Hubble Space Telescope Daily Report #3094 -15 Apr 2002

HUBBLE SPACE TELESCOPE

DAILY REPORT #3094

PERIOD COVERED: 0000Z (UTC) 04/12/02 – 0000Z (UTC) 04/15/02

Daily Status Report as of 105/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed ACS/HFC 9016 (Coronagraph Repeatability)

The Advanced Cmaera for Surveys (HFC) was used to: {1} determine
the relative positions of the coronagraph’s occulting spots and the “Fastie
Finger, ” and {2} monitor the stability of the HRC coronagraph by
repeatedly deploying the cal/coronagraph door mechanism and subsequently
recording a quasi-flat field image. All observations completed without
incident.

1.2 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 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 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.

1.3 Completed Ten Sets of ACS/WFC 8948 (CTE Test)

The Advanced Camera for Surveys (WFC) was used to measure the
baseline charge transfer efficiency {CTE} performance of the WFC detectors,
emulating the CTE ground calibration testing. Also, a similar program
will perform periodic measurements in order to track the change in the CTE
as damage due to radiation exposure accumulates. All observations were
successful.

1.4 Completed ACS/HRC 9020 (Preliminary ACS Sensitivity)

The Advanced Camera for Surveys (HFC) was used to observe a
spectrophotometric standard star through each filter of each camera to
assess the sensitivity of the instrument. The star is placed at the center
of the aperture, and two images are taken through each filter. There were
no reported problems.

1.5 Completed ACS/WFC 9032 (CCD Flash Calibration)

The Advanced Camera for Surveys (WFC) was used to provide a
preliminary baseline set of CCD FLASH exposure reference images for each
current level/shutter-side/detector combination, for the pair of FLASH LEDs
on the instrument side currently in use. It also tested the short-term
repeatability at the shortest FLASH exposure times that are expected to be
used {1.0 sec}. There were no reported problems.

1.6 Completed Two Sets of STIS/CCD 8588 (Gamma-Ray Bursts and their
Host Environments)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate the physics of gamma-ray bursts {GRBs} and the nature of their
host galaxies. The approach is three-pronged: 1} rapid HST ultraviolet
spectroscopy and Chandra imaging obtained within two days of an outburst
will allow probing the physics of the relativistic fireball and the nature
of the ISM surrounding the GRB; 2} long-term optical monitoring of the
optical transient {OT} will permit testing the hypothesis that GRBs are
frequently highly collimated and to determine whether supernovae underlie
GRBs; 3} Chandra and HST observations of “dark” GRBs will allow probing one
of the greater mysteries surrounding GRBs, the nature of the bursts without
optical counterparts. There were no reported problems.

1.7 Completed Eleven 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.

1.8 Completed Ten Sets of ACS/HRC 9019 (Flat Field Stability)

The Advanced Camera for Surveys (HRC) was used to assess the
stability and uniformity of the low-frequency flat fields {L-flat} of all
ACS detectors by using multiple pointing observations of the globular
clusters NGC104 and NGC6681 – thus imaging moderately dense stellar
fields. By placing the same star over different portions of the detectors
and measuring relative changes in its brightness it will be possible to
determine local variations in the response of the detectors. Based on
previous experience with STIS, it is deemed that a total of nine different
pointings will suffice to provide adequate characterization of the flat
field stability in any given band. For each filter to be tested, the
baseline consists of 9 pointings with steps of ~20% of the FOV in a
diagonal cross pattern. No anomalous activity was reported.

1.9 Completed Four 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.

1.10 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.

1.11 Completed Five 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.

1.12 Completed STIS/CCD 8908 (CCD Imaging Flats C10)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate flat-field stability over a monthly period. The proposal
completed with no reported problems.

1.13 Completed 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.

1.14 Completed STIS/CCD 9176 (LMC Eclipsing Binaries with Cepheid
Components: The Key to the Extragalactic Distance Scale)

The Space Telescope Imaging Spectrograph (CCD) was used to
determine the distance to the LMC and to observe the Cepheid P-L that form
the backbone of the Cosmic Distance Scale and the determination of
H_degrees. Unfortunately, in spite of concerted efforts of many
investigators, the zero point of the Cepheid P-L law and the LMC distance
remain controversial and uncertain to ~10-15, using eclipsing binaries
{EBs} as “standard candles” to include two recently discovered LMC
eclipsing binaries {EBs} with Cepheid components. These observations of
these extraordinary systems hold the key to determining simultaneously the
Cepheid P-L zero point and the LMC distance, and to provide a direct test
of the Baade-Wesselink parallax method. There were no reported problems.

