STEREO Weekly Meeting Minutes for 2015-12-15 (Week 51) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna with a one degree offset. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 50 (Dec 7-13) * On day 341 (Dec 7), during the ESA DSS-83 (Cebreros) support for Ahead, real-time receipt of telemetry occurred 1.7 hours late at 1339z due to a station configuration issue. SSR pointers were repositioned to minimize data loss. Due to insufficient time, the planned PLASTIC real-time commanding was moved to the day 342 (Dec 8). This anomaly resulted in the loss of 1.7 hours real-time telemetry, commanding, and tracking data. * On day 342 (Dec 8), the ESA DSS-84 (Malargue) support for Ahead, telemetry was lost in the MOC at 1953z due to a network issue at ESA. The station continued to track nominally and SSR data continued to be was received and recorded. After the issue was corrected, JPL re-established the telemetry link and telemetry was received again at 2217z. SSR data from this outage was retrieved from ESA the next day. This anomaly resulted in the loss of 2.4 hours of real-time telemetry data. * On day 342, during the ESA DSS-84 support for Ahead, DHS release 1.1.11 and MOps Macro release 1.1.28 were loaded to C&DH EEPROM at 1939z. These releases contained changes to reconfigure the SSR for resuming nominal daily science operations that were loaded to RAM on day 320. * On day 342, during the ESA DSS-84 support for Ahead, PLASTIC real-time commanding was conducted to switch geometric factors to improve science data return. * On day 344 (Dec 10), during the DSS-43 support for Ahead, turbo decoder lock was lost briefly at 2252z. This anomaly resulted in the loss of five frames of real-time data. * On day 345 (Dec 11), an additional 70m support for Ahead with DSS-14 was added for the next day to start at 346-2220z for a duration of 1.5 hours to minimize the track shortage. * The Ahead observatory operated nominally during this week resuming operations on the HGA main lobe riding along a one degree offset to prevent overheating of the HGA feed assembly which was at 119 degrees C with the HGA angle at 7.1 degrees, with respect to the spacecraft-Sun line. * Processing status of the in-situ instrument space weather data from Ahead recorded during the 15 months of side lobe operations: The MOC completed processing of the 15 months of in-situ instrument space weather data with the associated data products available on the MOC STEREO Data Server and GSFC SSC websites on day 330, November 26th. However, a final level zero file (.fin version) for each day for each instrument is being created. * The average daily science data return for Ahead, with the HGA on the main lobe riding along a one degree offset, was 4.1 Gbits during this week. * On day 344 (Dec 10), during the DSS-26 34m support for Behind using 80 kW transmitter, 185 commands were sent for battery state of charge recovery. * On day 345 (Dec 11), during the DSS-63 70m support for Behind, 189 commands were sent for battery state of charge recovery. * On day 346 (Dec 12), during the DSS-14 70m support for Behind, 620 commands were sent for transmitter carrier recovery. The DSN did not detect the downlink signal. Due to the duration of the support and the increased commands for each step, only 31 of the 36 frequency segments were commanded. Three commands must be received sequentially to power on the transmitter. The Green Bank Radio Telescope observed concurrently, however, no downlink signal was detected. * The fourth uplink array test with Ahead was carried out on Nov 19, using two 34 meter stations, one at 80 kW uplink power, and the other at 20 kW. An increase of 3 dBm was confirmed with the addition of the 20 kW station. The fifth uplink array test is scheduled for Jan 14, with three stations, one at 80 kW and the other two at 20 kW. The resulting power is expected to be twice that of a 70 meter station. The sixth and final test will combine these three stations with the frequency acquisition sequence. Use of uplink arrays with Behind could begin as early as March, depending on DSN resources. It is anticipated that this mode made by used once per month. Week 51 (Dec 14-20) * Ahead starts the week at an SPE angle of 6.8 degrees. * On Monday, Dec 14, the downlink rate for 34 m stations for Ahead was increased to 160 kbps. This rate will persist for the next several years. * Also on Monday, Dec 14, updated fault protection rules 2.3.18 for no-gyro-operations will be written to EEPROM. * Later today (Tuesday, Dec15) the MOC will adjust the G&C parameter on Ahead for controlling the maximum slew rate in preparation for the SECCHI step calibration in January. It will be lowered a bit for more control. * Ahead has nine tracks during the week, with seven tracks at 480 kbps, one track at 240 kbps (station 26), and one track at 160 kbps. Overall coverage is short 7.9 hours between Monday and Saturday (DOY 348 to 353). No loss of data for the in-situ instruments is anticipated, but SECCHI should plan for the shortfall. * Behind starts week with SPE angle of 4.7 deg. Recovery efforts for Behind are scheduled with three tracks Monday-Thursday, Dec 14-17. Week 52 (Dec 21-27) * The 83rd momentum on Ahead is scheduled for Monday, Dec 21, with ignition at 15:00 UT. This dump is scheduled earlier than usual because the previous momentum dump was short, while this will be a full dump. The telemetry rate during the track will be 360 kbps. * APL will be closed on Friday, Dec 25, for the Christmas holiday. * Ahead has 10 passes during the week, and overall coverage is nominal. Seven at 480 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 5.2 degrees. Recovery efforts for Behind are Thursday, Friday, and Saturday, Dec 24-26. Week 53 (Dec 28-Jan 3) * On