STEREO Weekly Meeting Minutes for 2020-12-15 (Week 51) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. PLASTIC is in operational mode, but with a high background rate. * 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 50 (Dec 7-13) * On day 344 (Dec 9), the 133rd momentum dump on Ahead was executed successfully at 1900z, which imparted an estimated delta V of 0.071 m/sec. This was the 52nd momentum dump conducted without gyro use. After thruster operations completed, there was a 0.4 degree of roll angle error. Fine pointing stabilized 2.3 minutes after completion of the momentum dump. * As of day 348 (Dec 13), all PLASTIC systems on Ahead 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 6.1 Gbits during this week. * The IMPACT team reports that the STE door did not close for the momentum dump. They are investigating the cause. The door actuator may be failing, and they may decide to leave the door open for future momentum dumps. Week 51 (Dec 14-20) * Ahead has ten passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and two at 480 kbps. Week 52 (Dec 21-27) * Ahead has eleven passes during the week, all at 720 kbps, and overall coverage is nominal. * The 56th SECCHI stepped calibration roll is scheduled for Monday, Dec 21, starting at 13:30 UT. This is the midpoint roll. * APL will be closed for a half day on Christmas Eve, Dec 24, and will be closed all day on Friday, Dec 25, for Christmas. Week 53 (Dec 28-Jan 3) * Ahead has thirteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and two at 480 kbps. * APL will be closed for a half day on New Year's Eve, Dec 31, and will be closed all day on Friday, Jan 1, for the New Year's holiday. Week 01 (Jan 4-10) * Ahead has ten tracks during the week, and overall coverage is nominal. There are five tracks at 720 kbps, four at 480 kbps, and one at 360 kbps. An ESA Cebreros pass is scheduled for Thursday, Jan 7, and an ESA New Norcia track is scheduled for Saturday, Jan 9. Week 02 (Jan 11-17) * Ahead has ten tracks during the week, and overall coverage is nominal. There are nine passes at 720 kbps, and one at 480 kbps. * The 134th momentum dump on Ahead is scheduled for Monday, Jan 11, with ignitition at 19:00 UT. * The seventh Parker Solar Probe perihelion pass is scheduled for Jan 13-23. Week 03 (Jan 18-24) * Ahead has nine passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, and four at 480 kbps. * Monday, Jan 18, is Martin Luther King Day, which is an APL holiday. * An ESA Cebreros pass is scheduled for Tuesday, Jan 19. * A return-to-service pass for station 43 is scheduled for Saturday, Jan 23. There will be no instrument commanding or SSR playback during this pass. Other * In consultation with the SECCHI team, the MOC has decided to schedule a momentum dump on Ahead on Feb 15. This is during a Solar Orbiter observing window, but it was decided that Feb 16-17 was of higher priority to SECCHI. * The predicted frequency for Ahead will be updated to be closer to the actual performance. * The DSN pointed out that, along with elevation constraints, the antennas also have azimuth constraints on the transmitters. When these constraints are reached, the transmitters are automatically turned off, and have to be reactivated by command. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 14 (349) T Dec 15 (350) W Dec 16 (351) T Dec 17 (352) F Dec 18 (353) S Dec 19 (354) S Dec 20 (355) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (356) Ahead: SECCHI stepped calibration roll, 13:30 UT T Dec 22 (357) W Dec 23 (358) T Dec 24 (359) F Dec 25 (360) Christmas S Dec 26 (361) S Dec 27 (362) ------------------------------------------------------------------------------- Scheduled activities for Week 53: M Dec 28 (363) T Dec 29 (364) W Dec 30 (365) T Dec 31 (366) 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) Ahead: Momentum dump, 19:00 UT T Jan 12 (012) W Jan 13 (013) Start of Parker Solar Probe perihelion pass T Jan 14 (014) F Jan 15 (015) S Jan 16 (016) S Jan 17 (017) Notes: * Parker Solar Probe perihelion pass, Jan 13-23. ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 18 (018) Martin Luther King Day T Jan 19 (019) W Jan 20 (020) T Jan 21 (021) F Jan 22 (022) S Jan 23 (023) Ahead: Return-to-service pass with station 43 S Jan 24 (024) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2021: * Jan 13-23 Parker Solar Probe perihelion pass * Feb 1-19 Solar Orbiter Remote Sensor Synoptics * Feb 15 Ahead: Momentum dump * Feb 20 Parker Solar Probe Venus flyby * Feb 20-25 Solar Orbiter Remote Sensor Checkout Window 2 * Mar 21-24 Solar Orbiter Remote Sensor Checkout Window 3 * Apr 21-28 Solar Orbiter Remote Sensor Synoptics * Apr 25-May 4 Parker Solar Probe perihelion pass * May 13-Jul 15 Betelgeuse visible in SECCHI HI2 with 180 degree roll * 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