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Daily Rpt #4994



 
 
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Old December 17th 09, 07:21 PM posted to sci.astro.hubble
Bassford, Lynn[_2_]
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Posts: 91
Default Daily Rpt #4994

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4994

PERIOD COVERED: 5am December 16 - 5am December 17, 2009 (DOY 350/10:00z-351/10:00z)

OBSERVATIONS SCHEDULED

WFC3/UVIS 11643

A Timeline for Early-Type Galaxy Formation: Mapping the Evolution of
Star Formation, Globular Clusters, Dust, and Black Holes

While considerable effort has been devoted to statistical studies of
the origin of the red sequence of galaxies, there has been relatively
little direct exploration of galaxies transforming from late to early
types. Such galaxies are identified by their post-starburst spectra,
bulge-dominated, tidally-disturbed morphologies, and current lack of
gas. We are constructing the first detailed timeline of their
evolution onto the red sequence, pinpointing when star formation ends,
nuclear activity ceases, globular clusters form, and the bulk of the
merging progenitors' dust disappears. Here we propose to obtain HST
and Chandra imaging of nine galaxies, whose wide range of
post-starburst ages we have precisely dated with a new UV-optical
technique and for which we were awarded Spitzer time. We will address
1) whether the black hole-bulge mass relation arises from nuclear
feedback, 2) whether the bimodality of globular cluster colors is due
to young clusters produced in galaxy mergers, and 3) what happens to
the dust when late types merge to form an early type.

COS/FUV 11625

Beyond the Classical Paradigm of Stellar Winds: Investigating
Clumping, Rotation and the Weak Wind Problem in SMC O Stars

SMC O stars provide an unrivaled opportunity to probe star formation,
evolution, and the feedback of massive stars in an environment similar
to the epoch of the peak in star formation history. Two recent
breakthroughs in the study of hot, massive stars have important
consequences for understanding the chemical enrichment and buildup of
stellar mass in the Universe. The first is the realization that
rotation plays a major role in influencing the evolution of massive
stars and their feedback on the surrounding environment. The second is
a drastic downward revision of the mass loss rates of massive stars
coming from an improved description of their winds. STIS spectroscopy
of SMC O stars combined with state-of-the-art NLTE analyses has shed
new light on these two topics. A majority of SMC O stars reveal
CNO-cycle processed material brought at their surface by rotational
mixing. Secondly, the FUV wind lines of early O stars provide strong
indications of the clumped nature of their wind. Moreover, we first
drew attention to some late-O dwarfs showing extremely weak wind
signatures. Consequently, we have derived mass loss rates from STIS
spectroscopy that are significantly lower than the current theoretical
predictions used in evolutionary models. Because of the limited size
of the current sample (and some clear bias toward stars with
sharp-lined spectra), these results must however be viewed as
tentative. Thanks to the high efficiency of COS in the FUV range, we
propose now to obtain high-resolution FUV spectra with COS of a larger
sample of SMC O stars to study systematically rotation and wind
properties of massive stars at low metallicity. The analysis of the
FUV wind lines will be based on our 2D extension of CMFGEN to model
axi-symmetric rotating winds.

WFC3/UVIS 11912

UVIS Internal Flats

This proposal will be used to assess the stability of the flat field
structure for the UVIS detector throughout the 15 months of Cycle 17.
The data will be used to generate on- orbit updates for the delta-flat
field reference files used in the WFC3 calibration pipeline, if
significant changes in the flat structure are seen.

COS/NUV 11896

NUV Spectroscopic Sensitivity Monitoring

The purpose of this proposal is to monitor sensitivity of each NUV
grating mode to detect any changes due to contamination or other
causes.

