STEREO Weekly Meeting Minutes for 2020-04-28 (Week 18) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. PLASTIC is back to operational mode, but with a higher background rate. More time is needed to understand the new calibraton. * Four years after the initial loss of communications anomaly with the Behind observatory, NASA has directed to cease periodic recovery operations with the last support on October 17, 2018. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 17 (Apr 20-26) * On day 111 (Apr 20), during the DSS-63 support for Ahead, the transmitter was declared red due to a power outage caused by weather. This anomaly resulted in the loss of 1.8 hours of real-time commanding and 2-way tracking data. MOPs moved the commanding activities to the subsequent DSS-25 support. See DR # M112239 for more information. * On day 112 (Apr 21), during the DSS-63 support for Ahead, initial acquisition of telemetry was 3.75 minutes late at 1923z, due to a ranging calibration failure. This anomaly resulted in the loss of 1.75 minutes of SSR data. See DR # M112244 for more information. * On day 113 (Apr 22), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently from 2025z through 2028z. This anomaly resulted in the loss of 27 frames of SSR data. * On day 117 (Apr 26), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently from 2045z through 2048z. This anomaly resulted in the loss of 75 frames of SSR data. * A turbo decoder lock workaround has now been implemented on all tracks using turbo encoding. The success of this workaround has not yet been determined. * On day 113 (Apr 22), the 53rd SECCHI stepped calibration was executed at 1350z for aphelion in the Ahead orbit. This was the 22nd SECCHI stepped calibration roll conducted without gyro use. * As of day 117 (Apr 26), all PLASTIC systems are behaving well, except there is a high background count rate, which the team is continuing to monitor. * The average daily science data return for Ahead was 7.2 Gbits during this week. Week 18 (Apr 27-May 3) * A track was added to the schedule, out of caution when station 55 started having tranmitter issues. However, Madrid was able to fix the issue within 24 hours, and the transmitter is now working again. * Ahead has fourteen passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and six at 360 kbps. To assist another mission, the 480 kbps station 54 pass on Friday, May 1, was changed to a 360 kbps support with station 65. * Solar Orbiter will be along the Sun-Earth line between Apr 27 to May 3. The SECCHI team has requested that spacecraft operations be avoided during this period. Week 19 (May 4-10) * Ahead has sixteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and five at 360 kbps. Week 20 (May 11-17) * Ahead has thirteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and two at 360 kbps. Week 21 (May 18-24) * Ahead has seventeen passes during the week, and overall coverage is nominal. There are twelve passes at 720 kbps, one at 480 kbps, and four at 360 kbps. * The 128th momentum dump on Ahead is scheduled for Monday, May 18, with ignition at 18:00 UT. Week 22 (May 25-31) * Ahead has eleven passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and three at 360 kbps. * Monday, May 25, is Memorial Day, which is a holiday at APL. Week 23 (Jun 1-7) * Ahead has fourteen passes during the week, and overall coverage is nominal. There are twelve passes at 720 kbps, one at 360 kbps, and one at 480 kbps. * The fifth Parker Solar Probe perihelion pass period is scheduled for days 154-164 (Jun 2-13). SECCHI will be supporting this pass. The exact SECCHI activities during this period are still TBD. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 18: M Apr 27 (118) T Apr 28 (119) W Apr 29 (120) T Apr 30 (121) F May 01 (122) S May 02 (123) S May 03 (124) Notes: * Apr 27-May 3 Solar Orbiter along Sun-Earth line ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 04 (125) T May 05 (126) W May 06 (127) T May 07 (128) F May 08 (129) S May 09 (130) S May 10 (131) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 11 (132) T May 12 (133) W May 13 (134) T May 14 (135) F May 15 (136) S May 16 (137) S May 17 (138) ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 18 (139) Ahead: Momentum dump, 18:00 UT T May 19 (140) W May 20 (141) T May 21 (142) F May 22 (143) S May 23 (144) S May 24 (145) ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 25 (146) Memorial Day T May 26 (147) W May 27 (148) T May 28 (149) F May 29 (150) S May 30 (151) S May 31 (152) ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 01 (153) T Jun 02 (154) W Jun 03 (155) T Jun 04 (156) F Jun 05 (157) S Jun 06 (158) S Jun 07 (159) Notes: * Parker Solar Probe perihelion pass, Jun 2-13. ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 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 * Jun 2-13 Parker Solar Probe perihelion pass * Jul 11 Parker Solar Probe Venus flyby, in HI2-A field-of-view * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter * Sep 22-Oct 2 Parker Solar Probe perihelion pass 2021: * Jan 13-23 Parker Solar Probe perihelion pass * Feb 20 Parker Solar Probe Venus flyby * Apr 25-May 4 Parker Solar Probe perihelion pass * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter * Aug 5-15 Parker Solar Probe perihelion pass * Oct 16 Parker Solar Probe Venus flyby * Nov 17-26 Parker Solar Probe perihelion pass 2022: * Feb 21-Mar 2 Parker Solar Probe perihelion pass * May 28-Jun 7 Parker Solar Probe perihelion pass * Sep 2-11 Parker Solar Probe perihelion pass * Dec 7-16 Parker Solar Probe perihelion pass 2023: * Mar 13-23 Parker Solar Probe perihelion pass * May 5 Behind: Mercury transit * Jun 17-27 Parker Solar Probe perihelion pass * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth * Aug 21 Parker Solar Probe Venus flyby * Sep 23-Oct 3 Parker Solar Probe perihelion pass * Dec 25-Jan 3 Parker Solar Probe perihelion pass 2024: * Mar 26-Apr 4 Parker Solar Probe perihelion pass * Jun 26-Jul 5 Parker Solar Probe perihelion pass * Sep 26-Oct 5 Parker Solar Probe perihelion pass * Nov 6 Parker Solar Probe Venus flyby, in HI2-A field-of-view * Dec 20-29 Parker Solar Probe perihelion pass 2025: * Mar 19-27 Parker Solar Probe perihelion pass * Apr 7 Ahead: Mercury transit * Jun 15-24 Parker Solar Probe perihelion pass 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit