HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT    # 4530

 

PERIOD COVERED: UT January 18,19,20,21, 2007 (DOY 018,019,020,021)

 

OBSERVATIONS SCHEDULED

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA calibration - CR Persistence Part 6

 

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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

 

NIC3 11331

 

NICMOS Cycle 16 Grism Calibration

 

A series of pointed NICMOS observations of the spectroscopic flux

calibrator P330E and two wavelength calibrators VY2-2 and HB12.

 

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.

 

FGS 11301

 

Dynamical Masses and Radii of Four White Dwarf Stars

 

This proposal uses the FGS1r in TRANS mode to resolve a pair of double

degenerate binary systems {WD1639+153 and WD 1818+26} in order to

determine their orbital elements. In addition, the binaries and several

nearby field stars are observed by FGS1r in POS mode to establish the

local inertial reference frame of each binary, as well as its parallax

and proper motion. This will allow for a direct measurement of the

distance and radius of each of the four WD stars. When combined with the

orbital elements, this leads to a dynamical mass measurement for each

WD, and a four calibration points of the WD mass-radius relation.

 

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 Spitzer

 

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 within 15 Mpc, each SN stands an excellent chance of detection with

HST and Spitzer and of resolving potential light echoes.

 

WFPC2 11222

 

Direct Detection and Mapping of Star Forming Regions in Nearby, Luminous

Quasars

 

We propose to carry out narrow-band emission line imaging observations

of 8 quasars at z=0.05-0.15 with the WFPC2 ramp filters and with the

NICMOS narrow-band filters. We will obtain images in the [O II], [O

III], H-beta, and Pa-alpha emission line bands to carry out a series of

diagnostic tests aimed at detecting and mapping out star-forming regions

in the quasar host galaxies. This direct detection of star-forming

regions will confirm indirect indications for star formation in quasar

host galaxies. It will provide a crucial test for models of quasar and

galaxy evolution, that predict the co-existence of starbursts and

"monsters" and will solve the puzzle of why different indicators of star

formation give contradictory results. A secondary science goal is to

assess suggested correlations between quasar luminosity and the size of

the narrow-line region.

 

FGS 11212

 

Filling the Period Gap for Massive Binaries

 

The current census of binaries among the massive O-type stars is

seriously incomplete for systems in the period range from years to

millennia because the radial velocity variations are too small and the

angular separations too close for easy detection. Here we propose to

discover binaries in this observational gap through a Faint Guidance

Sensor SNAP survey of relatively bright targets listed in the Galactic O

Star Catalog. Our primary goal is to determine the binary frequency

among those in the cluster/association, field, and runaway groups. The

results will help us assess the role of binaries in massive star

formation and in the processes that lead to the ejection of massive

stars from their natal clusters. The program will also lead to the

identification of new, close binaries that will be targets of long term

spectroscopic and high angular resolution observations to determine

their masses and distances. The results will also be important for the

interpretation of the spectra of suspected and newly identified binary

and multiple systems.

 

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 W Vir

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.

 

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 Monte Carlo technique to

optimally schedule our observations.

 

WFPC2 11134

 

WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge

 

The spectacular HST images of the interiors of merging galaxies such as

the Antennae and NGC 7252 have revealed rich and diverse populations of

star clusters created over the course of the interaction. Intriguingly,

our WFPC2 study of tidal tails in these and other interacting pairs has

shown that star cluster birth in the tails does not follow a similarly

straightforward evolution. In fact, cluster formation in these

relatively sparse environments is not guaranteed -- only one of six

tails in our initial study showed evidence for a significant population

of young star clusters. The tail environment thus offers the opportunity

to probe star cluster formation on the edge of the physical parameter

space {e.g., of stellar and gas mass, density, and pressure} that

permits it to occur. We propose to significantly extend our pilot sample

of optically bright, gas-rich tidal tails by a factor of 4 in number to

include a more diverse population of tails, encompassing major and minor

mergers, gas-rich and gas-poor tails, as well as early, late, and merged

interaction stages. With 21 orbits of HST WFPC2 imaging in the F606W and

F814W filters, we can identify, roughly age-date, and measure sizes of

star clusters to determine what physical parameters affect star cluster

formation. WFPC2 imaging has been used effectively in our initial study

of four mergers, and it will be possible in this program to reach

similar limits of Mv=-8.5 for each of 16 more tails. With the much

larger sample we expect to isolate which factors, such as merger stage,

HI content, and merger mass ratio, drive the formation of star clusters.

 

WFPC2 11125

 

The Dynamical Evolution of Globular Clusters

 

Globular clusters evolve through dynamical interactions, with primordial

binaries extending the time until core collapse by up to an order of

magnitude, depending on the initial binary fraction. These dynamical

interactions plus mass segregation causes the binary fraction to rise in

the core but fall at larger radii. We hope to eventually test these

broad predictions by comparing them to the binary properties for

globular clusters at different states of evolution, defined by the ratio

of their age to the dynamical relaxation time at the half-light radius.

The most important unknown aspects in the modeling process are the

initial conditions of binaries in the cluster. Here we propose to

determine the initial binary fraction as a function of radius by

studying three of the dynamically youngest globular clusters {NGC 5053,

NGC 5466, and NGC 5897}. The presence of binaries thickens the Main

Sequence in a color-magnitude diagram, which can be detected with deep

multicolor images.

 

WFPC2 11122

 

Expanding PNe: Distances and Hydro Models

 

We propose to obtain repeat narrowband images of a sample of eighteen

planetary nebulae {PNe} which have HST/WFPC2 archival data spanning time

baselines of a decade. All of these targets have previous high

signal-to-noise WFPC2/PC observations and are sufficiently nearby to

have readily detectable expansion signatures after a few years. Our main

scientific objectives are {a} to determine precise distances to these

PNe based on their angular expansions, {b} to test detailed and highly

successful hydrodynamic models that predict nebular morphologies and

expansions for subsamples of round/elliptical and axisymmetric PNe, and

{c} to monitor the proper motions of nebular microstructures in an

effort to learn more about their physical nature and formation

mechanisms. The proposed observations will result in high-precision

distances to a healthy subsample of PNe, and from this their expansion

ages, luminosities, CSPN properties, and masses of their ionized cores.

With good distances and our hydro models, we will be able to determine

fundamental parameters {such as nebular and central star masses,

luminosity, age}. The same images allow us to monitor the changing

overall ionization state and to search for the surprisingly

non-homologous growth patterns to bright elliptical PNe of the same sort

seen by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is a sure

sign of active pressure imbalances within the nebula that require

careful hydro models to understand.

 

WFPC2 11113

 

Binaries in the Kuiper Belt: Probes of Solar System Formation and

Evolution

 

The discovery of binaries in the Kuiper Belt and related small body

populations is powering a revolutionary step forward in the study of

this remote region. Three quarters of the known binaries in the Kuiper

Belt have been discovered with HST, most by our snapshot surveys. The

statistics derived from this work are beginning to yield surprising and

unexpected results. We have found a strong concentration of binaries

among low-inclination Classicals, a possible size cutoff to binaries

among the Centaurs, an apparent preference for nearly equal mass

binaries, and a strong increase in the number of binaries at small

separations. We propose to continue this successful program in Cycle 16;

we expect to discover at least 13 new binary systems, targeted to

subgroups where these discoveries can have the greatest impact.

 

NIC2 11101

 

The Relevance of Mergers for Fueling AGNs: Answers from QSO Host

Galaxies

 

The majority of QSOs are known to reside in centers of galaxies that

look like ellipticals. Numerical simulations have shown that remnants of

galaxy mergers often closely resemble elliptical galaxies. However, it

is still strongly debated whether the majority of QSO host galaxies are

indeed the result of relatively recent mergers or whether they are

completely analogous to inactive ellipticals to which nothing

interesting has happened recently. To address this question, we recently

obtained deep HST ACS images for five QSO host galaxies that were

classified morphologically as ellipticals {GO-10421}. This pilot study

revealed striking signs of tidal interactions such as ripples, tidal

tails, and warped disks that were not detected in previous studies. Our

observations show that at least some "elliptical" QSO host galaxies are

the products of relatively recent merger events rather than old galaxies

formed at high redshift. However, the question remains whether the host

galaxies of classical QSOs are truly distinct from inactive ellipticals

and whether there is a connection between the merger events we detect

and the current nuclear activity. We must therefore place our results

into a larger statistical context. We are currently conducting an HST

archival study of inactive elliptical galaxies {AR- 10941} to form a

control sample. We now propose to obtain deep HST/WFPC2 images of 13

QSOs whose host galaxies are classified as normal ellipticals. Comparing

the results for both samples will help us determine whether classical

QSOs reside in normal elliptical galaxies or not. Our recent pilot study

of five QSOs indicates that we can expect exciting results and deep

insights into the host galaxy morphology also for this larger sample of

QSOs. A statistically meaningful sample will help us determine the true

fraction of QSO hosts that suffered strong tidal interactions and thus,

whether a merger is indeed a requirement to trigger nuclear activity in

the most luminous AGNs. In addition to our primary science observations

with WFPC2, we will obtain NICMOS3 parallel observations with the

overall goal to select and characterize galaxy populations at high

redshifts. The imaging will be among the deepest NICMOS images: These

NICMOS images are expected to go to a limit a little over 1 magnitude

brighter than HUDF- NICMOS data, but over 13 widely separated fields,

with a total area about 1.5 times larger than HUDF-NICMOS. This

separation means that the survey will tend to average out effects of

cosmic variance. The NICMOS3 images will have sufficient resolution for

an initial characterization of galaxy morphologies, which is currently

one of the most active and promising areas in approaching the problem of

the formation of the first massive galaxies. The depth and area coverage

of our proposed NICMOS observations will also allow a careful study of

the mass function of galaxies at these redshifts. This provides a large

and unbiased sample, selected in terms of stellar mass and unaffected by

cosmic variance, to study the on-going star formation activity as a

function of mass {i.e. integrated star formation} at this very important

epoch.

 

WFPC2 11070

 

WFPC2 CYCLE 15 Standard Darks - part II

 

This dark calibration program obtains dark frames every week in order to

provide data for the ongoing calibration of the CCD dark current rate,

and to monitor and characterize the evolution of hot pixels. Over an

extended period these data will also provide a monitor of radiation

damage to the CCDs.

 

WFPC2 11038

 

Narrow Band and Ramp Filter Closeout

 

These observations are to improve calibration of narrow band and ramp

filters. We also test for changes in the filter properties during

WFPC2's 14 years on-board HST.

 

WFPC2 11024

 

WFPC2 CYCLE 15 INTERNAL MONITOR

 

This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays {both gain 7 and

gain 15 -- to test stability of gains and bias levels}, a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.

 

WFPC2 11002

 

A Census of LIRGs in Clusters of Galaxies in the First Half of the

Universe from the IRAC Shallow Survey

 

The incidence of LIRGs and ULIRGs is roughly two orders of magnitude

higher in the field at redshift z > 1, and at these redshifts such

objects dominate the global star formation activity. Mergers which fuel

such activity might be expected to enhance the frequency of LIRGs in

dense environments. We propose to use MIPS to obtain a census of LIRGs

in z > 1 galaxy clusters from a well defined sample found in the IRAC

Shallow Survey. Supporting IRAC and HST ACS data are also requested.

 

FGS 10998

 

Exoplanet XO-1b: light curve and parallax

 

We propose to measure the radius of the recently-discovered transiting

extrasolar planet XO-1b. XO-1b's nominal radius is 1.30 times the radius

of Jupiter, which is nearly as large as HD 209458b {1.32 R_J}. We will

use two independent methods to measure XO-1b's radius: 1} precision

light curve analysis, and 2} measurement of its trigonometric parallax

combined with its spectroscopically-determined effective temperature and

its apparent magnitude.

 

WFPC2 10901

 

UV-Luminous Globular Clusters in NGC 1399

 

Ultraviolet observations have revealed remarkable diversity among old

stellar populations in globular clusters and E/S0 galaxies. We recently

discovered with HST/STIS that globular clusters in the giant elliptical

galaxy M87 have the most heavily populated hot horizontal branches of

any stellar systems yet studied. Their far-UV/optical colors are up to 1

mag bluer than any Milky Way globular cluster and approach the

theoretical limits for production of hot-HB stars in old stellar

populations. The differences among the metal-poor clusters are

particularly interesting, because it is thought that these objects

reflect the earliest stages of galaxy formation at high redshifts. Here

we propose deep ACS far-UV imaging of a second gE galaxy, NGC 1399, with

a cluster system that is well-studied at longer wavelengths, to

determine whether it shares characteristics with M87. These observations

bear on aspects of advanced stellar evolution, on the histories of

globular clusters in different environments, and on the interpretation

of the "ultraviolet upturn'' phenomenon in elliptical galaxies and its

value as a population probe in distant galaxies.

 

WFPC2 10896

 

An Efficient ACS Coronagraphic Survey for Debris Disks around Nearby

Stars

 

We propose to finish our Cycle 11 optical survey for nearby debris disks

using the ACS/HRC coronagraph. Out of 43 orbits originally proposed for

the survey, 23 orbits were allocated, leading to a survey of 22 stars,

from which two new debris disks were imaged for the first time. Our

analysis of the initial survey gives an empirical estimate for the

detection rate of debris disks relative to heliocentric distance and

dust optical depth. Our target list for Cycle 15 is now optimized to

yield more frequent disk detections. Likewise our observing strategy is

improved to maximize sensitivity per telescope orbit allocated.

Therefore we present the most efficient survey possible. The scientific

motivation is to obtain scattered light images of previously unresolved

debris disks to determine their viewing geometry and physical

architecture, both of which may characterize the underlying planetary

system. We choose 25 debris disk targets for which we predict a

detection rate of 25% ? 5%. Four targets have extrasolar planets from

which the viewing geometry revealed by a disk detection will resolve the

v sin{i} ambiguity in the planet masses. These targets present the

remarkable opportunity of finally seeing a debris disk in system with

known planets.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS:

11152 - GSAcq(1,2,1) Fine Lock Backup on FGS 1

           GSACQ(1,2,1) at 020/03:10:45 acquired in fine lock backup on FGS 1 only,

           with QF2STOPF and QSTOP flags set on FGS 2 at 03:15:42. No other flags

           were seen. REACQ(1,2,1) at 04:44:33 was successful on both FGS 1 and 2.

 

 

11153 - REAcq(2,1,2) failed due to Scan Step Limit Exceeded on FGS 2

           At Acquisition of Signal @ 020/16:29:36 REAcq (2,1,2), scheduled from

           020/15:22:06-15:29:35, had failed due to Scan Step Limit Exceeded on FGS

           2. QF2SSLEX, QF2STOPF, QSTEPEXC & QSTOP flags were received.

           Pre-acquisition OBAD #1 RSS = 9.09 a-s, OBAD #2 RSS = 5.67 a-s.

           Post-acquisition OBAD Map was not scheduled. Next scheduled engineering

           data dump will occur at 020/21:46:02.

 

           REAcq (2,1,2) scheduled from 020/18:33:56-18:41:25 failed due to Scan

           Step Limit Exceeded on FGS 2. QF2SSLEX, QF2STOPF, QSTEPEXC & QSTOP flags

           were received. Pre-acquisition OBAD #1 RSS = 13.60 a-s, OBAD #2 RSS =

           6.25 a-s. Post-acquisition OBAD Map = 11.68 a-s. This REAcq used the

           same guide star pair as the REAcq @ 020/15:22:06. Initial analysis shows

           FGS 2 achieved Fine Lock @ 18:36:56 but, lost it @ 18:37:28. SAC

           processing shows a deviation of 8.15864 a-s.

 

 

11154 - GSAcq(2,3,2) failed

           GSACQ(2,3,2) at 021/01:20:23 failed to RGA control with QF2STOPF and

           QSTOP flags set at 01:24:24. No other flags were seen.

 

11156 - REacq results in high boresight jitter @2007/ 331/0244z Jitter

           determined from control law position path following this reacquisition

           was approximately 2X measured jitter following the Acq and first Reacq.

           Star quality is suspected

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                          SCHEDULED      SUCCESSFUL  

FGS GSacq                 27                    26       

FGS REacq                 31                    29        

OBAD with Maneuver 106                  105 

 

SIGNIFICANT EVENTS:

 

Flash Report: FSW/FGE Hybrid Mode Disabled:

 

Ops Request 18175 was successfully completed at 021/15:01 to disable

FSW/FGE hybrid mode.