STEREO Weekly Meeting Minutes for 2017-01-01 (Week 1) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Attempts to recover Behind have transitioned back to a monthly schedule. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 51 (Dec 19-25) * On day 355 (Dec 20), the 94th momentum dump on Ahead was executed successfully at 1530z, which imparted an estimated delta V of 0.102 m/sec. This was the 13th momentum dump that did not use the IMU. After thruster operations completed, there was a 0.36 degree of roll angle error which was dampened out over the next 7.7 minutes. Fine pointing stabilized 2.25 minutes after completion of the momentum dump. * On day 358 (Dec 23), the G&C wheel speed avoidance algorithm on Ahead failed to converge at 0934z resulting in the loss of fine pointing for 24 seconds at 1234z when the algorithm successfully converged. This coincides with when two of the wheels reached the wheel speed dead zone for zero speed avoidance. * The average daily science data return for Ahead was 5.0 Gbits during this week. * There were no tracks for Behind during the week. Week 52 (Dec 26-Jan 1) * On day 363 (Dec 28), during the DSS-63 support for Ahead, the MOC lost real-time telemetry and monitor data at 1050z due to a disk anomaly on the primary command workstation. The MOC switched to the backup command workstation to continue command and control operations at 1104z. The primary command workstation was rebooted and placed back on-line at 1303z. All SSR data were received. * On day 366 (Dec 31), the G&C wheel speed avoidance algorithm on Ahead failed to converge at 1558z resulting in the intermittent loss of fine pointing for a total of 46 seconds through 2158z when the algorithm successfully converged. This coincides when two of the wheels reached the wheel speed dead zone for zero speed avoidance. * On day 366 (Dec 31), a leap second was applied on Ahead to UTC at 23:59:60z. * The average daily science data return for Ahead was 5.0 Gbits during this week. * There were no tracks for Behind during the week. The next recovery attempts for Behind are on Jan 20-22. Week 1 (Jan 2-8) * Yesterday (Jan 2), during the station 14 pass for Ahead, Turbo decoder lock was lost intermittently between 17:12-17:36 UT, right after the beginning of track, due to weather at the Goldstone station, resulting in the loss of 16,000 telemetry frames, equivalent to about 3.4 minutes of data. * Ahead has 11 passes during the week, and overall coverage is nominal. There are five tracks at 720 kbps, one at 240 kbps, and five at 160 kbps. * There are no tracks for Behind during the week. Week 2 (Jan 9-15) * Ahead has 9 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and one at 240 kbps. * Behind has no passes during the week. Week 3 (Jan 16-22) * Monday, Jan 16, is Martin Luther King Day. This is a federal holiday, but APL will be open. * The 95th momentum dump on Ahead is scheduled for Thursday, Jan 19, with ignition at 21:00 UT. This will be the 14th dump without using the gyros. * Federal government offices in the DC area will be closed on Friday, Jan 20, for the presidential inauguration. * Ahead has 8 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, two at 240 kbps, and one at 160 kbps. * Battery recovery tracks are on Friday, Jan 20, with station 14, and on Saturday, Jan 21, with the 80 kW transmitter on station 26. A carrier recovery track will be carried out with station 14 on Sunday, Jan 22. The radio science receiver will be used with the station 14 tracks. Week 4 (Jan 23-29) * Ahead has 9 passes during the week, and overall coverage is now nominal. An additional pass with station 63 was added on Tuesday. There are currently six tracks at 720 kbps, one at 240 kbps, and two at 160 kbps. * Behind has no passes during the week. Week 5 (Jan 30-Feb 5) * Ahead has 12 tracks during the week, and overall coverage is nominal. There are five passes at 720 kbps, one at 360 kbps, three at 240 kbps, and two at 160 kbps. Two ESA Malargue passes were added for Jan 30,31. * Behind has no passes during the week. Week 6 (Feb 6-12) * A 1.6 hour project interface test with Ahead using station 26 is scheduled for Sunday, Feb 12. There will be no SSR playback or instrument commanding during this pass. The telemetry rate will be 240 kbps. * Ahead has 8 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, one at 240 kbps, and one at 160 kbps. * There are no passes for Behind during the week. Week 7 (Feb 13-19) * A 1.5 hour project interface test with Ahead using station 63 is scheduled for Tuesday, Feb 14. There will be no SSR playback or instrument commanding during this pass. The telemetry rate will be 720 kbps. * Ahead has 9 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, and two at 240 kbps. * Recovery attempts for Behind are scheduled for Friday, Saturday, and Sunday, Feb 17-19. The first two passes are for battery recovery, and will use the 80 kW transmitter on station 26. The carrier recovery track using station 14 on Sunday will include the radio science receiver. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 02 (002) New Year holiday T Jan 03 (003) W Jan 04 (004) T Jan 05 (005) F Jan 06 (006) S Jan 07 (007) S Jan 08 (008) ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 09 (009) T Jan 10 (010) W Jan 11 (011) T Jan 12 (012) F Jan 13 (013) S Jan 14 (014) S Jan 15 (015) ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 16 (016) Martin Luther King Day T Jan 17 (017) W Jan 18 (018) T Jan 19 (019) Ahead: Momentum dump, 21:00 UT F Jan 20 (020) Inauguration Day Behind: Battery recovery track with station 14 S Jan 21 (021) Behind: Battery recovery track with station 26 S Jan 22 (022) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 23 (023) T Jan 24 (024) W Jan 25 (025) T Jan 26 (026) F Jan 27 (027) S Jan 28 (028) S Jan 29 (029) ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Jan 30 (030) T Jan 31 (031) W Feb 01 (032) T Feb 02 (033) F Feb 03 (034) S Feb 04 (035) S Feb 05 (036) ------------------------------------------------------------------------------- Scheduled activities for Week 06: M Feb 06 (037) T Feb 07 (038) W Feb 08 (039) T Feb 09 (040) F Feb 10 (041) S Feb 11 (042) S Feb 12 (043) Ahead: Project interface test with station 26 ------------------------------------------------------------------------------- Scheduled activities for Week 07: M Feb 13 (044) T Feb 14 (045) Ahead: Project interface test with station 26 W Feb 15 (046) T Feb 16 (047) F Feb 17 (048) Behind: Battery recovery track with station 26 S Feb 18 (049) Behind: Battery recovery track with station 26 S Feb 19 (050) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 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 2022: 2023: * May 5 Behind: Mercury transit * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth 2024: 2025: * Apr 7 Ahead: Mercury transit 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit