STEREO Weekly Meeting Minutes for 2011-03-08 (Week 10) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 9 * On day 059 (Feb 28), during the DSS 26 support for Ahead, the transmitter tripped off-line at 1419z. The support continued with a downlink only since there was another pass coming up. The transition from two-way to one-way communications resulted in the loss of several minutes of instrument SSR data. See DR# G111136 for more information. * On day 060 (Mar 1), PLASTIC partition on Ahead began overwriting for 10 minutes at 0647z through 0657z due to the lost downlink from snow last week on day 057 (Feb 26) with DSS 25. * On day 061 (Mar 2), during the DSS 14 support for Ahead, initial telemetry lock was three minutes late due to an antenna pointing anomaly. Telemetry lock occurred at 1313z. This resulted in the loss of three minutes of real-time data. All SSR data were received. See DR# G111146 for more information. * On day 061 (Mar 2), during the DSS 43 support for Ahead, the turbo decoder lost lock intermittently from 2023z to 2025z. This resulted in the loss of 10 frames of SECCHI SSR data. See DR# N107197 for more information. * On day 065 (Mar 6), during the DSS 26 support for Ahead, turbo decoder lost lock briefly from 1422z. This resulted in the loss of 165 frames of instrument SSR data, equivalent to several minutes. A DR has been requested. * On day 060 (Mar 1), DHS release 1.1.2 was loaded to C&DH RAM on Ahead which added IMPACT APID 0x201 to the RT telemetry for downlink rates 240, 160, 120, and 96 kbps. This APID is already downlinked for higher rates, so with this change the IMPACT and PLASTIC teams will always get APID 201 in the realtime telemetry. This APID is for the memory dump. The same DHS release was loaded to Behind on day 061 (Mar 2). These will be written to EEPROM in two weeks. * On day 060 (Mar 1), the playback of SECCHI SSR2, special event partition #20, was enabled on Ahead at 1349z. To optimize downlink bandwidth, after playing back the recorded data, the playback was disabled at 063-1445z (Mar 2). * On day 060 (Mar 1), the star track on Ahead reset at 20:20:27z due to a CPU error. Fault protection autonomously reconfigured and promoted the star track back to AAD mode at 20:20:39z. This was the second occurrence of the star track reset on the AHEAD observatory. The previous event took several days to recover, as opposed to a few seconds this time. * On day 059 (Feb 28), during the DSS 63 support for Behind, turbo decoder lost lock briefly from 2024z. This resulted in the loss of four frames of instrument SSR data. See DR# N107194 for more information. * On day 061 (Mar 2), during the DSS 65 support for Behind, turbo decoder lost lock briefly from 1954z and again at 2015z. This resulted in the loss of three frames SSR data. See DR# N107193 for more information. * On day 063 (Mar 4), at the start of the DSS 65 support for Behind, telemetry lock was intermittent beginning at 1315z for the first 31 minutes of the track due to heavy snow. After the downlink signal stabilized, the SSR pointers were repositioned and all SSR data were received. See DR# M106206 for more information. * On day 065 (Mar 6), during the DSS 55 support for Behind, turbo decoder lost lock briefly from 1722z. This resulted in the loss of two frames of instrument SSR data. See DR# N107197 for more information. * On day 059 (Feb 28), the playback of SECCHI SSR2, special event partition #20, was enabled on Behind at 1745z. To optimize downlink bandwidth, after playing back the recorded data, the playback was disabled at 060-1936z (Mar 1). * The average daily SSR downlink volume was 5.1 gigabits for Ahead, and 5.0 gigabits for Behind. * SECCHI asked whether the disabling of playback of SSR2 happened during the track or after the track. It is done during the track, via realtime command. The MOC is changing their playback macro to force the write pointer to be the lead pointer on playback to avoid problems where the read pointer sometimes becomes the lead pointer. Week 10 * The 36th momentum dump on Ahead was completed successfully this morning (Mar 8), with ignition occuring at 16:00 UT. * Playback of the SECCHI SSR2 partition was enabled for Ahead this morning (Mar 8), and for Behind last night (Mar 7). * The 30th momentum dump on Behind will be carried out on Thursday, Mar 10, with ignition at 19:45 UT. * A