HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4916
PERIOD
COVERED: 5am August 24 - 5am August 25, 2009 (DOY 236/09:00z-237/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC3
11465
ACS
CCD Monitoring and Calibration for WFC3
This
program is a smaller version of our routine CCD monitoring program,
designed
to run throughout SMOV, after which our regular Cycle 17 CAL
proposal
will begin. This program obtains the bias and dark frames
needed
to generate reference files for calibrating science data, and
allows
us to monitor detector noise and the growth of hot pixels.
COS
11484
COS
FUV Optics Alignment and Focus
After
FUV detector functionality has been confirmed in COS25 (program
11483)
and the initial focus updates determined in COS08 and COS 09
(programs
11468 and 11469), a sequence of 13 FUV focus-sweep exposures
of
a sharp-lined external target will be made with each grating (4
orbits
per grating) to perform a fine-focus sweep. After the data are
analyzed,
a patchable constant SMS update of OSM1 focus for each grating
will
be uplinked. A verification visit will be executed after the
uplink.
Observations require high S/N and should be taken in TIME-TAG
(FLASH=YES)
mode.
COS23
11356
COS
FUV Initial On-Orbit Turn-On
This
proposal specifies the procedure for SMOV initial HV turn-on and
ramp-up
of the COS FUV detector. (The FUV will have been commanded to
its
Operate state to support execution of proposal 11353.) The procedure
is
detailed in the Observing Description, but in summary, the following
is
done: The initial transition from FUV Operate to HVLow is broken into
two
parts, with a gap of 4 hours between turning on the HV and ramping
to
the HVLow (SAA) voltage. This will be followed by 5 cycles of HV
ramp-up
and return to HVLow. Cycles will ramp up to successively higher
(magnitude)
voltage, with the fifth cycle going to the nominal operating
values.
There will be a gap of at least 4 hours between cycles. All HV
ramp-up
will be done at 10 sec per HV "step". The step rate and cycle
voltage
values (for Segments A and B) must be patched in FSW in each
cycle
prior to the HV ramp commanding. Memory monitors will be set on
the
patched memory locations. Immediately after any HV commanding, and 4
hours
after ramp-up commanding, the DCE memory will be dumped.
Immediately
after HV ramp-up commanding higher than HVLow, short DARK &
WAVE
exposures will be obtained. Visits 01 and 02, and all the
subsequent
even numbered visits (the ones 4 hours after HV ramp-ups),
end
with NSSC-1 COS event flag 3 being set. If the flag remains set,
subsequent
FUV commanding will be skipped. Thus, Operations Requests
must
be in place to clear the flag prior to those subsequent visits.
Real-time
monitoring of the telemetry will be used to guide the
decisions
whether or not to clear the flag. The final visit (13)
provides
a scheduled final opportunity to clear flag 3, and if the flag
is
cleared, initiates nominal FUV HV commanding and requests a DARK
exposure.
STIS/CCD
11844
CCD
Dark Monitor Part 1
Monitor
the darks for the STIS CCD.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
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.
STIS/CCD
11852
STIS
CCD Spectroscopic Flats C17
Obtain
pixel-to-pixel lamp flat fields for the STIS CCD in spectroscopic
mode.
STIS20
11402
STIS-20
NUV MAMA Dark Monitor
The
STIS NUV-MAMA dark current is dominated by a phosphorescent glow
from
the detector window. Meta-stable states in this window are
populated
by cosmic ray impacts, which, days later, can be thermally
excited
to an unstable state from which they decay, emitting a UV
photon.
The equilibrium population of these meta-stable states is larger
at
lower temperatures; so warming up the detector from its cold safing
will
lead to a large, but temporary, increase in the dark current.
To
monitor the decay of this glow, and to determine the equilibrium dark
current
for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be
taken
each week during the SMOV period. Once the observed dark current
has
reached an approximate equilibrium with the mean detector
temperature,
the frequency of this monitor can be reduced to one pair of
darks
per week.
STIS26
11395
STIS-26
MAMA Image Stability
The
maximum thermal motion of the MAMA detectors occurs in the first
portion
of the orbit immediately following a large angle maneuver
leading
to maximum external changes on the portion of axial bay closest
to
the STIS instrument. By the second orbit on the same target, the
thermal
motions settle down to a significant displacement right after
target
rise, a possible change later in the orbit due to sun/bright
earth/dark
earth/ deep space. We will follow these changes for two
orbits
with each MAMA with internal lamp and the medium dispersion
echelle
formats in order to obtain a two-dimension series of reference
points
on the 2-dimensional detector format. Exposures will be done
using
the 0.1X0.03 aperture and medium resolution echelle gratings, and
will
have exposure times of 120 seconds for deep, sharp spectral line
images.
For
each orbit, six spectral line images will follow each other, then
dark
frames are interposed with exposure times extending from 300
seconds
to 600 seconds. This provides frequent sampling in the portion
of
the orbit where thermal flexure is largest, while avoiding excessive
lamp
use when shifts are expected to be slower. The dark frames will
also
provide a useful addition to the calibration of the MAMA detector
dark
current.
Note
that E140M test is from hot to cold and the E230M test is from cold
to
hot. If noticeable changes are measured, the complimentary test pair
should
be considered at a later date.
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 (11909), will be
used
to generate the necessary superbias and superdark reference files
for
the calibration pipeline (CDBS).
WFC3/UVIS
11908
Cycle
17: UVIS Bowtie Monitor
Ground
testing revealed an intermittent hysteresis type effect in the
UVIS
detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially
found via an unexpected bowtie-shaped feature in flatfield
ratios,
subsequent lab tests on similar e2v devices have since shown
that
it is also present as simply an overall offset across the entire
CCD,
i.e., a QE offset without any discernable pattern. These lab tests
have
further revealed that overexposing the detector to count levels
several
times full well fills the traps and effectively neutralizes the
bowtie.
Each visit in this proposal acquires a set of three 3x3 binned
internal
flatfields: the first unsaturated image will be used to detect
any
bowtie, the second, highly exposed image will neutralize the bowtie
if
it is present, and the final image will allow for verification that
the
bowtie is gone.
WFC3/UVIS/IR
11549
UVIS
and IR Pointing Stability
This
calibration proposal measures the pointing stability of the WFC3
UVIS
and IR channels.
Three
conditions will be tested: 1) 2-orbit stability after sitting at a
constant
thermal attitude for 10 orbits 2) 2-orbit stability after
sitting
at a hot thermal attitude for 10 orbits and then slewing to a
cold
attitude 3) 2-orbit stability after sitting at a cold thermal
attitude
for 10 orbits and then slewing to a hot attitude
Stability
measurements will be made by a series of short observations of
a
globular cluster.
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
05
05
FGS
REAcq
12
12
OBAD
with Maneuver
02
02
SIGNIFICANT
EVENTS: (None)