HUBBLE SPACE TELESCOPE - Continuing to collect World
Class Science
DAILY REPORT #4874
PERIOD COVERED: 5am June 24 - 5am June 25, 2009 (DOY
175/0900z-176/0900z)
OBSERVATIONS SCHEDULED
ACS/WFC 11369
ACS CCD functional test for WFC
During the ACS Repair (ACS-R) conducted during Hubble
Servicing Mission
4 (SM4), astronauts will install a CCD Electronics Box
Replacement
(CEB-R) and Low-Voltage Power Supply Replacement (LVPS-R). A
rudimentary
aliveness/functional test (AT/FT) will be conducted on-orbit
during SM4.
Shortly after SM4, the more comprehensive CCD function test (FT)
defined
in this program will be conducted as part of SMOV. This program
is
modeled after the original CCD functional test (HST program 9005,
PI
Mark Clampin) conducted following the initial installation of ACS
during
Hubble Servicing Mission 3B. This WFC-only proposal has a companion
HRC
proposal 11396.
COS23/FUV/S/C 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.
STIS07/CCD 11404
CCD Dark and Bias Monitor for SMOV4/Cycle 17 Activity
STIS-07
Monitor the darks for the STIS CCD. 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 11420
IR Detector Functional Test
This program measures the baseline performance and
operability of the IR
detector using only internal observations: darks and
internal (WFC3
calsystem) flatfields. The images will be used to evaluate
readnoise,
dark current, gain, and cursory characterization of the
reference
pixels. Most data will be taken in default full-frame readout
mode
(four-amp, gain 2.5 setting), but in addition darks and flats will
be
taken in each of the 4 subarrays. A set of internal flatfields will
be
acquired to provide absolute gain measurements for each amplifier at
the
nominal setting (2.5 e-/DN).
WFC3/IR 11421
WFC3 Channel Select Mechanism Test
The operation and positioning of the Channel Select
Mechanism (CSM) will
be verified for the WFC3 UVIS and IR channels. An
extended target will
be observed in both channels to verify that the field of
view is not
blocked or vignetted in any way when the CSM is set for UVIS and
IR
channel operations. Internal IR flat field images will also be used
to
verify the correct positioning of the IR diffuser paddle. This
proposal
corresponds to activity ID WFC3-08.
WFC3/IR/S/C 11543
IR Tungsten Lamp Cross-Check
This proposal will verify the operation of the spare IR
channel
calsystem tungsten lamp. A baseline image set will be established
by
obtaining one internal flatfield in each IR filter using the
channel's
spare lamp, plus one dark in each of the different sample sequence
types
used. An earlier proposal (11423) will have already verified
the
operation of the FSM and the primary tungsten bulb. Separate
proposals
will obtain additional darks and flatfields in each filter for
CDBS
reference file generation (proposals 11447 and 11433)
WFC3/UV 11808
WFC3 UVIS Bowtie Monitor
The UVIS detector was observed during ground testing to
occasionally
exhibit flat field and dark variations with a bowtie pattern.
These
variations are most significant as ~1% flat field (gain)
variations
across the field of view. It is believed that this represents a
state or
condition into which the detector can transition for reasons and
under
circumstances which are not currently understood. It is also
very
unlikely that most science observations will determine the state
(bowtie
or no-bowtie) of the detector. Ground test data indicates that
this
state is long lived (many hours to ~one day). Hysteresis or memory
of
past light exposure is also associated with this state.
Recent evidence suggests that exposing the detector to
~200k to 500k
electrons may quench this state. This proposal obtains an
internal flat
field sequence of three exposures: one at 10x full well with
two at 0.5x
full well immediately before and after. Each exposure is 3x3
binned to
reduce the data volume required.
These visits should be scheduled 2x per day until
further direction is
provided.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
11897 - GSacq(1,3,3) scheduled at
176/01:42:39 failed at 176/01:49:53 after
4
attempts.
Observation affected, None
11898 - FGS-1 initiated unscheduled reacquisition @
176/06:45:54z, the
REAcq
was successful. HST was in SAA level 1. This is a possible bit
flip.
FGS-1 returned to the default position prior to the start of the
REAcq. The REAcq was successful.
COMPLETED OPS REQUEST: None
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq
5 4
FGS
REAcq
2
2
OBAD with Maneuver
5
5
SIGNIFICANT EVENTS:
Flash Report: VDT Gyro Configuration (06/24/09,
5:53pm)
Ops. Request 18553 commanding completed at 175/21:22:10. The gyro
motor
current safemode limits were established for 3-gyro operations, gyro
3
was removed from the vehicle control law, and bias and offset
tables
were loaded. Subsequent pointing control system performance was
nominal.