HUBBLE SPACE TELESCOPE

       DAILY REPORT #3104

PERIOD COVERED:  0000Z (UTC) 04/26/02 - 0000Z (UTC) 04/29/02

Daily Status Report as of 119/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Nine 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.

    1.2 Completed STIS/CCD/MA1/MA2 9113 (Solar UV Radiation and the Origin 
of Life on Earth)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to observe chromospheric models that will enable the proposers to 
predict the extreme-UV emission of the early Sun and its consequences for 
the erosion of the early Earth's atmosphere and the altered oxidation state 
of the planet, and investigate the effect of metallicity on the UV emission 
and its consequences for the photochemistry of Earth-like planets.  There 
was no anomalous activity.

    1.3 Completed Nine 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 Eight 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.

    1.5 Completed Twenty-eight 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.  As described in 2.1 and HSTAR 8628, the 
acquisition of the ninth iteration of this proposal defaulted to fine lock 
backup on one FGS only, possibly affecting the observations in this 
iteration.  No other problems were encountered.

    1.6 Completed Twenty 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.

    1.7 Completed Eight 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.

    1.8 Completed Six 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.

    1.9 Completed Two Sets of WF/PC-2 9180 (Gamma-ray Burst Progenitors: 
Probing Their Environment)

        The WF/PC-2 was used to perform a target of opportunity observation 
of gamma ray burster (GRB), GRB-020405.   GRB astronomy is a field maturing 
at a phenomenal rate.  Three important new observational and theoretical 
discoveries, formulated over the last twelve months, allow the proposer to 
address new, and in many cases, more sophisticated questions than could 
have been posed previously.  These developments: the discovery of X-ray 
lines in GRB 991216; the observation that N_H as deduced from X-ray 
afterglow are one to two orders of magnitude larger than the dust 
extinction inferred from optical afterglow; and the growing realization 
that the afterglow emission may exhibit features of dust echoes, appear to 
offer unexpected and new diagnostics that will directly inform us about the 
progenitor, the circum-progenitor material and the immediate interstellar 
environs.  There were no reported problems.

    1.10 Completed Seven 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.

    1.11 Completed Three 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.

    1.12 Completed Three Sets of ACS/WFC/HRC 9566 (CCD Hot Pixel Annealing)

        The Advanced Camera for Surveys (WFC and HRC) was used to perform 
hot pixel annealing that will be performed once per month.  The CCD TECs 
will be turned off and heaters will be activated to bring the WFC detector 
temperature to about +10C.  The HRC temperature will reach about 30C. This 
state will be held for approximately 24 hours, after which the heaters are 
turned off, the TECs turned on, and the CCDs returned to normal operating 
condition.  The proposal completed without incident.

    1.13 Completed Three Sets of STIS/MA2 9573 (NUV-MAMA Daily Dark Monitor)
Abstract

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
perform daily monitoring of the NUV MAMA detector dark noise, monitoring 
the effects of thermal changes on the NUV dark rate.  No anomalous activity 
was noted.

    1.14 Completed Two Sets of STIS/CCD/MA2 9161 (The Ultraviolet 
Properties of Obscured QSOs)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
observe a subset of The Two Micron All-Sky Survey {2MASS} -discovered QSOs 
to: 1} determine if UV absorption- line features are present as seen in 
several other highly polarized AGN populations; 2} test relationships 
between X-ray and UV/optical attenuation, AGN spectral type, optical 
polarization, and detected UV absorption-line features; and 3} characterize 
the spectral energy distributions and UV properties of obscured 
QSOs.  There were no problems.

    1.15 Completed STIS/CCD/MA2 9146 (Cepheid Masses: Y Car)

        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to 
examine the quantitative understanding of classical Cepheids in order to 
provide confidence in their use as primary extragalactic distance 
indicators, as well as in the understanding of the evolution of more 
massive stars and more evolved stars.  All observations completed nominally.

    1.16 Completed STIS/CCD 9050 (Outflow Collimation in Bipolar Symbiotic 
Nebulae)

        The Space Telescope Imaging Spectrograph (CCD) 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.

    1.17 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.

    1.18 Completed Four Sets of 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}.  As described in 2.1 and HSTAR 8628, the acquisition of the first 
iteration of this proposal defaulted to fine lock backup on one FGS only, 
possibly affecting the observations in this iteration.  No other problems 
were seen.

    1.19 Completed Three Sets of WF/PC-2 9319 (POMS Test Proposal: WFII 
Backup Parallel Archive Proposal II)

        The WF/PC-2 was used to execute a POMS test proposal, designed to 
simulate future scientific plans.  As described in 2.1 and HSTAR 8628, the 
acquisition of the first iteration of this proposal defaulted to fine lock 
backup on one FGS only, possibly affecting the observations in this 
iteration.  Otherwise, the proposal completed without further incident.

    1.20 Completed Six 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.

    1.21 Completed Five Sets of 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.

    1.22 Completed WF/PC-2/STIS/MA2 8675 (The Massive Star Content of NGC 6822)

        The WF/PC-2 and the Space Telescope Imaging Spectrograph (MA2) were 
used to characterize the young, coeval stellar population discovered with 
WFPC2 multiband imaging in a NGC6822 star-forming region, with follow-up 
spectroscopy of the massive star candidates.  The proposal completed with 
no reported problems.

    1.23 Completed STIS/CCD/MA1 9090 (Transition Region Emission in Very 
Low Mass Stars)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
determine the origin of the magnetic heating which produces hot outer 
atmospheres in late-type stars and is one of the most interesting, and 
elusive, problems in stellar astrophysics.  No anomalies were encountered.

