< STEREO Weekly Meeting Minutes for 2011-11-22 (Week 47) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 46 (Nov 14-20) * On day 318 (Nov 14), in the MOC, the level zero telemetry files and associated data products for Ahead contained no data due to a filled disk on a RAID array archive server. As there was sufficient disk space on other RAID array disks, space was freed and data products were regenerated for days 318 and 319. This anomaly resulted in a one day delay in delivery the Ahead data products. * On day 320 (Nov 16), during the DSS 25 support for Ahead, turbo decoder lock was lost briefly beginning at 1402z. This anomaly resulted in the loss of one frame of SSR data. A DR has been requested. * On day 322 (Nov 18), during the DSS 63 support for Ahead, turbo decoder lock was lost briefly beginning at 0955z. This anomaly resulted in the loss of one frame of SSR data. A DR has been requested. * On day 323 (Nov 19), during the DSS 63 support for Ahead, turbo decoder lock was lost briefly beginning at 0923z. This anomaly resulted in the loss of one frame of SSR data. A DR has been requested. * On day 319 (Nov 15), the 42nd momentum dump on Ahead was successfully executed at 1630Z, which imparted a delta V of 0.0893 m/sec. * On day 321 (Nov 17), the SECCHI Ahead instrument reset at 19:02:03z. The SECCHI team reconfigured the instrument to operational mode at 322-1200z. This was the 24th reset of SECCHI on the Ahead spacecraft. * On day 318 (Nov 14), for the DSS 55 support for Behind, telemetry lock was lost intermittently beginning at 1503z through 1515z and again at 1744z through 1800z due to heavy rain at the Madrid complex. SSR pointers were repositioned twice. This anomaly caused the IMPACT and SWAVES science partitions to overwrite on days 319 and 320. Specifically, IMPACT overwrote for 0.9 hours beginning at 319-1822z and for 1.7 hours beginning at 320-1735z. SWAVES overwrote for 3.7 hours beginning at 319-1534z and for 5.5 hours beginning at 320-1347z. See DR# M106529 for more information. * On day 319 (Nov 15), during the DSS 14 support for Behind, turbo decoder lock was lost briefly at 1952z. This anomaly resulted in the loss of one frame of SSR data. See DR# N107747 for more information. * On day 320 (Nov 16), the BEHIND MOC successfully supported a PIT test with the DSN to test the new Downlink Signal Generator equipment at DSS 15. * On day 322 (Nov 18), the DSS 34 support for Behind was deleted due to the TDRS10 spacecraft emergency. SSR pointers were repositioned to prevent immediate data loss. This anomaly caused the IMPACT and SWAVES science partitions to overwrite on day 324. Specifically, IMPACT overwrote for 0.6 hours beginning at 324-1445z. SWAVES overwrote for 0.9 hours beginning at 324-1423z. * On day 324 (Nov 20), during the DSS 25 support for Behind, turbo decoder lock was lost briefly at 2139z. This anomaly resulted in the loss of one frame of SSR data. See DR# N107755 for more information. * On day 320 (Nov 16), the 36th momentum dump on Behind was successfully executed at 2200Z, which imparted a delta V of 0.0686 m/sec. * The average daily SSR playback volume was 4.6 gigabits for Ahead, and 3.7 gigabits for Behind. * There was some discussion about the fact that IMPACT and SWAVES saw data losses during the week, while PLASTIC and SECCHI did not. PLASTIC has reduced their telemetry rate to the point where they had sufficient SSR capacity to ride out the telemetry shortage. The same is also true for SECCHI; in addition, they reduced their telemetry rate after the loss of the pass to avoid overfilling their buffer. * The IMPACT STE-D door on Behind was reading as not completely open after the momentum dump on Nov 16. The command was sent to open the door the next day, which resolved the problem. The IMPACT team will look at the science data to see if the door really was open or closed. This is the same anomaly that occurred last April. The housekeeping rate was bumped up to take a better look if this problem repeated. The currents will be examined. Week 47 (Nov 21-27) * The launch window for the MSL (Curiosity) mission has been delayed one day to Saturday, starting at 15:02 UT due to a battery anomaly. Contingency schedules have been implemented, and the updated weekly schedules have been released. The Ahead spacecraft actually gains 3.5 hours of telemetry on Saturday (Nov 26), and losses 10 minutes on day 346 (Dec 12). The Sunday schedule is unchanged. The Behind schedule is unaffected. * Thanksgiving is on Thursday, Nov 24. The following Friday is also a holiday at APL. * Ahead has a 70 meter pass tomorrow (Nov 23) using station 14. There are 12 passes during the week, and overall coverage is nominal. The station 15 pass on Tuesday, Nov 22, and the station 26 pass on Saturday, Nov 26, will be carried out at 240 kbps. * Behind has 70 meter passes on Tuesday, Nov 22 (D63 and D14), Wednesday, Nov 23 (D14 at 720 kbps), Thursday, Nov 24 (D14), and Friday, Nov 25 (D14 at 720 kbps). There are 13 passes during the week, and overall coverage is nominal. Week 48 (Nov 28-Dec 4) * A replay of the SECCHI stepped calibration roll on Ahead for aphelion is scheduled for Tuesday, Nov 29, starting at 09:00 UT. System momentum is expected to be 5 N-m-s. This will be the 19th SECCHI stepped calibration roll on Ahead. * The MOPs macro 1.1.13 changes to protect the battery during conditioning will be written to EEPROM on both spacecraft on Wednesday, Nov 30. * Friday, Dec 2, marks the end of the use of the 34 meters with the low gain antenna (LGA) for emergencies. Use of the LGA with 70 meter stations will continue through the rest of the mission, though