HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

PERIOD COVERED: 5am June 24 - 5am June 25, 2009 (DOY 175/0900z-176/0900z)

OBSERVATIONS SCHEDULED

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.

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.

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.

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 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.

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 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

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.