WFC3/UVIS 11714

Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters

Planetary nebulae (PNe) in globular clusters (GCs) raise a number of
interesting issues related to stellar and galactic evolution. The
number of PNe known in Milky Way GCs, four, is surprisingly low if one
assumes that all stars pass through a PN stage. However, it is likely
that the remnants of stars now evolving in galactic GCs leave the AGB
so slowly that any ejected nebula dissipates long before the star
becomes hot enough to ionize it. Thus there should not be ANY PNe in
Milky Way GCs--but there are four! It has been suggested that these
Pne are the result of mergers of binary stars within GCs, i.e., that
they are descendants of blue stragglers. The frequency of occurrence
of PNe in external galaxies poses more questions, because it shows a
range of almost an order of magnitude.

I propose a SNAPshot survey aimed at discovering PNe in the GC systems
of Local Group galaxies outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which
easily discloses PNe. This proposal continues a WFPC2 program started
in Cycle 16, but with the more powerful WFC3. As a by-product, the
survey will also produce color-magnitude diagrams for numerous
clusters for the first time, reaching down to the horizontal branch.

WFC3/IR 11712

Calibration of Surface Brightness Fluctuations for WFC3/IR

We aim to characterize galaxy surface brightness fluctuations (SBF),
and calibrate the SBF distance method, in the F110W and F160W filters
of the Wide Field Camera 3 IR channel. Because of the very high
throughput of F110W and the good match of F160W to the standard H
band, we anticipate that both of these filters will be popular choices
for galaxy observations with WFC3/IR. The SBF signal is typically an
order of magnitude brighter in the near-IR than in the optical, and
the characteristics (sensitivity, FOV, cosmetics) of the WFC3/IR
channel will be enormously more efficient for SBF measurements than
previously available near-IR cameras. As a result, our proposed SBF
calibration will allow accurate distance derivation whenever an
early-type or bulge- dominated galaxy is observed out to a distance of
150 Mpc or more (i.e., out to the Hubble flow) in the calibrated
passbands. For individual galaxy observations, an accurate distance is
useful for establishing absolute luminosities, black hole masses,
linear sizes, etc. Eventually, once a large number of galaxies have
been observed across the sky with WFC3/IR, this SBF calibration will
enable accurate mapping of the total mass density distribution in the
local universe using the data available in the HST archive. The
proposed observations will have additional important scientific value;
in particular, we highlight their usefulness for understanding the
nature of multimodal globular cluster color distributions in giant
elliptical galaxies.

ACS/WFC3 11879

CCD Daily Monitor (Part 1)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 352 orbits (22 weeks) from 31 August
2009 to 31 January 2010.

ACS/WFC3/SBC 11564

Optical and Ultraviolet Photometry of Isolated Neutron Stars

We propose ultraviolet and B-band observations of 5 nearby, thermally
emitting neutron stars. These data will measure the Rayleigh-Jeans
tails of their spectra, providing a vital complement to X-ray
spectroscopy and helping to constrain atmospheric models, working
toward the ultimate goal of unraveling the physics of neutron stars.
With these data we will have good-quality optical and UV data for the
full sample of these objects, allowing detailed comparisons between
them. Finally, the data should allow us to measure proper motions for
one or two objects, and will serve as the reference data for the
remaining objects; such proper motions allow ages to be determined for
these objects by tracing them back to likely birth locations.

COS/NUV/FUV 11528

COS-GTO: Studies of the He II Reionization Epoch

Intergalactic Ly-alpha opacity suggests that H I was reionized at z ~
6, while He II reionization was delayed to z ~ 3. Both epochs are
slightly in disagreement with recent (WMAP-3) inferences from the CMB
optical depth, which suggest that IGM reionization occurred at z =
10.7 (+2.7, -2.3) (Spergel et al. 2007). However, these two methods
are sensitive to different ranges of ionization (neutral fractions),
which allows a partially ionized IGM between z = 6-10 produced by
early stars and black holes. One of the major contributions of FUSE to
cosmological studies was the detection of He II Ly-alpha
(Gunn-Peterson) absorption in the spectra of two AGN at redshifts z =
2.72-2.89. The He II absorption is quite patchy between redshifts z =
2.6 and 3.2 probably because the IGM is clumpy and the reionization
process is affected by source fluctuations, spectra, and radiative
transfer through the IGM. Observations of the He II absorption can
therefore be used as diagnostics of the ionizing sources and radiative
transport over large (30-50 Mpc) distances through the IGM. The
ionizing radiation field appears to be softer (higher He II/H I) in
the galaxy voids. These void regions may be ionized by local soft
sources (dwarf starburst galaxies), or the QSO radiation may softened
by escape from AGN cores and transport through denser regions in the
cosmic web. With COS, we will observe the brightest He II target,
HE2347-4342, a QSO with z_em = 2.885. Our goal is to obtain a G130M
moderate-resolution (R = 20, 000) spectrum from 1145-1450A. Because
COS has far greater throughput than either STIS or FUSE, we will be
able to resolve and characterize the He II absorption lines. The
region shortward of the redshifted He II (Ly-alpha) corresponds to z =
2.77-2.92, where He II exhibits patchy transmission and absorption.
The ratio of He II/H I (Ly-alpha line) opacities will provide
information on the ionizing radiation field (and ionizing sources) at
1 and 4 ryd. We will perform similar He II studies on three other
targets, HS1700+6416, PKS1935-692, and Q0302-003.

COS/NUV/FUV 11532

COS-GTO: Activity of Solar Mass Stars from Cradle to Grave

COS spectra will be very useful for answering the question of how
chromospheric and coronal activity of stars decline as stars lose
angular momentum and magnetic fields with age. This question is
important for modeling the atmospheres of young planets that are
blasted by strong ultraviolet radiation and winds from young stars.
COS will obtain spectra of solar mass stars with a range of ages from
10 Myr to 7 Gyr.

COS/NUV/FUV/STIS/CCD/MA1 11692

The LMC as a QSO Absorption Line System

We propose to obtain high resolution, high signal-to-noise
observations of QSOs behind the Large Magellanic Clouds. These QSOs
are situated beyond the star forming disk of the galaxy, giving us the
opportunity to study the distribution of metals and energy in regions
lacking significant star formation. In particular, we will derive the
metallicities and study the ionization characteristics of LMC gas at
impact parameters 3-17 kpc. We will compare our results with high-z
QSO absorption line systems.

STIS/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

STIS/CCD 11846

CCD Bias Monitor-Part 1

The purpose of this proposal is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up
high-S/N superbiases and track the evolution of hot columns.

WFC3/IR 11208

The Co-Evolution of Spheroids and Black Holes in the Last Six Billion
Years

The masses of giant black holes are correlated with the luminosities,
masses, and velocity dispersions of the bulges of their host galaxies.
This empirical correlation of phenomena on widely different scales
(from pcs to kpcs) suggests that the formation and evolution of
galaxies and central black holes are closely linked. In Cycle 13, we
have started a campaign to map directly the co-evolution of spheroids
and black-holes by measuring in observationally favorable redshift
windows the empirical correlations connecting their properties. By
focusing on Seyfert 1s, where the nucleus and the stars contribute
comparable fractions of total light, black hole mass and bulge
dispersion are obtained from Keck spectroscopy. HST is required for
accurate measurement of the non- stellar AGN continuum, the morphology
of the galaxy, and the structural parameters of the bulge. The results
at z=0.36 indicate a surprisingly fast evolution of bulges in the past
4 Gyrs (significant at the 95%CL), in the sense that bulges were
significantly smaller for a given black hole mass. Also, the large
fraction of mergers and disturbed galaxies (4+2 out of 20) identifies
gas-rich mergers as the mechanisms responsible for bulge- growth.
Going to higher redshift - where evolutionary trends should be
stronger - is needed to confirm these tantalizing results. We propose
therefore to push our investigation to the next suitable redshift
window z=0.57 (lookback-time 6 Gyrs). Fifteen objects are the minimum
number required to map the evolution of the empirical correlations
between bulge properties and black-hole mass, and to achieve a
conclusive detection of evolution (99%CL).

