STEREO Weekly Meeting Minutes for 2010-12-21 (Week 51) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 50 * On day 347 (Dec 13), due to the loss of two scheduled tracks in the previous week, the in-situ instrument partitions on Ahead began overwriting at 0126z, and again at 1635z on day 348 (Dec 14), and again 0355z on day 349 (Dec 15). This resulted in the loss of two to seven hours of in-situ instrument SSR data on each of these days. A 70 meter track on Thursday, Dec 16 finally cleared out the telemetry buffers. * On day 347 (Dec 13), during the DSS 65 support for Ahead, turbo decoder lock was lost briefly at 0723z. This resulted in the loss of six frames of instrument SSR data. See DR# N106391 for more information. * On day 351 (Dec 17), during the DSS 26 support for Ahead, transmitter was red at BOT at 1215z. The transmitter was repaired and was ready for use at 1354z; however, this track remained downlink only to avoid the loss of SSR data. All instrument SSR data were recovered. This resulted in the loss of 99 minutes of commanding and two-way tracking data. See DR# G110867 for more information. * An additional SECCHI stepped calibration roll for Ahead was carried out on day 350 (Dec 16), starting at 13:20 UT. This was to take care of a change in the COR1-A background. * On day 347 (Dec 13), during the DSS 26 support for Behind, turbo decoder lock was lost briefly at 0127z. This resulted in the loss of eight frames of instrument SSR data. See DR# N106913 for more information. * On day 348 (Dec 14), during the DSS 45 support for Behind, telemetry lock was three minutes late at BOT at 0730z due to heavy rain at Canberra. Since playback had not yet begun, all instrument SSR data were recovered. See DR# C107803 for more information. * On day 351 (Dec 17), during the DSS 25 support for Behind, telemetry lock was interrupted when the transmitter tripped off-line at 0236z. This resulted in the loss of several minutes of instrument SSR data. See DR# G110866 for more information. * On day 352 (Dec 18), during the DSS 25 support for Behind, telemetry lock was interrupted when the transmitter tripped off-line at 2006z. This resulted in the loss of several minutes of instrument SSR data. See DR# G110873 for more information. * On day 353 (Dec 19), during the DSS 24 support for Behind, turbo decoder lock was intermittent beginning at 2359z and again at 0158z on day 344 (Dec 20) due to rain at Goldstone. This resulted in the loss of several minutes of instrument SSR data. * On day 349 (Dec 15), the 28th momentum dump was successfully executed on Behind at 1730z, which imparted a delta V of 0.069 m/sec. * The average daily SSR downlink was 4.9 gigabits for Ahead, and 4.8 gigabits for Behind. Week 51 * The station 25 transmitter went offline at 14:48 UT during the Ahead pass this morning (Dec 21). The link was needed to finish the weekly commanding. Several minutes of SSR data were lost during the resweep. * Christmas is on Saturday, Dec 25. Friday, Dec 24 is a holiday at APL. * Ahead has 720 kbps passes on Monday Dec 20 (D43), Wednesday, Dec 22 (D43), and Saturday, Dec 25 (D43). There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Dec 20 (D63), Tuesday, Dec 21 (D63), Thursday, Dec 23 (D14), and Saturday, Dec 25 (D43). There are 10 passes during the week, and overall coverage is 3.2 hours below nominal. * There is only a short 3.8 hour track for Behind on Wednesday, Dec 22. The in situ instruments may come close to filling the SSR buffers. The passes on either side are both 70 meter stations. Week 52 * New Year's Day is on Saturday, Jan 1. Friday, Dec 31 is a holiday at APL. * Ahead has a 720 kbps pass on Wednesday, Dec 29 using station 43. There are 14 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Friday, Dec 31, using station 43. There are 12 passes during the week, and overall coverage is 1.75 hours above nominal. Week 1 * 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), Tuesday, Jan 4 (D43), Wednesday, Jan 5 (D63), Thursday, Jan 6 (D63), and Friday, Jan 7 (D63). There are 15 passes during the week, and overall coverage is 2 hours over nominal. * There is ongoing discussion about an upcoming power upgrade at Goldstone which may affect the schedule during the week. The MOC needs to know soon about any changes, due to the upcoming holidays. 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 19th 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. Other * SECCHI requests that extra calibration rolls be scheduled for both spacecraft within a week of when the two spacecraft are 180 degrees apart, which occurs on Feb 6. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 20 (354) Ahead: 720 kbps downlink on station 43 Behind: 720 kpbs downlink on station 63 T Dec 21 (355) Behind: 720 kpbs downlink on station 63 W Dec 22 (356) Ahead: 720 kbps downlink on station 43 T Dec 23 (357) Behind: 720 kpbs downlink on station 14 F Dec 24 (358) S Dec 25 (359) Christmas Ahead: 720 kbps downlink on station 43 Behind: 720 kpbs downlink on station 43 S Dec 26 (360) Notes: * APL will be closed on Dec 24 ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 27 (361) T Dec 28 (362) W Dec 29 (363) Ahead: 720 kbps downlink on station 43 T Dec 30 (364) F Dec 31 (365) Behind: 720 kpbs downlink on station 43 S Jan 01 (001) New Years S Jan 02 (002) Notes: * APL will be closed on Dec 31 ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 03 (003) Behind: 720 kpbs downlink on station 63 T Jan 04 (004) Behind: 720 kpbs downlink on station 43 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) T Jan 18 (018) Behind: SECCHI stepped calibration roll, 09:20 W Jan 19 (019) Ahead: Momentum dump, 20:00 UT T Jan 20 (020) F Jan 21 (021) S Jan 22 (022) S Jan 23 (023) ------------------------------------------------------------------------------- Upcoming events: 2011: * Feb 6 STEREO spacecraft at 180 degree separation SECCHI requests calibration rolls on both spacecraft * 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