- Press Release
- Dec 2, 2022
NASA Hubble Space Telescope Daily Report #4862
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT #4862
PERIOD COVERED: 5am June 8 – 5am June 9, 2009 (DOY 159/0900z-160/0900z)
ACS CEB-R Optimization Iteration 3
During the early weeks of SMOV the ACS-R team will work to find the best parameters for CEB-R and the WFC CCD operations before continuing with the normal SMOV activities and eventually enable science operations. This optimization needs to be done in an iteratively way. The plan is to have up to eight iterations spread out through SMOV week 2-4. A core-set of observations aimed to assess the performance of the CCDs and to check the relative phasing between the internal ASIC signal and the incoming video signal will be repeated in all iterations. In any given iteration a specific test will be run to determine the best value for a given parameter. Data collected in each iteration will be quickly analyzed and if needed, new parameters will be uploaded in real time before the following iteration. The data will consist of a mix of normal data (bias, flat, EPER, darks) and O-mode data. In order to facilitate the program implementation, data collection and reduction, the program will be implemented in eight different proposals. 11811 covers the third iteration.
NUV Detector Dark
Measure the NUV 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.
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.
Optimizing FGS2R2 Performance with the AMA
This proposal satisfies SMOV4 AD OTA/FGSS-054. S-curves with PUPIL and F583W will be obtained at selected locations within the FGS2R2 FOV during SMOV4. These data will be will be used to adjust the AMA so as to align the HST pupil onto the interferometer’s Koesters prisms. The final AMA position will be set to produce an acceptable set of S-curves across the FGS2R2 FOV. The AMA will be adjusted using CCL/instructions from the ground. It is intended that this proposal executes during the SMOV4 BEA and will require several (on the order of 4) iterations to achieve optimal interferometric performance.
CCD Dark and Bias Monitor for SMOV4/Cycle 17 Activity STIS-07
Monitor the darks for the STIS CCD. Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns.
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
This program (WFC3 SMOV program WFC3-01) verifies that WFC3 is in the same condition after release from the Shuttle as during the Functional Test (FT), which was conducted with HST in the Shuttle’s payload bay. This analog test will be implemented in stored commanding that will be generated from a Phase II proposal, whereas the in-bay FT was run with real-time CCLs.
The purpose of the FT was to demonstrate that WFC3 is viable for scientific research. This was accomplished by demonstrating that WFC3 can be commanded to the nominal scientific operating state and can carry out nominal scientific operations of the UVIS and IR channels, including operation of the thermoelectric coolers (TECs), corrector and focus mechanisms, UVIS shutter, SOFA and FSM filter wheels, detectors, and Control Section (CS). Only one Side of the CS is verified.
This test is compatible with execution during the post-FT, Safe-Protect period. Operability of the TECs is not demonstrated in this test, but is demonstrated in the SMOV Detector & TEC activation programs, WFC3-04 and WFC3-05.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
COMPLETED OPS REQUEST:
18498-0 – Clear COS Event Flag 3 after FUV initial turn on Part 3-1 completes @ 159/1341z
18476-0 – WFC3 Transition Heaters From Protect to Normal @ 159/1820z
COMPLETED OPS NOTES: (None)
FGS GSAcq 6 6
FGS REAcq 4 4
OBAD with Maneuver 3 3
-At 159/1819 WFC3 was successfully transition from Protect Operate to Operate.
-At 159/19:38z COS FUV HV was partially ramped to HVNom -5010/-4963V volts) on both segment A and B respectively.