Monday, Dec 28, the downlink rate for 70 meter stations for Ahead will increase to 720 kbps. The HGA will be centered on the main lobe on Dec 30. * APL will be closed on Friday, Jan 1, for the New Year holiday. * Ahead has 10 tracks during the week, and overall coverage is nominal. Seven tracks are at 720 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 5.7 degrees. Recovery efforts for Behind are Wednesday, Thursday, and Friday, Dec 30-Jan 1. * If Behind is recovered by then, the high gain antenna will be on the main lobe with a 1 degree offset on Jan 2. Week 01 (Jan 4-10) * Ahead has 10 tracks during the week, and overall coverage is nominal. There are four tracks at 720 kbps, two at 240 kbps, and four at 160 kbps. * Behind starts the week at an SPE angle of 6.2 deg. Recovery efforts for Behind are Monday, Tuesday, and Wednesday, Jan 4-6. The battery recovery tracks will be performed with the 80 kW transmitter on station 26. Week 02 (Jan 11-17) * The 32nd SECCHI stepped calibration roll on Ahead is tentatively scheduled for Tuesday, Jan 12, starting at 12:30 UT, depending on both the MOC and SECCHI being ready. This will be the first stepped roll without the IMU. The MOC is tuning up the sequence for this roll. It is anticipated that the roll duration will be increased from about 3 hours to 5 hours, with about 10 minutes of additional slew time for each roll step. * Ahead will be at perihelion on Thursday, Jan 14. * The fifth uplink array test is scheduled for Thursday, Jan 14, with stations 24, 25, and 26. The test duration will be about 4 hours. There will be no instrument commanding or SSR playback during this test. * Ahead has 9 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, one at 240 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 6.7 deg. Recovery efforts for Behind are Friday, Saturday, and Sunday, Jan 11-17. The first two tracks will be undertaken with station 26 using the 80 kW transmitter. Week 03 (Jan 18-24) * A 2.6 hour ranging test with station 15 with Ahead will be carried out on Monday, Jan 18. There will be no instrument commanding or SSR playback during this test. The telemetry rate will be 160 kbps. * The 84th momentum dump for Ahead is scheduled for Thursday, Jan 21, with ignition at 23:00 UT. The telemetry rate will be 120 kbps. * Ahead has 10 passes during the week, and overall coverage is nominal. There are four passes at 720 kbps, two passes at 240 kbps, and four passes at 160 kbps. * Behind starts the week at an SPE angle of 7.2 deg. Recovery efforts for Behind are Monday, Tuesday, and Wednesday, Jan 18-20. The Tuesday pass will be undertaken with station 26 using the 80 kW transmitter. Week 04 (Jan 25-31) * Ahead has 11 passes during the week, and overall coverage is nominal. There are two passes at 720 kbps, three passes at 240 kbps, and six passes at 160 kbps. * Behind starts the week at an SPE angle of 7.7 deg. Recovery efforts for Behind are Wednesday, Thursday, and Friday-Saturday. The first two tracks will be undertaken with station 26 using the 80 kW transmitter. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 14 (348) Ahead: 160 kbps on 34 meter stations T Dec 15 (349) W Dec 16 (350) T Dec 17 (351) F Dec 18 (352) S Dec 19 (353) S Dec 20 (354) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (355) Ahead: Momentum dump, 15:30 UT T Dec 22 (356) W Dec 23 (357) T Dec 24 (358) F Dec 25 (359) Christmas S Dec 26 (360) S Dec 27 (361) ------------------------------------------------------------------------------- Scheduled activities for Week 53: M Dec 28 (362) Ahead: Main lobe, riding soft stop, 720 kbps (70 m) T Dec 29 (363) W Dec 30 (364) Ahead: HGA on main lobe T Dec 31 (365) F Jan 01 (001) New Year S Jan 02 (002) S Jan 03 (003) ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 04 (004) T Jan 05 (005) W Jan 06 (006) T Jan 07 (007) F Jan 08 (008) S Jan 09 (009) S Jan 10 (010) ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 11 (011) T Jan 12 (012) Ahead: First NGO SECCHI stepped calib. roll 12:30 (TBC) W Jan 13 (013) T Jan 14 (014) Ahead: Perihelion Ahead: Uplink array test with stations 24,25,26 F Jan 15 (015) S Jan 16 (016) S Jan 17 (017) ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 18 (018) Ahead: Ranging test with station 15 T Jan 19 (019) W Jan 20 (020) T Jan 21 (021) Ahead: Momentum dump, 23:00 UT F Jan 22 (022) S Jan 23 (023) S Jan 24 (024) ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 25 (025) T Jan 26 (026) W Jan 27 (027) T Jan 28 (028) F Jan 29 (029) S Jan 30 (030) S Jan 31 (031) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2016: * Jan 2 Behind: HGA on main lobe, offpoint 1 degree, 240 kbps Behind: Resume space weather broadcast to NOAA stations * Jan 5 Behind: HGA on main lobe, riding soft stop, 360 kbps Behind: SSR playback and reconfiguration * Jan 6 Behind: Instrument recommissioning, IMPACT SWEA/STE on * Jan 9 Behind: HGA on main lobe, riding soft stop, 480 kbps * Jan 11 Behind: HGA on main lobe, riding soft stop, 720 kbps * Jan 12 Behind: HGA on main lobe * Jan 27 Both: HGA calibration (NGO) * Mar 3 Behind: Resume LGA uplink capability on 70 m DSN * Apr 6 Ahead: Resume LGA uplink capability on 70 m DSN * May 16 Both: Post Solar Conjunction Assessment Review * Jul 5 Juno arrival at Jupiter * Dec Behind: Resume LGA downlink capability on 70 m DSN 2017: 2018: * Mar 5 Ahead: Mercury transit 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Apr Behind: Switch downlink rate to 240 kbps for 34 meter 2020: * May Behind: Switch downlink rate to 360 kbps for 34 meter * Jun Ahead: Switch downlink rate to 360 kbps for 34 meter * Jun Behind: Switch downlink rate to 480 kbps for 34 meter * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter 2021: * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter