STEREO Weekly Meeting Minutes for 2011-11-29 (Week 48) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 47 (Nov 21-27) * On day 323 (Nov 19), the MSL mission launch was delayed one day with the actual launch on day 330-1502z (Nov 26). As a result, the AHEAD observatory track schedule had two changes; the DSS-55 track on day 330 (Nov 26) gained 3.9 hours at the beginning and the DSS-63 support on day 346 (Dec 12) will lose 10 minutes off the beginning. The track coverage for the BEHIND observatory was not affected. * On day 327 (Nov 23), for the DSS-55 support for Ahead, initial telemetry lock was delayed 2.1 hours due to a receiver anomaly. The low noise amplifier control processor was replaced and telemetry lock was established at 0723z. SSR pointers were repositioned to minimize science data loss. This anomaly resulted in the loss of all tracking, telemetry, and commanding for 128 minutes. All SSR data were recovered. See DR# M106536 for more information. * On day 329 (Nov 25), for the DSS-55 support for Ahead, telemetry lock was lost beginning at 0848z due to a receiver anomaly. The low noise amplifier control processor was reset and telemetry lock was re-established at 0944z. This anomaly resulted in the loss of all tracking, telemetry, and commanding for 56 minutes and approximately three hours of SSR data for each instrument. See DR# M106546 for more information. * On day 330 (Nov 26), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly beginning at 0820z. Later in the support, real-time telemetry was lost for five seconds in the MOC beginning at 1039z due to the MOC ground software rejecting transfer frames with the private annotation field = U. This anomaly resulted in the loss of 88 frames of SSR data. A DR has been requested. * On day 327 (Nov 23), the SECCHI Ahead instrument reset at 05:27:08z. The SECCHI team reconfigured the instrument to operational mode at 327-1500z. This was the 25th reset of SECCHI on the Ahead spacecraft. * On day 322 (Nov 18), the DSS-34 support for Behind was deleted due to the TDRS10 spacecraft emergency. While SSR pointers were repositioned on day 322 to minimize immediate data loss, there was not sufficient track time until day 326 to prevent SSR data loss. This anomaly caused the IMPACT and SWAVES science partitions to overwrite on days 324, 325, and 326 (Nov 20-22). Specifically, SWAVES overwrote: for 0.9 hours beginning at 324-1423z (Nov 20) for 0.7 hours beginning at 325-1459z (Nov 21) for 3.5 hours beginning at 326-0946z (Nov 22) and IMPACT overwrote: for 0.6 hours beginning at 324-1445z (Nov 20) for 2.3 hours beginning at 325-1326z (Nov 21) for 0.2 hours beginning at 325-2138z (Nov 21) for 4.7 hours beginning at 326-0833z (Nov 22). * On day 329 (Nov 25), for the DSS-34 support for Behind, telemetry lock was lost intermittently beginning at 1014z through 1029z due to heavy rain at the Canberra complex. This anomaly resulted in the intermittent loss of approximately 40 minutes of SSR data for each instrument. See DR# C108331 for more information. * On day 329 (Nov 25), for the DSS 14 support for Behind, telemetry lock was lost beginning at 2137z due to the antenna brakes being set. The antenna controller was reset and telemetry lock was reestablished at 2151z. This anomaly resulted in the loss of 45 minutes of SSR data for each instrument. See DR# G112148 for more information. * The average daily SSR playback volume was 4.4 gigabits for Ahead, and 4.8 gigabits for Behind. Week 48 (Nov 28-Dec 4) * No monitor data were received during the station 63 pass for Ahead yesterday (Nov 28). * The monitor data for Ahead arrived late today (Nov 29) during the station 63 pass. Normally, sending of monitor data is automatic. DSN will look into the monitor data subsystem on station 63. * A replay of the SECCHI stepped calibration roll on Ahead for aphelion took place this morning (Nov 29), starting at 09:00 UT. * The MOPs macro 1.1.13 changes to protect the battery state of charge during conditioning will be written to EEPROM on both spacecraft tomorrow (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. This same event will occur for Ahead in April/May 2012. * 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. * The MOC is trying to schedule more ESA tests during December. 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. * A C&DH macro change will be written to RAM on both spacecraft on Wednesday, Dec 7. This macro will collect more diagnostic data if the star tracker resets and fails to automatically recover, a situation which has been seen in the past. * 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 (Dec 5) and Thursday (Dec 8) 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). There are 13 passes during the week, and overall coverage is nominal. The station 25 pass on Dec 15 will be carried out at 240 kbps. Week 51 (Dec 19-25) * Momentum dumps are scheduled during the week. These are a bit early, but have been moved forward because of the subsequent holidays. * A momentum dump on Behind is scheduled for Monday, Dec 19, with ignition at 16:00 UT. * The 43rd momentum dump on Ahead is scheduled for Tuesday, Dec 20, with ignition at 17:00 UT. * The C&DH macro change for the star tracker will be loaded into EEPROM on both spacecraft on Tuesday, Dec 20. * December 25 is Christmas day. Monday, Dec 26, is a holiday at APL. * 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. Week 52 (Dec 26 - Jan 1) * Ahead has 70 meter passes on Thursday, Dec 29, and Sunday, Jan 1, both using station 14. There are 15 passes during the week, and overall coverage is nominal. The station 34 pass on Saturday, and the station 54 pass on Sunday, will be carried out at 240 kbps. * Behind has a 70 meter pass on Tuesday, Dec 27, at 720 kbps using station 63. There are 11 passes during the week, and overall coverage is nominal. The station 34 pass early on Sunday, Jan 1, will be carried out at 240 kbps. Week 1 (Jan 2-8) * Monday, Jan 2, is a holiday at APL. * Tracks using the ESA New Norcia station are scheduled for Jan 5 on Ahead, and Jan 8 on Behind. These will appear on the schedule as station 32. Currently, the ESA stations do not have frequency authorization for STEREO, so they are currently scheduled as downlink only. If the authorization goes through in time, then the station will be used for commanding. * Ahead has 70 meter passes on Monday, Jan 2, and Saturday, Jan 7, both using station 14. There are 14 passes during the week, and overall coverage is nominal. The station 26 pass on Thursday, and the station 45 pass on Sunday, will be carried out at 240 kbps. * Behind a 70 meter passes on Saturday, Jan 7, using station 43. There are 12 passes during the week, and overall coverage is nominal. The station 15 pass on Wednesday will be carried out at 240 kbps. Other * SECCHI asked if enhanced downlink will be used for the ESA stations if the spacecraft is at high elevation throughout the pass. Currently, the ESA passes all will be carried out at 160 kbps until the performance can be better understood. ESA measures station performance differently from NASA. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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) Behind: Momentum dump, 16:00 UT Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Dec 20 (354) Ahead: Momentum dump, 17:00 UT 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 ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 26 (360) T Dec 27 (361) Behind: 70 meter downlink on station 63 W Dec 28 (362) T Dec 29 (363) Ahead: 70 meter downlink on station 14 F Dec 30 (364) S Dec 31 (365) S Jan 01 (001) Ahead: 70 meter downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 02 (002) Ahead: 70 meter downlink on station 14 T Jan 03 (003) W Jan 04 (004) T Jan 05 (005) F Jan 06 (006) S Jan 07 (007) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 43 S Jan 08 (008) ------------------------------------------------------------------------------- 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