HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      #4898

PERIOD COVERED: 5am July 29 - 5am July 30, 2009 (DOY 210/09:00z-211/09:00z)

OBSERVATIONS SCHEDULED

COS 11474

COS NUV Internal/External Wavelength Scales

Observe external radial velocity standard targets (preferably, though

not required, in CVZ) in TIME-TAG (FLASH=YES) mode with as many grating

and central wavelength combinations as feasible. The purpose is to

obtain zero-point offsets for the wavelength scale (internal wavecal

lamp scale to external standard wavelength scale) for all central

wavelengths. Following this determination, adjustments of the nominal

science target spectral range for each grating and central wavelength

combination will be made via SMS patchable constant for nominal OSM2

positions corresponding to each central wavelength. Subsequent to this

modification of the wavelength scale (and its verification in COS 15 -

program 11475), NUV science-related operations and wavelength-scale

dependent EROs can commence.

COS 11478

COS NUV Flat Fields

Acquire long NUV flat field exposures using the internal deuterium

calibration lamp with the G185M grating. Use central wavelengths of 1835

angstroms, 1850 angstroms, and 1864 angstroms. Based on data taken

during thermal vacuum testing in 2003 (Test 1750), a total of 65,000

seconds of data should be sufficient to obtain ~7.5x10^7 total counts in

the science region of the detector (> 200 counts per pixel, or 1800

counts per 3 x 3 pixel resolution element).

This is SMOV4 Activity COS-18.

STIS07 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.

STIS18 11351

NUV MAMA HV Recovery

This proposal addresses the concerns over Cesium migration from the NUV

MAMA photocathode into the pores of the microchannel plate and lays out

the procedures necessary to permit a safe and controlled recovery of the

NUV-MAMA detector to science. This procedure should only be used during

the SMOV4 high voltage recommissioning phase for the NUV-MAMA. After,

the normal ramping procedure should be used. This proposal is loosely

based on proposal 10036, STIS MAMA Anomalous Recovery, with the

differences summarized below: (1) additional plateaus during voltage

commanding, (2) longer dwells after each 50 V step, (3) intermediate

ramp re-structured into 2 parts, (4) change in yellow and red limits and

the MCP Hi limit, setting new values for the next plateau, and (5)

adding a fold test at 300V below the nominal MCP voltage. The recovery

consists of four separate procedures (visits) and they must be completed

successfully and in order. They are: (1) a signal processing electronics

check, (2) 1st high voltage ramp-up to an intermediate MCP voltage of

-1500 V with limits modifications and voltage plateaus, (3) 2nd high

voltage ramp-up to an intermediate MCP voltage of -1750 V (300 V below

the nominal MCP voltage) with limits modifications and voltage plateaus

followed by a fold distribution test, and (4) a final high voltage

ramp-up to the full operating voltage, again with limits modifications

and voltage plateaus, followed by a fold distribution test. During the

1st high voltage ramp- up, diagnostics are performed followed by a dark

exposure. During the 2nd and 3rd high voltage ramp-ups, diagnostics are

performed followed by a dark, flat field ACCUMs, and a fold analysis

test. All required parameters are defined in 07-248 FUV and NUV SMOV

Ramp-up Parameters Excel workbook. Supports Activity STIS-18.

WFC3 11426

UVIS SMOV Contamination Monitor

The UV throughput of WFC3 during SMOV is monitored via weekly standard

star observations in a subset of key filters (as many as will fit into a

single orbit but to include at a minimum F218W, F225W, F275W, and

F606W). The data will provide a measure of throughput levels as a

function of time and wavelength, allowing for detection of the presence

of possible contaminants. In addition, a small set of internal exposures

are included with the externals, to provide verification of detector

stability.

This proposal corresponds to Activity WFC3-13.

WFC3 11798

UVIS PSF Core Modulation

UVIS shutter consists of two blades (or Sides). It rotates in one

direction, so Side 1 and Side 2 alternately shade consecutive exposures.

The shutter movement causes vibrations of the UVIS channel that affect

the UVIS PSF peak in the short exposures. The peak-to-peak effect will

be evaluated. Subarray images of a moderately bright, isolated star will

be obtained with a series of increasing exposures times designed to

obtain very high SNR in the central pixel of the PSF.

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: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL

FGS GSAcq              05                  05              

FGS REAcq               12                 12            

OBAD with Maneuver 04                 04           

SIGNIFICANT EVENTS: (None)