STEREO Weekly Meeting Minutes for 2011-04-05 (Week 14) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 13 * On day 087 (Mar 28), during the DSS 14 support for Ahead, initial telemetry lock at BOT was delayed five minutes due to the antenna pointing model. A conscan was initiated and telemetry lock occurred at 1255z. This anomaly resulted in the loss of several minutes of SECCHI instrument SSR data. See DR# G111276 for more information. * On day 088 (Mar 29), during the DSS 55 support for Ahead, turbo decoder lock was lost intermittently beginning at 0715z through 0716z and again at 0749z through 0750z. This resulted in the loss of 19 frames of instrument SSR data. See DR# N107263 for more information. * On day 088 (Mar 29), during the DSS 26 support for Ahead, the uplink was swept twice as the Doppler residual was higher than normal. The uplink was established at 1325z. This is a known problem with receiver software version 10.1.7 and documented in AR# 116727. SSR pointers were repositioned and all SSR data were recovered. See DR# N107258 for more information. * On day 090 (Mar 31), during the DSS 25 support for Ahead, the uplink was swept twice as the Doppler residual was again higher than normal. The uplink was established at 1322z. A redundant receiver was added and telemetry lock was re-established at 1338z. SSR pointers were repositioned and all SSR data were recovered. See DR# G111293 for more information. * On day 092 (Apr 2), during the DSS 26 support for Ahead, turbo decoder lock was lost briefly beginning at 1348z. This resulted in the loss of four frames of instrument SSR data. See DR# N107265 for more information. * On day 093 (Apr 3), during the DSS 14 support for Ahead, initial telemetry lock at BOT was delayed nine minutes due to the antenna pointing model. A conscan was initiated and telemetry lock occurred at 1254z. This anomaly resulted in the loss of several minutes of SECCHI instrument SSR data. See DR# G111302 for more information. * On day 087 (Mar 28), the playback of SECCHI SSR2, special event partition #20, was disabled on Ahead at 1333z. * On day 089 (Mar 30), the playback of SECCHI SSR2, special event partition #20, was enabled on Ahead at 1322z. To optimize downlink bandwidth, after playing back the recorded data, the playback was disabled at 091-1326z. * On day 088 (Mar 29), during the DSS 15 support for Behind, turbo decoder lock was lost briefly beginning at 0359z due to a transmitter anomaly. This resulted in the loss of 19 frames of SECCHI instrument SSR data. See DR# G111279 for more information. * On day 088 (Mar 29), during the DSS 15 support for Behind, real-time tracking data stopped flowing to the FDF. On day 094, the TDS was restarted at 1808z which corrected the anomaly. Tracking data from the missed 12 supports was retransmitted to the FDF. See DR# N107268 for more information. * On day 088 (Mar 29), during the DSS 63 support, initial telemetry lock at BOT was delayed 22 minutes due to an antenna pointing problem in elevation. The anomaly was resolved and the antenna began tracking at 1702z. SSR pointers were repositioned and all SSR data were recovered. See DR# M106268 for more information. * On day 088 (Mar 29), the playback of SECCHI SSR2, special event partition #20, was enabled at 1747z. To optimize downlink bandwidth, after playing back the recorded data, the playback was disabled at 089-1441z. * The average daily SSR playback volume was 5.7 gigabits for Ahead, and 5.5 gigabits for Behind. * The question was raised whether the problem with the Doppler residual was new. The MOC reports that this happened once or twice on Ahead late last year. DSN reports that the high residuals have been seen in multiple missions, and generally take from 20 seconds to a minute to clear. Resweeping should not be necessary. This will be communicated to the station operators. Week 14 * Downloading of SECCHI SSR2 partition was re-enabled on Ahead yesterday (Apr 4) at 13:19 UT, and disabled this morning (Apr 5). * The SECCHI stepped calibration roll was carried out on Ahead this morning (Apr 5), apparently successfully. * Testing of the Space Link Extension (SLE) between the MOC and DSN is being carried out today (Apr 5). This test is for telemetry receipt--SLE is already being used for commanding. The test is causing some instrument teams to see weird packets in their realtime data, but these test packets will not show up in the telemetry products. * There was a DCD failover during the station 24 pass for Behind today. The ground support team is trying to recover the data affected by this. * Downloading of SECCHI SSR partition was enabled on Behind yesterday (Apr 4) at 17:16. * 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 and Saturday, Apr 9. There are 15 passes during the week, and overall coverage is 10.6 hours over nominal. * The SECCHI team reports larger than usual jitter on Ahead on day 89. The spacecraft was going through a zero speed crossing around that time, which may account for the jitter. * SECCHI has planned a test of disabling cosmic ray scrubbing on the HI1 telescope on Ahead today (Apr 5) between 20-24 UT. However, there was a problem with the command upload, and the test may or may not happen. SECCHI will not try to recommand, to avoid the possibility of problems. 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 14 passes during the week, and overall coverage is 14.75 hours above nominal. * The schedule for weeks 15, 16, and 17 have been adjusted to accommodate the MESSENGER mission, whose schedule has been shifted by two hours after insertion. This mostly affects the Behind spacecraft. Week 16 * The 31st momentum dump will be carried out on Behind on Wednesday, Apr 20, with ignition at 18:00 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 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 14 tracks during the week, and overall coverage is 16.1 hours above nominal. * Easter is on Sunday, Apr 24. Many people at the MOC may be on leave on Friday, Apr 22. Week 17 * The Ahead spacecraft will reach perihelion on Apr 28, and the Behind spacecraft on Apr 29. * There will be a return-to-service track on station 63 for the Behind spacecraft on Apr 29, shadowing a track on station 65. There will be no uplink during this track. * Ahead has 720 kbps passes on Monday, Apr 25 (D43 (twice) and D14), and Tuesday, Apr 26 (D43). There are 11 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 4.6 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 PIT test of ground software version 10.3 using station 25 for Behind on Thursday, May 5. There will be no uplink during this track. * There will be a return-to-service track for Behind on station 24 on Friday, May 6. There will be no uplink during this track. The track will be shadowed by station 15. * 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 * There is a return-to-service track for station 24 for Ahead on May 9. This will be shadowed by a track using station 15. There will be no uplink during this track. * 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. Week 20 * Ahead has a 720 kbps pass on Wednesday, May 18 (D63), and Sunday, May 22 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, May 16 (D63), Thursday, May 19 (D63), and Sunday, May 22 (D43), for a total of three 70 meter passes. There are 14 passes during the week, and overall coverage is 2.3 hours above nominal. Week 21 * Ahead has a 720 kbps pass on Thursday, May 26 (D43), and Sunday, May 29 (D63). There are 10 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Saturday, May 28, using station D63. There are 12 passes during the week, and overall coverage is 5.7 hours above nominal. Week 22 * In preparation for switching to the 160 kbps downlink rate in late June, early July, the DSN time will be increased to 8 hours/day on both spacecraft. * Ahead has 720 kbps passes on Monday, May 30 (D14 and D43), Thursday, Jun 2 (D14 and D43), and Friday, Jun 3 (D63). There are 13 passes during the week, and overall coverage is nominal. * Behind has 720 kbsp passes on Tuesday, May 31 (D63), Wednesday, Jun 1 (D63), Thursday, Jun 2 (D63), Friday, Jun 3 (D63), Saturday, Jun 4 (D63), and Sunday, Jun 5 (D43). There are 12 passes during the week, and overall coverage is nominal. Other: * There is a new downlink performance data product on the STEREO Data Server. This consists of plots showing the number of dropped frames and the station number. * IMPACT is looking for a .fin telemetry file for day 327 from last year. The SSC copy of this file was truncated for an unknown reason within the SSC. APL will look into recovering this file from tape backup. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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) Ahead: SECCHI stepped calibration roll, 9:00 UT Ahead: Cosmic ray scrub disabled on HI1-A for test, 20-24 UT W Apr 06 (096) T Apr 07 (097) F Apr 08 (098) Ahead: 720 kbps downlink on station 14 S Apr 09 (099) Behind: 720 kbps downlink on station 14 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) 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 Behind: Momentum dump, 18:00 UT 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 (twice) 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) Behind: Return-to-service track on D63, shadowed by D65 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) Behind: PIT test using station D25, shadowed by D15 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) Ahead: Return-to-service track on station D24 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 ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 16 (136) Behind: 720 kbps downlink on station 63 T May 17 (137) W May 18 (138) Ahead: 720 kbps downlink on station 63 T May 19 (139) Behind: 720 kbps downlink on station 63 F May 20 (140) S May 21 (141) S May 22 (142) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 23 (143) T May 24 (144) W May 25 (145) T May 26 (146) Ahead: 720 kbps downlink on station 43 F May 27 (147) S May 28 (148) Behind: 720 kbps downlink on station 63 S May 29 (149) Ahead: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 30 (150) Ahead: 720 kbps downlink on stations 14 and 43 T May 31 (151) Behind: 720 kbps downlink on station 63 W Jun 01 (152) Behind: 720 kbps downlink on station 63 T Jun 02 (153) Ahead: 720 kbps downlink on stations 14 and 43 Behind: 720 kbps downlink on station 63 F Jun 03 (154) Ahead: 720 kbps downlink on station 63 Behind: 720 kbps downlink on station 63 S Jun 04 (155) Behind: 720 kbps downlink on station 63 S Jun 05 (156) Behind: 720 kbps downlink on station 43 Notes: * Changing to 8 hours/day of downlink on both spacecraft in preparation for switching to 160 kbps downlink rate in late June, early July. ------------------------------------------------------------------------------- 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