1.15 Completed STIS/CCD 9110 (A Search for Kuiper Belt Object Satellites)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate whether the large number of collisions thought to have taken
place in the primordial Kuiper belt suggest that many Kuiper belt objects
{KBOs} could have suffered binary-forming collisions similar to that which
formed the Pluto — Charon binary. Detection of such KBO satellites would
allow measurement of KBO masses, would help to understand the past
collisional environment of the Kuiper belt, and would give a context to the
otherwise unique-seeming formation of the Pluto — Charon binary. The
proposal completed with no reported problems

1.16 Completed STIS/CCD/MA1 8962 (Contamination Monitor)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
observe the flux standard GRW +70 5824 to assess whether FUV sensitivity is
significantly below performance obtained during execution of 8961 {End of
BEA Test} and prior to SM3B. Significantly degraded sensitivity will
trigger additional observations of flux standards to validate the initial
result and/or track subsequent {de}contamination. GRW +70 5824 is observed
bimonthly in the same mode as part of the regular STIS monitoring
program. Measurement accuracy will be limited global sensitivity
fluctuations {less than 5%}, rather than photon counting statistics. No
anomalous activity was observed.

1.17 Completed Two Sets of FGS/1 8898 (Calibrating FGS1r’s
Interferometric Response as a Function of Spectral Color)

Fine Guidance Sensor #1 was used to obtain reference point source
Transfer Functions {S-Curves} through the F583W filter and the F5ND
attenuator at the center position of the FGS1r FOV for a variety of stellar
spectral colors. The data will be added to the library of point source
interferograms that was assembled from the Cycles 8 and 9 calibration
program. These Transfer Functions are needed to support the analysis of GO
science data for the study of close and wide binary star systems and for
determining the angular diameter of extended sources. The proposal
completed with no reported problems.

1.18 Completed ACS/HRC/WFC 9292 (The Nature of Galaxies at z > 4)

The Advanced Camera for Surveys (HRC and WFC) was used to further
look into recent discoveries of a number of galaxies and quasars at
redshifts greater than 5 that has identified the z>5-6 epoch as key to
understanding the earliest formation phases for galaxies. However,
establishing the characteristics and properties of these earliest galaxies
is proving to be a particularly difficult. They are faint, with I{AB}
magnitudes around 26-27. Thus, substantial investments of time are needed
to obtain high S/N images, while ground-based spectroscopy, even with 8-10
m class telescopes, has provided little more than redshifts. Establishing
the physical properties of these galaxies will be a challenge for the
foreseeable future. However, there is a subset of this high redshift
population that is amenable to more detailed study. These are sources that
have been strongly lensed by low redshift clusters. No problems were reported.

1.19 Completed WF/PC-2 9145 (A Snapshot Survey of the Optically
Selected Type-2 Quasars)

The WF/PC-2 was used to observe an identified population of
emission-line objects in DPOSS, which can be plausibly interpreted as the
long-sought type-2 quasars. They have high-ionization Seyfert-2 like
spectra, but with narrow-line luminosities comparable to those of the
luminous type-1 quasars in the same redshift range. This population may be
a major contributor to the cosmic hard x-ray background. It is proposed to
obtain multi-color images of a representative sample of these objects, in
order to examine their morphology. We may be able to detect point-like
nuclei which are not detectable in ground-based images, the dust lanes
hiding them from our view, possible evidence for tidal interactions and the
overall morphology of their hosts, etc. The proposal completed with no
reported problems.

1.20 Completed 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}. No problems were seen.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 25

Successful: 25

The acquisition at 105/063254Z defaulted to fine lock back-up on
FGS-1 only when FGS-3 failed to achieve lock. HSTAR 8607 was written. Two
proposals (ACS 8947 and STIS 9846), each occurring during the period of the
next report may have been affected.

Scheduled Re-acquisitions: 29

Successful: 29

2.2 FHST Updates:

Scheduled: 39

Successful: 38

The roll delay update at 103/070750Z failed due to tracker 2. The
subsequent acquisition, however, was successful. HSTAR 8604 was written.

2.3 Operations Notes:

The NICMOS Cryo Cooler has achieved its predicted endpoints,
allowing some delayed portions of the Servicing Mission Orbital
Verification (SMOV) to proceed.

During the weekend, the following operations notes were executed:

• Adjust ACS Error Count Limit
  
• ACS STB 935
  
• Change Limits MAMA Threshold Voltage
  
• Change Limits MCE-2 Reset Det
  
• Change Limits MAMA Threshold
  
• Tabulation of Slew Attitude Error (Miss-distance)
  
• COMMAND PROBLEM
  

The CCS engineering status buffer limit for SESBSLD was adjusted
twice per ROP DF-18A.

Using ROP SR-1A, the SSR-1 EDAC error counter was cleared at 102/1107Z.

An operations request was executed at 102/1331Z to allow future ACS
SBC MAMA high voltage turn-ons.

A TTR was written for a required re-transmit at 103/034017Z during
a NSSC-1 load. SI C&DH errors were reset at 103/0345Z as directed by ROP
NS-05.

The SSR-3 EDAC error counter was cleared at 103/0347Z and at
103/0755Z per ROP SR-9A.

Per HSTAR 8606, at 104/231851Z, HGA2XPOS flagged out-of-limits with
a value of 86.6051 for 10 seconds. It flagged twice more for 10 seconds at
104/233951Z and at 104/234141Z.

Systems Engineering personnel observed the nominal ACS SBC MAMA low
voltage turn-on at 105/0425Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of SMOV and the gradual resumption of normal science
observations and calibrations.