HUBBLE SPACE TELESCOPE

       DAILY REPORT #2530

PERIOD COVERED:  0000Z (UTC) 12/30/99 - 0000Z (UTC) 01/03/00

Daily Status Report as of 003/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed Two Sets of S/C 8518 (Vehicle Disturbance Test)

        The Vehicle Disturbance Test {VDT} is used to characterize the HST 
dynamic response due to environmental disturbances during extended gyro 
hold intervals.  Disturbances are caused by on-board mechanism motion and 
transient effects resulting from thermal strain.  These disturbances excite 
the natural modes of HST structural appendages and produce vehicle dynamic 
response as measured by the rate gyros.  Disturbance signatures are 
compared with signatures taken after previous servicing missions to 
identify changes in mechanisms or structures since the last VDT.  The 
disturbances observed will be used as the nominal on-orbit disturbances in 
pointing control simulations until the next VDT is run.  At least 5 orbits 
at +V3 sunpoint {with 90-degree solar array angle} and 3 orbits at -V1 
sunpoint {with 0-degree solar array angle} are required for this 
test.  Using two different solar array orientations allows additional 
identification of disturbances induced by the solar arrays.  Low bandwidth 
attitude control gains are used to configure the HST for "nearly open-loop" 
dynamic response during the test.  This configuration allows observation of 
HST disturbance response that is nearly independent of the affects of the 
pointing control law.  No science instruments are used during this 
test.  The test completed with no reported problems.

    1.2 Completed Six Sets of STIS/CCD 8507 (CCD Darks)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
weekly updates to the hot pixel list.   The proposal completed as planned.

    1.3 Completed Five Sets of STIS/CCD 8508 (CCD Bias Monitor C8)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
updates to the weekly superbiases.  The proposal was completed as planned.

    1.4 Completed Ten Sets of STIS/CCD 8530 (SMOV3a STIS BEA Science)

        The Space Telescope Imaging Spectrograph (CCD) was used to obtain 
SMOV3a Bright Earth Avoidance time period for science exposures with the 
STIS CCD.  Various kinds of targets are observed.  During the ninth 
iteration of this proposal, the loss of lock described in 2.1 and HSTAR 
7454 occurred.  The Science Init Flag never came up.  Otherwise, the 
proposals completed nominally.

    1.5 Completed Eight Sets of FGS 8532 (White Dwarf and M-Stars in the 
Solar Neighborhood; Revealing Binarity)

        FGS-1 was used to conduct a high angular resolution survey with 
FGS1r to detect binarity among nearby M dwarfs and white dwarfs.   During 
fourth, fifth and seventh iterations of this proposal, the Astrometry FGS 
failed the search radius limit test.  HSTARs 7453, 7450, and 7457 were 
written.  Otherwise, the remaining observations completed with no reported 
problems.

    1.6 Completed Two Sets of STIS/CCD/MA1/MA2 8514  (Contamination Test)

        The Space Telescope Imaging Spectrograph (CCD/MA1/MA2) was used to 
investigate whether there is excessive Lyman Alpha contamination {decrease 
in throughput} for WFPC2 observations.  The observations completed with no 
reported problems.

    1.7 Completed Three Sets of STIS/MA1/MA2 8504 (SM3A MAMA Turn-on)

        The Space Telescope Imaging Spectrograph (MA1/MA2) was used to turn 
on MAMA high voltages and take darks three times per day.  The observations 
completed nominally.

    1.8 Completed WF/PC-22 8498 (Internal Monitor - Post-TEC Turn On)

        The WF/PC-2 was used to obtain routine internal observations in 
order to monitor basic instrument health, and optical alignment (K-spots, 
INTFLATS, VISFLATS, UVFLATS, bias, Darks).  The observations completed 
nominally.

    1.9 Completed Two Sets of WF/PC-2 8491 (Transition to hold, Decon and 
Cool Down Procedure)

        This program covers the transition from Protect Safe Mode to Hold 
Mode, then performs a Protect Decontamination. This is followed by a series 
of UV monitors and focus checks at -43C, then a special decon to take the 
instrument to -88C.  The program completed nominally.

    1.10 Completed STIS/MA1 8510 (FUV MAMA Darks)

        The Space Telescope Imaging Spectrograph (MA1) was used to 
determine the health of the FUV MAMA detector by monitoring the background 
count rate.  The observations completed with no reported problems.

    1.11 Completed Four Sets of STIS/MA2 8509 (NUV MAMA Darks)

        The Space Telescope Imaging Spectrograph (MA2) was used to 
determine the health of the FUV MAMA detector by monitoring the background 
count rate.  The observations completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions: 47
Successful: 47
  Scheduled Re-acquisitions: 16
Successful: 16

        HSTARs 7450, 7453 and 7457 document cases where a successful 
acquisition was followed by the astrometry FGS-1 failing the search radius 
limit test.  The proposal detailed in  was affected.

        Per HSTAR 7454, there was a loss of lock at 002/005623Z.  The 
proposal described in 1.4 was affected.

    2.2 FHST Updates:
Scheduled: 137
Successful: 137

        Although the roll delay update at 365/032635Z, using FHST-2, 
succeeded, the target suppression B-2 flag was out-of-limits (usually 
indicating failure).  This occurred with the FHST assigned to both 
electronics A and B.  The mnemonic remained out-of-limits until the tracker 
was commanded closed for the type 2 slew.  HSTAR 7451 was written.

    2.3 Operations Notes:

        Servicing Mission Orbital Verification (SMOV) continues.

       The correctable SSR EDAC error counter was reset six times per ROP 
SR-1A.

        During the weekend, the SSR science playback pointer was set four 
times as directed by ROP SR-3.  Per NS-5, the SI C&DH error counter was 
reset (for Exec 101, ENGREP 0) twice.

        Four TTRs were written for transmitter scheduling errors during the 
long weekend period: for day 364 there was seven errors; for day 365, ten 
errors: for day 001, 19 errors: and for day 002, 24 errors.

        Another TTR was written for a 6 minute, unrecoverable loss of 32k 
engineering data due to an HGA spline and an MA transmitter switch during 
the support at 365/0304Z..

        At 365/105725, the coarse sun sensor #1 temperature (GCSS1T) 
flagged out-of-limits low with a value of -45.1 deg. C for one six-second 
sample.  HSTAR 7452 was written.

        The Y2K rollover occurred with no problems reported.

        There was a STIS MCE-1 reset at 001/172502Z while the low voltage 
was on and while outside any SAA interval.  The STIS flight software error 
counter was reset at 001/1832Z per ROP-NS-12.  The STIS MAMA-1 was 
recovered at 003/0959Z, the time that the high voltage was commanded on via 
the SMS.

        The FHST-21 temperature flagged out-of-limits high at 002/110225Z 
for one telemetry sample.  This was documented in HSTAR 7455.

        At 002/172859Z, the FHST-21 shelf temperature flagged out-of-limits 
high (12.0 deg. C) several times during an eight minute time period.  HSTAR 
7456 was written.  The limit was raised to 13.0 deg. C per an operations note.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of SMOV and normal science observations and calibrations.

/CAW