HUBBLE SPACE TELESCOPE

   DAILY REPORT #2594

PERIOD COVERED:  0000Z (UTC) 04/03/00 - 0000Z (UTC) 04/04/00

Daily Status Report as of 095/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed STIS/CCD 8439 (Bias Monitor-Part 2 C8)

        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 reported problems.

    1.2 Completed Three Sets of WF/PC-2 8460 (Cycle 8 Supplemental Darks pt2/3)

        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 observations completed with no reported problems.

    1.3 Completed Two Sets of STIS/CCD 8437 (Dark Monitor-Part 2 C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to monitor 
the darks.  The proposal completed nominally.

    1.4 Completed Two Sets of WF/PC -2 8177 (Investigating Type Ia 
Supernovae and an Accelerating Universe)

        The WF/ P C-2 was used to obtain rest frame U and B photometry for 
four z~ 0.85 Supernova (SN) Ia.  These observations will be coupled to 
ground-based rest frame V photometry and spectra.  These data, combined 
with previous samples, will extend the D_L vs. z diagram for SN Ia to 
z~0.85, and allow us to discriminate the redshift dependence of supernova 
magnitudes in an accelerating Universe from that expected to result from 
systematic effects such as age of the stellar population, chemical 
evolution, a drift in the properties of dust, and weak gravitational 
lensing.  The proposal completed with no reported problems.

    1.5 Completed Five Sets of STIS/CCD 8549 (POMS Test Proposal: 
Non-Scripted Parallel Proposal Continuation I)

        The Space Telescope Imaging Spectrograph (CCD) was used to make low 
galactic latitude, non-scripted parallel observations as part of a POMS 
test proposal.  The observations were completed as planned, and no 
anomalies were reported.

    1.6 Completed FGS 8292 (Calibrating the Mass-Luminosity Relation at the 
End of the Main Sequence)

        The Fine Guidance Sensor (FGS1R) was used to make astrometric 
observations of the star GJ1081-051 and other nearby reference stars.  This 
is part of a study to calibrate the mass-luminosity relation for stars less 
massive than 0.2 Msun, with special emphasis on objects near the 
stellar/brown dwarf border.  The observations were completed as planned, 
and no problems were reported.

    1.7 Completed Six Sets of WF/PC-2 8090 (POMS Test Proposal: WF-II 
Parallel Archive Proposal Continuation)

        The WF/PC-2 was used in the parallel mode to make some low galactic 
latitude archive observations.  The program will be used to take parallel 
images of random areas of the sky.  The observations were executed as 
scheduled, and no anomalies were noted.

    1.8 Completed Two Sets of WF/PC-2 8448 (Cycle 8 INTFLAT Sweeps, VISFLAT 
Mini-Sweep, and Linearity Test)

         The WFPC2 was used to monitor the pixel to pixel flatfield 
response and the VISFLAT lamp degradation, as well as detect any possible 
changes due to contamination.  The observations completed nominally.

    1.9 Completed WF/PC-2 8396 (WF/PC-2 Observations of Astrophysically 
Important Visual Binaries - Continued)

        The WF/PC-2 was used to make observations of the visible binary 
system G107-70.  These observations promise to add two accurate masses to 
the tiny handful of white-dwarf masses that are directly known from 
dynamical measurements.  The observations were completed as planned, and no 
anomalies were reported.

    1.10 Completed STIS/CCD/MA2 8233 (UV Imaging of Optical Jets: A New 
Window on the Physics of Jets)

        The Space Telescope Imaging Spectrograph (CCD and MA2)  was used to 
observe extragalactic radio jets which are highly collimated beams of high 
energy particles and magnetic fields issuing forth at relativistic speeds 
from sub-parsec scale regions, extending hundreds of kpc through 
interstellar and intergalactic space.  They are unique in their scope, 
power, and size. The jets affect their host galaxies and environments, 
through kinetic energy output and through deposition of cosmic rays and 
magnetic fields into interstellar and intergalactic space.  Despite years 
of study, fundamental jet parameters such as the magnetic field strength, 
particle density, jet configuration, bulk Lorentz factor, and the nature of 
particle acceleration in the flow remain unknown.  The observations 
completed with no anomalous activity.

    1.11 Completed Three Sets of WF/PC-2 8457 (UV Earth Flats)

        The WF/PC-2 was used to obtain a series of Ultraviolet Earth 
flats.  The observations were completed with no reported problems.

    1.12 Completed Two Sets of STIS/MA2 8426 (Cycle 8 MAMA Dark Measurements)

        The Space Telescope Imaging Spectrograph (MA2) was used to make a 
routine Cycle-8 MAMA dark noise calibration measurement.  This proposal 
will provide the primary means of checking on the health of the MAMA 
detectors.  This is done through frequent monitoring of the background 
count rate.  The observations were completed as planned, and no problems 
were reported.

    1.13 Completed Four Sets of WF/PC-2 8442 (Cycle 8 Standard Darks)

        The WF/PC-2 was used to obtain dark calibration dark frames every 
week in order to provide data for the ongoing calibration of the CCD dark 
current rate, and to monitor and characterize the evolution of hot 
pixels.  Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.  The proposal completed with no reported 
anomalies.

    1.14 Completed STIS/CCD/MA1 8279 (Cataclysmic Variable Disk Winds: A 
High Time and Spectral Resolution Study of  Flow Inhomogeneity)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
observe disks and disk winds which are found in many astrophysical 
settings.  The proposal completed nominally.

    1.15 Completed STIS/CCD/MA1 8241 (A Snapshot Survey of Interstellar 
Absorption Lines)

        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to 
make high resolution Echelle spectrographic observations of the standard 
ultraviolet star HD198478 as part of a snapshot survey of interstellar 
absorption lines.  A wavelength calibration image was also taken.  The 
observations were executed as scheduled, and no anomalies were noted.

    1.16 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) 000301C 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.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 6
Successful: 6

  Scheduled Re-acquisitions: 9
Successful: 9

    2.2 FHST Updates:
Scheduled: 17
Successful: 17

    2.3 Operations Notes:

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

        Per HSTAR 7567, the Battery #6 recharge ratio flagged out-of-limits 
with a value of 1.25 (the exact upper limit for suntimes less than 64 
minutes).  At the time, all six recharge ratios were higher than 
usual.  The parameter cam back into bounds during the next orbit day.

        Operations returned to CCS string "A" at 094/1625Z.

        The STIS MCE-2 reset at 094/180754Z while the high voltage was on 
and while outside any SAA interval.  ROP NS-12 was executed at 094/1919Z in 
order to reset the STIS flight software error counter.  MAMA-2 will be 
recovered at 095/2038Z, the time of the next SMS-commanded high voltage on 
commanding.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW