STEREO Weekly Meeting Minutes for 2011-01-11 (Week 02) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * The IMPACT/PLASTIC IDPU was autonomously switched off due to high current on January 8. See below for details. Otherwise, all subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 1 * On day 007 (Jan 7), during the DSS 65 support for Ahead, turbo decoder lock was lost intermittently at 0743z and 0809z due to rain at the Madrid complex. This resulted in the loss of several minutes of instrument SSR data. See DR# N106992 for more information. * On day 003 (Jan 3), during the DSS 63 support for Behind, turbo decoder lock was lost briefly at 1732z. This resulted in the loss of several minutes of instrument SSR data. See DR# N106990 for more information. * On day 006 (Jan 6), during the DSS 25 support for Behind, ranging lock was 11 minutes late at 0033z due to a software anomaly at the station. This resulted in the loss of 11 minutes of ranging data. All SSR data were recovered. See DR# G110954 * On day 008 (Jan 8) on the Behind spacecraft, IMPACT IDPU/MAG high power consumption autonomy rule 64 fired at 21:28:37z. This powered off all of IMPACT and PLASTIC instruments. After investigating all recovered data, IMPACT IDPU/MAG, SWEA/STE, and SEP/SEPT2 and PLASTIC instruments were safely powered on again by 011-1700z. Instrument reconfiguration back to the nominal operational state, including high voltage ramp-ups, is planned for the next few days. As yet no reason has been found for the current anomaly. * The average daily SSR playback volume was 4.7 gigabits for Ahead, and 5.8 gigabits for Behind. The high data return on Behind was due to having several 70 meter downlink stations during the week. Week 2 * SECCHI-Ahead had a watchdog reset at 00:15:51 UT this morning (Jan 11), and was recovered by 15:15 UT. There have been several recent watchdog resets on Ahead. The most recent reset was 9 days earlier, on Jan 9. After the reset on Nov 20, the patch intended to avoid resets was omitted. It was then reinstated after the reset on Dec 3, but omitted for the two resets after that. The patch is still in place on Behind. It's clear that the patch does not prevent the resets. * Turbo decoder lock was lost briefly at 19:26 UT today (Jan 11) during the station 65 pass for Behind. This resulted in the loss of several minutes of SSR data. * The 13th HGA calibrations are scheduled for Behind tomorrow, Jan 12, and for Ahead on Thursday, Jan 13, starting at 16:00 UT each day. These activities will last about two hours, and will involve rolls of 0.5 degrees. The track times have been extended to 7 hours, and SSR downlink will be stopped during the calibration. * New SECCHI software version 5.16 will be activated on Behind on Thursday, Jan 13. Coordination with the MOC is required because the guide telescope needs to be disabled and then re-enabled. The two-way light travel time for realtime commanding is currently 24 minutes. * Ahead had a 720 kbps pass on Monday, Jan 10, using station 43. There are 13 tracks during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Friday, Jan 14, using station 14. There are 14 tracks during the week, and overall coverage is 4.6 hours over nominal. Week 3 * A momentum dump will be carried out on Ahead on Wednesday, Jan 19, with ignition at 20:00 UT. * There was some discussion about about trying to use the SECCHI HI telescopes to observe the effects of the thruster firings during the momentum dump. This would be helpful for planning for future missions. Normally, SECCHI doesn't schedule images during thruster firings, but special observations with HI can be planned. * The SECCHI stepped calibration roll on Behind originally scheduled for Tuesday, Jan 18, has been cancelled since another roll is scheduled for February 8. * The track schedule for the week has changed. * Ahead has 720 kbps passes on Tuesday, Jan 18, and on Wednesday, Jan 19, both using station 43. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Jan 17, using station 63, and two passes on Friday, Jan 21, using stations 43 and 63. There are 11 passes during the week, and overall coverage is nominal. The previously anticipated shortfall should now be filled in. Week 4 * The 29th momentum dump will be carried out on Behind on Thursday, Jan 27, starting at 19:00 UT. * Ahead has 720 kbps passes on Monday, Jan 24 (D14), Wednesday, Jan 26 (D63), Thursday, Jan 27 (D63), and Sunday, Jan 30 (D63). There are 12 passes during the week, and overall coverage is nominal. * Behind has two 720 kbps passes on Sunday, Jan 30, on stations D43 and D14. There are 11 passes during the week, and overall coverage is nominal. Week 5 * The two STEREO spacecraft will reach 180 degrees separation on Sunday, Feb 6. For the next 8 years, when combined with SDO data, the full solar sphere will be visible. This is also a calibration opportunity for the SECCHI telescopes, because they will be looking through the same material. The period of several months around Feb 6 is useful for triangulation. * SECCHI has requested that extra calibration rolls be scheduled for both spacecraft within a week of Feb 6, to assist in their calibration activities. The roll for Ahead has been scheduled for Tuesday, Feb 1, starting at 13:15 UT. This is also the normal midpoint roll. The corresponding roll for Behind has been scheduled for Feb 8. * Ahead has a 720 kbps pass on Thursday, Feb 3, using station D43. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Friday, Feb 4, using station D63, and twice on Sunday, Feb 6, using stations D63 and D14. There are 14 passes during the week, and overall coverage is 6.9 hours over nominal. Week 6 * The stepped calibration roll for Behind is scheduled for Tuesday, Feb 8, starting at 12:00 UT. This also serves as the midpoint roll. * Ahead has a 720 kbps pass on Wednesday, Feb 9, on station D43. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Saturday, Feb 12, and Sunday, Feb 13, both using station D63. There are 12 passes during the week, and overall coverage is nominal. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 10 (010) Ahead: 720 kbps downlink on station 43 Behind: Start of recovery operations for IMPACT/PLASTIC T Jan 11 (011) Ahead: SECCHI watchdog reset, 00:16-15:15 UT W Jan 12 (012) Behind: HGA calibration, 16:00 UT T Jan 13 (013) Ahead: HGA calibration, 16:00 UT F Jan 14 (014) Behind: 720 kbps downlink on station 14 S Jan 15 (015) S Jan 16 (016) Notes: * IMPACT/PLASTIC recovery operations on Behind will continue during the week. ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 17 (017) Behind: 720 kbps downlink on station 63 T Jan 18 (018) Ahead: 720 kbps downlink on station 43 W Jan 19 (019) Ahead: Momentum dump, 20:00 UT Ahead: 720 kbps downlink on station 43 T Jan 20 (020) F Jan 21 (021) Behind: 720 kbps downlink on stations 43 and 14 S Jan 22 (022) S Jan 23 (023) ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 24 (024) Ahead: 720 kbps downlink on station 14 T Jan 25 (025) W Jan 26 (026) Ahead: 720 kbps downlink on station 63 T Jan 27 (027) Behind: Momentum dump, 19:00 UT Ahead: 720 kbps downlink on station 63 F Jan 28 (028) S Jan 29 (029) S Jan 30 (030) Ahead: 720 kbps downlink on station 63 Behind: 720 kbps downlink on stations 43 and 14 ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Jan 31 (031) T Feb 01 (032) Ahead: SECCHI stepped calibration roll, 13:15 UT W Feb 02 (033) T Feb 03 (034) Ahead: 720 kbps downlink on station 63 F Feb 04 (035) Behind: 720 kbps downlink on station 63 S Feb 05 (036) S Feb 06 (037) STEREO spacecraft at 180 degree separation Behind: 720 kbps downlink on stations 63 and 14 ------------------------------------------------------------------------------- Scheduled activities for Week 06: M Feb 07 (038) T Feb 08 (039) Behind: SECCHI stepped calibration roll, 12:00 UT W Feb 09 (040) T Feb 10 (041) F Feb 11 (042) S Feb 12 (043) S Feb 13 (044) ------------------------------------------------------------------------------- Upcoming events: 2011: * Jun 27 Ahead: Switch downlink rate to 160 kbps * Jun 27 Ahead: End use of 720 kbps on 70 m DSN subnet * Jul 15 Behind: Switch downlink rate to 160 kbps * Jul 15 Behind: End use of 720 kbps on 70 m DSN subnet * 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: * Jan 20 Behind: End use of 480 kbps on 70 m DSN subnet * Apr 21 Behind: Resume use of 480 kbps on 70 m DSN subnet * Apr 29 Behind: Mercury transit * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet 2015: * Feb DAWN - Ceres arrival * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar 17 - Jul 14 (TBC) Ahead: Spacecraft behind Sun * Jul 2 Behind: Resume use of 480 kbps on 70 m DSN subnet * Aug 25 - Oct 19 (TBC) Behind: Spacecraft behind Sun * Sep 25 Behind: End use of 480 kbps on 70 m DSN subnet * Jul DAWN - End of nominal mission 2016: * Apr 3 Behind: Resume use of 480 kbps on 70 m DSN subnet 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