HUBBLE SPACE TELESCOPE

   DAILY REPORT #2871

PERIOD COVERED:  0000Z (UTC) 05/11/01 - 0000Z (UTC) 05/14/01

Daily Status Report as of 134/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Nine 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.

    1.2 Completed Six 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.

    1.3 Completed WF/PC-2 8626 (Spatially Resolved Spectroscopy of 
APM08279+5255)

        The WF/PC-2 was used to obtain spatially resolved, high resolution 
spectra of the z=3.911 BAL quasar, APM 08279+5255.  All observations 
completed nominally.

    1.4 Completed Twenty-four Sets of STIS/CCD 9248 (Probing the Large 
Scale Structure: Cosmic Shear Observations)

        The Space Telescope Imaging Spectrograph (CCD) was used to measure 
the distortion of light bundles from distant galaxies that probe the 
statistical properties of the intervening inhomogeneous {dark} matter 
distribution.  Its tidal gravitational field distorts the observable image 
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}.  As 
detailed in 2.1 and HSTAR 8216, the acquisition for the twelfth iteration 
of this proposal failed, affecting one observation.  Otherwise, the 
observations completed nominally.

    1.5 Completed Three Sets of 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.  The proposal completed with no anomalous activity.

    1.6 Completed STIS/CCD/MA1/MA2 8857 (MAMA Sensitivity and Focus Monitor C9)

        The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to monitor the sensitivity of each MAMA grating mode to detect any 
change due to contamination or other causes.  There were no problems.

    1.7 Completed Two Sets of STIS/CCD/MA1 8662 (A Snapshot Survey of the 
Hot Interstellar Medium)

        The Space Telescope Imaging Spectrograph (CCD And MA1) was used to 
obtain snapshot STIS echelle observations of key tracers of hot 
interstellar gas {C IV, N IV, and Si IV} for selected FUSE Team O VI survey 
targets with known UV fluxes.  By taking advantage of the snapshot 
observing mode we will efficiently obtain a large number of spectra 
suitable for the study of the highly ionized hot component of the 
interstellar medium {ISM}.  Our goals are to explore the physical 
conditions in and distribution of such gas, as well as to explore the 
nature of the interfaces between the hot ISM and the other interstellar gas 
phases.  The observations completed with no reported problems.

    1.8 Completed Six 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.  The observations completed with no anomalous 
activity.

    1.9 Completed Two Sets of WF/PC-2 8585 (Cosmological Parameters from 
Type Ia Supernovae at High Redshift)

        The WF/PC-2 was used to measure the cosmological parameters, Omega, 
Lambda, and thus the curvature, Omega_k, using Type Ia supernovae {SNe Ia} 
as calibrated standard candles.  There were no reported problems.

    1.10 Completed WF/PC-2 8390 (Expansion Parallax Distances to Planetary 
Nebulae)

        The WF/PC-2 was used to make observations of the planetary nebula 
IC2448 in order to study its parallax distance.  The largest impediment to 
our understanding of planetary nebulae is the lack of reliable 
distances.  The observations were executed as scheduled, and no anomalies 
were noted.

    1.11 Completed WF/PC-2 8604 (Stellar Populations Across the Small 
Magellanic Cloud (SMC) : History and Structure)

        The WF/PC-2 was to be used to investigate the structure and 
evolutionary history of the SMC by obtaining a series of 50 three-color 
snapshots of selected SMC regions.  As detailed in 2.1 and HSTAR 8216, the 
acquisition for this proposal failed, affecting all three observations.

    1.12 Completed Seven Sets of WF/PC-2 8581 (A Search For Low-Mass 
Companions To Ultracool Dwarfs)

        The WF/PC-2 was used to search for very low-mass {VLM} companions 
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the 
2MASS and SDSS surveys.  The primary goal is to determine the multiplicity 
of M < 0.1 M_odot dwarfs.  In particular, we aim to identify binary systems 
suitable for long-term astrometric monitoring and mass measurement, and 
systems with cool, sub-1000K companions.  The proposal completed with no 
reported problems.

    1.13 Completed WF/PC-2 8723 (A Snapshot Survey of Galactic Globular 
Clusters)

        The WF/PC-2 was used to observe the crowded centers of globular 
clusters {GCs} that heretofore have produced intriguing discoveries of new 
phenomena, most of which are not understood theoretically.  The 
observations completed with no reported problems.

