HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       #4886

 

PERIOD COVERED: 5am July 13 - 5am July 14, 2009 (DOY 194/0900z-195/0900z)

 

OBSERVATIONS SCHEDULED

 

COS 11469

 

COS NUV Optics Alignment and Focus

 

This program has stringent guide star and timing requirements. Refer to

the observing description section for complete details.

 

This program determines the fine focus using NUV MIRRORA exposures of

the same target as COS08 (program 11468 - COS to FGS Alignment (NUV)).

This program must

 

commence execution approximately 48 hours after completion of visit 1 of

COS08 and as soon as possible after the uplink in visit 2 of COS08.

Three fine focus visits are executed to establish on-orbit nominal

focus. Two detailed verification visits are executed after the three

focus-sweep visits. Approximately 48 hours after each odd-numbered visit

an uplink of new information is required.

 

COS 11482

 

FUV Detector Dark

 

Measure the FUV detector dark rate by taking long science exposures with

no light on the detector. The detector dark rate and spatial

distribution of counts will be compared to pre-launch data in order to

verify the nominal operation of the detector, and for use in the CalCOS

calibration pipeline. Variations of count rate as a function of orbital

position will be analyzed to find dependence of dark rate on proximity

to the SAA.

 

This is SMOV Activity COS-24.

 

WFC3 11433

 

IR Internal Flat Fields

 

This proposal corresponds to WFC3-20, and depends on the completion of

the IR initial alignment (proposal 11425, WFC3-12). In this test, we

will study the stability and structure of the IR channel flat field

images through all filter elements in the WFC3-IR channel. Flat field

images for each filter will be combined in order to produce a

calibration-quality flat field image. High signal observations will

provide a map of the pixel-to-pixel flat field structure, as well as

identify the positions of any dust particles.

 

WFC3 11442

 

WFC3 FGS-UVIS Alignment

 

Mapping of the WFC3 UVIS detector coordinate frame to the FGS frame will

be determined from observations of an astrometric field with the WFC3

UVIS channel. Image quality over the field will also be assessed to

verify the final adjustments to the corrector mechanisms from program

11434.

 

This proposal is Activity ID WF29.

 

WFC3 11443

 

WFC3 FGS-IR Alignment

 

Mapping of the WFC3 IR detector coordinate frame to the FGS frame will

be determined from observations of an astrometric field with the WFC3 IR

channel. Image quality over the field will also be assessed to verify

the final adjustments to the corrector mechanisms from program 11435.

 

WFC3 11450

 

UVIS Photometric Zero Points

 

This proposal obtains the photometric zero points in 16 WFC3/UVIS

priority-1 filters, 20 WFC3/UVIS priority-2 filters, and 1 WFC3/UVIS ERO

filter using a hot DA white dwarf. The observations are repeated at

intervals of 1 day, 7 days, and 30 days, to monitor photometric

stability in 8 of the priority-1 filters, with emphasis in the UV where

contamination would have the strongest effects.

 

WFC3 11451

 

IR Photometric Zero Points

 

This proposal obtains the photometric zero points in all 15 WFC3/IR

filters using two stars with distinct temperatures (a hot DA white dwarf

and a solar analog). The observations are repeated at intervals of 1

day, 7 days, and 30 days, to monitor photometric stability in all

filters.

 

WFC3 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: (None)

 

COMPLETED OPS REQUEST:

18602-0 - Adjust NCS CPL Setpoint @ 194/1351z

18621-0 - Update COS Aperture positions in FSW @ 194/1424z

 

COMPLETED OPS NOTES: (None)

 

               SCHEDULED      SUCCESSFUL

FGS GSAcq          04            04                 

FGS REAcq          10            10           

OBAD with Maneuver 05            05           

 

SIGNIFICANT EVENTS: (None)