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Дата изменения: Sat Apr 19 00:48:38 1997 Дата индексирования: Thu Feb 27 23:56:10 2014 Кодировка: Поисковые слова: m 43 |
SMOV STATUS & PLANNING MEETING - 11 APR. 97 NOTE: The next meeting is April 14, 8:30 AM. STATUS REPORTS 1. Observatory Status - All systems nominal. The spacecraft entered "zero-gyro" safemode at 099/1717z (9Apr97, 1:17 pm EDT), about 85 minutes after the apparent failure of gyro 4. Recovery to Software Sunpoint was accomplished at 2306z. Currently the Spacecraft is operating under a Health & Safety SMS in 3-gyro low-mode configuration, H format telemetry, and HGA enabled. The Aperture Door was re-opened around noon yesterday and an ARU/PRT was done last night. SSR diagnostics were run and all remaining science data recovered from the recorder. Gyro cals are being done this morning. Yesterday, VEST simulations were able to reproduce the failure scenario given the same input conditions. The PASS recovery load was also verified as was the 3-gryo control law, currently in use. The H&S load runs to noon today at which time the SMS (SMS101), which has already been uplinked, resumes science/SMOV operations. The current SI status: FOC Safe WFPC2 Standby COSTAR Hold NICMOS SAA Operate STIS Hold, TEC on @ -83 degC The SMOV activities lost to the safemode are: 7150 NICMOS Coarse Alignment Part 2 (aka temporary Focus Monitor) 7063 STIS CCD Contamination Monitor 7092 STIS CCD Dark Rate & Read Noise 7120 NICMOS ERO - IRC+10216 7128 NICMOS ERO - Cone Nebula 7130 STIS ERO - GL229B 7049 NICMOS Absolute Photometry The first three are repetitive by design and are therefore re- scheduled by default. The EROs and the photometric test will be intentionally rescheduled in the SMS118. 2. WFPC2 Status - Proceeding nominally with Cycle 6 science and remaining SMOV monitors. 3. NICMOS Status - Engineering Status - The cold well (ice) temperature is 59.9 degK, and appears stable. The VCS Cold Mask temperature is 98.0 degK., with a warming rate approaching zero deg./day. The detector temperatures were not given, but the rate of change appears close to zero. The cryogen is venting at a rate of ~ 160 grams/day, with an estimate of approximately 95.5% of the cryogen remaining. The pressure is 47.3 Torr and increasing at a steady rate of +0.2 Torr/day. In general the indications are that the instrument is reaching thermal equilibrium. The NICMOS Dewar heaters suffered an SAA-induced thermal set point corruption at 5:15 EDT this morning. The dewar heaters were commanded back off, per STOCC procedure, fairly quickly, thought the exact time was not known at this meeting. The SMS101 (noon today and subsequent SMSs) is edited by the STScI to produce a dewar heater set point refresh after every SAA passage. Therefore the STOCC need not take any action to reset the set point, unless the corruption occurs outside of the SAA. Under the current plans, the SMS125 will initiate FSW management of the heater set point refresh/reset. - Science Status - ERO data reduction is going fairly well. The Absolute Photometry Test (7049) is very important for the absolute confirmation of the HST's low thermal background. Rodger Thompson said that such confirmation may indicate a need to revise the Exposure Time Calcu- lator which currently may be leading proposers to specify exposure times that result in saturation. During the 7034 FOM test, carried out early Monday, the FOM appears to have executed properly. The resulting data will be sufficient to verify the operational algorithm and will generally indicate how well the FOM works. However it appears that the exposure times were designed too short to provide good PSF information at various FOM positions, a result that, in any case, was not a primary purpose of the activity. It was noted that the FOM is not used much at all in the rest of SMOV, but will be used heavily with the onset of NICMOS science. It was also noted that the 11 milliarcsecond FOM positioning requirement could be relaxed because the FOM is no longer expected to be used for target acqui- sitions. 4. STIS Status - Engineering Status - Nominal. - Science Status - Nothing new to report. Planned corrective actions for the FSW/SOIF problem are for the STScI to add an appropriate offset to each of the SOIF locations, starting with the SMS111. Then the SOIF files will be corrected in a later PDB release in conjuction with a planned mid-May DF224 FSW 9.8 delivery. 5. FGS status - No new activities. 6. FOC/COSTAR status- The FOC SMOV program is complete. The SMOV TTRB has enabled the resumption of FOC science. PLANNING REPORTS 1. Status of Upcoming SMSs - SMS101 - The Science/SMOV intercept SMS. Has been built uplinked. - SMS104 and subsequent SMSs remain unchanged. 2. Replans STIS - MAMA HV Turn-on (7105) is currently planned for SMS111 and SMS118. Downstream MAMA scheduling is being assessed. NICMOS - No significant replans have yet been identified. OPERATIONS STATUS 1. OPUS - Nominal. "Re-use Target Offsets" are planned next week for a NICMOS activity and a STIS ERO. 2. Archive - Nominal.