Notice: Due to the conversion of some ACS WFC or HRC
observations into
WFPC2, or NICMOS observations after the loss of ACS CCD
science
capability in January, there may be an occasional
discrepancy between a
proposal's listed (and correct) instrument usage and the
abstract that
follows it.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4424
PERIOD COVERED: UT August 10,11,12, 2007 (DOY 222, 223,
224)
OBSERVATIONS SCHEDULED
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
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 DARKs. 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.
WFPC2 11312
The Local Cluster Substructure Survey {LoCuSS}: Deep
Strong Lensing
Observations with WFPC2
LoCuSS is a systematic and detailed investigation of the
mass,
substructure, and thermodynamics of 100 X-ray luminous
galaxy clusters
at 0.15<z<0.3. The primary goal is to test our
recent suggestion that
this population is dominated by dynamically immature
disturbed clusters,
and that the observed mass-temperature relation suffers
strong
structural segregation. If confirmed, this would represent
a paradigm
shift in our observational understanding of clusters, that
were hitherto
believed to be dominated by mature, undisturbed systems.
We propose to
complete our successful Cycle 15 program {SNAP:10881}
which prior to
premature termination had delivered robust weak-lensing
detections in 17
clusters, and candidate strongly-lensed arcs in 11 of these
17. These
strong and weak lensing signals will give an accurate
measure of the
total mass and structure of the dark matter distribution
that we will
subsequently compare with X-ray and Sunyaev Zeldovich
Effect
observables. The broader applications of our project
include 1} the
calibration of mass-temperature and mass-SZE scaling
relations which
will be critical for the calibration of proposed dark
energy
experiments, and 2} the low redshift baseline study of the
demographics
of massive clusters to aid interpretation of future high
redshift {z>1}
cluster samples. To complete the all-important high
resolution imaging
component of our survey, we request deep WFPC2
observations of 20
clusters through the F606W filter, for which wide-field
weak-lensing
data are already available from our Subaru imaging
program. The
combination of deep WFPC2 and Subaru data for these 20
clusters will
enable us to achieve the science program approved by the
Cycle 15 TAC.
WFPC2 11307
Completing the ACS Nearby Galaxy Survey with WFPC2
We are requesting 25 orbits of Director's Discretionary
Time to complete
the primary science goals of our highly-ranked ACS Nearby
Galaxy Survey
Treasury program {ANGST}. Our program lost ~2/3 of its
orbits due to the
ACS failure. Roughly half of these were restored as a
result of an
appeal to the Telescope Time Review Board which re-scoped
the program.
The Board's response to our appeal was explicit in terms
of which
targets were to be observed and how. We were directed to
request
Director's discretionary time for the components of the
appeal which
were not granted by the Review Board, but which were vital
to the
success of the program. The observing strategy for ANGST
is two-fold: to
obtain one deep field per galaxy which enables derivation
of an accurate
ancient star formation history, and to obtain radial
tilings sufficient
for recovering the full star formation history. The Review
Board granted
WFPC2 observations for deep fields in 7 galaxies, but no
time for radial
tilings. However, recovering the full star formation
history of a galaxy
is not possible without additional radial coverage. We
have searched the
archives for observations which may be used in place of
the tilings
{conceding some of the Treasury goals, but providing
significant
constraints on the full star formation history}, and have
identified
suitable observations for all but two of the galaxies.
Here we request
DD time for radial tilings for those last two galaxies.