WFC3/IR 12044

DD Observations of the Coldest Brown Dwarf

We request DD observations of the SDWFS J1433+35, which is a strong
candidate for the coldest brown dwarf yet discovered and the first
example of the elusive "Y-dwarf" spectral class. This source was
discovered from a deep, wide-field survey of 10 square degrees with
the IRAC instrument on Spitzer, and is redder in both [3.6]-[4.5] and
H-[4.5] than any published brown dwarfs. The spectrum falls beyond 5
microns, strongly implying that the red mid-infrared colors are due to
methane absorption in the IRAC 3.6 micron channel rather than dust
obscuration. The source is undetected in deep, ground- based near-IR
images, with a H24.2 (Vega) limit derived from Keck AO imaging. The
proposed WFC3 imaging should provide detections in two near-infrared
bands. By showing the target is morphologically unresolved and that it
has the non-uniform spectral energy distribution of an ultracool brown
dwarf, the proposed observations will definitely show that (i) SDWFS
J1433+35 is the coldest brown dwarf known, (ii) test models of
ultracool, planet-like, brown dwarf atmospheres, and (iii) refine
predictions and strategies for the Wide-Field Infrared Survey Explorer
(WISE; planned to launch this December).

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by Gos in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UVIS 11588

Galaxy-Scale Strong Lenses from the CFHTLS Survey

We aim to investigate the origin and evolution of early-type galaxies
using gravitational lensing, modeling the mass profiles of objects
over a wide range of redshifts. The low redshift (z = 0.2) sample is
already in place following the successful HST SLACS survey; we now
propose to build up and analyze a sample of comparable size (~50
systems) at high redshift (0.4 z 0.9) using HST WFC3 Snapshot
observations of lens systems identified by the SL2S collaboration in
the CFHT legacy survey.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

WFC3/UVIS/IR 11644

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the Formation of the Outer Solar System

The eight planets overwhelmingly dominate the solar system by mass,
but their small numbers, coupled with their stochastic pasts, make it
impossible to construct a unique formation history from the dynamical
or compositional characteristics of them alone. In contrast, the huge
numbers of small bodies scattered throughout and even beyond the
planets, while insignificant by mass, provide an almost unlimited
number of probes of the statistical conditions, history, and
interactions in the solar system. To date, attempts to understand the
formation and evolution of the Kuiper Belt have largely been dynamical
simulations where a hypothesized starting condition is evolved under
the gravitational influence of the early giant planets and an attempt
is made to reproduce the current observed populations. With little
compositional information known for the real Kuiper Belt, the test
particles in the simulation are free to have any formation location
and history as long as they end at the correct point. Allowing
compositional information to guide and constrain the formation,
thermal, and collisional histories of these objects would add an
entire new dimension to our understanding of the evolution of the
outer solar system. While ground based compositional studies have hit
their flux limits already with only a few objects sampled, we propose
to exploit the new capabilities of WFC3 to perform the first ever
large-scale dynamical-compositional study of Kuiper Belt Objects
(KBOs) and their progeny to study the chemical, dynamical, and
collisional history of the region of the giant planets. The
sensitivity of the WFC3 observations will allow us to go up to two
magnitudes deeper than our ground based studies, allowing us the
capability of optimally selecting a target list for a large survey
rather than simply taking the few objects that can be measured, as we
have had to do to date. We have carefully constructed a sample of 120
objects which provides both overall breadth, for a general
understanding of these objects, plus a large enough number of objects
in the individual dynamical subclass to allow detailed comparison
between and within these groups. These objects will likely define the
core Kuiper Belt compositional sample for years to come. While we have
many specific results anticipated to come from this survey, as with
any project where the field is rich, our current knowledge level is
low, and a new instrument suddenly appears which can exploit vastly
larger segments of the population, the potential for discovery -- both
anticipated and not -- is extraordinary.

WFC3/UVIS/IR 11700

Bright Galaxies at z7.5 with a WFC3 Pure Parallel Survey

The epoch of reionization represents a special moment in the history
of the Universe as it is during this era that the first galaxies and
star clusters are formed. Reionization also profoundly affects the
environment where subsequent generations of galaxies evolve. Our
overarching goal is to test the hypothesis that galaxies are
responsible for reionizing neutral hydrogen. To do so we propose to
carry out a pure parallel WFC3 survey to constrain the bright end of
the redshift z7.5 galaxy luminosity function on a total area of 176
arcmin^2 of sky. Extrapolating the evolution of the luminosity
function from z~6, we expect to detect about 20 Lyman Break Galaxies
brighter than M_* at z~8 significantly improving the current sample of
only a few galaxies known at these redshifts. Finding significantly
fewer objects than predicted on the basis of extrapolation from z=6
would set strong limits to the brightness of M_*, highlighting a fast
evolution of the luminosity function with the possible implication
that galaxies alone cannot reionize the Universe. Our observations
will find the best candidates for spectroscopic confirmation, that is
bright z7.5 objects, which would be missed by small area deeper
surveys. The random pointing nature of the program is ideal to beat
cosmic variance, especially severe for luminous massive galaxies,
which are strongly clustered. In fact our survey geometry of 38
independent fields will constrain the luminosity function like a
contiguous single field survey with two times more area at the same
depth. Lyman Break Galaxies at z7.5 down to m_AB=26.85 (5 sigma) in
F125W will be selected as F098M dropouts, using three to five orbits
visits that include a total of four filters (F606W, F098M, F125W,
F160W) optimized to remove low-redshift interlopers and cool stars.
Our data will be highly complementary to a deep field search for
high-z galaxies aimed at probing the faint end of the luminosity
function, allowing us to disentangle the degeneracy between faint end
slope and M_* in a Schechter function fit of the luminosity function.
We waive proprietary rights for the data. In addition, we commit to
release the coordinates and properties of our z7.5 candidates within
one month from the acquisition of each field.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#12126 COS Status Buffer message #913 (External shutter open move was
blocked because the TDF was down) received during LOS @350/10:47z due
to 350/10:42:33z REAcq(1,2,1) FGS 1 searching for ~25 arcseconds
before acquiring the star and SCI INIT achieved @350/10:46:59z.

Observations possibly affected: COS #59-63 Proposal #11532

#12127 REAcq(1,0,1) takes two attempts to achieve FL @350/16:01z

Observations possibly affected: WFC3 #57-59 Proposal #12044

#12129 GSAcq(1,2,1) @350/21:26z failed to gyro control with search
radius limit exceeded on FGS-2 @ 350/21:29z

Observations affected: COS #64-70 Proposal #11528; WFC3 #70-76
Proposal #11905; STIS #19-22 Proposal #11846

#12130 GSAcq(1,2,1) @351/02:57:49z Search Radius Limit exceeded on FGS
1 and 2

Observations affected: COS #71-78 Proposal #11692; WFC3 #77-83
Proposal #11912

#12132 GSAcq(1,2,1) @351/06:06:09z and REAcq(1,2,1) @351/06:52:29z
Failed with Search Radius Limit exceeded on FGS 1

Observations affected: COS #79-88 Proposal #11625

#12133 GSAcq(1,2,1) @351/07:51z failed with Search Radius Limit
exceeded on FGS 1

Observations affected: WFC3 #84 Proposal #11714

#12134 During LOS, both GSAcq(1,2,1) @351/08:49:50z cycled through
Loss of Lock until 351/09:16z and REAcq(1,2,1) @351/10:25z failed to
gyro control

Observations affected: WFC3 #85-95 Proposal #11643

DOY 338:

#12124 SE PTAS processing found that REAcq(1,2,1) @338/00:19:10z took
2 attempts to achieve FL

Observations possibly affected: COS #38-41 Proposal #11896; ACS #69-70
Proposal #11879; WFC3 #87-88 Proposal #11905; STIS #56-57 Proposal
#11844.

DOY 339:

#12125 SE PTAS processing found that GSAcq(2,1,1) @339/01:49:53z
failed to FLBU (2,0,2)

Observation possibly affected: WFC3 #123 Proposal #11714

DOY 344:

#12128 SE PTAS processing found that REAcq(2,1,1) @344/01:11:27z took
2 attempts to achieve FL

Observations possibly affected: WFC3 #117-120 Proposal #11712; STIS
#26-28 Proposal #11846; WFC3 #121-122 Proposal #11905

COMPLETED OPS REQUEST:

#18781-4 Configure Gyro 3 Heater to Backup Controller @ 350/2147z
#18568-1 LBBIAS Updates for Extended Gyro Guiding Intervals (Generic)
@ 351/00:06z, 351/01:43z, 351/03:31z, 351/04:56z, 351/05:04z,
351/06:34z, 351/09:45z
#18562-1 CONTINGENCY: Continuous FGS Loss of Lock looping (Generic) @
351/03:14z, 351/09:16z
#18784-0 LBBIAS Gyro Bias Update @ 351/06:34z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 8 3
FGS REAcq 5 4
OBAD with Maneuver 4 4
LOL 1

SIGNIFICANT EVENTS:

Flash Report: Gyro 3 Reconfiguration to Backup Heater

Approval to switch the Gyro 3 heater controller to the backup heater
at 352/00:30 was given at the FRR on Wednesday, December 16.
Subsequently, HSTAR 12126 was generated on the GS re-acquisition at
350/10:44 which required a 25 arcsecond spiral search and appeared to
be related to a high uncompensated observer bias. Additionally, HSTAR
12127 was generated on the GS re-acquisition at 16:01 which required
two attempts to converge on the vehicle bias and acquire the guide
stars prior to the Loss of Lock check, also indicating a high
uncompensated observer bias.

In reviewing these events with the STScI planning group, it was
suggested that the heater switch be performed at 350/21:45 in order to
avoid failures of critical science observations on day 351 while
risking minor transient responses from the gyro 3 heater controller
switch. This plan was proposed to project management and approved.
However, the GS acquisition at 350/21:27 failed to RGA hold due to a
search radius limit exceed. An initial review of the failure indicates
that the problem was due to star issues and not a bias problem. This
FGS guiding interval was a CVZ observation scheduled to last
approximately 3 orbits. Since interference with science observations
was no longer an issue, approval was given to proceed with the heater
controller switch via Ops Request 18781-4.

The heater controller switch was executed at 350/21:47:30. As expected
the heater caused transients in the motor current, heater duty cycle
and temperature. The heater duty cycle initially jumped to 66%,
quickly dropped to 13% and then gradually rose back to its previous
operational level of 23% all over a period of 3 minutes. The motor
current had two samples to 120.4 milliamps, one count above the
pre-switch range of 114.8 to 117.6 (a one count toggle range) and
subsequently 3 samples to 112.0 milliamps, one count below the
pre-switch range, before returning to the pre-switch range. The
temperature rose by one count (56.9 to 57.2 degC) and remained there
for approximately 2 minutes before returning to 56.9 degC. All of this
telemetry has been trending nominally since the initial transient.

With the failure of the GS acquisition at 21:27, the FOT was directed
to execute the generic Ops Request 18568-1, LBBIAS Updates for
Extended Gyro Guiding Intervals, in order to correct residual gyro
bias and to correct any vehicle attitude error prior to the GS
acquisition at 351/02:58. Initial biases measurements up to 351/01:50
were nominal and the LBBIAS was successfully uplinked at 351/01:46.
However the GS acquisition at 351/02:57 failed to Loss of Lock (LOL)
looping which is indicative of a bias issue. Subsequent biases
appeared to increase in the V2 and V3 axes and acquisitions between
06:07 and 10:27 failed due to search radius limit exceeds (SRLEX) or
LOL looping while efforts were made to correct the bias. The GS
acquisition at 12:01 was successful and performed an onboard bias
update. The GS acquisition at 13:05 failed due to a dim star and
another full acquisition will not occur until 19:01. Another LBBIAS
update is in work to correct the bias.

 




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