    1.24 Completed FGS/1 9089 (Parallaxes of Cataclysmic Variables: 
Understanding Their Peculiar Secondary Stars)

        Fine Guidance Sensor #1R was used to measure precise parallaxes for 
three additional CVs {WZ Sge, RU Peg, and YZ Cnc}, whose orbital periods 
span a much larger range than explored in previous observations, allowing 
examination of how the accretion luminosity and secondary star change with 
orbital period.  There were no problems.

    1.25 Completed FGS/1 9183 (Completing the Astrometric Orbit for a Pair 
of Pre-Main Sequence Low-Mass Stars)

        Fine Guidance Sensor #1 was used to resolve a visual binary that is 
part of the closest system of pre-main sequence stars, HD 98800.  This 
system is 50 pc away and this binary has a period just under a year, 
meaning the separation is about 20 milliarcsec.  The two stars have similar 
brightnesses.  The goal is to determine an astrometric orbit which, when 
combined with radial velocity observations, leads to the first 
dynamically-determined masses for low-mass pre-main sequence stars.  All 
observations completed normally.

    1.26 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.  The proposal completed uneventfully.

    1.27 Completed WF/PC-2 9043 (Cepheid Distances to Early-type Galaxies)

        The WF/PC-2 was used to continue observations in the HST Key 
Project on the Extragalactic Distance Scale and the HST project on the 
"Calibration of Nearby Type Ia Supernovae'' that have greatly improved our 
knowledge of the Hubble Constant by providing a solid zero point for the 
Tully- Fisher {TF} relation and Type Ia Supernovae {SNIa}.  However, severe 
inconsistencies remain for distance estimators to early-type galaxies such 
as surface brightness fluctuations {SBF}, the planetary nebula luminosity 
function {PNLF}, the fundamental plane {FP}, and the globular cluster 
luminosity function {GCLF}.  As a result, the distance to the Virgo cluster 
core remains uncertain by as much as 20 determination is directly affected 
by a lingering 0.1 mag {5 uncertainty in the photometric calibration of the 
WFPC2.  Resolving these issues is essential not only to firm up the 
extragalactic distance scale, but also to understand the mass and velocity 
structure of the local universe. SBF in particular is emerging as the 
method of choice for mapping local velocity fields to 10, 000 kms because 
it offers an order of magnitude less Malmquist bias than TF, and SNIa are 
too rare to study large scale flows effectively.  This project will tighten 
the photometric calibration of the WFPC2, and provide a solid Cepheid 
calibration for SBF and PNLF.  The observations completed nominally.

    1.28 Completed STIS/CCD 8687 (Elliptical Galaxies With Nuclear Disks of 
Stars: Black Hole Search and Stellar Populations)

        The Space telescope Imaging Spectrograph (CCD) was used to observe 
galaxy NGC 5845 to search for supermassive black holes {BHs}.  The 
observations completed and no anomalous activity occurred.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 22
    Successful: 22

        Per HSTAR 8628, the acquisition at 116/163308Z defaulted to fine 
lock backup on GFS-3 only when the scan step limit was exceeded on 
FGS-1.  The proposals detailed in 1.5, 1.18 and 1.19 may have been affected.
  Scheduled Re-acquisitions: 11
    Successful: 11

    2.2 FHST Updates:
    Scheduled: 80
    Successful: 80

    2.3 Operations Notes:

        The results of all three iterations of the NICMOS filter wheel test 
were as expected and closely matched the results obtained in 1997.

        Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 116/0948Z.

        During the weekend, the following operations requests were executed:
16714-0 - Enable Filter Wheel Move, Day 116 @116/1858z
16715-1 - Enable Filter Wheel, Day 117-1 @116/2320z
16726-0 - Configure Tasking Order for FW @116/1811z,117/1724z,118/1755z
16727-1 - Configure Tasking Order after FSW Test Activities
      @116/2102z,118/0055z & 1928z
16729-1 - Update NCC PID Setpoint @116/1746z
16730-0 - HLGBU-GYRO Triplets U/L @116/0153z
16716-0 - Enable Filter Wheel Move, Day 117-2 @117/1900z
16717-0 - Enable Filter Wheel Move, Day 118-1 @118/0054z
16733-0 - HLGBU-GYRO Triplets U/L @118/0151z
16718-0 - Enable Filter Wheel Move, Day 118-2 @118/1732z
16732-0 - Enable Filter Wheel Move, Day 119-1 @118/2223z
16736-0 - HLGBU-GYRO Triplets U/L @119/0023z

        The following two operations notes were performed during the weekend:
996 - Raise Battery Temp Limit to 2 DEG @116/1346z
995 - Adjust Recharge Ratio for High Sun/Orbit Time @118/0002z

        At 116/205255Z, the GEA1 -X gimbal temperature went out-of-limits 
low with a value of 9.69592 for six seconds.  HSTAR 8629 was written.

        SSA transmitter #2 was turned on for the intervals 116/2305Z to 
116/2332Z and from 117/2125Z to 117/2155Z as directed by ROP IC-2.

        A TTR was generated for an incorrect SSAR frequency scheduled for a 
contact at 116/2307Z.

        Another TTR was written when there was a required re-transmit at 
117/1919Z during a NSSC-1 load.  SI C&DH errors were reset at 117/1934Z per 
ROP NS-5.

        The TRI module was rest at 117/2054Z and at 118/1926Z, per ROP SR-1A.

        The SSR-3 EDAC error counter was cleared at 118/1832Z and at 
118/2242Z, using ROP SR-9A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

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

/CAW