FGS 11298
Calibrating Cosmological Chronometers: White Dwarf Masses
We propose to use HST/FGS1R to determine White Dwarf {WD}
masses. The
unmatched resolving power of HST/FGS1R will be utilized to
follow up
four selected WD binary pairs. This high precision
obtained with
HST/FGS1R simply cannot be equaled by any ground based
technique. This
proposed effort complements that done by CoI Nelan in
which a sample of
WDs is being observed with HST/FGS1R. This proposal will
dramatically
increase the number of WDs for which dynamical mass
measurements are
possible, enabling a better calibration of the WD
mass-radius relation,
cooling curves, initial to final mass relations, and
ultimately giving
important clues to the star formation history of our
Galaxy and the age
of its disk as well as in other galaxies. {This project is
part of
Subasavage's PhD thesis work at
WFPC2 11289
SL2S: The Strong Lensing Legacy Survey
Recent systematic surveys of strong galaxy-galaxy lenses
{CLASS, SLACS,
GOODS, etc.} are producing spectacular results for galaxy
masses roughly
below a transition mass M~10^13 Mo. The observed lens
properties and
their evolution up to z~0.2, consistent with numerical
simulations, can
be described by isothermal elliptical potentials. In
contrast, modeling
of giant arcs in X-ray luminous clusters {halo masses M
>~10^13 Mo}
favors NFW mass profiles, suggesting that dark matter
halos are not
significantly affected by baryon cooling. Until recently,
lensing
surveys were neither deep nor extended enough to probe the
intermediate
mass density regime, which is fundamental for
understanding the assembly
of structures. The CFHT Legacy Survey now covers 125
square degrees, and
thus offers a large reservoir of strong lenses probing a
large range of
mass densities up to z~1. We have extracted a list of 150
strong lenses
using the most recent CFHTLS data release via automated
procedures.
Following our first SNAPSHOT proposal in cycle 15, we
propose to
continue the Hubble follow-up targeting a larger list of
130 lensing
candidates. These are intermediate mass range candidates
{between
galaxies and clusters} that are selected in the redshift
range of 0.2-1
with no a priori X-ray selection. The HST resolution is
necessary for
confirming the lensing candidates, accurate modeling of
the lenses, and
probing the total mass concentration in galaxy groups up
to z~1 with the
largest unbiased sample available to date.
WFPC2 11229
SEEDS: The Search for Evolution of Emission from Dust in
Supernovae with
HST and
The role that massive stars play in the dust content of
the Universe is
extremely uncertain. It has long been hypothesized that
dust can
condense within the ejecta of supernovae {SNe}, however
there is a
frustrating discrepancy between the amounts of dust found
in the early
Universe, or predicted by nucleation theory, and inferred
from SN
observations. Our SEEDS collaboration has been carefully
revisiting the
observational case for dust formation by core-collapse
SNe, in order to
quantify their role as dust contributors in the early
Universe. As dust
condenses in expanding SN ejecta, it will increase in
optical depth,
producing three simultaneously observable phenomena: {1}
increasing
optical extinction; {2} infrared {IR} excesses; and {3}
asymmetric
blue-shifted emission lines. Our SEEDS collaboration
recently reported
all three phenomena occurring in SN2003gd, demonstrating
the success of
our observing strategy, and permitting us to derive a dust
mass of up to
0.02 solar masses created in the SN. To advance our
understanding of the
origin and evolution of the interstellar dust in galaxies,
we propose to
use HST's WFPC2 and NICMOS instruments plus Spitzer's
photometric
instruments to monitor ten recent core- collapse SNe for
dust formation
and, as a bonus, detect light echoes that can affect the
dust mass
estimates. These space-borne observations will be
supplemented by
ground- based spectroscopic monitoring of their optical
emission line
profiles. These observations would continue our 2-year HST
and Spitzer
monitoring of this phenomena in order to address two key
questions: Do
all SNe produce dust? and How much dust do they produce?
As all the SN
are witin 15 Mpc, each SN stands an excellent chance of
detection with
HST and Spitzer and of resolving potential light echoes.
FGS 11211
An Astrometric Calibration of Population II Distance
Indicators
In 2002 HST produced a highly precise parallax for RR
Lyrae. That
measurement resulted in an absolute magnitude, M{V}=
0.61+/-0.11, a
useful result, judged by the over ten refereed citations
each year
since. It is, however, unsatisfactory to have the direct,
parallax-based, distance scale of Population II variables
based on a
single star. We propose, therefore, to obtain the
parallaxes of four
additional RR Lyrae stars and two Population II Cepheids,
or
stars. The Population II Cepheids lie with the RR Lyrae
stars on a
common K-band Period-Luminosity relation. Using these
parallaxes to
inform that relationship, we anticipate a zero-point error
of 0.04
magnitude. This result should greatly strengthen
confidence in the
Population II distance scale and increase our
understanding of RR Lyrae
star and Pop II Cepheid astrophysics.
