        The Advanced Camera for Surveys (WFC) was used to test ACS pure 
parallels in POMS.  There were no reported problems.

    1.3 Completed Seven Sets of WF/PC-2 9318 (POMS Test Proposal: WFII 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used to perform the generic target version of the 
WFPC2 Archival Pure Parallel program.  The program was used to take 
parallel images of random areas of the sky, following the recommendations 
of the Parallels Working Group.  There were no reported problems.

    1.4 Completed Eleven Sets of NICMOS/1/2/3 8945 (Cooling System Monitoring)

        The Near Infrared Camera and Multi-Object Camera (NIC1, NIC2 and 
NIC3) was used 1) to measure NICMOS detector performance during the 
cool-down and steady state operation of the NCS. 2}. to demonstrate 
stability {+/-0.1K} of the NICMOS detector temperature at the optimal 
science operating temperature. and 3}.to demonstrate repeatability {+/-0.1 
K} of NICMOS detector temperature following changes from the optimal 
science operating temperature.  No problems were encountered.

    1.5 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.

    1.6 Completed Two Sets of 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.

    1.7 Completed Five 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.

    1.8 Completed STIS/CCD 8902 (Dark Monitor-Part 2)

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

    1.9 Completed Two Sets of STIS/CCD 9496 (UV Spectroscopic Investigation 
of Any Bright, Newly Discovered Comet)

        The Space Telescope Imaging Spectrograph (CCD) was used to perform 
a Target of Opportunity program to investigate any bright comet 
{mboxV<=sssim7} that is newly discovered during Cycle 11, including comets 
of any dynamical class.  The main scientific objective is to obtain 
accurate abundance measurements for several key cometary species: CO from 
the CO 4PG bands, cotwo from the CO Cameron bands, stwo from the stwo B-X 
bands, cstwo from CS emissions, and water from OH emissions.  The UV 
Cameron band emission is currently the only way to probe cotwo in 
comets.  No anomalous activity occurred.

    1.10 Completed STIS/CCD/MA1 9067 (UV Detectability of Bright Quasars in 
the Sloan Fields)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
take MAMA spectra of approximately 30 new, bright, high-redshift quasars in 
each of the next three cycles.  The observations completed with no reported 
problems.

    1.11 Completed STIS/MA2 9573 (NUV-MAMA Daily Dark Monitor)

        The Space Telescope Imaging Spectrograph (MA2) was used to perform 
daily monitoring of the NUV MAMA detector dark noise in order to monitor 
the effects of thermal changes on the NUV dark rate.  No problems occurred.

    1.12 Completed STIS/CCD 9110 (A Search for Kuiper Belt Object Satellites)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate whether the large number of collisions thought to have taken 
place in the primordial Kuiper belt suggest that many Kuiper belt objects 
{KBOs} could have suffered binary-forming collisions similar to that which 
formed the Pluto -- Charon binary.  Detection of such KBO satellites would 
allow measurement of  KBO masses, would help to understand the past 
collisional environment of the Kuiper belt, and would give a context to the 
otherwise unique-seeming formation of the Pluto -- Charon binary.  The 
proposal completed with no reported problems.

    1.13 Completed Two Sets of STIS/MA2 8920 (Cycle 10 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA2) was used to perform 
the routine monitoring of the MAMA detector dark noise, and is the primary 
means of checking on health of the MAMA detectors systems through frequent 
monitoring of the background count rate.  The proposal completed with no 
reported anomalous activity.

    1.14 Completed STIS/CCD 9163 (Kinematics Of Emission-Line Gas Disks In 
Radio-Quiet Galaxies)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
central black hole {BH} masses from the rotation rate of the emission-line 
gas, and to determine the nature and structure of the gas disks. Three 
galaxies with no radio jets and with Halpha+[NII] emission have been 
identified, which have dust disks similar to those commonly seen in our 
sample of radio-loud active galaxies.  All observations completed nominally.

    1.15 Completed FGS/1 9168 (The Distances to AM CVn Stars)

        Fine Guidance Sensor (FGS) #1R was used to determine the parallaxes 
and proper motions of the five brightest of the seven known AM CVn 
systems.  AM CVn systems are binaries where mass is transferred from a 
completely hydrogen-deficient, degenerate mass donor to a white dwarf 
primary through a helium accretion disk.  A better understanding of these 
systems is crucial for a number of reasons: (1) to study the late stages of 
binary evolution, (2) to study the effect of chemical composition on the 
physics of accretion discs, (3) to estimate their contribution to the 
Supernovae Ia rate, and (4) to estimate their contribution to the 
gravitational radiation background.  All observations completed with no 
reported problems.

    1.16 Completed Two Sets of STIS/CCD 9317 (Pure Parallel Imaging 
Program: Cycle 10)

        The Space Telescope Imaging Spectrograph (CCD) was used to perform 
the default archival pure parallel program for STIS during cycle 10.  There 
were no reported problems.

    1.17 Completed STIS/CCD 9139 (Variability in the UV Spectrum of 3C 279: 
Testing Models for the Gamma-Ray Emission in Blazars)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
determine whether gamma- rays are produced on the scale of the broad line 
region, using multi-epoch UV snapshots of 3C 279 to find and characterize 
its LyAlpha variability.  This will validate the mirror model for 
generating the intense gamma-ray emission from blazars.  3C 279 is the 
best-studied blazar from radio to gamma-ray wavelengths, showing frequent 
large flares over days to months.  Variability in the UV continuum and 
LyAlpha will directly reveal any coupling between the jet ionizing flux and 
the broad-line region emission, providing clues to the physics and 
energetics of all radio-loud AGN.  All observations completed without 
reported incident.

    1.18 Completed Five Sets of NICMOS/1/2/3 8944 (Filter Wheel/Mechanisms 
Mini-Functional Test)

        The Near Infrared Camera and Multi-Object Camera (NIC1, NIC2 and 
NIC3) was used to perform an early engineering test to verify the 
aliveness, functionality, operability, and electro-mechanical calibration 
of the NICMOS filter wheel motors and assembly.  This was the first use of 
the NICMOS filter wheel mechanisms since they were disabled by ground 
command in January, 1999.  This test was designed to obviate concerns over 
possible deformation or breakage of the fitter wheel "soda-straw" shafts 
due to excess rotational drag torque and/or bending moments which may be 
imparted due to changes in the dewar metrology from warm-up/cool-down.  No 
anomalous incident occurred.

    1.19 Completed Three Sets of ACS/WFC/HRC 9075 (Cosmological Parameters 
from Type Ia Supernovae at High Redshift)

        The Advanced Camera for Surveys (WFC and HRC) was used to obtain a 
Hubble diagram of Type Ia supernovae {SNe Ia} that will be of long lasting 
value as a record of the expansion history of the universe.  No problems 
were encountered.

    1.20 Completed Five Sets of 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.

    1.21 Completed WF/PC-2 8940 (Cycle 10 Earth Flats)

        The WF/PC-2 was used to monitor flatfield stability by obtaining 
sequences of Earth streak flats to construct high quality flat fields for 
the WF/PC-2 filter set.  These flat fields will allow mapping of the OTA 
illumination pattern and will be used in conjunction with previous internal 
and external flats to generate new pipeline superflats.  The proposal 
completed without incident.

2.0 FLIGHT OPERATIONS SUMMARY:

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

        The acquisition at 114/084229Z defaulted to fine lock backup on 
FGS-2 only when the scan step limit for FGS-1 was exceeded.  HSTAR 8626 was 
written.  Three proposals occurring during the period of the next report, 
STIS 9051, NICMOS 8945, and WF/PC-2 8941, may have been affected.
  Scheduled Re-acquisitions:  4
    Successful:  4

    2.2 FHST Updates:
    Scheduled: 33
    Successful: 33

    2.3 Operations Notes:

        Operations requests were utilized to set up the tasking orders for 
the NICMOS filter wheel test at 113/1207Z and to establish the NICMOS 
memory monitors for the test at 113/1214Z.  Then, at 113/1548Z, another 
operations request enabled the filter wheel move.  Between 113/1717Z and 
113/1738Z, the filter wheels were moved and data was collected.  Initial 
analysis of the data indicated that the mechanism voltages and current 
during the moves was as expected and very close to the last on-orbit test 
in 1997.  There was no significant temperature change.  During the moves, 
the voltage dropped approximately 0.3V on all three wheels and the current 
spiked by 0.75A.  There were no retries on filter wheel 1, and that wheel 
moved within 14 counts of its commanded position.  The return to blank was 
within 16 counts of the commanded position.  There was one retry on filter 
wheel 2.  This is not anomalous or cause for concern.  The position was off 
by 126 counts (the tolerance is 110 counts) which caused the retry.  On the 
second attempt, the filter wheel reached its position within nine 
counts.  There was an expected overshoot of four steps.  There were no 
retries on filter wheel 3.  That wheel moved 60 steps as expected.  The 
return to blank was 64 steps.  The final position was within 58 counts of 
the commanded position.  This test will continue over the next several days.

        The NCC PID control was returned to the weighted neon temperatures 
from the NICMOS dewar temperature at 113/1755Z, per an operations request.

        Using ROP SR-9a, the SSR-3 EDAC error counter was cleared at 113/1929Z.

        The SSR-1 EDAC error counter was cleared at 113/2110Z per ROP SR-1A.

        The SSR-3 playback pointer was set at 114/0348Z as directed by ROP 
SR-3.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

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

/CAW