STEREO Weekly Meeting Minutes for 2010-07-13 (Week 28) ANNOUNCEMENTS ------------- INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 27 * The beginning of track for Ahead was 50 minutes late on day 187 (Jul 6) due to a problem with the antenna controller. The controller was reset, and the rest of the pass was okay. Pointers were repositioned, no data were lost. * The average daily SSR downlink was 4.9 gigabits on Ahead and 4.3 gigabits on Behind. Week 28 * There will be a 70 meter track for Ahead early tomorrow (Jul 14), on station 63 in Madrid. This track will be carried out at 720 kbps. * The 12th HGA calibration will be carried out on Ahead on Thursday, day 196 (Jul 15), starting at 15:00 UT. * The 31st momentum dump will be carried out on Ahead on Friday, Jul 16, starting at 14:00 UT. * Ahead coverage is 1.4 hours above nominal during the week. Behind coverage is 4 hours below nominal, but the tracks are well spaced. The in situ instrument partitions are not expected to overwrite, but it may be close for PLASTIC. Week 29 * Ahead will have a 70 meter track on Jul 19, using station 63 in Madrid. This track is 7 hours long, and will be carried out at 720 kbps. * The 25th momentum dump on Behind will be carried out on Thursday, Jul 22, starting at 17:00 UT. * There is a 3 hour track on Behind on Wednesday, Jul 21. No spacecraft telemetry will be downloaded during this track. * Ahead coverage is 4.8 hours above nominal during the week, and Behind coverage is 8 hours above nominal. Week 30 * Ahead coverage is 4.5 hours above nominal during the week. Behind coverage is 4.8 hours below nominal, but the tracks are well spaced. Week 31 * Ahead will have a 70 meter track late on Aug 5, using station 43 in Goldstone. This track will be carried out at 720 kbps. No spacecraft telemetry will be downloaded during this 3 hour track. * The 14th SECCHI stepped calibration roll will be carried out on Behind on Aug 3, starting at 14:00 UT. * Behind will have a 70 meter track on Aug 7, using station 43 in Goldstone. This track will be carried out at 720 kbps. * Track coverage for both Ahead and Behind during the week is about even. Behind has 3 short tracks on Tuesday, Wednesday, and Thursday. Spacecraft housekeeping will not be read out during these tracks. Week 32 * The 14th SECCHI stepped calibration roll on Ahead will be carried out on Aug 10 starting at 08:10 UT. The system momentum will be about 1-2 N-m-s. * Track coverage during the week will be about 4.7 hours above nominal for Ahead, and 1.8 hours above nominal for Behind, with good spacing. Week 33 * Ahead will have a 70 meter track on Thursday, Aug 19, using station 63 in Madrid. This track will be carried out at 720 kbps. * Ahead has short tracks on Monday, Tuesday, and Thursday. No spacecraft telemetry will be downloaded during these tracks. * Overall track coverage for Ahead is 4.7 hours above nominal during the week. * Behind will have a 70 meter track on Saturday, Aug 21 using the station 43 in Canberra. This track will be carried out at 720 kbps. * Overall track coverage for Behind is 3.1 hours below nominal, but no in situ data are expected to be lost. Week 34 * Ahead will have a 70 meter track on Aug 26. This track will be carried out at 720 kbps. It was originally expected that Ahead would drop to 480 kbps on Aug 23, but the use of 720 kbps has been extended for about two months (TBC). This is due to changing the signal margin for the 70 meter dishes from 3 dB to 2 dB, as has already been done for the 36 meter dishes. A new operations schedule showing these changes is forthcoming. This new schedule will also examine the telemetry rates when the spacecraft is at the far side of the Sun. There is some possibility that the telemetry rate of 96 kbps can be maintained. If this is not the case, then the rate is expected to drop to either 80 or 60 kbps. The schedule will also look into the minimum angular distance from the Sun that can be used for communications. * Behind will have a 70 meter track on Aug 29. This track will be carried out at 720 kbps. * Overall track coverage during the week is 1.4 hours above nominal for Ahead, and 3.3 hours above nominal for Behind. Week 35 * There may be a momentum dump for Ahead during the week, but it has not been scheduled yet. * There are several short tracks for Ahead during the week. No spacecraft telemetry will be downloaded during this track. * There will be a 70 meter track for Ahead on Aug 31, and a 70 meter track for Behind on Sep 1, both using station 63 in Madrid. These tracks will be carried out at 720 kbps. Other * There is a regularly scheduled NCAS audit today of the STEREO mission operations at APL. * The STEREO Science Center made a prediction for the state of the Sun during the total solar eclipse on Jul 11, using STEREO Behind data from Jul 6 at the same heliographic longitude. This prediction appeared to work fairly well compared to LASCO observations during the eclipse. * There was a question about the Random Drift Improvement function in the STEREO IMUs, and whether this function was disabled. This question relates to similar IMUs for the LRO mission. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 12 (193) T Jul 13 (194) W Jul 14 (195) Ahead: 720 kbps downlink on station 63 T Jul 15 (196) Ahead: HGA Calibration, 15:00 UT F Jul 16 (197) Ahead: Momentum dump, 14:00 UT S Jul 17 (198) S Jul 18 (199) ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 19 (200) Ahead: 720 kbps downlink on station 63 T Jul 20 (201) W Jul 21 (202) T Jul 22 (203) Behind: Momentum dump, 17:00 UT F Jul 23 (204) S Jul 24 (205) S Jul 25 (206) ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 26 (207) T Jul 27 (208) W Jul 28 (209) T Jul 29 (210) F Jul 30 (211) S Jul 31 (212) S Aug 01 (213) ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Aug 02 (214) T Aug 03 (215) Behind: SECCHI stepped calibration roll, 14:00 UT W Aug 04 (216) T Aug 05 (217) Ahead: 720 kbps downlink on station 43 F Aug 06 (218) S Aug 07 (219) Behind: 720 kbps downlink on station 43 S Aug 08 (220) ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 09 (221) T Aug 10 (222) Ahead: SECCHI stepped calibration roll, 08:10 UT W Aug 11 (223) T Aug 12 (224) F Aug 13 (225) S Aug 14 (226) S Aug 15 (227) ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 16 (228) T Aug 17 (229) W Aug 18 (230) T Aug 19 (231) Ahead: 720 kbps downlink on station 63 F Aug 20 (232) S Aug 21 (233) Behind: 720 kbps downlink on station 43 S Aug 22 (234) ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 23 (235) T Aug 24 (236) W Aug 25 (237) T Aug 26 (238) Ahead: 720 kbps downlink on station 63 F Aug 27 (239) S Aug 28 (240) S Aug 29 (241) Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 30 (242) T Aug 31 (243) Ahead: 720 kbps downlink on station 63 W Sep 01 (244) Behind: 720 kbps downlink on station 63 T Sep 02 (245) F Sep 03 (246) S Sep 04 (247) S Sep 05 (248) Notes: * A momentum dump on Ahead may be scheduled during the week. ------------------------------------------------------------------------------- Upcoming events: 2010: SECCHI Stepped calibration rolls Ahead: Nov 2 Behind: Oct 12 * Jul/Aug (TBC) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Sep (TBC) Ahead: End use of 720 kbps on 70 m DSN subnet * Sep 6 (TBC) Behind: End use of 720 kbps on 70 m DSN subnet * 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 * Feb 6 STEREO spacecraft at 180 degree separation * Mar 18 Messenger - Mercury orbital insertion * Apr 11 Ahead: Switch downlink rate to 120 kbps * Jul DAWN - Vesta arrival * Jul 13 Both: HGA calibration * Sep 19 Behind: Switch downlink rate to 96 kbps * Sep 26 Ahead: Switch downlink rate to 96 kbps 2012: * Jan 9 (TBC) Behind: End use of 480 kbps on 70 m DSN subnet * Jan 11 Both: HGA calibration * Jun 25 (TBC) Ahead: End use of 480 kbps on 70 m DSN subnet * Jul DAWN - Vesta departure * Jul 11 Both: HGA calibration * Aug 20 Both: Switch downlink rate to 30 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * Nov 25 (TBC) Behind: End use of 360 kbps on 70 m DSN subnet * Dec 12 Ahead: Mercury transit 2014: * Apr 29 Behind: Mercury transit 2015: * Feb DAWN - Ceres arrival * Jan 10 - Apr 12 (TBC) Behind: Spacecraft behind Sun * Feb 17 - Aug 2 (TBC) Ahead: Spacecraft behind Sun * May 25 (TBC) Ahead: End use of 360 kbps on 70 m DSN subnet * Aug 10 (TBC) Ahead: Begin use of 360 kbps on 70 m DSN subnet * Jul 23 - Nov 10 (TBC) Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission 2016: 2017: 2018: * Mar 5 Ahead: Mercury transit