this use will be restricted to higher elevations later in the mission. * Ahead has 70 meter passes on Monday, Nov 28 (D63), Tuesday, Nov 29 (D63 and D14), and Wednesday, Nov 30 (D14). There are 12 passes during the week, and overall coverage is nominal. The station 54 and 15 passes on Friday, Dec 2, and the station 55 pass on Saturday, Dec 3, will be carried out at 240 kbps. * Behind has 70 meter passes on Monday, Nov 28 (D63), Wednesday, Nov 30 (D14), Thursday, Dec 1 (D63), Friday, Dec 2 (D63), and Sunday, Dec 4 (D63). There are 13 passes during the week, and overall coverage is nominal. The station 15 pass on Thursday, Dec 1, will be carried out at 240 kbps. Week 49 (Dec 5-11) * A second data flow test with the ESA reference station is scheduled for Tuesday, Dec 6, 15-17 UT. Old data will be flowing during this time. * A battery discharge cycle on Behind is scheduled for Dec 8, 14:00-14:18 UT. The entire operation will take just over an hour. The battery will be discharged to around 85% full, which is enough to redistribute the electrolytes. Some missions, such as Hubble, have more deeply discharged their batteries down to around 15% to reduce the pressure, but this is not needed for STEREO. The battery pressure on Ahead is back to where it started before its recent reconditioning. * Ahead has 70 meter passes on Tuesday, Dec 6 (D63), Wednesday, Dec 7 (D14), Thursday, Dec 8 (D14), Saturday, Dec 10 (D14, D43 at 720 kbps), and Sunday, Dec 11 (D14). There are 11 passes during the week, and overall coverage is nominal. The station 26 passes on Monday and Thursday will be carried out at 240 kbps. * Behind has 70 meter passes on Monday, Dec 5 (D63), Wednesday, Dec 7 (D14), Thursday, Dec 8 (D63), and Saturday, Dec 10 (D14). There are 13 passes during the week, and overall coverage is nominal. Week 50 (Dec 12-18) * Ahead has 70 meter passes on Monday, Dec 12 (D63 at 720 kbps), Wednesday, Dec 14 (D14 at 720 kbps), Thursday, Dec 15 (D14), Saturday, Dec 17 (D63), and Sunday, Dec 18 (D14, D43 at 720 kbps). There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Dec 12 (D63), Friday, Dec 16 (D43), and Sunday, Dec 18 (D63). The station 25 pass on Dec 15 will be carried out at 240 kbps. Week 51 (Dec 19-25) * December 25 is Christmas day. * Ahead has 70 meter passes every day during the week. The station 14 pass on Wednesday, Dec 21 will be carried out at 720 kbps. There are 9 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Dec 19 (D63), Tuesday, Dec 20 (D63), Wednesday, Dec 21 (D63), Friday, Dec 23 (D43 at 720 kbps), Saturday, Dec 24 (D14 at 720 kbps), and Sunday, Dec 25 (D63). There are 11 passes during the week, and overall coverage is nominal. The station 15 pass on Dec 21 will be carried out at 240 kbps. Other * The MOC is trying to schedule more ESA tests. The original concept was to look for opportunities for shadow tracks with DSN stations, but none were found. The current strategy is to look for open time followed by 70 meter tracks. * The MOC is looking to schedule some ESA time in January to fill in DSN shortfalls. The negotiation process still needs to be worked out. * The authorization for ESA stations expires in June. More contentions are expected next fall, and the authorization needs to be renewed. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 21 (325) T Nov 22 (326) Behind: 70 meter downlink on stations 63 and 14 W Nov 23 (327) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 14 T Nov 24 (328) Thanksgiving Behind: 70 meter downlink on station 14 F Nov 25 (329) Behind: 70 meter downlink on station 14 S Nov 26 (330) S Nov 27 (331) Notes: * Both Thursday and Friday, Nov 24-25, are holidays at APL. ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 28 (332) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Nov 29 (333) Ahead: SECCHI stepped calibration roll, 09:00 UT Ahead: 70 meter downlink on stations 63 and 14 W Nov 30 (334) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 14 T Dec 01 (335) Behind: 70 meter downlink on station 63 F Dec 02 (336) Behind: 70 meter downlink on station 63 S Dec 03 (337) S Dec 04 (338) Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Dec 05 (339) Behind: 70 meter downlink on station 63 T Dec 06 (340) Ahead: 70 meter downlink on station 63 W Dec 07 (341) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 14 T Dec 08 (342) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 F Dec 09 (343) S Dec 10 (344) Ahead: 70 meter downlink on stations 14 and 43 Behind: 70 meter downlink on station 14 S Dec 11 (345) Ahead: 70 meter downlink on station 14 Notes: * Ahead test with ESA reference station Dec 6, 15-17 UT, using simulated data ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 12 (346) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Dec 13 (347) W Dec 14 (348) Ahead: 70 meter downlink on station 14 T Dec 15 (349) Ahead: 70 meter downlink on station 14 F Dec 16 (350) Behind: 70 meter downlink on station 43 S Dec 17 (351) Ahead: 70 meter downlink on station 63 S Dec 18 (352) Ahead: 70 meter downlink on stations 14 and 43 Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 19 (353) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Dec 20 (354) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 W Dec 21 (355) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 T Dec 22 (356) Ahead: 70 meter downlink on station 14 F Dec 23 (357) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 43 S Dec 24 (358) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 14 S Dec 25 (359) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Upcoming events: 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