return-to-service track on Ahead will be performed using station 15 on Friday, Mar 11, shadowing a track on station 26. Current plans are to perform the uplink and downlink on station 15, using station 26 as the shadow track. * Daily savings time in U.S. starts Sunday, Mar 13. * Ahead had a 720 kbps pass last night (Mar 7). There are 12 tracks during the week, and overall coverage is 4 hours above nominal. * Behind has 720 kbps passes on Monday, Mar 7 (D43), Wednesday, Mar 9 (D14), Friday, Mar 11 (D14), and Sunday, Mar 13 (D14). There are 14 passes during the week, and overall coverage is nominal. Week 11 * The data handling system release will be written to EEPROM on Thursday, Mar 17, on both spacecraft. * Ahead has 720 kbps passes on Monday, Mar 14, Thursday, Mar 17 (D43), Friday, Mar 18 (D43), Saturday, Mar 19 (D14), and Sunday, Mar 20 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Mar 14 (D14), Friday, Mar 18 (D63), and Sunday, Mar 20 (D14). There are 12 passes during the week, and overall coverage is 1.6 hours above nominal. * Messenger will begin orbital insertion around Mercury on Thursday night, Mar 17, starting at 8:45 P.M. EDT. Week 12 * Ahead will have an additional SECCHI stepped calibration roll on Mar 22, starting at 9:15 UT, to assist with the recent change in the COR1-A background. The system momentum will be around 6 N-m-s. * 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 3.1 hours above nominal. Week 13 * Ahead has 720 kbps passes on Monday, Mar 28 (D43), 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 5.3 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 6.6 hours above nominal. Other * It was pointed out that when both STEREO spacecraft are on the far side of the Sun, it will then be possible to swap 70 meter support between Ahead and Behind, since both will be up at the same time. * SWAVES points out a hiccup in the sequencing of the Behind telemetry products. No version 3 was produced for day 59 (Feb 28), and the day 55 (Feb 24) telemetry file was late. No final (.fin) version was produced for day 29 (Jan 29). The MOC reports that this was due to a network error which interrupted processing on Feb 28. * IMPACT also asked why there were two .fin telemetry files for Jan 3-5 on Ahead. This was because the MOC was trying to recover data that was originally lost because of problems with the new DCD system. A new DCD software version was installed last week which may solve some of the recent problems. * IMPACT also asked about differences in file permissions which was causing problems with their ingest script. The SSC currently preserves the file permissions from the STEREO Data Server at APL. Some files produced via special processing may have different permissions because they were produced using personal accounts. * There was a particularly fast CME yesterday with a speed of 2300 km/s. There were two CMEs observed yesterday--the fast CME was the second of the two. The first CME was associated with an M2 flare, and set off the CME trigger on SECCHI Ahead. The data from the SSR2 buffer was cleared out, and writing to the buffer was re-enabled before the second (fast) CME, which was associated with an M4 flare. The second CME triggered the SECCHI CME flag on both spacecraft. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 07 (066) Ahead: 720 kbsp downlink on station 43 Behind: 720 kbps downlink on station 43 T Mar 08 (067) Ahead: Momentum dump, 16:00 UT W Mar 09 (068) Behind: 720 kbps downlink on station 14 T Mar 10 (069) Behind: Momentum dump, 19:45 UT F Mar 11 (070) Ahead: Return-to-service track on station 15, shadowed by 26 Behind: 720 kbps downlink on station 14 S Mar 12 (071) S Mar 13 (072) Start of daylight savings time in US Behind: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 14 (073) Ahead: 720 kbps downlink (TBC) T Mar 15 (074) W Mar 16 (075) T Mar 17 (076) Ahead: 720 kbps downlink on station 43 F Mar 18 (077) Ahead: 720 kbps downlink on station 43 Messenger - Mercury orbital insertion S Mar 19 (078) Ahead: 720 kbps downlink on station 14 S Mar 20 (079) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- 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 43 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 ------------------------------------------------------------------------------- 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