    1.14 Completed WF/PC-2 8719 (A Continuation Of A Snapshot Survey Of X- 
Ray Selected Central Cluster Galaxies)

        The WF/PC-2 was used to perform snapshot images of a representative 
subset of the central cluster galaxies from an X-ray selected cluster 
sample that would provide important constraints on the formation and 
evolution of dust in cluster cores that cannot be obtained from 
ground-based observations.  The observations completed as planned.

    1.15 Completed STIS/MA1 8658 (Atmospheric Escape and the D/H Ratio in 
Mars' Atmosphere)

        The Space Telescope Imaging Spectrograph (MA1) was used to observe 
the highly extended upper atmosphere and the UV airglow of Mars that have 
not been studied by any in situ spacecraft since Mariner 9 in 1972.  At the 
same time, one of the main elements of NASA's space science program today 
is the study of Mars and how it has evolved over time to a hostile 
environment, compared with the favorable conditions on the Earth.  The 
availability of long aperture spatially resolved UV spectra with STIS makes 
it possible to obtain unique information on the extended upper atmosphere 
of Mars by mapping the H and O dayglow emissions with altitude above the 
limb.  It is  proposed to make these observations just before Mars 
opposition near the end of HST cycle 9.  Initial modeling indicates that we 
will have sufficient angular resolution and sensitivity to measure the 
scale heights of the suprathermal atom populations of H and O atoms.  We 
also propose to determine accurate values for the D and H columns, and the 
D/H ratio, in the upper atmosphere of Mars.  The present-day D/H ratio 
gives vital information leading to understanding the evolution of Mars' 
atmosphere, the historic escape of water into space, and potentially the 
remaining water abundance on Mars.  The observations completed with no 
problems.

    1.16 Completed STIS/CCD 8846 (Imaging Flats C9)

        The Space Telescope Imaging Spectrograph (CCD) was used to 
investigate flat-field stability over a monthly period.  The proposal 
completed nominally.

    1.17 Completed STIS/CCD/MA1 8651 (UV Spectroscopy in the Magellanic 
Bridge: A Typical QSO Absorption Line System?)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
perform echelle UV absorption line spectroscopy through the Magellanic 
Bridge {near the SMC} to probe the temperature, ionization, and kinematic 
structure in a metal- poor environment like those observed in the early 
universe.  The sightline toward the QSO B0312-770 is especially interesting 
because of the proximity of the absorber  and the radio loud background 
source.  The observations completed nominally.

    1.18 Completed WF/PC-2 8682 (A Snapshot Study of 0bservational Cosmology)

        The WF/PC-2 was used to examine the observational constraints on 
the cosmic star formation history that is currently among the most active 
fields in observational cosmology.  The most widely used tracer of the 
co-moving volume-averaged star formation rate {SFR} is the UV luminosity 
density, which early results found to peak at z~1- 2.  The apparent 
identification of the primary epoch of metal production and star formation 
in the Universe led to intense theoretical and observational 
interest.  Nevertheless, and remarkably for such a fundamental observation, 
little is known about the history of star formation in the Universe beyond 
its global average.  There were no reported anomalies.

    1.19 Completed STIS/CCD 8189 (The Source of Gamma Ray Bursts and the 
Nature of their Hosts)

        The Space Telescope Imaging Spectrograph (CCD) was used to make 
high resolution optical and ultraviolet observations of the Gamma Ray 
Burster (GRB) 970508 and its host galaxy.  This comprehensive set of 
observations will provide new insights into the astrophysics of GRBs and 
their high redshift host galaxies.  The observations were completed as 
planned, and no problems were reported.

    1.20 Completed Three Sets of WF/PC-2 8583 (Imaging Snapshots of Asteroids)

        The WF/PC-2 was used to obtain images of the fifty largest main 
belt asteroids that have favorable apparitions during cycle 9.  The images 
will be searched for companion bodies, as well as mineralogical variegation 
on the resolved main bodies.  There were no reported problems.

    1.21 Completed Two Sets of FGS/1 9240 (Astrometric Mass Determination 
of an Extrasolar Planet Candidate)

        Fine Guidance Sensor-1R was used to perform astrometric 
observations that will allow a quick measure of the sky-plane motion of 55 
Cancri, a G star with an Msin{i} = 0.9 MJ radial velocity companion with a 
14 day period.  By using 7 pairs of visits, where each visit within a pair 
has the same parallax factor, we will be able to accurately determine the 
stars's proper motion.  The reflex motion of the star, due to its orbit 
about the star-companion barycenter, will manifest itself as a systematic 
residual to the measured proper motion if the companion is sufficiently 
massive.  There were no reported problems.

    1.22 Completed STIS/CCD/MA1/MA2 8635 (A Test Of Pulsation And Diffusion 
Theory For Subluminous B Stars)

        The Space telescope Imaging Spectrograph (CCD, MA1 and MA2) was 
used to confirm the recent discovery of radial and nonradial mode 
pulsations in nearly 20 sdB stars that makes it possible to use 
asteroseismology to probe the internal structure of these stars and discern 
their evolutionary status. This is needed for reasons as diverse as 
understanding the late stages of stellar evolution and the calibration of 
the observed ultraviolet upturn in giant elliptical galaxies as an age 
indicator.  The observations completed with no anomalous activity.

    1.23 Completed Two Sets of WF/PC-2 8602 (A Snapshot Survey of the Sites 
of Recent, Nearby Supernovae)

        The WF/PC-2 was used to conduct a snapshot survey in V and I of the 
sites of the nearby SNe, which have precisely known positions, to obtain 
high-resolution information on their local environment.  The proposal 
completed with no reported problems.

    1.24 Completed WF/PC-2 8584 (Calibrating the Metallicity Dependence of 
the Cepheid PL Relation)

        The WF/PC-2 was used to determine the uncertainty in the metal 
abundance dependence of the Cepheid PL relation that remains as one of the 
largest sources of systematic error in the Cepheid distance scale and in 
the extragalactic distance scale as a whole.  There were no reported problems.

    1.25 Completed Two Sets of WF/PC-2 8577 (Ozone, Condensates, and Dust 
in the Martian Atmosphere)

        The WF/PC-2 was used to study the spatial and seasonal variations 
in ozone, condensates, and dust in the Martian atmosphere.  The data 
obtained promise to be critical in addressing recent breakthroughs in 
understanding the basic radiative, transport, and microphysical processes 
that provide for both long-term and short-term balance within the global 
Mars climate system.  There were no reported problems.

    1.26 Completed STIS/CCD 8591 (The Smallest Nuclear Black Holes)

        The Space Telescope Imaging Spectrograph (CCD) was used to observe 
small nuclear black holes which are the last major unexplored part of BH 
parameter space, searching for the smallest BHs that HST can possibly 
find.  The proposal completed with no reported anomalies.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 34
Successful: 33

        HSTAR 8216 documents a failed acquisition at 131/202351Z when the 
search radius limit was exceeded on FGS-2.  The proposals described in 1.4 
and 1.11 were affected.
  Scheduled Re-acquisitions: 11
Successful: 11

    2.2 FHST Updates:
Scheduled: 73
Successful: 73

    2.3 Operations Notes:

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

        On two occasions, the CCS engineering status buffer (ESB) limit was 
adjusted for SESBSLD per ROP DF-18A.  The same ROP was used twice to dump 
and clear the CCS ESB.

        TTRs were generated for two required re-transmits during NSSC-1 
uplinks.

        ROP NS-5 was used to reset SI C&DH errors at 132/1235Z.

        A TTR was written when GCMRs were not being sent at WSGT at 
131/1500Z.  This resulted in a 32k data loss from 131/145448Z until 
131/145908Z.

        HSTAR 8215 documents that NICMOS parameter ND1DRET1, which measures 
the NICMOS current, flagged out-of-limits low red at 131/165213Z.  It was 
back in bounds at 131/165243Z.

        GMT14AMBV flagged out-of-limits with a value of -20 from 132/030116 
until 132/030119Z.  HSTAR 8218 was written.

        SSR-1 was commanded to record at 133/1435Z in order to cover a lost 
TDRS service.

        Another TTR was created when weather problems at WSGT caused data 
dropout at 134/0200Z, resulting in 17-seconds and 10-seconds unrecoverable 
losses of data.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW