STEREO Weekly Meeting Minutes for 2010-08-31 (Week 35) ANNOUNCEMENTS ------------- * The network at APL will be upgraded on Saturday, Sep 11, from 11:30-15:00 UT. The duration for this work has been extended. The MOC will be unreachable via email or pagers during this time, but cell phones will still work. Spacecraft operations will be unaffected. Instrument connectivity for telemetry receipt and commanding should be unaffected. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 34 * Station 15 was declared red before the Behind pass on day 236 (Aug 24). The pass was switched to station 26, but the pass duration was only 2.1 hours instead of 7. This resulted in the loss of several hours of SECCHI data. * Turbo decoder lock was lost momentarily at 19:39 UT during the station 55 pass on Behind on day 240 (Aug 28). This resulted in the loss of 40 frames of instrument data. * The average daily SSR downlink was 5.0 gigabits for Ahead, and 5.0 gigabits for Behind. * SECCHI-Behind commands intended for day 238 (Aug 26) did not get transmitted to the spacecraft. This was caused by an automation problem due to the track change. The instrument command queues did not get opened up. These SECCHI commands were a response to the lost track. Because the commands didn't get up, the SECCHI SSR buffer hit 100%. In all, several hours of SECCHI data were lost each day for three days. Week 35 * The 32nd momentum dump for Ahead was just completed this morning (Aug 31), starting at 13:30 UT. A delta-V of 0.082 m/s was imparted. * There will be a 70 meter track for Ahead on day 246 (Sep 3), and a 70 meter track for Behind on day 244 (Sep 1), both using station 63 in Madrid. These tracks will be carried out at 720 kbps. No spacecraft telemetry will be read out during the Ahead track on day 246 (Sep 3). * There will be a shadow track for Ahead on Sep 4 using station 15, overlapping coverage from station 26. This will be downlink only, and will test the upcoming CDR replacement. * There will be a track change for Behind for Thursday (Sep 2) to support ring occultation measurements by Cassini. The track start time will change by either 15 minutes or 2.6 hours, depending on the negotiations. The exact details of the change will be known later today (Aug 31). The in situ instruments should not see any effects, but SECCHI may be impacted. Week 36 * Monday is the Labor Day holiday. * A Project Interface Test (PIT) has been scheduled for Ahead on Wednesday, day 251 (Sep 8) to test a new interface, replacing the current CDR. A second PIT test is scheduled on Friday, day 253 (Sep 10). The first test will be using the old software, while the second test will be using the new hardware and software. Both tracks are relatively short, at 3 and 2.5 hours respectively. No SSR data will be downloaded during these tests, and no POC commanding will be performed. No in situ data should be lost because of these tests. Because there is a lot of coverage during the week, SECCHI data volume shouldn't be affected. * There are a number of 70 meter stations scheduled during the week. These tracks will be carried out at 720 kbps. 70 meter tracks for Ahead occur on days 249 (Sep 6), 252 (Sep 9) and 255 (Sep 12), all using station 63 in Madrid. Behind has 70 meter tracks on day 250 (Sep 7) using station 43 in Canberra, and on day 253 (Sep 10) using station 63 in Madrid. * Overall coverage during the week for Ahead is even, and 1.2 hours above nominal for Behind. * The network at APL will be upgraded on Saturday, Sep 11, from 11:30-15:00 UT. See announcement above for details. * The 26th momentum dump on Behind will be carried out on day 250 (Sep 7), starting at 22:30 UT, during an 8 hour pass. Week 37 * Ahead has 720 kbps passes using station 63 on Monday, day 256 (Sep 13), Wednesday, day 258 (Sep 15), and Saturday, day 261 (Sep 18). * Behind has a 720 kbps pass on day 256 (Sep 13) using station 63. No spacecraft telemetry will be downlinked during this pass. * Overall coverage for the week is 1 hour over nominal for Ahead, and 4.8 hours over nominal for Behind. Week 38 * There will be a return-to-service track for station 65 on Ahead on Sep 22. This will overlap with the Madrid pass on station 55. The MOC will be able to see the telemetry during the pass, but will otherwise not use the pass. * Ahead will have 720 kbps passes using station 63 on Tuesday, day 264 (Sep 21), Thursday, day 266 (Sep 23), and Friday, day 267 (Sep 24). There will be another 720 kbps on day 267 (Sep 24) using station 43. Overall, there are 14 tracks for Ahead during the week. * Behind will have a 720 kbps pass on Wednesday, day 265 (Sep 22) using station 63 in Madrid. * Overall coverage is 3.75 hours over nominal for Ahead, and 2 hours over nominal for Behind. Week 39 * Sep 30 marks the end of the first extended mission. * Ahead has 70 meter tracks on Monday, Sep 27, Wednesday, Sep 29, Friday, Oct 1, and Saturday, Oct 2, all using station 63 in Madrid. Overall, there are 14 tracks for Ahead during the week. * There was a slight track change for Behind on Monday, Sep 27. The track on station 15 was switched to station 24. * There is no 70 meter track for Behind during the week. * Overall coverage is 4.5 hours over nominal for Ahead, and 3.4 hours over nominal for Behind. Other * SECCHI pointed out that no level-0 telemetry files were created on Aug 29, and as a consequence the versions are delayed by one day. They expect this situation to be back to normal in a day or two. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 30 (242) T Aug 31 (243) Ahead: 720 kbps downlink on station 63 Ahead: Momentum dump, 13:30 UT W Sep 01 (244) Behind: 720 kbps downlink on station 63 T Sep 02 (245) F Sep 03 (246) Ahead: 720 kbps downlink on station 63 S Sep 04 (247) Ahead: Shadow track on station 15 for testing S Sep 05 (248) ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 06 (249) Ahead: 720 kbps downlink on station 63 T Sep 07 (250) Behind: 720 kbps downlink on station 43 Behind: Momentum dump, 22:30 UT W Sep 08 (251) Ahead: PIT test T Sep 09 (252) Ahead: 720 kbps downlink on station 63 F Sep 10 (253) Behind: 720 kbps downlink on station 63 Ahead: PIT test S Sep 11 (254) S Sep 12 (255) Ahead: 720 kbps downlink on station 63 Notes: * Network maintenance at APL, Sep 11, 11:30-15:00 UT ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 13 (256) Ahead: 720 kbps downlink on station 63 Behind: 720 kbps downlink on station 63 T Sep 14 (257) W Sep 15 (258) Ahead: 720 kbps downlink on station 63 T Sep 16 (259) F Sep 17 (260) S Sep 18 (261) Ahead: 720 kbps downlink on station 63 S Sep 19 (262) ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 20 (263) T Sep 21 (264) Ahead: 720 kbps downlink on station 63 W Sep 22 (265) Ahead: Return-to-service track on station 65 Behind: 720 kbps downlink on station 63 T Sep 23 (266) Ahead: 720 kbsp downlink on station 63 F Sep 24 (267) Ahead: 720 kbps downlink on station 63, and on station 43 S Sep 25 (268) S Sep 26 (269) ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 27 (270) Ahead: 720 kbps downlink on station 63 T Sep 28 (271) W Sep 29 (272) Ahead: 720 kbps downlink on station 63 T Sep 30 (273) End of extended mission #1 F Oct 01 (274) Ahead: 720 kbps downlink on station 63 S Oct 02 (275) Ahead: 720 kbps downlink on station 63 S Oct 03 (276) ------------------------------------------------------------------------------- Upcoming events: 2010: SECCHI Stepped calibration rolls Ahead: Nov 2 Behind: Oct 12 2011: * Spring/Summer Ahead: End use of 720 kbps on 70 m DSN subnet * Spring/Summer Behind: End use of 720 kbps on 70 m DSN subnet * Jan 12 Both: HGA calibration * Feb 6 STEREO spacecraft at 180 degree separation * Jun 27 Ahead: Switch downlink rate to 160 kbps * Jul 15 Behind: Switch downlink rate to 160 kbps * Mar 18 Messenger - Mercury orbital insertion * Jul DAWN - Vesta arrival * Jul 13 Both: HGA calibration 2012: * Jan 11 Both: HGA calibration * Jul DAWN - Vesta departure * Jul 11 Both: HGA calibration * Nov 4 Behind: Switch downlink rate to 120 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * May 3 Ahead: Switch downlink rate to 120 kbps * Dec 12 Ahead: Mercury transit 2014: * Apr 29 Behind: Mercury transit 2015: * Feb DAWN - Ceres arrival * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar 17 - Jul 14 (TBC) Ahead: Spacecraft behind Sun * Aug 25 - Oct 19 (TBC) Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission 2016: 2017: * Jul 11 Ahead: Switch downlink rate to 160 kbps * Jul 22 Behind: Switch downlink rate to 160 kbps 2018: * Mar 5 Ahead: Mercury transit