STEREO Weekly Meeting Minutes for 2015-12-22 (Week 52) 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 51 (Dec 14-20) * On day 350 (Dec 16), MOps was alerted that DSS-63 had been declared red due to a mechanical drive problem, with an ETRO of DOY 357-1800z (Dec 23). As a result, the 350-0920z/1120z (Dec 16) and 351-0925z/1230z (Dec 17) DSS-63 tracks for Ahead were missed. The day 354-0925z/1225z (Dec 20) and day 355-1240z/1610z (Dec 21) DSS 63 tracks were deleted from the schedule. Thankfully, STEREO has access to the ESA stations and three ESA tracks added, one on day 351 (Dec 17) and two on day 355 (Dec 21) to minimize data loss. See DR# M109112 for more information. * On day 351 (Dec 17), an ESA Malargüe DSS-84 support for Ahead was added with duration of 6.3 hours to start at 1650z to replace the DSS-63 support which was declared red. As this track change occurred with short notice, a blind acquisition was conducted with the downlink rate at 160 kbps. This loss of the DSS-63 supports, for days 350 and 351, resulted in the loss of 1.7 days of instrument and spacecraft SSR data from 349-1903z through 351-1209z (Dec 15-17). * On day 352 (Dec 18), during the DSS-14 support, initial telemetry acquisition occurred 34 minutes late at 1704z due to an antenna pointing issue. SSR pointers were repositioned to minimize data loss. This anomaly resulted in the loss of 34 minutes real-time telemetry, commanding, and tracking data, and seven frames of SSR data. See DR# G116814 for more information. * 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 120 degrees C with the HGA angle at 7.1 degrees, with respect to the spacecraft-Sun line. After 15 months of side lobe and superior solar conjunction operations, on day 321, November 17th, nominal daily science operations resumed. * On day 348 (Dec 14), Fault Protection release 2.3.18 and MOps macro 505 were loaded to C&DH EEPROM on Ahead and verified. This release contains changes for deploying the No Gyro Operations concept which preserves the remaining IMU lifetime for fault protection use only. * On day 349 (Dec 15), the G&C maximum slew rate parameter was updated to limit the maximum slew rate about the X-axis to 0.5 degrees/second and the maximum slew rate about Y & Z axes to 1.0 degree/second in G&C RAM. This update is in preparation for the SECCHI stepped calibration event with no gyro use. * Processing status of the in-situ instrument space weather data 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. A final level zero file (.fin version) for each day, specifically days 2014-230 )Aug 18) through 2015-319 (Nov 15), for each instrument has been created and is available on the MOC STEREO Data Server and GSFC SSC websites. Note for some days there is more than one version, use the latest version. Some days the files will be empty as the instruments were off during solar conjunction as follows: IMPACT & PLASTIC = days 2015-080 through 189 SWAVES = days 2015-135, 136, 138, 139, 141, 142, 144, & 145 (due to sLVS occurrences) SECCHI = days 2015-080 through 191 * The SSC reports that reprocessing has begun of the IMPACT and PLASTIC data from the .fin files for the SSC website. So far, the data for 2014 have been reprocessed, and the data for 2015 should be ready in a day or two. Plots of SWAVES data depends on processing by the SWAVES team, who report that they are working on it. * The average daily science data return for Ahead, with the HGA on the main lobe riding along a one degree offset, was 2.5 Gbits during this week. * On day 348 (Dec 14), during the DSS-43 70m support for Behind, 189 commands were sent for battery state of charge recovery. * On day 349 (Dec 15), during the DSS-43 70m support for Behind, 189 commands were sent for battery state of charge recovery. * On day 350 (Dec 16), during the DSS-14 70m support for Behind, 380 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 19 of the 36 frequency segments were commanded. Three commands must be received sequentially to power on the transmitter. Week 52 (Dec 21-27) * The 83rd momentum on Ahead was successfully carried out yesterday (Dec 21). This was the second momentum dump without gyros. A full momentum dump was carried out. * The station 14 transmitter was red at the beginning of the track for Ahead today (Dec 22), resulting in delay of 1 hour. The SSR pointers were repositioned to prevent data loss. * APL will be closed for a half day on Thursday, Dec 24, and for a full day on Friday, Dec 25, for the Christmas holiday. * Ahead has 11 passes during the week, and overall coverage is nominal. Six passes are at 480 kbps, and five are 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 for a half day on Thursday, Dec 31, and for a full day 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. * Ahead will be at perihelion on Thursday, Jan 14. * The fifth uplink array test is scheduled for Thursday, Jan 14, with stations 24 and 25 at 20 kW, and station 26 at 80 kW. 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, Jan 20-23. The first two tracks will be undertaken with station 26 using the 80 kW transmitter. Week 05 (Feb 1-7) * Ahead has 10 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, three passes at 240 kbps, and four passes at 160 kbps. * Recovery efforts for Behind are Monday, Tuesday, and Thursday, Feb 1-4. The battery recovery tracks will be undertaken with the 80 kW transmitter on station 26. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (355) Ahead: Momentum dump, 20:00 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 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) ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Feb 01 (032) T Feb 02 (033) W Feb 03 (034) T Feb 04 (035) F Feb 05 (036) S Feb 06 (037) S Feb 07 (038) ------------------------------------------------------------------------------- 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