STEREO Weekly Meeting Minutes for 2009-10-13 (Week 42) ANNOUNCEMENTS ------------- * A pointing anomaly occurred on Behind on Oct 8. The GT alignment is borderline along the Y axis, and a wheel speed avoidance rule took it out of the linear regime. It took about 2.5 hours to bring it back within the linear regime. There is software on board which could be enabled to pull it in faster to the linear regime, but it's never been tested in a real-world situation. Wheel speed avoidances happen twice each momentum cycle (~6 weeks). The timing of these events can only be coarsely predicted. Behind was close to perihelion at the time, which is also a contributing factor. * The weekly telecon normally scheduled for October 27th will be canceled because of the STEREO Science Working Group meeting occurring at the same time. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 41 * During the Ahead pass on day 281 (Oct 8), the station 25 transmitter went offline at 10:15 UT. It was recalibrated and brought back online at 10:55. This resulted in the loss of 40 minutes of commanding and tracking data, and about 2 minutes of SECCHI SSR data. * During the Behind pass on day 283 (Oct 10), the station 45 transmitter went offline at 9:15 UT. It was recalibrated and brought back online at 9:42. This resulted in the loss of 27 minutes of commanding and tracking data, and a few minutes of SSR data for all instruments. * ON day 284 (Oct 11), during the Behind pass on station 26, the transmitter controller rebooted at 21:30. The transmitter was brought back online, but at only 9 kW power, which was sufficient for STEREO. This resulted in the loss of 224 minutes of commanding and tracking data, and several minutes of SSR data for all instruments. * The average daily downlink was 5.3 gigabits for Ahead, and 6.8 gigabits for Behind. Week 42 * MESSENGER went into safe mode last night (Oct 12), and needed track time. This resulted in the loss of two hours of track time on station 54 for Ahead this morning (Oct 13). All instruments should expect loss of SSR data. * The 25th momentum dump for Ahead will be carried out on day 288 (Oct 15) at 17:00 UT. * There are a few slightly shorter tracks during the week. Week 43 * Five hour tracks are scheduled for Ahead on Friday and Saturday (Oct 23, 24), and for Behind on Friday. Week 44 * Behind reaches L5 on day 299 (Oct 26). This is also the third anniversary of the STEREO launch. * Daylight savings ends on day 305 (Nov 1) at 06:00 UT. * Shorter tracks are scheduled for Ahead on Friday and Saturday (Oct 30-31), and on Behind on Monday (Oct 26) and Thursday (Oct 29). Other * The SWAVES team noticed a couple of 1553 bus transaction anomalies recently on Ahead, and has asked the MOps team to look into how often they have occurred during the mission so far. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 12 (285) T Oct 13 (286) W Oct 14 (287) T Oct 15 (288) Ahead: 25th momentum dump, 17:00 UT F Oct 16 (289) S Oct 17 (290) S Oct 18 (291) Notes: * JOP 224, Solar Tomography with Minimal Solar Rotation, Sep 27-Oct 27 ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 19 (292) T Oct 20 (293) W Oct 21 (294) T Oct 22 (295) F Oct 23 (296) S Oct 24 (297) S Oct 25 (298) Notes: * JOP 224, Solar Tomography with Minimal Solar Rotation, Sep 27-Oct 27 ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Oct 26 (299) Behind: At L5 Lagrange point T Oct 27 (300) W Oct 28 (301) T Oct 29 (302) F Oct 30 (303) S Oct 31 (304) S Nov 01 (305) Daylight savings ends in U.S., 06:00 UT Notes: * JOP 224, Solar Tomography with Minimal Solar Rotation, Sep 27-Oct 27 ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Oct 12-16, Dec 14-18 SECCHI Stepped calibration rolls Ahead: Nov 24 Behind: Dec 22 * Mar 16-Sep LASCO C2pB for Tomography Reconstruction * Mar 27-... JOP 222, Origin of SEPS, Target of opportunity * Sep 27-Oct 27 JOP 224, Solar Tomography with Minimal Solar Rotation * Oct 8,15 EIT shutterless (TBC) * Oct 26 Behind at L5 Lagrange point * Nov 1-Dec 15 SUMER campaign (TBC) * Nov 30 Behind: Begin 7 hour daily DSN tracks * Dec 7 Behind: Switch downlink rate to 240 kbps 2010: SECCHI Stepped calibration rolls Ahead: Feb 23, May 18, Aug 10, Nov 2 Behind: Apr 6, Jul 13, Oct 12 * Jan 6 Both: HGA calibration * Jan 7,15 EIT shutterless (TBC) * Spring (TBD) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Apr 19 Ahead: Begin 7 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 240 kbps * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * 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 * Mar 18 Messenger - Mercury orbital insertion * Apr 11 Ahead: Switch downlink rate to 120 kbps * Jul 13 Both: HGA calibration * Aug DAWN - Vesta arrival * Sep 19 Behind: Switch downlink rate to 96 kbps * Sep 26 Ahead: Switch downlink rate to 96 kbps 2012: * Jan 11 Both: HGA calibration * May DAWN - Vesta departure * Jul 11 Both: HGA calibration * Aug Both: Switch downlink rate to 30 kbps * Nov 13 Total solar eclipse, south Pacific 2013: 2014: 2015: * Feb DAWN - Ceres arrival * Jan 10 - Apr 12 Behind: Spacecraft behind Sun * Feb 17 - Aug 2 Ahead: Spacecraft behind Sun * Jul 23 - Nov 10 Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission