STEREO Weekly Meeting Minutes for 2021-03-02 (Week 9) 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 08 (Feb 22-28) * On day 058 (Feb 27), during the DSS-43 support for Ahead, the transmitter tripped off at 0838z. This anomaly resulted in the loss of 1384 frames of SSR data during the downlink receiver transition from 2-way to 1-way mode. The MOPs team decided to remain downlink only for the remaining 1.8 hours of the support to avoid any further data loss by re-sweeping the uplink. The MOPs team repositioned the SSR pointers on the subsequent DSS-14 support and recovered all the affected data. See DR #C115497 for more information. * On day 055 (Feb 24), the Ahead star tracker reset at 03:15:46z. Fault protection immediately promoted the star tracker back to AAD mode at 03:16:11z. The diagnostic data indicated that the reset cause was due to a CPU Error, same as previous resets. The anomaly resulted in a momentary loss of fine pointing with a 0.2 degree of roll angle error. This was the eighth star tracker reset on the Ahead observatory. * As of day 059 (Feb 28), 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 6.4 Gbits during this week. Week 09 (Mar 1-7) * Ahead has eleven passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps, and two 480 kbps. Week 10 (Mar 8-14) * Ahead has ten passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, two at 480 kbps, and one at 360 kbps. An ESA New Norcia pass is scheduled for Monday, Mar 8. * Daily savings time in the US starts on Sunday, Mar 14. Week 11 (Mar 15-21) * Ahead has ten passes during the week, and overall coverage is nominal, all at 720 kbps. * The 57th stepped calibration roll on Ahead is scheduled for Thursday, Mar 18, starting at 13:30 UT. * Solar Orbiter Remote Sensor Checkout Window 3 starts on day 80 (Mar 21), and continues through day 83 (Mar 24). Week 12 (Mar 22-28) * Ahead has eleven passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and two at 480 kbps. * The 10th annual battery discharge maintenance will occur on Wednesday, Mar 24, starting at approximately 20:00 UT during a station 63 pass. Week 13 (Mar 29-Apr 4) * Ahead has eleven passes during the week, all at 720 kbps, and overall coverage is nominal. * The 136th momentum dump is scheduled for Wednesday, Mar 31, starting at 16:30 UT. Week 14 (Apr 5-11) * AHead has twelve passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and one at 480 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Mar 01 (060) T Mar 02 (061) W Mar 03 (062) T Mar 04 (063) F Mar 05 (064) S Mar 06 (065) S Mar 07 (066) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 08 (067) T Mar 09 (068) W Mar 10 (069) T Mar 11 (070) F Mar 12 (071) S Mar 13 (072) S Mar 14 (073) Start of daylight savings time in US ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 15 (074) T Mar 16 (075) W Mar 17 (076) T Mar 18 (077) Ahead: Stepped calibration roll, 13:30 UT F Mar 19 (078) S Mar 20 (079) S Mar 21 (080) Start of Solar Orbiter Remote Sensor Checkout Window 3 Notes: * Solar Orbiter Remote Sensor Checkout Window 3, Mar 21-24. ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 22 (081) T Mar 23 (082) W Mar 24 (083) End of Solar Orbiter Remote Sensor Checkout Window 3 Ahead: Battery discharge maintenance, 20 UT T Mar 25 (084) F Mar 26 (085) S Mar 27 (086) S Mar 28 (087) Notes: * Solar Orbiter Remote Sensor Checkout Window 3, Mar 21-24. ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 29 (088) T Mar 30 (089) W Mar 31 (090) Ahead: Momentum dump, 16:30 UT T Apr 01 (091) F Apr 02 (092) S Apr 03 (093) S Apr 04 (094) ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 05 (095) T Apr 06 (096) W Apr 07 (097) T Apr 08 (098) F Apr 09 (099) S Apr 10 (100) S Apr 11 (101) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2021: * 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 5 Solar Orbiter along Sun-Earth line * 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