Hubble Space Telescope Daily Report #3083 – 29 Mar 2002

HUBBLE SPACE TELESCOPE

DAILY REPORT #3083

PERIOD COVERED: 0000Z (UTC) 03/28/02 – 0000Z (UTC) 03/29/02

Daily Status Report as of 088/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed 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 Twelve 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.

1.3 Completed WF/PC-2 8950 (SM3B Cool Down, Contamination Monitor, and
Focus Check)

The WF/PC-2 was used to monitor the planned cooldown to -88C,
followed by UV monitors, focus checks, as well as decons and associated
monitors. No problems were noted.

1.4 Completed Three Sets of WF/PC-2 8698 (Identification of the
Galaxy’s Missing Mass)

The WF/PC-2 was used to observe the nature of dark matter that is
one of the key astrophysical questions of the day. The existence of dark
matter and its dynamical dominance in the outer parts of our Galaxy and
spiral galaxies with flat rotation curves is well established. The MACHO
project has identified ~half of the Milky Way’s dark matter with stellar
objects of ~0.5 M_sun, probably white dwarfs. But the location of the
microlensing in the halo is disputed. Several have detected two candidate
halo white dwarfs of L/L_sun ~ 10^-5 in the Hubble Deep Field with 25 +/- 5
mas/year proper motions. The observations completed with no reported problems.

1.5 Completed Two Sets of STIS/CCD 8963 (CCD Bias)

The Space Telescope Imaging Spectrograph (CCD) was used to measure
CCD read noise from multiple bias frames obtained in common science modes:
amplifier D, gains 1 and 4 electrons/DN, and binning factors of 1×1, 1×2,
2×1, and 2×2. The read noise measurements before and after NCC turn-on are
then compared, and standard calibration reference files for use in pipeline
reduction of SMOV3B data are constructed. The proposal had no reported
problems.

1.6 Completed ACS/WFC/HRC 9031 (CCD Hot Pixel Annealing)

The Advanced Camera for Surveys (WFC and HRC) was used to perform
hot pixel annealing, which will be done 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. To assess the effectiveness of this procedure, a bias and two
dark images will be taken before and after the annealing procedure for both
WFC and HRC. There were no reported problems.

1.7 Completed STIS/CCD 8964 (CCD Darks)

The Space Telescope Imaging Spectrograph (CCD) was used to obtain
dark frames twice daily, as in a corresponding calibration
program. Standard calibration reference darks are constructed and hot
pixel lists are updated for use in pipeline reduction of SMOV3B data. All
observations completed without incident.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 4

Successful: 4

Per HSTAR 8584, following a successful re-acquisition at
087/181114Z, a loss-of-lock occurred at 087/181352Z. No observations were
affected.

Scheduled Re-acquisitions: 10

Successful: 10

2.2 FHST Updates:

Scheduled: 5

Successful: 5

2.3 Operations Notes:

The NICMOS Cryo Cooler (NCC) cooldown continues nominally.

SI C&DH errors were reset three times per ROP NS-5.

The following Operations Notes were executed during this
operational day;

• Adjust ACS Error Counter Limit @087/1446z
  
• Equipment Shelf by FHST Temp Limit Change @087/1448z
  
• NICMOS Safing Status Buffer Messages @087/1910z
  
• 3 Gyro Configurations Limit Changes @087/2057z
  
• Reset NICMOS MEB Radiator 2 Default Limit @087/2059z
  
• 3 Gyro Configurations Limit Changes @087/2343z
  
• Turn Off ACS HRC/SBC Corrector Status limit @088/0350z
  
• NICMOS Bad Mode Count OFF while NICMOS is safed @088/0359z
  

Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 087/1013Z.

The FHST 21 Shelf Temperature (ESHLF21T) flagged out-of-limits high
at 087/122400Z with a value of 13.06189 degC (the limit is 13.0
degC). HSTAR 8583 was written.

As directed by an operations request, the ACS Coarse Corrector
Alignment — Part 3 was performed at 087/1446Z.

Per an operations request, Gyro 1 was powered off at
087/192058Z. Commanding to change the gyro configuration in the PSEA went
smoothly, completing its reconfiguration at 087/192854Z. Final commanding
to adjust gyro safemode test limits finished at 087/011418Z. Attitude
errors from a Real Time Fine Attitude Determination showed approximately 11
arc-seconds of error (RSS) an hour after the gyro reconfiguration, well
within the nominal errors. A second map showed slightly higher errors (~46
arc-seconds), not unexpected, and an ARU/PRT was scheduled to buy back
additional margin to ensure the success of the Guide Star Acquisition. The
following FHST Updates and Guide Star Acquisition were successful. SAC has
fully reconfigured their software to match the current on-orbit
configuration. These updated configuration files have been transported to
all of the CCS operational strings.

NICMOS was safed at 087/1910Z to help the NCS cooldown process.

At 087/1910, using an operations request, STIS and ACS high voltage
turn-ons (via SMS commanding, were inhibited until a sufficiently low
temperature is reached during the NCC cooldown.

A TTR was generated when a GCMR was not acknowledged by WSGT at
087/2302Z.

ROP DF-18A was utilized to change an engineering status buffer
limit System Monitor=11) at 088/0341Z.

Per HSTAR 8585, the Zone 3B temperature (OTCZ3BT) began
intermittently flagging out-of-limits low at 088/070758Z with a value of
17.8714 degC.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

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