Daily #3934

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3934

PERIOD COVERED: UT August 29, 2005 (DOY 241)

OBSERVATIONS SCHEDULED

ACS/HRC 10377

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

ACS/HRC 10458

ACS and WFPC2 TGSMOV Two-Gyro PSF, Pointing, and Dither Test

Goals: PSF, PSF repeatability, pointing and stability within orbit and
between orbits. Also test results for different targets. {F2G
requirements 1a, 1c, 2 ,

ACS/HRC 10460

ACS Two-Gyro mode coronography test

This test of the coronagraphic procedure will be run soon after
entering the two gyro mode. It duplicates observations that have been
taken in normal 3-gyro mode in proposals 9667 or 9668 and is simalar
to the 2-Gyro test of Feb 2005. One orbit is used to measure the light
which gets around the coronagraph in four filters. The second orbit is
a test of the repeatibility and the third orbit replicates the others
but at a different roll angle to permit a more detailed analysis of
the coronagraphic performance. We include two pairs of HRC earth
flats, immediately following the coronagraphic observations, taken
with the coronagraph in place to measure the exact position of the
spot.

ACS/HRC/WFC 10389

ACS CCDs daily monitor - Cycle 13 - Part 2

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This program will be
for the entire lifetime of ACS.

ACS/HRC/WFC 10514

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically
hot and cold subpopulations we will be able to answer, with
statistical significance, the question of whether these groups differ
in the abundance of binaries as a result of their particular dynamical
paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of
the final stages of giant-planet building and migration; binaries may
offer some of the best preserved evidence of that long-ago era.

ACS/WFC/NIC3/WFPC2 10530

Probing Evolution And Reionization Spectroscopically {PEARS}

While imaging with HST has gone deep enough to probe the highest
redshifts, e.g. the GOODS survey and the Ultra Deep Field,
spectroscopic identifications have not kept up. We propose an ACS
grism survey to get slitless spectra of all sources in a wide survey
region {8 ACS fields} up to z =27.0 magnitude, and an ultradeep field
in the HUDF reaching sources up to z =28 magnitude. The PEARS survey
will: {1} Find and spectrocopically confirm all galaxies between
z=4-7. {2} Probe the reionization epoch by robustly determining the
luminosity function of galaxies and low luminosity AGNs at z = 4 - 6.
With known redshifts, we can get a local measure of star formation and
ionization rate in case reionization is inhomogeneous. {3} Study
galaxy formation and evolution by finding galaxies in a contiguous
redshift range between 4 z 7, and black hole evolution through a
census of low-luminosity AGNs. {4} Get a robust census of galaxies
with old stellar populations at 1 z 2.5, invaluable for checking
consistency with heirarchical models of galaxy formation. Fitting
these galaxies' spectra will yield age and metallicity estimates. {5}
Study star-formation and galaxy assembly at its peak at 1 z 2 by
identifying emission lines in star-forming galaxies, old populations
showing the 4000A break, and any combination of the two. {6} Constrain
faint white dwarfs in the Galactic halo and thus measure their
contribution to the dark matter halo. {7} Derive spectro-photometric
redshifts by using the grism spectra along with broadband data. This
will be the deepest unbiased spectroscopy yet, and will enhance the
value of the multiwavelength data in UDF and the GOODS fields to the
astronomical community. To this end we will deliver reduced spectra to
the HST archives.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

A new procedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour 23, and every time a NICMOS exposure is scheduled within 50
minutes of coming out of the SAA. The darks will be obtained in
parallel in all three NICMOS Cameras. The POST-SAA darks will be
non-standard reference files available to users with a USEAFTER
date/time mark. The keyword 'USEAFTER=date/time' will also be added to
the header of each POST-SAA DARK frame. The keyword must be populated
with the time, in addition to the date, because HST crosses the SAA ~8
times per day so each POST-SAA DARK will need to have the appropriate
time specified, for users to identify the ones they need. Both the raw
and processed images will be archived as POST-SAA DARKSs. Generally we
expect that all NICMOS science/calibration observations started within
50 minutes of leaving an SAA will need such maps to remove the CR
persistence from the science images. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.

NIC2 10464

NICMOS 2-gyro Coronagraphic Performance Assessment

Coronagraphic acquisition should not be affected by transitioning from
3-gyro to 2-gyro mode guiding. However, coronagraphic performance is
dependent upon positioning of a target within the coronagraphic hole
and the ability to obtain a second observation with a roll of the
telescope within the same visibility period. Observations of a bright
target are needed to verify and confirm the coronagraphic performance,
the ability to suppress the diffractive energy background and the
stability to image coronagraphically occulted targets at two field
orientations {rolls}.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS Gsacq 11 11
FGS Reacq 03 03
OBAD with Maneuver 26 26


SIGNIFICANT EVENTS:

Flash Report for TGS Transition" - (ldunham, 241/12:30) -- All
commanding for the transition to Two Gyro Science mode was successful.
Operations requests 17528, 17530, and 17522 were executed beginning at
241/00:02. Commanding included modifying control law gains for T2G,
loading FSW support files for TGS, modifying +D SPA commanding in new
TGS safemode macros, transitioning to TGS mode, and performing a full
RAM dump. Transition to TGS mode took place at 241/0217. The first FGS
guide acquisition at 0812 was successful, as have all subsequent
acquisitions. No HSTARs have been generated. From integrated gyro data
processed, M2G (MSS/2 Gyro mode) attitude errors were maintained
within 3 degrees. The largest correction of 3 OBAD (FHST On Board
Attitude Determination) pairs was 0.82 degrees. The largest correction
for the second OBAD of each pair was 11 arcseconds. Jitter in F2G
(FGS/2 Gyro mode) was measured at approximately 3 milliarcseconds. All
three acquisitions performed have been successful with no LOL.