STEREO Weekly Meeting Minutes for 2009-09-15 (Week 38) ANNOUNCEMENTS ------------- * This weekend the SSC may be unavailable for less than 1 hour (ideally) starting around 5 pm on Friday, while machines are transitioned from using soho-archive. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 37 * There was a DSN test track using station 47 on Ahead concurrently with the station 45 track on day 249. The station 47 track was downlink only. * Behind transitioned to 360 kbps on day 249 and Ahead transitioned on day 251. * There was a four hour return-to-service for Behind using station 54 on day 251. * On day 252 (Ahead), during the DSS 26 support, the antenna stopped tracking at 1657z for 31 minutes due to a power glitch. This resulted in the loss of less than an hour of tracking data. SSR pointers were repositioned and all SSR data was recovered. See DR# G109680 for more information. * On day 252 (Behind), during the DSS 45 support, telemetry lock at BOT, 0610z, was 11 minutes due to a failed DCC3 receiver assembly. All SSR data was recovered. See DR# C107084 for more information. * On day 253 (Ahead), during the DSS 25 support, concurrent with the fault isolation for the Ahead G&C attitude anomaly (see next bullet), the received signal on DCC7 was found to be 4 dBm lower than the backup DCC5 at 1845z. The station switched to DCC5. See DR# G109684 for more information. * On day 253 (Ahead), during the DSS 25 support, the received signal strength started to decrease at 1630z and telemetry lock was lost at 1715z due to a G&C attitude anomaly. Uplink and downlink communications were re-established at 1845z. The SSR playback was disabled and the newly added G&C algorithm to use Guide Telescope data to update the quaternion was disabled. RF communications were lost again briefly from 1942z to 1944z. After the downlink signal stabilized, the SSR playback was restarted. G&C performance has been nominal since this anomaly. This resulted in the loss of several hours of SSR data for each instrument. G&C is investigating the cause of the anomaly. * On day 253 (Behind), autonomy rule version 2.3.11 was loaded to C&DH RAM & EEPROM. This version removed the response to the G&C software bug, for the loss of GT rate usage, for which the recently loaded G&C FSW 3.2.6 corrected. * On day 253 (Ahead), the 10th SECCHI stepped calibration, at the aphelion/perihelion midpoint, was executed successfully. * On day 255, the Ahead S/C reached the L4 libration point. * On day 255 (Behind), during the DSS 55 support, telemetry lock was lost at 1405z for 9 minutes due to heavy rain at the station. This resulted in the loss of less than an hour of SSR data for each instrument. See DR# M105479 for more information. * On day 256 (Ahead), during the DSS 55 support, telemetry lock was lost at 1229z for 13 minutes due to heavy rain at the station. This resulted in the loss of less than an hour of SSR data for each instrument. See DR# M105480 for more information. * The average daily SSR downlink was 5.0 gigabits for Ahead, and 6.8 gigabits for Behind. Week 38 * The 18th momentum dump on Behind is scheduled for day 259 (Sep 16), with ignition at 17:00 UT. * There are a number of DSN contentions during the week which will lead to shortened tracks, primarily due to the LCROSS mission. On Sep 15, the Ahead pass will be 4.5 hours, and the Behind pass will be 3.7 hours. Short Behind passes will also occur on Thursday (Sep 10) for 2 hours, Friday (Sep 11) for 3.3 hours, and Saturday (Sep 12) for 3.7 hours. * The Herschel sounding rocket is scheduled for launch on Monday, Sept 14. Week 39 * G&C software load 3.2.6 will be written to copy 1 on Behind on day 265 (Sep 22). This is the same version currently in use in copy 2. * JOP 224, "Solar Tomography with Minimal Solar Rotation", starts on Sep 27, and runs through Oct 27. * More short passes will occur for Ahead on Wednesday (Sep 23) for 4.3 hours, Thursday (Sep 24) for 5.1 hours, and Friday (Sep 25) for 5 hours. Short passes for Behind occur on Tuesday (Sep 22) for 4.7 hours, Wednesday (Sep 23) for 5.3 hours, Thursday (Sep 24) for 5.9 hours, Friday (Sep 25) for 3.7 and 5 hours, and Saturday (Sep 26) for 5.3 hours. Week 40 * G&C software load 3.2.6 will be written to copy 1 on Ahead on day 272 (Sep 29). * Messenger flies by Mercury on day 272 (Sep 29). * Several shortened passes are scheduled on both Ahead and Behind during the week. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 07 (250) Labor day T Sep 08 (251) Behind: Switch downlink rate to 360 kbps W Sep 09 (252) T Sep 10 (253) Ahead: SECCHI stepped calibration roll, 12:45 UT F Sep 11 (254) S Sep 12 (255) Ahead at L4 Lagrange point S Sep 13 (256) ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 14 (257) ICAL14, Herschel sounding rocket launch, 17:40 UT http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf T Sep 15 (258) W Sep 16 (259) Behind: Momentum dump, 17:00 UT T Sep 17 (260) F Sep 18 (261) S Sep 19 (262) S Sep 20 (263) ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 21 (264) Behind: apehelion T Sep 22 (265) W Sep 23 (266) T Sep 24 (267) F Sep 25 (268) S Sep 26 (269) S Sep 27 (270) Start of JOP 224 Notes: * JOP 224, Solar Tomography with Minimal Solar Rotation, Sep 27-Oct 27 ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Sep 28 (271) T Sep 29 (272) Messenger - Mercury fly-by W Sep 30 (273) T Oct 01 (274) F Oct 02 (275) S Oct 03 (276) S Oct 04 (277) Notes: * JOP 224, Solar Tomography with Minimal Solar Rotation, Sep 27-Oct 27 ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Sep 14-18, Oct 12-16, Dec 14-18 SECCHI Stepped calibration rolls Ahead: Sep 2, Nov 24 Behind: Sep 22, 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 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