FGS 11210
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony
makes that
prediction. It is, however, a prediction of extrasolar
planetary system
architecture as yet untested by direct observation for
main sequence
stars other than the Sun. To provide such a test, we propose
to carry
out FGS astrometric studies on four stars hosting seven
companions. Our
understanding of the planet formation process will grow as
we match not
only system architecture, but formed planet mass and true
distance from
the primary with host star characteristics for a wide
variety of host
stars and exoplanet masses. We propose that a series of
FGS astrometric
observations with demonstrated 1 millisecond of arc per-
observation
precision can establish the degree of coplanarity and
component true
masses for four extrasolar systems: HD 202206 {brown
dwarf+planet}; HD
128311 {planet+planet}, HD 160691 = mu Arae
{planet+planet}, and HD
222404AB = gamma Cephei {planet+star}. In each case the
companion is
identified as such by assuming that the minimum mass is
the actual mass.
For the last target, a known stellar binary system, the
companion orbit
is stable only if coplanar with the AB binary orbit.
WFPC2 11202
The Structure of Early-type Galaxies: 0.1-100 Effective
Radii
The structure, formation and evolution of early-type
galaxies is still
largely an open problem in cosmology: how does the
Universe evolve from
large linear scales dominated by dark matter to the highly
non-linear
scales of galaxies, where baryons and dark matter both
play important,
interacting, roles? To understand the complex physical
processes
involved in their formation scenario, and why they have
the tight
scaling relations that we observe today {e.g. the
Fundamental Plane}, it
is critically important not only to understand their
stellar structure,
but also their dark-matter distribution from the smallest
to the largest
scales. Over the last three years the SLACS collaboration
has developed
a toolbox to tackle these issues in a unique and
encompassing way by
combining new non-parametric strong lensing techniques,
stellar
dynamics, and most recently weak gravitational lensing,
with
high-quality Hubble Space Telescope imaging and VLT/Keck
spectroscopic
data of early-type lens systems. This allows us to break
degeneracies
that are inherent to each of these techniques separately
and probe the
mass structure of early-type galaxies from 0.1 to 100
effective radii.
The large dynamic range to which lensing is sensitive
allows us both to
probe the clumpy substructure of these galaxies, as well
as their
low-density outer haloes. These methods have convincingly
been
demonstrated, by our team, using smaller pilot- samples of
SLACS lens
systems with HST data. In this proposal, we request
observing time with
WFPC2 and NICMOS to observe 53 strong lens systems from
SLACS, to obtain
complete multi-color imaging for each system. This would
bring the total
number of SLACS lens systems to 87 with completed HST
imaging and
effectively doubles the known number of galaxy-scale
strong lenses. The
deep HST images enable us to fully exploit our new
techniques, beat down
low-number statistics, and probe the structure and
evolution of
early-type galaxies, not only with a uniform data-set an
order of
magnitude larger than what is available now, but also with
a fully
coherent and self-consistent methodological approach!
WFPC2 11178
Probing Solar System History with Orbits, Masses, and
Colors of
Transneptunian Binaries
The recent discovery of numerous transneptunian binaries
{TNBs} opens a
window into dynamical conditions in the protoplanetary
disk where they
formed as well as the history of subsequent events which
sculpted the
outer Solar System and emplaced them onto their present
day heliocentric
orbits. To date, at least 47 TNBs have been discovered,
but only about a
dozen have had their mutual orbits and separate colors
determined,
frustrating their use to investigate numerous important
scientific
questions. The current shortage of data especially
cripples scientific
investigations requiring statistical comparisons among the
ensemble
characteristics. We propose to obtain sufficient
astrometry and
photometry of 23 TNBs to compute their mutual orbits and
system masses
and to determine separate primary and secondary colors,
roughly tripling
the sample for which this information is known, as well as
extending it
to include systems of two near-equal size bodies. To make
the most
efficient possible use of HST, we will use a
optimally schedule our observations.
NIC2 11157
NICMOS Imaging Survey of Dusty Debris Around Nearby Stars
Across the
Stellar Mass Spectrum
Association of planetary systems with dusty debris disks
is now quite
secure, and advances in our understanding of planet
formation and
evolution can be achieved by the identification and
characterization of
an ensemble of debris disks orbiting a range of central
stars with
different masses and ages. Imaging debris disks in
starlight scattered
by dust grains remains technically challenging so that
only about a
dozen systems have thus far been imaged. A further advance
in this field
needs an increased number of imaged debris disks. However,
the technical
challenge of such observations, even with the superb
combination of HST
and NICMOS, requires the best targets. Recent HST imaging
investigations
of debris disks were sample-limited not limited by the
technology used.
We performed a search for debris disks from a
IRAS/Hipparcos cross
correlation which involved an exhaustive background contamination
check
to weed out false excess stars. Out of ~140 identified
debris disks, we
selected 22 best targets in terms of dust optical depth
and disk angular
size. Our target sample represents the best currently
available target
set in terms of both disk brightness and resolvability.
For example, our
targets have higher dust optical depth, in general, than
newly
identified Spitzer disks. Also, our targets cover a wider
range of
central star ages and masses than previous debris disk
surveys. This
will help us to investigate planetary system formation and
evolution
across the stellar mass spectrum. The technical
feasibility of this
program in two-gyro mode guiding has been proven with on-
orbit
calibration and science observations during HST cycles 13,
14, and 15.
WFPC2 11156
Monitoring Active Atmospheres on Uranus and Neptune
We propose Snapshot observations of Uranus and Neptune to
monitor
changes in their atmospheres on time scales of weeks and
months. Uranus
equinox is only months away, in December 2007. Hubble
Space Telescope
observations during the past several years {Hammel et al.
2005, Icarus
175, 284 and references therein} have revealed strongly
wavelength-dependent latitudinal structure, the presence
of numerous
visible-wavelength cloud features in the northern
hemisphere, at least
one very long-lived discrete cloud in the southern
hemisphere, and in
2006 the first dark spot ever seen on Uranus. Long-term
ground-based
observations {Lockwood and Jerzekiewicz, 2006, Icarus 180,
442; Hammel
and Lockwood 2007, Icarus 186, 291} reveal seasonal
brightness changes
whose origins are not well understood. Recent near-IR
images of
obtained using adaptive optics on the Keck Telescope,
together with HST
observations {Sromovsky et al. 2003, Icarus 163, 256 and
references
therein} which include previous Snapshot programs {GO
8634, 10170,
10534} show a general increase in activity at south
temperate latitudes
until 2004, when
Further Snapshot observations of these two dynamic planets
will
elucidate the nature of long-term changes in their zonal
atmospheric
bands and clarify the processes of formation, evolution,
and dissipation
of discrete albedo features.
WFPC2 11100
Two new `bullets' for MOND: revealing the properties of
dark matter in
massive merging clusters
The principal objective of this proposal is to study the
physical nature
of dark matter by using two, massive, newly-identified
merging clusters
of galaxies. As shown by the pioneering example of the
``bullet
cluster'' {1E0657-56}, such systems are ideal laboratories
for detecting
dark matter and distinguishing between cold dark matter
{CDM} and other
scenarios {e.g. self-interacting dark matter}. Our limit
on the
self-interaction cross-section of dark matter relies on
the assumption
of a normal pre-merger mass-to-light ratios, and a small
impact
parameter during the collision of the two clusters. In
order to mitigate
any possible systematic effects, it is vital to extend
this work to
other, similar systems. With detailed observations of new
systems, the
systematic uncertainties in the dark matter cross section
calculations
can be improved substantially, allowing us to move from
rough order of
magnitude estimates to measurements with quantifiable
uncertainties that
can be compared usefully with the predictions from
numerical
simulations. Our targets are two extraordinary,
high-redshift, merging
galaxy clusters recently discovered by the Massive Cluster
Survey
{MACS}. This survey is by far the best matched to this
study, since it
selects medium redshift {optimal for gravitational lensing
studies} and
X-ray luminous {hence massive} objects. We have selected
the best
candidates with clear evidence for considerable offsets
between the hot
X-ray emitting gas and optically luminous stellar
material. The two most
striking examples are the targets of this proposal. To pin
down the
position of the dark matter component we require high
resolution,
absolutely calibrated mass maps. The combination of weak
and strong
lensing measurements is needed to attain this goal. This
can only be
achieved with the excellent resolving power of the HST {in
combination
with wide-field, multicolor Subaru data already in hand}.
We therefore
request multicolor HST/WFPC2 observations of the two
merging clusters.
