Status Report

Hubble Space Telescope Daily Report #3101 – 24 Apr 2002

By SpaceRef Editor

April 24, 2002

Filed under Hubble Space Telescope, Space Telescope Science Institute, US

HUBBLE SPACE TELESCOPE

DAILY REPORT #3101

PERIOD COVERED: 0000Z (UTC) 04/23/02 – 0000Z (UTC) 04/24/02

Daily Status Report as of 114/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed STIS/CCD 9139 (Variability in the UV Spectrum of 3C 279:
Testing Models for the Gamma-Ray Emission in Blazars)

The Space Telescope Imaging Spectrograph (CCD) was used to
determine whether gamma- rays are produced on the scale of the broad line
region, using multi-epoch UV snapshots of 3C 279 to find and characterize
its LyAlpha variability. This will validate the mirror model for
generating the intense gamma-ray emission from blazars. 3C 279 is the
best-studied blazar from radio to gamma-ray wavelengths, showing frequent
large flares over days to months. Variability in the UV continuum and
LyAlpha will directly reveal any coupling between the jet ionizing flux and
the broad-line region emission, providing clues to the physics and
energetics of all radio-loud AGN. All observations completed without
reported incident.

1.2 Completed Three Sets of ACS/WFC 9575 (Default {Archival} Pure
Parallel Program)

The Advanced Camera for Surveys (WFC) was used to test ACS pure
parallels in POMS. There were no reported problems.

1.3 Completed Seven Sets of WF/PC-2 9318 (POMS Test Proposal: WFII
Parallel Archive Proposal Continuation)

The WF/PC-2 was used to perform the generic target version of the
WFPC2 Archival Pure Parallel program. The program was used to take
parallel images of random areas of the sky, following the recommendations
of the Parallels Working Group. There were no reported problems.

1.4 Completed Eleven 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.

1.5 Completed Three 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.

1.6 Completed Two 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.

1.7 Completed Five 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 STIS/CCD 8902 (Dark Monitor-Part 2)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. No problems were reported.

1.9 Completed Two Sets of STIS/CCD 9496 (UV Spectroscopic Investigation
of Any Bright, Newly Discovered Comet)

The Space Telescope Imaging Spectrograph (CCD) was used to perform
a Target of Opportunity program to investigate any bright comet
{mboxV<=sssim7} that is newly discovered during Cycle 11, including comets of any dynamical class. The main scientific objective is to obtain accurate abundance measurements for several key cometary species: CO from the CO 4PG bands, cotwo from the CO Cameron bands, stwo from the stwo B-X bands, cstwo from CS emissions, and water from OH emissions. The UV Cameron band emission is currently the only way to probe cotwo in comets. No anomalous activity occurred.

1.10 Completed STIS/CCD/MA1 9067 (UV Detectability of Bright Quasars in
the Sloan Fields)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
take MAMA spectra of approximately 30 new, bright, high-redshift quasars in
each of the next three cycles. The observations completed with no reported
problems.

1.11 Completed STIS/MA2 9573 (NUV-MAMA Daily Dark Monitor)

The Space Telescope Imaging Spectrograph (MA2) was used to perform
daily mo*qéring of the NUV MAMA detector dark noise in order to monitor
the effects of thermal changes on the NUV dark rate. No problems occurred.

1.12 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.

1.13 Completed Two Sets of STIS/MA2 8920 (Cycle 10 MAMA Dark Measurements)

The Space Telescope Imaging Spectrograph (MA2) was used to perform
the routine monitoring of the MAMA detector dark noise, and is the primary
means of checking on health of the MAMA detectors systems through frequent
monitoring of the background count rate. The proposal completed with no
reported anomalous activity.

1.14 Completed STIS/CCD 9163 (Kinematics Of Emission-Line Gas Disks In
Radio-Quiet Galaxies)

The Space Telescope Imaging Spectrograph (CCD) was used to measure
central black hole {BH} masses from the rotation rate of the emission-line
gas, and to determine the nature and structure of the gas disks. Three
galaxies with no radio jets and with Halpha+[NII] emission have been
identified, which have dust disks similar to those commonly seen in our
sample of radio-loud active galaxies. All observations completed nominally.

1.15 Completed FGS/1 9168 (The Distances to AM CVn Stars)

Fine Guidance Sensor (FGS) #1R was used to determine the parallaxes
and proper motions of the five brightest of the seven known AM CVn
systems. AM CVn systems are binaries where mass is transferred from a
completely hydrogen-deficient, degenerate mass donor to a white dwarf
primary through a helium accretion disk. A better understanding of these
systems is crucial for a number of reasons: (1) to study the late stages of
binary evolution, (2) to study the effect of chemical composition on the
physics of accretion discs, (3) to estimate their contribution to the
Supernovae Ia rate, and (4) to estimate their contribution to the
gravitational radiation background. All observations completed with no
reported problems.

1.16 Completed Two Sets of STIS/CCD 9317 (Pure Parallel Imaging
Program: Cycle 10)

The Space Telescope Imaging Spectrograph (CCD) was used to perform
the default archival pure parallel program for STIS during cycle 10. There
were no reported problems.

1.17 Completed STIS/CCD 9139 (Variability in the UV Spectrum of 3C 279:
Testing Models for the Gamma-Ray Emission in Blazars)

1.18 Completed Five Sets of NICMOS/1/2/3 8944 (Filter Wheel/Mechanisms
Mini-Functional Test)

The Near Infrared Camera and Multi-Object Camera (NIC1, NIC2 and
NIC3) was used to perform an early engineering test to verify the
aliveness, functionality, operability, and electro-mechanical calibration
of the NICMOS filter wheel motors and assembly. This was the first use of
the NICMOS filter wheel mechanisms since they were disabled by ground
command in January, 1999. This test was designed to obviate concerns over
possible deformation or breakage of the fitter wheel “soda-straw” shafts
due to excess rotational drag torque and/or bending moments which may be
imparted due to changes in the dewar metrology from warm-up/cool-down. No
anomalous incident occurred.

1.19 Completed Three Sets of ACS/WFC/HRC 9075 (Cosmological Parameters
from Type Ia Supernovae at High Redshift)

The Advanced Camera for Surveys (WFC and HRC) was used to obtain a
Hubble diagram of Type Ia supernovae {SNe Ia} that will be of long lasting
value as a record of the expansion history of the universe. No problems
were encountered.

1.20 Completed Five Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.21 Completed WF/PC-2 8940 (Cycle 10 Earth Flats)

The WF/PC-2 was used to monitor flatfield stability by obtaining
sequences of Earth streak flats to construct high quality flat fields for
the WF/PC-2 filter set. These flat fields will allow mapping of the OTA
illumination pattern and will be used in conjunction with previous internal
and external flats to generate new pipeline superflats. The proposal
completed without incident.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 9

Successful: 9

The acquisition at 114/084229Z defaulted to fine lock backup on
FGS-2 only when the scan step limit for FGS-1 was exceeded. HSTAR 8626 was
written. Three proposals occurring during the period of the next report,
STIS 9051, NICMOS 8945, and WF/PC-2 8941, may have been affected.

Scheduled Re-acquisitions: 4

Successful: 4

2.2 FHST Updates:

Scheduled: 33

Successful: 33

2.3 Operations Notes:

Operations requests were utilized to set up the tasking orders for
the NICMOS filter wheel test at 113/1207Z and to establish the NICMOS
memory monitors for the test at 113/1214Z. Then, at 113/1548Z, another
operations request enabled the filter wheel move. Between 113/1717Z and
113/1738Z, the filter wheels were moved and data was collected. Initial
analysis of the data indicated that the mechanism voltages and current
during the moves was as expected and very close to the last on-orbit test
in 1997. There was no significant temperature change. During the moves,
the voltage dropped approximately 0.3V on all three wheels and the current
spiked by 0.75A. There were no retries on filter wheel 1, and that wheel
moved within 14 counts of its commanded position. The return to blank was
within 16 counts of the commanded position. There was one retry on filter
wheel 2. This is not anomalous or cause for concern. The position was off
by 126 counts (the tolerance is 110 counts) which caused the retry. On the
second attempt, the filter wheel reached its position within nine
counts. There was an expected overshoot of four steps. There were no
retries on filter wheel 3. That wheel moved 60 steps as expected. The
return to blank was 64 steps. The final position was within 58 counts of
the commanded position. This test will continue over the next several days.