STEREO Weekly Meeting Minutes for 2011-03-22 (Week 12) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 11 * On day 075 (Mar 16), during the DSS 65 support for Ahead, turbo decoder lock was lost intermittently beginning at 0739z through 0823z. This resulted in the loss of several minutes of instrument SSR data. See DR# N107209 for more information. * On day 079 (Mar 20), during the DSS 14 support for Ahead, initial telemetry lock at BOT was delayed seven minutes due to the antenna pointing model. A conscan was initiated telemetry lock occurred at 1307z. Later, a DCD anomaly occurred at 1335z which caused intermittent loss of telemetry through 1526z. The downlink receivers were switched to correct this problem. These anomalies resulted in the loss of several minutes of instrument SSR data. See DR# G111231 and G111233 for more information. * On day 074 (Mar 15), DHS release 1.1.2 was loaded to C&DH EEPROM on both spacecraft, which added IMPACT APID 0x201 to the RT telemetry for downlink rates 240, 160, 120, and 96 kbps. * On day 076 (Mar 17), PLASTIC-Ahead science SSR partition began overwriting at 1535z due to insufficient track coverage. This resulted in the loss of 2.8 hours of science data. * On day 074 (Mar 15), during the DSS 14 support for Behind, telemetry lock was lost at 0121z due to antenna brakes setting. The antenna brakes were reset and the station was back on-point at 0125z. Later in the support, the DCD failed over twice to the redundant side at 0133z and at 0155z. These anomalies resulted in the loss of several hours of instrument SSR data. See DR# G111202 & G111203 for more information. * On day 075 (Mar 16), during the DSS 55 support for Behind, turbo decoder lock was lost briefly at 2036z. This resulted in the loss of 18 frames of SECCHI SSR data. See DR# N107213 for more information. * On day 077 (Mar 18), during the DSS 45 support for Behind, telemetry lock was lost at 0822z due to antenna brakes setting during the transition from generator to commercial power. The antenna controller was reset and the station was back on-point at 0900z. SSR pointers were repositioned during the next track and all instrument SSR data was recovered. See DR# C107990 for more information. SSR pointers for SWx partitions were not moved back; thus, 38 minutes of SWx data were lost. * On day 079 (Mar 20), during the DSS 65 support for Behind, turbo decoder lock was lost briefly at 1832z. This resulted in the loss of two frames of SECCHI SSR data. See DR# N107221 for more information. * On day 076 (Mar 17), the playback of SECCHI-Behind SSR2, special event partition #20, was enabled at 1754z. Playback is still enabled. SECCHI requests that playback be disabled once the buffer is empty. This is their current plan for operations. * On day 078 (Mar 19), SECCHI-Behind SSR1 synoptic science SSR partition filled at 1959z due to moving SSR pointers on day 077. This resulted in the loss of 39 minutes of science data. * The average daily SSR downlink was 5.4 gigabits each on both Ahead and Behind. * A question was raised about the missing Ahead data due to the DCD problems on day 70 (Mar 11). Those data have been determined to be lost, as are the Behind data affected by the DCD problems on day 74 (Mar 15). Week 12 * There were several problems during the station 15 support for Ahead yesterday (Mar 21). Station 15 was returned to service only a few days ago. A DCD anomaly caused data to be lost between 13:40 and 14:29 UT. At 14:41 the transmitter was declared red, and at 15:53 the antenna was declared red. SSR pointers were repositioned. However, the SECCHI SSR1 partition filled today (Mar 22), which may have resulted in the loss of part of the calibration roll data. The SECCHI team will examine the data to see if the calibration roll needs to be rescheduled. * There was a DCD failover during the station 55 support for Behind yesterday (Mar 21) between 18:18 and 18:25 UT. This led to at least a few minutes of lost data. * Ranging lock was lost during the station 25 support for Behind starting yesterday (Mar 21). Receivers were switched, which resulted in the loss of a few minutes of data. * There was an additional SECCHI stepped calibration roll on Ahead this morning (Mar 22), starting at 9:15 UT, to assist with the recent changes in the COR1-A background. However, some of the data from the roll may be lost--see above. * Readout of the SECCHI SSR2 partition on Ahead was enabled yesterday (Mar 21). The MOC is still examining CONOPS for the SECCHI SSR2 partition, and will set up a telecon with the SECCHI team to discuss it. * Ahead has 720 kbps passes on Tuesday, Mar 22, Wednesday, Mar 23, Thursday, Mar 24, and Sunday, Mar 27, all using station 43. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Wednesday, Mar 23 (D43 and D63), Thursday, Mar 24 (D63), Friday, Mar 25 (D63), and Sunday, Mar 27 (D43). There are 14 passes during the week, and overall coverage is 2.4 hours above nominal. Week 13 * Track changes were made for the Ahead spacecraft on Monday, Mar 28, swapping two passes for other stations. There is now a 2.25 hour pass on station 14, and a 3.25 hour pass on station 34. These changes were made in support of the Kepler mission. * Ahead has 720 kbps passes on Monday, Mar 28 (D14), Thursday, Mar 31 (D43), and Sunday, Apr 3 (D14). There are 12 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Tuesday, Mar 29, using station 63. There are 14 passes during the week, and overall coverage is 4.3 hours above nominal. Week 14 * Ahead has 720 kbps passes on Monday, Apr 4 (D43), and Friday, Apr 8 (D14). There are 12 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Monday, Apr 4, using station 63. There are 13 passes during the week, and overall coverage is 8.2 hours over nominal. Week 15 * Ahead has 720 kbps passes on Monday, Apr 11 (D14), Tuesday, Apr 12 (D43), Wednesday, Apr 13 (D14), Friday, Apr 15 (D14), Saturday, Apr 16 (D14), and Sunday, Apr 17 (D14), for a total of 6 passes. There are in all 9 passes during the week, and overall coverage is nominal. * Behind has no 720 kbps passes during the week. There are 13 passes during the week, and overall coverage is 9.4 hours above nominal. Week 16 * The 31st momentum dump will be carried out on Behind on Monday, Apr 18, with ignition at 19:00 UT. * The 37th momentum dump will be carried out on Ahead on Wednesday, Apr 20, with ignition at 21:00 UT. * Ahead has 720 kbps passes on Monday, Apr 18 (D43), Tuesday, Apr 19 (D43), Wednesday, Apr 20 (D43), Thursday, Apr 21 (D14), and Friday, Apr 22 (D43). There are 11 tracks during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Thursday, Apr 21 using station D43. There are 15 tracks during the week, and overall coverage is 11 hours above nominal. * Easter is on Sunday, Apr 24. Many people at the MOC may be on leave on Friday, Apr 22. Week 17 * Ahead has 720 kbps passes on Monday, Apr 25 (D43 and D14), and Tuesday, Apr 26 (D43). There are 13 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Tuesday, Apr 26, and Wednesday, Apr 27, both using station D43. There are 15 passes during the week, and overall coverage is 3.6 hours above nominal. Week 18 * SECCHI stepped calibration rolls will be carried out on both spacecraft on Tuesday, May 3. The Ahead roll will be at 08:20 UT, and the Behind roll will be at 14:15 UT. These will be the perihelion rolls. The actual dates of perihelion are day 118 (Apr 28) for Ahead, and day 119 (Apr 29) for Behind--the rolls were shifted to May 3 due to system momentum. * There will be a return-to-service track for Behind on station 24 on Friday, May 6. Command uplink will be performed during this track. The track will be shadowed by station 15, which will be downlink only. * Ahead has 720 kbps passes on Monday, May 2, Wednesday, May 4, and Sunday, May 8, all using station D14. There are 11 tracks during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Monday, May 2, using station D43. There are 14 passes during the week, and overall coverage is 9.7 hours above nominal. Week 19 * Ahead has a 720 kbps pass on Sunday, May 15, using station D14. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, May 9, Tuesday, May 10, Wednesday, May 11, Thursday, May 12, Saturday, May 14, and Sunday, May 15, all using station D63 for a total of six 70 meter passes. There are 14 passes during the week, and overall coverage is 6.8 hours above nominal. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 21 (080) T Mar 22 (081) Ahead: SECCHI stepped calibration roll, 9:15 UT Ahead: 720 kbps downlink on station 43 W Mar 23 (082) Ahead: 720 kbps downlink on station 43 Behind: 720 kbps downlink on stations 43 and 63 T Mar 24 (083) Ahead: 720 kbps downlink on station 43 Behind: 720 kbps downlink on station 63 F Mar 25 (084) Behind: 720 kbps downlink on station 63 S Mar 26 (085) S Mar 27 (086) Ahead: 720 kbps downlink on station 43 Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 28 (087) Ahead: 720 kbps downlink on station 14 T Mar 29 (088) Behind: 720 kbps downlink on station 63 W Mar 30 (089) T Mar 31 (090) Ahead: 720 kbps downlink on station 43 F Apr 01 (091) S Apr 02 (092) S Apr 03 (093) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 04 (094) Ahead: 720 kbps downlink on station 43 Behind: 720 kbps downlink on station 43 T Apr 05 (095) W Apr 06 (096) T Apr 07 (097) F Apr 08 (098) Ahead: 720 kbps downlink on station 14 S Apr 09 (099) S Apr 10 (100) ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 11 (101) Ahead: 720 kbps downlink on station 14 T Apr 12 (102) Ahead: 720 kbps downlink on station 43 W Apr 13 (103) Ahead: 720 kbps downlink on station 14 T Apr 14 (104) F Apr 15 (105) Ahead: 720 kbps downlink on station 14 S Apr 16 (106) Ahead: 720 kbps downlink on station 14 S Apr 17 (107) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 18 (108) Ahead: 720 kbps downlink on station 43 Behind: Momentum dump, 19:00 UT T Apr 19 (109) Ahead: 720 kbps downlink on station 43 W Apr 20 (110) Ahead: Momentum dump, 21:00 UT Ahead: 720 kbps downlink on station 43 T Apr 21 (111) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 F Apr 22 (112) Ahead: 720 kbps downlink on station 43 S Apr 23 (113) S Apr 24 (114) Easter ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 25 (115) Ahead: 720 kbps downlink on stations 43 and 14 T Apr 26 (116) Ahead: 720 kbps downlink on station 43 Behind: 720 kbps downlink on station 43 W Apr 27 (117) Behind: 720 kbps downlink on station 43 T Apr 28 (118) F Apr 29 (119) S Apr 30 (120) S May 01 (121) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M May 02 (122) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 T May 03 (123) Ahead: SECCHI calibration roll, 08:20 UT Behind: SECCHI calibration roll, 14:15 UT W May 04 (124) Ahead: 720 kbps downlink on station 14 T May 05 (125) F May 06 (126) Behind: Return-to-service track on D24, shadowed by D15 S May 07 (127) S May 08 (128) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 09 (129) Behind: 720 kbps downlink on station 63 T May 10 (130) Behind: 720 kbps downlink on station 63 W May 11 (131) Behind: 720 kbps downlink on station 63 T May 12 (132) Behind: 720 kbps downlink on station 63 F May 13 (133) S May 14 (134) Behind: 720 kbps downlink on station 63 S May 15 (135) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- 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 * 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