STEREO Weekly Meeting Minutes for 2011-01-04 (Week 01) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 52 * On day 361 (Dec 27), during the DSS 54 support for Ahead, turbo decoder lock was lost briefly at 0758z. This resulted in the loss of several minutes of instrument SSR data. A DR has been requested. This appears to be different from the more usual Turbo software problem. * On day 364 (Dec 30), during the DSS 54 support for Ahead, real-time telemetry data and monitor data were lost from the Madrid complex at 0535z through 0657z due to a DCD failover. Another brief DCD anomaly occurred at 0815z. Currently, several hours of instrument SSR data are missing for which the DSN is attempting to recover. See DR# M106105 and M106107 for more information. * On day 365 (Dec 31), during the DSS 15 support for Ahead, the uplink was swept twice as the Doppler residual was higher than normal. The uplink was established at 1314z. As the science playback was already in progress, due to skipping the spacecraft telemetry playback, this resulted in loss of several minutes of instrument SSR data. See DR# G110923 for more information. * On day 002 (Jan 2), during the DSS 45 support for Ahead, turbo decoder lock was lost briefly at 1731z. This resulted in the loss of several minutes of instrument SSR data. A DR has been requested. * On day 002 (Jan 2), the SECCHI-Ahead instrument reset at 05:54:56z. The SECCHI team reconfigured the instrument to operational mode at 002-1400z. This was the 20th reset of SECCHI on the Ahead spacecraft. * On day 364 (Dec 30), during the DSS 25 support for Ahead, telemetry lock was lost at 0315z for the last five minutes of the pass when the antenna was stowed due to high winds at Goldstone. This resulted in the loss of several minutes of instrument SSR data. See DR# G110917 for more information. * On day 365 (Dec 31), during the DSS 26 support for Behind, real-time telemetry was lost from the Goldstone complex at 0258z due to a DCD failover. This resulted in the loss of an hour of instrument SSR data which cannot be located. See DR# G110922 for more information. * On day 365 (Dec 31), during the DSS 43 support for Behind, the command bind was established 46 minutes late at 0655z due to an equipment anomaly at the station. All planned commands were transmitted successfully. See DR# C107839 for more information. * The average daily SSR downlink was 4.5 gigabits for Ahead, and 5.0 gigabits for Behind. Week 1 * The STEREO Data Server at APL was rebooted yesterday (Jan 3), and was unavailable for about 1 hour. * Turbo decoder lock was momentarily lost yesterday (Jan 3) at 17:33 UT during the Behind pass on station 63. This resulted in the loss of some data. * Ahead has two 720 kbps passes on Wednesday, Jan 5 using stations 14 and 43. There are 14 passes during the week, and overall coverage is nominal * Behind has 720 kbps passes on Monday, Jan 3 (D63), Wednesday, Jan 5 (D63), Thursday, Jan 6 (D63), and Friday, Jan 7 (D63). There are 14 passes during the week. The 720 kbps pass originally scheduled for today (Jan 4) was dropped. Week 2 * The 13th HGA calibrations are scheduled for Behind on Wednesday, 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. * Ahead has 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 * The 16th SECCHI stepped calibration is scheduled for Tuesday, Jan 18, starting at 09:20 UT. This is the midpoint roll. The system momentum is expected to be about 5 N-m-s. * A momentum dump will be carried out on Ahead on Wednesday, Jan 19, with ignition at 20:00 UT. * 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 on Friday, Jan 21, using station 43. There are 12 passes during the week, and overall coverage is 3.3 hours below nominal. Almost all of the shortfall occurs on Thursday, Jan 20; however, this will be followed by a 70 meter pass. 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 extra stepped calibration roll for Behind is scheduled for Tuesday, Feb 8, starting at 12:00 UT. * 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. Other * SECCHI needs to schedule a flight software update for Behind. This update is related to their event detection module. They would like to upload the new software sometime either late this week, or early next week. This will require turning COP1 off. They would then like to activate the software sometime next week. This will involve disabling the guide telescope and re-enabling it. Coordination will also be needed with the SSC, because new beacon processing software will be needed. The same change for Ahead will be scheduled sometime later in the month. * The STEREO Science Center experienced problems with its NFS mounts over the Christmas holiday weekend. This was eventually traced to a DNS problem, and has been corrected. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 03 (003) Behind: 720 kpbs downlink on station 63 T Jan 04 (004) W Jan 05 (005) Ahead: 720 kbps downlink on both stations 14 and 43 Behind: 720 kpbs downlink on station 63 T Jan 06 (006) Behind: 720 kpbs downlink on station 63 F Jan 07 (007) Behind: 720 kpbs downlink on station 63 S Jan 08 (008) S Jan 09 (009) ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 10 (010) Ahead: 720 kbps downlink on station 43 T Jan 11 (011) 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) ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 17 (017) Behind: 720 kbps downlink on station 63 T Jan 18 (018) Behind: SECCHI stepped calibration roll, 09:20 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 station 43 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