The combination of constraints from multiply lensed images
{identified
via morphology and color information} and high-resolution
weak lensing
data will allow us to construct, self-consistently, their
mass
distribution from the very centers to the outskirts.
Gravitational
lensing thus provides a unique tool transforming these
clusters into
dark matter laboratories. They will supply us with answers
as to the
nature and properties of dark matter, and how it shapes
galaxies and
galaxy clusters and their evolution through cosmic time.
NIC1 11057
Cycle 15 NICMOS dark current, shading profile, and read
noise monitoring
program
The purpose of this proposal is to monitor the dark
current, read noise,
and shading profile for all three NICMOS detectors
throughout the
duration of Cycle 15. This proposal is a slightly modified
version of
proposal 10380 of cycle 13 and 9993 of cycle12 and is the
same as Cycle
14. that we cut down some exposure time to make the
observation fit
within 24 orbits.
WFPC2 11030
WFPC2 WF4 Temperature Reduction #3
In the fall of 2005, a serious anomaly was found in images
from the WF4
CCD in WFPC2. The WF4 CCD bias level appeared to have
become unstable,
resulting in sporadic images with either low or zero bias
level. The
severity and frequency of the problem was rapidly
increasing, making it
possible that WF4 would soon become unusable if no
work-around were
found. Examination of bias levels during periods with
frequent WFPC2
images showed low and zero bias episodes every 4 to 6
hours. This
periodicity is driven by cycling of the WFPC2 Replacement
Heater, with
the bias anomalies occurring at the temperature peaks. The
other three
CCDs {PC1, WF2, and WF3} appear to be unaffected and
continue to operate
properly. Lowering the Replacement Heater temperature set
points by a
few degrees C effectively eliminates the WF4 anomaly. On 9
January 2006,
the upper set point of the WFPC2 Replacement Heater was
reduced from
14.9C to 12.2C. On 20 February 2006, the upper set point
was reduced
from 12.2C to 11.3C, and the lower set point was reduced
from 10.9C to
10.0C. These changes restored the WF4 CCD bias level;
however, the bias
level has begun to trend downwards again, mimicking its
behavior in late
2004 and early 2005. A third temperature reduction is
planned for March
2007. We will reduce the upper set point of the heater
from 11.3C to
10.4C and the lower set point from 10.0C to 9.1C. The
observations
described in this proposal will test the performance of
WFPC2 before and
after this temperature reduction. Additional temperature
reductions may
be needed in the future, depending on the performance of
WF4. Orbits:
internal 26, external 1
NIC1 10889
The Nature of the Halos and Thick Disks of Spiral Galaxies
We propose to resolve the extra-planar stellar populations
of the thick
disks and halos of seven nearby, massive, edge-on galaxies
using ACS,
NICMOS, and WFPC2 in parallel. These observations will
provide accurate
star counts and color-magnitude diagrams 1.5 magnitudes
below the tip of
the Red Giant Branch sampled along the two principal axes
and one
intermediate axis of each galaxy. We will measure the
metallicity
distribution functions and stellar density profiles from
star counts
down to very low average surface brightness’s,
equivalent to ~32 V-mag
per square arcsec. These observations will provide the
definitive HST
study of extra-planar stellar populations of spiral galaxies.
Our
targets cover a range in galaxy mass, luminosity, and
morphology and as
function of these galaxy properties we will provide: - The
first
systematic study of the radial and isophotal shapes of the
diffuse
stellar halos of spiral galaxies - The most detailed
comparative study
to date of thick disk morphologies and stellar populations
- A
comprehensive analysis of halo and thick disk metallicity
distributions
as a function of galaxy type and position within the
galaxy. - A
sensitive search for tidal streams - The first opportunity
to directly
relate globular cluster systems to their field stellar
population We
will use these fossil records of the galaxy assembly
process preserved
in the old stellar populations to test halo and thick disk
formation
models within the hierarchical galaxy formation scheme. We
will test
LambdaCDM predictions on sub-galactic scales, where it is
difficult to
test using CMB and galaxy redshift surveys, and where it
faces its most
serious difficulties.
WFPC2 10884
The Dynamical Structure of Ellipticals in the Coma and
Abell 262
Clusters
We propose to obtain images of 13 relatively luminous
early type
galaxies in the Coma cluster and Abell 262 for which we
have already
collected ground based major and minor axis spectra and
images. The
higher resolution HST images will enable us to study the
central regions
of these galaxies which is crucial to our dynamical
modeling. The
complete data set will allow us to perform a full
dynamical analysis and
to derive the dark matter content and distribution, the
stellar orbital
structure, and the stellar population properties of these
objects,
probing the predictions of galaxy formation models. The
dynamical
analysis will be performed using an up-to-date
axi-symmetric orbit
superposition code.
NIC2 10852
Coronagraphic Polarimetry with NICMOS: Dust grain
evolution in T Tauri
stars
The formation of planetary systems is intimately linked to
the dust
population in circumstellar disks, thus understanding dust
grain
evolution is essential to advancing our understanding of
how planets
form. By combining {1} the coronagraphic polarimetry
capabilities of
NICMOS, {2} powerful 3-D radiative transfer codes, and {3}
observations
of objects known to span the Class II-III stellar
evolutionary phases,
we will gain crucial insight into dust grain growth. By
observing
objects representative of a known evolutionary sequence of
YSOs, we will
be able to investigate how the dust population evolves in
size and
distribution during the crucial transition from a
star+disk system to a
system containing planetesimals. When combine with our
previous study on
dust grain evolution in the Class I-II phase, the proposed
study will
help to establish the fundamental time scales for the
depletion of
ISM-like grains: the first step in understanding the
transformation from
small submicron sized dust grains, to large millimeter
sized grains, and
untimely to planetary bodies.
WFPC2 10841
A Proper Motion Search for Intermediate Mass Black Holes
in Globular
Clusters {2nd Epoch Observations}
Establishing the presence or absence of intermediate-mass
black holes
{IMBH} in globular clusters is crucial for understanding
the evolution
of dense stellar systems. Observationally, this search has
been hampered
by the low number of stars with known velocities in the
central few
arcseconds. This limits our knowledge of the velocity
dispersion in the
region where the gravitational influence of any IMBH would
be felt. In
Cycle 13, we successfully obtained ACS/HRC images of the
centers of five
carefully chosen Galactic globular clusters {GO-10401} for
a new proper
motion study. Although the science case was approved and
the first epoch
images obtained, the requested future cycle observations
were not
granted {due to a general policy decision based on the
strong
uncertainties at the time concerning the immediate future
of HST}. We
have now assessed the quality of the first epoch
observations. The HRC
resolution reveals many isolated stars in to the very
center of each
cluster that remained blended or unresolved in previous
WFPC2 data.
Given a two year baseline, we are confident that we can
achieve the
proper motion precision required to place strict limits on
the presence
of an IMBH. Therefore, we request the second-epoch,
follow-up
observations to GO-10401 in order to measure the proper
motions of stars
in our target clusters. These velocity measurements will
allow us to:
{i} place constraints on the mass of a central black hole
in each
cluster; {ii} derive the internal velocity dispersion as a
function of
cluster radius; {iii} verify or reject previous reports of
cluster
rotation; and {iv} directly measure velocity anisotropy as
a function of
radius. If no second epoch data are obtained then the
observing time
already invested in the first epoch will have been wasted.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
#10939 REACQ(1,3,3) failed.
Upon acquisition of signal at 223/15:29:24 HST was in gyro
control with
QF1STOPF and QSTOP flags set. REACQ(1,3,3) at 223/15:08:46
failed to RGA
control. At acquisition of signal vehicle had OBAD RSS
error of 2.46
arcseconds. Initial GSCAQ(1,3,3) at 13:32:51 and
subsequent REACQ(1,3,3)
at 16:44:42 were successful.
#10940 REacq(1,2,1) failed to RGA control.
REacq(1,2,1) scheduled at 224/02:39:00 failed at 02:42:09
due to scan
step limit exceeded on FGS 1. OBAD1 showed errors of
V1=7.41, V2=423.15,
V3=17.34, RSS=423.57. OBAD2 showed errors of V1=-35.71,
V2=-21.75,
V3=-36.81, RSS=55.70.
COMPLETED OPS REQUEST: (None)
SCHEDULED SUCCESSFUL
FGS
GSacq
16
16
FGS
REacq
26
24
OBAD with Maneuver
84
84
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None