UVCS MISSION LOG ---------------- Date: 08 July 2003 ----- Last revision: 09 July 2003 (Wu) -------------- File Name: 2003.07.08.a.log ----------- Compiled by: R. Wu ------------ UVCS Activity: UVCS in Modified Hard Safe Configuration -------------- UVCS in Modified Hard Safe Configuration at New Nominal Spacecraft Roll SOHO Activity: Received in email from SOC on Tue, 8 July 2003 -------------- @ 07:20:51UT: SOHO went into Emergency Sun Reacquisition (ESR) mode at about 04:10 UT on 8 July 2003 - the cause is yet unknown. Low rate telemetry was acquired at 04:22; A spacecraft emergency was declared to assure sufficient DSN resources (D65 and D66 was brought up to cover a gap in the already scheduled 34 meter contact periods). ESR recovery began shortly after 0500 UT. Further details will follow when available. Naturally, the situatoin has an impact on today's scheduled Station Keeping/Momentum Management/Roll maneuver. CDS, LASCO, and UVCS were already safed in preparation for the maneuver, and had been taken off the ESR flag warning list. Received in email from SOC on Tue, 8 July 2003 @ 15:13:25 UT: We were in CRP mode by 11:18 UT. The spacecraft emergency was lifted shortly thereafter. We have already done the Nominal Roll Attitude Recovery part of the standard ESR recovery scenario, starting at about +60 degrees away from nominal roll attitude. However, we naturally went to the planned, 180 degrees off-nominal roll position straight away. A momentum management will be needed to take us through to the next keyhole. It is possible that the momentum management and a station keeping will be performed today - there is also a chance that it will be postponed until later. Received in email from SOC on Tue, 8 July 2003 @ 20:53:27 UT: Offpoint flags were enabled to MDI, LASCO, UVCS at 20:49 UT. Received in email from SOC on Tue, 8 July 2003 @ 20:57:27 UT: ESR flag was enabled to UVCS and SWAN at 20:55 UT. Received in email from SOC on Tue, 8 July 2003 @ 20:59:36 UT: The Station Keeping was done at 17:40-17:58 UT. The Momentum Management was done at 19-19:58 UT. Some instrument recovery was done today and the teams that would normally have recovered tomorrow and Thursday from maneuvers will do so as planned. The pass is just ending so no additional activities should take place today. We have a pass tonight from 00:40-02:45 UT. We have a student ECS operator who will be here for the pass. If you need anything, call the SOC office and she can help or she can call me at home. Additional Notes: Cause now thought to be the same as ESR-14, which was a false dectection in the Fine Sun Pointing Detector (FSPAD). Roll to new nominal position occurred during time period between 13:24 - 13:42 UT. EOF Staff: M. Uzzo: Lead Scientist ---------- Y.-K. Ko R. Wu Command file: No Commanding Activity: --------- 1) UVCS in Modified Hard Safe Configuration Sequence: None SCI_SPEC: Following completion of Coronal Jets Study for 24 June 2003, UVCS is placed into a modified Hard Safe configuration in preparation for the SOHO HGA Blackout Period. Detector High Voltage is then ramped down and turned off, OVI Slit is closed from 150 microns to 100 microns, instrument is rolled to the nominal East (35156 Engineering Units), and Mirror / Occulter is moved to 1.5 Solar Radii with 1.5 mm overocculting. UVCS Aperture Door is also closed 708 steps, Internal Mirror / Occulter Heater set to 100% duty cycle. Internal Spectrometer Heater is not turned on. In addition to "traditional" Hard Safe configuration, UVCS Detector Power is turned off. FOT Monitoring UVCS using ESR Limit Table, TSU Substitution Heater (Circuit #84) and set duty cycle to 60%. Expected Limit Violation sheets submitted to FOT via SOC for any expected limit violations during this time. FOT told to ignore USDR = MOVING condition, but to notify UVCS representative should this condition change for more than two minutes. Experiment Offpoint, and ESR Flags are disabled. OBS_PROG: SCI_OBJ: OBJ: CMP_NAME: CMP_NUM: Duration: start: 2003.06.25.18:44 end: 2003.07.08.13:42 ONUMs = 20026 Instrument configuration: - Pointing: Sun center - Spacecraft Roll: 0 Degrees - Roll: 90 Degrees (35156) - Mirror/Occulter: 1.5 Ro 1.5 mm overocculting - LYA Slit: 50 um - OVI Slit: 100 um - LYA GRTPOS: 128000 - OVI GRTPOS: 192000 - LYA HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - OVI HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - VLD HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - LYA DETECTOR POWERED OFF - OVI DETECTOR POWERED OFF - VLD DETECTOR POWERED OFF - LYA mask: LYA_93_1sec in slot 2 - OVI mask: OVI_Syn_192 in slot 2 Fits Files: 2) UVCS in Modified Hard Safe Configuration at New Nominal Roll Sequence: None SCI_SPEC: Following completion of Coronal Jets Study for 24 June 2003, UVCS is placed into a modified Hard Safe configuration in preparation for the SOHO HGA Blackout Period. Detector High Voltage is then ramped down and turned off, OVI Slit is closed from 150 microns to 100 microns, instrument is rolled to the nominal East (35156 Engineering Units), and Mirror / Occulter is moved to 1.5 Solar Radii with 1.5 mm overocculting. UVCS Aperture Door is also closed 708 steps, Internal Mirror / Occulter Heater set to 100% duty cycle. Internal Spectrometer Heater is not turned on. In addition to "traditional" Hard Safe configuration, UVCS Detector Power is turned off. FOT Monitoring UVCS using ESR Limit Table, TSU Substitution Heater (Circuit #84) and set duty cycle to 60%. Expected Limit Violation sheets submitted to FOT via SOC for any expected limit violations during this time. FOT told to ignore USDR = MOVING condition, but to notify UVCS representative should this condition change for more than two minutes. Experiment Offpoint, and ESR Flags are disabled (until below). Offpoint flags were re-enabled to MDI, LASCO, UVCS at 20:49 UT, 08 July 2003. ESR flag was re-enabled to UVCS and SWAN at 20:55 UT, 08 July 2003. OBS_PROG: SCI_OBJ: OBJ: CMP_NAME: CMP_NUM: Duration: start: 2003.07.08.13:42 end: 2003.07. ONUMs = 20026 Instrument configuration: - Pointing: Sun center - Spacecraft Roll: 180 Degrees - Roll: 270 Degrees (35156) - Mirror/Occulter: 1.5 Ro 1.5 mm overocculting - LYA Slit: 50 um - OVI Slit: 100 um - LYA GRTPOS: 128000 - OVI GRTPOS: 192000 - LYA HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - OVI HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - VLD HIGH VOLTAGE RAMPED DOWN DOWN AND POWERED OFF - LYA DETECTOR POWERED OFF - OVI DETECTOR POWERED OFF - VLD DETECTOR POWERED OFF - LYA mask: LYA_93_1sec in slot 2 - OVI mask: OVI_Syn_192 in slot 2 Fits Files: