STEREO Weekly Meeting Minutes for 2011-01-25 (Week 04) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 3 * On day 017 (Jan 17), during the DSS 54 support for Ahead, turbo decoder lock was lost briefly at 0807z. This resulted in the loss of several minutes of instrument SSR data. See DR# N107023 for more information. * On day 021 (Jan 21), during the DSS 26 support for Ahead, the DCD failed over to the redundant side at 1507z. All SSR data was recovered, and should show up shortly. * On day 019 (Jan 19), the 35th momentum dump for Ahead was successfully executed at 2000Z, which imparted a delta V of 0.0931 m/sec. * On day 020 (Jan 20), SECCHI activated FSW IP version 5.16 on Ahead. * On day 020 (Jan 20), during the DSS 65 support for Behind, the DCD failed over to the redundant side at 1825z. All SSR data should be recovered, although a small amount of data loss is still being investigated. * On day 023 (Jan 23), during the DSS 54 support for Behind, turbo decoder lock was lost briefly at 1649z. This resulted in the loss of four frames of instrument SSR data. * The average daily SSR playback volume was 4.7 gigabits for Ahead, and 5.1 gigabits for Behind. Week 4 * Turbo decoder lock was lost briefly yesterday (Jan 24) during the Behind pass on station 65. This was due to a DCD software error, and was fixed by switching to a redundant receiver. * 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 12 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. System momentum will be about 7 N-m-s. This is also the normal midpoint roll. The corresponding roll for Behind has been scheduled for Feb 8. * Due to work on the station 26 transmitter, the passes using that station, for Ahead on Thursday, Feb 3 and Behind on Friday, Feb 4, will be downlink only. * 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 16th SECCHI 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. Week 7 * Ahead has no 720 kbps passes. There are 14 passes during the week with 1.7 hours over baseline coverage. * Behind has a 720 kbps pass using D14 starting Friday Feb 18. There are 12 passes during the week, and overall coverage is nominal. Week 8 * Ahead has 720 passes on Monday (Feb 21) and Thursday (Feb 24) on D43. There are 13 passes during the week, and overall coverage is nominal. * Behind has a 720 pass on Sunday (Feb 27) on D43. There are 15 tracks during the week (some very short), and there are 5.7 hours over baseline coverage. Week 9 * Ahead has 720 kbps passes on Tuesday, Mar 1 (D63), Wednesday, Mar 2 (D14 and D43), Thursday, Mar 3 (D63), Friday, Mar 4 (D43), and Sunday, Mar 6 (D14), for a total of six 70 meter passes. There are 13 passes, and overall coverage is nominal. * Behind has two 720 kbps passes (both D63) on Monday and Tuesday. There are 16 passes, and 4.8 hours over baseline. Week 10 * Daily savings time in U.S. starts Sunday, Mar 13. * The 36th momentum dump on Ahead will be carried out on Tuesday, Mar 8, with ignition at 16:00 UT. * The 30th momentum dump on Behind will be carried out on Thursday, Mar 10, with ignition at 19:45 UT. * A return-to-service track on Ahead will be performed using station 15 on Friday, Mar 11, shadowing a track on station 26. * Ahead has 720 kbps passes on Monday, Mar 7 (D43), Wednesday, Mar 9 (D14), and Friday, Mar 11 (D63). There are 11 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Mar 7 (D43), Wednesday, Mar 9 (D14), Friday, Mar 11 (D14), and Sunday, Mar 13 (D14). There are 14 passes during the week, and overall coverage is nominal. Other * There was some discussion about the effects of momentum dumps on the instruments. SWAVES sees effects which last for seconds. Effects are also seen on the MAG and SWEA instruments, and which linger longer. The effects are delayed a few seconds. An initial look at some data taken during the last momentum dump on Ahead shows nothing in HI data. However, the thrusters used are on the other side of the spacecraft. The HI measurements will be repeated on Behind. IMPACT will examine a future momentum dump by triggering the burst mode. * APID 201 will be added to the realtime IMPACT telemetry to help in debugging software issues. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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 Behind: Downlink only pass on station 26 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) Ahead: 720 kbps downlink on station 43 T Feb 10 (041) F Feb 11 (042) S Feb 12 (043) Behind: 720 kbps downlink on station 63 S Feb 13 (044) Behind: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 07: M Feb 14 (045) T Feb 15 (046) W Feb 16 (047) T Feb 17 (048) F Feb 18 (049) Behind: 720 kbps downlink on station 14 S Feb 19 (050) S Feb 20 (051) ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 21 (052) Ahead: 720 kbps downlink on station 43 T Feb 22 (053) W Feb 23 (054) T Feb 24 (055) Ahead: 720 kbps downlink on station 43 F Feb 25 (056) S Feb 26 (057) S Feb 27 (058) Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 28 (059) Behind: 720 kbps downlink on station 63 T Mar 01 (060) Ahead: 720 kbps downlink on station 63 Behind: 720 kbps downlink on station 63 W Mar 02 (061) Ahead: 720 kbps downlink on station 14 and 43 T Mar 03 (062) Ahead: 720 kbps downlink on station 63 F Mar 04 (063) Ahead: 720 kbps downlink on station 43 S Mar 05 (064) S Mar 06 (065) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 07 (066) Ahead: 720 kbsp downlink on station 43 Behind: 720 kbps downlink on station 43 T Mar 08 (067) Ahead: Momentum dump, 16:00 UT W Mar 09 (068) Ahead: 720 kbsp downlink on station 14 Behind: 720 kbps downlink on station 14 T Mar 10 (069) Behind: Momentum dump, 19:45 UT F Mar 11 (070) Ahead: Return-to-service track on station 15 Ahead: 720 kbsp downlink on station 63 Behind: 720 kbps downlink on station 14 S Mar 12 (071) S Mar 13 (072) Start of daily savings time in US Behind: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- 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 * Jul 25 Behind: Close approach by comet Elenin * 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