STEREO Weekly Meeting Minutes for 2009-08-11 (Week 33) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 32 * The start of the station 14 track on Ahead on day 216 (Aug 4) was 4 minutes late due to the antenna brakes being set. The controller was reset, and the pass continued without problem. This was the pass used to reset the spacecraft. * During the same pass, voice communication lines were down between the ROC and the station. The contingency black phone was used instead. * On day 220 (Aug 8) during the station 55 pass on Ahead, the antenna brakes were set at 11:06. The antenna was back online 33 minutes later. This resulted in the loss of several hours of SSR data for all instruments. * The primary activity for this week was the flight software activation on Ahead on day 216 (Aug 4). IMPACT and PLASTIC high voltages were ramped down during the station 55 track. The instruments were turned off at 09:50 UT at the start of the main station 14 pass. The command to reset the spacecraft was sent at 10:10 UT. The spacecraft was then recovered to nominal operations within 4 hours. All instruments were back on by 15:18. By the end of the track, SECCHI and SWAVES were back to nominal operations. * PLASTIC and IMPACT/SWEA were recovered to nominal operations by the end of the station 14 track on day 217 (Aug 5). * IMPACT/SEP was back to nominal operations by 13:15 UT on day 218 (Aug 6). * The 60 hour software command loss timer on Ahead was disabled during the station 55 pass on day 220 (Aug 8) due to an anticipated 57 hour gap caused by station 24 going red. Some data was recovered with a two hour track on station 25. This track was performed with a 360 kbps downlink. Station 24 is expected to be back up tonight (Aug 11) for a Behind pass. * On day 215 (Aug 3), during the station 24 pass on Behind, tracking analysis seemed to show a thrusting event at 23:04 UT. However, further analysis showed that this was a database glitch, and use of the correct database shows no such apparent event. An email will be sent to Dan Ossing for distribution explaining what happened. * A power glitch caused the station 24 antenna to stop tracking during the Behind pass on day 219 (Aug 7). When the antenna was returned to tracking, the receiver could not lock up. The station was declared red. This resulted in the loss of several hours of data on days 218 and 219 (Aug 6-7) for all instruments. * Another Behind track on day 219 (Aug 7) was switched to station 15 due to station 24 being red. * The SECCHI instrument on Behind had a watchdog reset at 21:33:41 UT on day 218 (Aug 6). It was reconfigured back to normal operation by 02:00 the next day. This is the 8th SECCHI reset on Behind. * The 7th HI 180 degree roll was carried out on Behind on day 217 (Aug 5). * The average daily SSR downlink was 5.6 gigabits on Ahead and 6.0 gigabits on Behind. Week 33 * Pointers were moved several times during the station 15 pass on Ahead this morning to mitigate the effect of the loss of the station 24 pass. All partitions were full at the start of the pass, and some data are expected to be lost. * SECCHI activated a new flight software module on Ahead this morning (Aug 11) to improve their HI-2 space weather beacon data. The results should be available this afternoon. The same activation will be made on Behind on Aug 13 around 00:30 UT. * The 60 hour timer was reenabled on Ahead. * The 8th HI 180 degree roll is scheduled for Thursday, Aug 13, starting at 01:50 UT. * The test track for the 360 kbps rate on Ahead has been moved to Thursday, Aug 13. Ahead will be switching to 360 kbps next week, and Behind on Sep 8. Track durations of 6 hours started on Monday (Aug 10). * A DSN engineering test track was carried out last night (Aug 10) on station 25 in parallel with a regular track. Simultaneous uplinks from both stations interfered with the downlink, and several hours of data were lost. Week 34 * Ahead will transition to 360 kbps starting on Monday, Aug 17. * Behind will have a short track of 4.4 hours on Thursday, Aug 20. Week 35 * The 24th momentum dump will be carried out on Ahead on Wednesday, Aug 26 at 14:00 UT. * The 8th HI 180 degree roll will be carried out on Behind on Wednesday, Aug 26 at 13:50 UT. Other * A question was asked about what happens to the uplink rate when the downlink rate is adjusted. The uplink rate stays constant at 2 kbps throughout the mission. * IMPACT raised a question about automatically moving pointers during a pass to minimize data losses when the gap between passes is longer than normal. * LRO will be performing orbital maneuvers later this month, which may put constraints on the DSN schedule. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 10 (222) Both: Begin 6 hour daily DSN tracks T Aug 11 (223) W Aug 12 (224) T Aug 13 (225) Ahead: SECCHI HI 180 degree roll, 01:50 UT Ahead: Test of 360 kbps downlink rate F Aug 14 (226) S Aug 15 (227) S Aug 16 (228) ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 17 (229) Ahead: Switch downlink rate to 360 kbps T Aug 18 (230) W Aug 19 (231) T Aug 20 (232) F Aug 21 (233) S Aug 22 (234) S Aug 23 (235) ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 24 (236) T Aug 25 (237) W Aug 26 (238) Ahead: Momentum dump, 14:00 UT Behind: SECCHI HI 180 degree roll, 13:50 UT T Aug 27 (239) F Aug 28 (240) S Aug 29 (241) S Aug 30 (242) ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Jun 15-19, Jul 13-17, Aug 17-21, Sep 14-18, Oct 12-16, Dec 14-18 SECCHI Stepped calibration rolls Ahead: Sep 2, Nov 24 Behind: Sep 22, Dec 22 * Mar 16-Sep LASCO C2pB for Tomography Reconstruction * Mar 27-... JOP 222, Origin of SEPS, Target of opportunity * Aug/Sep TBD ICAL14, Herschel sounding rocket launch http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf * Sep 8 Behind: Switch downlink rate to 360 kbps * Sep 10 Ahead at L4 Lagrange point * Sep 27-Oct 27 JOP 224, Solar Tomography with Minimal Solar Rotation * Sep 29 Messenger - Mercury fly-by * Oct 8,15 EIT shutterless (TBC) * Oct 21 Behind: SECCHI HI 180 degree roll * Oct 26 Behind at L5 Lagrange point * Nov 1-Dec 15 SUMER campaign (TBC) * Nov 30 Behind: Begin 7 hour daily DSN tracks * Dec 7 Behind: Switch downlink rate to 240 kbps 2010: SECCHI Stepped calibration rolls Ahead: Feb 23, May 18, Aug 10, Nov 2 Behind: Apr 6, Jul 13, Oct 12 * Jan 6 Both: HGA calibration * Jan 7,15 EIT shutterless (TBC) * Spring (TBD) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Apr 19 Ahead: Begin 7 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 240 kbps * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * Sep 7 Both: Begin 8 hour daily DSN tracks * Sep 13 Both: Switch downlink rate to 160 kbps * Nov 15 Behind: Switch downlink rate to 120 kbps 2011: * Jan 12 Both: HGA calibration * Mar 18 Messenger - Mercury orbital insertion * Apr 11 Ahead: Switch downlink rate to 120 kbps * Jul 13 Both: HGA calibration * Aug DAWN - Vesta arrival * Sep 19 Behind: Switch downlink rate to 96 kbps * Sep 26 Ahead: Switch downlink rate to 96 kbps 2012: * Jan 11 Both: HGA calibration * May DAWN - Vesta departure * Jul 11 Both: HGA calibration * Aug Both: Switch downlink rate to 30 kbps 2013: 2014: 2015: * Feb DAWN - Ceres arrival * Jan 10 - Apr 12 Behind: Spacecraft behind Sun * Feb 17 - Aug 2 Ahead: Spacecraft behind Sun * Jul 23 - Nov 10 Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission