STEREO Weekly Meeting Minutes for 2010-06-29 (Week 26) ANNOUNCEMENTS ------------- * July 5 will be a holiday at APL. * A momentum dump on Ahead originally scheduled for Jul 19 has been rescheduled for Jul 16. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 25 * Turbo decoder lock was lost momentarily at 05:49 UT during the station 65 pass for Ahead on day 176 (Jun 25), due to heavy rain. This resulted in the loss of 1 frame of SECCHI data. * The partitions for the in situ instruments on Behind started overwriting during the week. This was not predicted. This resulted in the loss of 1.5 hours of PLASTIC data on day 174 (Jun 23) and 7.5 hours on day 175 (Jun 24). Also on day 175 (Jun 24), 1.6 hours of IMPACT data, and 6.5 hours of SWAVES data were lost. * IMPACT performed realtime commanding on day 174 (Jun 23) to correct a checksum error. However, this attempt was unsuccessful due to a small mistake in a command. IMPACT will attempt this again tomorrow (Jun 30). PLASTIC will hold off on HV activities until the checksum error is corrected. * The average daily SSR downlink was 4.8 gigabits for Ahead, and 4.7 gigabits for Behind. Week 26 * On Jul 1, the 12th HGA calibration will be carried out on Behind starting at 21:00 UT, during a 10 hour track. * Behind will have a 720 kbps pass on Jul 3 using the 70 meter station 43 at Canberra. The track duration is 7 hours. * The overall coverage for Ahead is 8.5 hours over nominal. The coverage for Behind is 1.4 hours less than nominal, but this should be made up for by the 720 kbps track. Week 27 * There are many shorter tracks on Ahead during the week, but the overall coverage is 8.3 hours above nominal. Behind is 1.4 hours below nominal, but with no major gaps. * There is a total solar eclipse on Jul 11 in the south Pacific. There are no special requirements for STEREO observations, but interruptions in observations should be avoided. Week 28 * There will be a 70 meter track for Ahead on Wednesday, day 195 (Jul 14), on station 63 in Madrid. This track will be carried out at 720 kbps. * An HGA calibration will be carried out on Ahead on day 196 (Jul 15), starting at 15:00 UT. This track is not 10 hours long, but this will be made up for by another track a couple of hours later. * The 31st momentum dump will be carried out on Ahead on Friday, Jul 16, starting at 14:00 UT. This activity was moved from Jul 19 to accommodate another mission. * Ahead coverage is 1.4 hours above nominal during the week. Behind coverage is 4 hours below nominal, but the tracks are well spaced. 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. * 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 on Aug 5, using station 43 in Goldstone. This track will be carried out at 720 kbps. * Behind will have a 70 meter track on Aug 5, 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 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. Other * The ability to use 720 kbps on 70 meter stations is expected to end for Ahead on Aug 23. MOPS is checking the accuracy of this date. * The IMPACT and PLASTIC teams looked at the periods when PLASTIC appeared to exceed their telemetry allocation. They found that the average telemetry rate did not change, but the peaks rates were higher. The limits will be adjusted to not flag this as an error. * The telemetry rate on both spacecraft will drop to 160 kbps in September. IMPACT has already made the changes needed for this telemetry rate. However, PLASTIC will require an onboard software change, and it's not clear whether this software change will be ready for September. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 28 (179) T Jun 29 (180) W Jun 30 (181) T Jul 01 (182) Behind: HGA Calibration, 21:00 UT F Jul 02 (183) S Jul 03 (184) Behind: 720 kbps on station 43 S Jul 04 (185) Notes: * SUMER campaign, June 18-29 * JOP 227, Doppler shift oscillations of AR loops, June 20-30 ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jul 05 (186) T Jul 06 (187) W Jul 07 (188) T Jul 08 (189) F Jul 09 (190) S Jul 10 (191) S Jul 11 (192) Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html Notes: * HOP 114: Coordinated Diagnostics of Prominence Cavities, to run concurrent with solar eclipse, Jul 11 ------------------------------------------------------------------------------- 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) 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) ------------------------------------------------------------------------------- Upcoming events: 2010: SECCHI Stepped calibration rolls Ahead: Aug 10, Nov 2 Behind: Jul 13, Oct 12 * Jun/Jul (TBC) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Aug 23 Ahead: End use of 720 kbps on 70 m DSN subnet * Sep 6 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 Behind: End use of 480 kbps on 70 m DSN subnet * Jan 11 Both: HGA calibration * Jun 25 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 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 Behind: Spacecraft behind Sun * Feb 17 - Aug 2 Ahead: Spacecraft behind Sun * May 25 Ahead: End use of 360 kbps on 70 m DSN subnet * Aug 10 Ahead: Begin use of 360 kbps on 70 m DSN subnet * Jul 23 - Nov 10 Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission 2016: 2017: 2018: * Mar 5 Ahead: Mercury transit