Daily Report #4916

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)