HUBBLE SPACE TELESCOPE

       DAILY REPORT #3103

PERIOD COVERED:  0000Z (UTC) 04/25/02 - 0000Z (UTC) 04/26/02

Daily Status Report as of 116/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed WF/PC-2 9058 (Trigonometric Parallax of the Globular 
Cluster 47 Tucanae)

        The WF/PC-2 was used measure the trigonometric parallax of 47 Tuc, 
which is about 1/4 milliarcsec, to an accuracy of 10%.  By repeating a 
field that was observed in 1995, we will measure the secular motion of the 
cluster stars with respect to the SMC background with sufficient accuracy 
that the parallax can be measured directly from the displacements within 
Cycle 10.  Constraints of orientation, and the shape of the WFPC2 
footprint, require that we take images at 3-month intervals, rotating 90 
degrees each time.  The proposal completed with no reported problems.

    1.2 Completed Six 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.

    1.3 Completed Two 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.

    1.4 Completed Ten 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 Two 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 8902 (Dark Monitor-Part 2)

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

    1.7 Completed Seven 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 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.

    1.9 Completed WF/PC-2 9050 (Outflow Collimation in Bipolar Symbiotic 
Nebulae)

        The WF/PC-2 was used to observe flow collimation in evolved stars 
that is neither expected nor understood.  Classical theories of stellar 
evolution do not predict and cannot explain this bipolarity.  More exotic 
concepts {binary interactions, spun-up atmospheres, poloidal or toroidal 
magnetized winds} have been proposed, but observations are yet to verify or 
falsify any of their predictions.  This proposal will probe the 
near-nuclear morphology and kinematics of four bright, low-extinction 
targets whose large-scale structure is highly bipolar.  The goal is to 
provide a detailed description of the circumnuclear outflows, to uncover 
the physical structure and nature of the collimator, and to evaluate the 
speculative collimation mechanisms.  The bright nucleus has hampered 
efforts to explore the nebular collimators that lie close to the star, so 
we'll use STIS to disperse the nuclear light and, thus, to avoid its 
glare.  A secondary goal is to obtain second-epoch WFPC2 images of all 
targets.  There were no reported problems.

    1.10 Completed Three 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.

    1.11 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 9157 (Fundamental Properties Of L-Type Dwarfs 
In Binaries)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
characterize the physical properties of eight L-dwarfs in four binary 
systems.  The goal is to obtain astrometric, photometric and spectroscopic 
measurements of each component that will yield basic information on 
atmospheric and dynamical properties.  The proposal completed nominally.

    1.13 Completed Two 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.

    1.14 Completed ACS/WFC 9584 (ACS Default {Archival} Pure Parallel 
Program II)

        The Advanced Camera for Surveys (WFC) was used to test ACS pure 
parallels.  The proposal completed with no reported problems.

    1.15 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.

    1.16 Completed Four 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.

    1.17 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.

    1.18 Completed STIS/CCD/MA1 8962 (Contamination Monitor)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe a flux standard GRW +70 5824 to assess whether FUV sensitivity is 
significantly below performance obtained during execution of 8961 {End of 
BEA Test} and prior to SM3B.  Significantly degraded sensitivity will 
trigger additional observations of flux standards to validate the initial 
result and/or track subsequent {de}contamination.  GRW +70 5824 is observed 
bimonthly in the same mode as part of the regular STIS monitoring 
program.  Measurement accuracy will be limited global sensitivity 
fluctuations {less than 5%}, rather than photon counting statistics.  No 
anomalous activity was observed.

2.0 FLIGHT OPERATIONS SUMMARY:

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

  Scheduled Re-acquisitions:  5
    Successful:  5

    2.2 FHST Updates:
    Scheduled: 26
    Successful: 25

      Per HSTAR 8627, the roll delay update at 115/220401Z failed due to 
tracker #1.  The subsequent full maneuver updates were successful.

    2.3 Operations Notes:

        The NSSC-1 status buffer was dumped and reset a5 115/1116Z per ROP 
NS-3.

        Operations requests were used to:
Enable Filter Move, Day 115-1 @115/1618z
Enable Filter Wheel Move, Day 115-2 @115/2236z
Vehicle Control Law Rate Gain Factor Change @115/1526z
HLGBU GYRO Triplets U/L @115/1447z
Configure SDH Science Tasking Orders @115/1610z
Set Up Tasking Order for FSW Test @115/1616z
Configure Tasking Order after FSW Test Activities @115/2304z

        A TTR was generated when there was a required re-transmits (at 
115/190618Z and at 115/191520Z) during a NSSC-1 uplink.  Accordingly, SI 
C&DH error were reset at 115/1917Z, using ROP NS-5.

        The 486 engineering status buffer limits were adjusted at 115/2213Z 
as directed by ROP DF-18A.

        Using ROP DF-01A, a 486 table was dumped at 115/1923Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

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

/CAW