STEREO Weekly Meeting Minutes for 2010-07-06 (Week 27) ANNOUNCEMENTS ------------- * 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. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 26 * The PLASTIC SSR partition on Ahead started overwriting on day 180 (Jun 29) due to insufficient track coverage. This gap was unanticipated, and was due to the spacing of the tracks. A total of 2.25 hours of PLASTIC data was lost. * Command uplink was late during the station 26 pass for Ahead on day 181 (Jun 30) due to an overload condition on the motor. Station 25 was brought online, and uplink was established for 1.5 hours starting at 13:15 UT. This resulted in the loss of 194 minutes of commanding and tracking data, and several minutes of SSR data. * Turbo decoder lock was lost briefly during the station 24 pass on Behind on day 180 (Jun 29) at 20:24 UT and again at 21:09 UT. This resulted in the loss of 13 frames of SSR data. * Telemetry lock was lost for 3 minutes starting at 21:46 UT during the station 25 pass on Behind on day 182 (Jul 1) due to a misconfiguration. This was right after the HGA calibration, and before the SSR playback was started, so no data were lost. * The checksum error on the IMPACT/PLASTIC IDPU on Behind was successfully cleared on day 181 (Jun 30). * The 12th HGA calibration was successfully carried out on Behind on day 182 (Jul 1). * The average daily SSR playback was 5.4 gigabits for Ahead, and 5.0 gigabits for Behind. Week 27 * The beginning of track for Ahead was 50 minutes late this morning (Jul 6) due to a problem with the antenna controller. Pointers were repositioned, no data were lost. There is another track later this evening. * 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. * PLASTIC would like to perform realtime commanding on Ahead for about 1-1.5 hours. There is a suitable track tomorrow. Command loads should be done around 10 o'clock, and the track continues until around 2:30 in the afternoon. 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. * 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 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 track. * 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 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. Soon after this, the STEREO data rate on 70 meter stations will drop down to 480 kbps, on Aug 23 on Ahead, and Sep 6 on Behind. * Ahead has short tracks on Monday, Tuesday, and Thursday. No spacecraft telemetry will be downloaded during these tracks. * Overall track coverage for Ahead is 2.1 hours above nominal during the week. * Behind will have a 70 meter track on Saturday, Aug 21. 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 480 kbps. * 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. Other * The nominal track duration will change to 8 hours for both spacecraft on Tuesday, Sep 7. * Both spacecraft will switch to 160 kbps on Sep 13. * There was some discussion about the PLASTIC preparations for the switch to 160 kbps. A statement of work has been sent to Joe Gurman listing the changes which the team intends to make. The onboard software will be changed to lengthen integration times, and to switch off APIDs 31A and 31B. If necessary, the change to remove APIDs 31A and 31B will be made first, to be ready in time for the September change in telemetry rates. The contractor is lined up and ready to go with the changes. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------- 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) Ahead: End use of 720 kbps on 70 m DSN subnet T Aug 24 (236) W Aug 25 (237) T Aug 26 (238) Ahead: 480 kbps downlink on station 63 F Aug 27 (239) S Aug 28 (240) S Aug 29 (241) Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- 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 * 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