STEREO Weekly Meeting Minutes for 2010-05-04 (Week 18) ANNOUNCEMENTS ------------- * Commercial power will be out at APL during Memorial Day weekend from Friday (May 28) to Monday (May 31). The MOC will be operating on UPS and a generator. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 17 * New DSN configuration files G161 were tested for both spacecraft on day 119 (Apr 29), during the station 45 pass for Ahead, and the station 54 pass for Behind. These have now been deployed, and will be needed for the new CDR replacement. * Ahead switched to 240 kbps rate on day 116 (Apr 26). * SECCHI-Ahead had a watchdog reset at 18:48:42 UT on day 117 (Apr 27), and was recovered by 14:00 on day 118 (Apr 28). This is the 16th reset on Ahead. * Because of the watchdog reset, the planned SECCHI-driven GT calibration offpoint planned starting 7:30 UT on Wednesday, Apr 28, did not occur on Ahead, but did occur on Behind. The offpoint will need to be replanned for Ahead, based on telemetry availability. * MOps permanent release 1.1.3 was uploaded to C&DH EEPROM and RAM on Ahead on day 118 (Apr 28). * Uplink was late at 20:05 UT during the Behind pass on day 116 (Apr 26), due to a transmitter anomaly before BOT. Uplink was re-established at 20:44. This resulted in the loss of 39 minutes of command and tracking data, and 2 hours of in-situ spaceweather SSR playback data. * PLASTIC and SWAVES partitions reached full on day 122 (May 2). This was because of a long gap between passes followed by two short tracks. There was some discussion about the need to feed back to DSN the fact that data are being lost. * The 23rd momentum dump was carried out on Behind on day 117 (Apr 27), starting at 20:30 UT. A delta-V of 0.0575 m/s was imparted. * The average daily SSR downlink was 5.1 gigabits on Ahead, and 4.2 gigabits on Behind. Week 18 * SECCHI/HI calibration offpoints are scheduled for Thursday, May 6, at 09:35 UT on Ahead, and 17:50 UT on Behind. The maximum offset is about 1.25 degrees about the spacecraft Y axis, and the activity lasts about 90 minutes. * Station 45 lost telemetry lock during the Behind pass last night (May 3) for seven minutes due to heavy rain. This resulted in some data loss. * The PLASTIC, IMPACT, and SWAVES partitions on Behind reached capacity on Monday (May 3). The partitions are expected to be close to empty after the DSN pass late this afternoon (May 4). * It has been determined that the worst-case requirement for DSN transmission power is 10 kW, instead of the 20 kW which has been used up until now. Using lower power will help keep the transmitters operating longer. This change will go into effect on Friday, May 7. * Ahead is short about 1.3 hours during the week, while Behind is short about 1.1 hours. Week 19 * 70 meter support is planned for both spacecraft on Monday, May 10, using Madrid station 63 for Ahead, and Canberra station 43 for Behind. These will be carried out at 720 kbps. * Ahead is about 2.7 hours short of track coverage during the week, while Behind is about even. Week 20 * Events on other missions are affecting the STEREO DSN schedule during the week. The Japanese JAXA mission Akatsuki (PLANET-C, previously known as Venus Climate Orbiter) is scheduled for launch on Monday, May 17, at 21:44 UT. Because of this, the Ahead pass on Thursday, May 20 will follow a 34 hour gap. * There is a 31.75 gap on Behind between Monday and Tuesday, and a 32 hour gap between Wednesday and Thursday. * Ahead will be at perihelion on May 18. The 13th SECCHI stepped calibration roll is scheduled for 00:25 on that day. The system momentum is expected to be ~2 N-m-s. * Pointers will be moved during the week to avoid losing data. * Behind in-situ partitions are expected to fill up towards the end of the week. * There is a 2.7 hour pass for Behind on station 34 on Friday, May 21. Because of the short duration, no spacecraft data will be downlinked, only science data. * There will be a 70 meter downlink on station 43 for the Ahead spacecraft on May 23. This will be carried out at 720 kbps. Because the pass duration is just 2 hours, only science data will be downlinked. * Some spacecraft data will be recovered in later passes. About 10-12 hours of spacecraft data may be lost for Ahead, and about 8 hours for Behind. Week 21 * Behind in-situ partions are expected to reach 100% full on Sunday. Overall the pass schedule for Behind is about 7.9 hours short, and Ahead is about 2.9 hours short. * APL is planning a new data product to highlight periods of of low telemetry. * Commercial power will be out at APL during Memorial Day weekend from Friday (May 28) to Monday (May 31). The MOC will be operating on UPS and a generator. Other * There was some discussion about whether the problems with the in-situ partitions filling up could be solved by changing the DFD partitions to bring down the in-situ data quicker. This would have a negative effect on SECCHI during periods of constrained telemetry, but not during periods of good coverage. APL will look into this. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 26 (116) Ahead: Switch downlink rate to 240 kbps T Apr 27 (117) Behind: Momentum dump, 20:30 UT Ahead: SECCHI watchdog reset, 18:49 UT W Apr 28 (118) Behind: SECCHI-driven GT calibration offpoint, 7:30 UT Ahead: Recovery from watchdog reset, 13:08 UT T Apr 29 (119) F Apr 30 (120) S May 01 (121) S May 02 (122) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M May 03 (123) EVE calibration sounding rocket launch, 18:12 UT T May 04 (124) EVE calibration sounding rocket launch backup, 18:12 UT W May 05 (125) T May 06 (126) SECCHI HI stray light cal. offpoint, Ahead: 09:35, Behind: 17:50 F May 07 (127) S May 08 (128) S May 09 (129) ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 10 (130) Both: 720 kbps downlink T May 11 (131) W May 12 (132) T May 13 (133) F May 14 (134) S May 15 (135) S May 16 (136) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 17 (137) T May 18 (138) Ahead: SECCHI stepped calibration roll, 00:25 UT Ahead: Perihelion, 18:57 UT Behind: 31 hour gap between passes W May 19 (139) T May 20 (140) Ahead: 34 hour gap between passes F May 21 (141) Behind: 35.5 hour gap between passes S May 22 (142) S May 23 (143) Ahead: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 24 (144) T May 25 (145) W May 26 (146) T May 27 (147) F May 28 (148) S May 29 (149) S May 30 (150) Notes: * Commercial power will off at APL during Memorial Day weekend, May 28-31. The STEREO MOC will be operating on UPS and a generator. ------------------------------------------------------------------------------- Upcoming events: 2010: ICAL-001: May 3-7 SECCHI Stepped calibration rolls Ahead: Aug 10, Nov 2 Behind: Jul 13, Oct 12 * Jun 8 SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Jul 8,15 EIT shutterless (TBC) * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * 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