STEREO Weekly Meeting Minutes for 2021-06-22 (Week 25) 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 24 (Jun 14-20) * On day 167 (Jun 16), during the DSS-34 support for Ahead, turbo decoder lock was lost briefly at 1044z. This anomaly resulted in the loss of four frames of SSR data. * On day 166 (Jun 15), the 138th momentum dump was executed successfully on Ahead at 1500z, which imparted an estimated delta V of 0.073 m/sec. This was the 57th momentum dump conducted without gyro use. After thruster operations completed, there was a 0.2 degree of roll angle error. Fine pointing stabilized three minutes after completion of the momentum dump. * As of day 171 (Jun 20), 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 7.0 Gbits during this week. Week 25 (Jun 21-27) * Ahead has twelve tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, and four at 480 kbps. * Yesterday, Jun 21, APL successfully upgraded the IoNet firewall. * The Ahead spacecraft will be rolled by 180 degrees on Saturday, Jun 26, between 14-16 UT to allow the SECCHI HI-2 telescope to observe Betelgeuse. Week 26 (Jun 28-Jul 4) * Ahead has eleven tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, and three at 480 kbps. * More MOC network maintenance is scheduled for Monday, Jun 28, between 11:30-13:30 UT. This is outside the DSN schedule. The network will be tested after the maintenance ends. * The Ahead spacecraft will be rolled by 180 degrees on Friday, Jul 2, between 20-22 UT to allow the SECCHI HI-2 telescope to observe Betelgeuse. * Sunday, Jul 4, is Independence Day. The holiday will be observed on Monday, Jul 5. Week 27 (Jul 5-11) * Ahead has thirteen tracks during the week, and overall coverage is nominal. There are eleven tracks at 720 kbsp, and two at 480 kbps. * APL will be closed Jul 5 for the Independence Day weekend. * The Ahead spacecraft will be rolled by 180 degrees on Friday, Jul 9, betwen 18-20 UT to allow the SECCHI HI-2 telescope to observe Betelgeuse. This will be the last in this series of Betelgeuse observations. Week 28 (Jul 12-18) * Ahead has twelve tracks during the week, and overall coverage is nominal. There are nine tracks at 720 kbps, and three at 480 kbps. * A return-to-service track for station 63 is scheduled for Monday, Jul 12. There will be no instrument commanding or SSR playback during this track. Week 29 (Jul 19-25) * Ahead has thirteen tracks during the week, and overall coverage is nominal. There are twelve tracks at 720 kbps, and one at 480 kbps. Week 30 (Jul 26-Aug 1) * Ahead has thirteen tracks during the week, and overall coverage is nominal. There are nine tracks at 720 kbps, and four at 480 kbps. * The 139th momentum dump on Ahead is scheduled for Tuesday, Jul 27, with ignition at 19:00 UT. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 25: M Jun 21 (172) T Jun 22 (173) W Jun 23 (174) T Jun 24 (175) F Jun 25 (176) S Jun 26 (177) Ahead: 180 degree roll to observe Betelgeuse, 14-16 UT S Jun 27 (178) ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 28 (179) T Jun 29 (180) W Jun 30 (181) T Jul 01 (182) F Jul 02 (183) Ahead: 180 degree roll to observe Betelgeuse, 20-22 UT S Jul 03 (184) S Jul 04 (185) Independence Day ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jul 05 (186) Independence Day observed T Jul 06 (187) W Jul 07 (188) T Jul 08 (189) F Jul 09 (190) Ahead: 180 degree roll to observe Betelgeuse, 18-20 UT S Jul 10 (191) S Jul 11 (192) ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 12 (193) Ahead: Return-to-service track with station 63. T Jul 13 (194) W Jul 14 (195) T Jul 15 (196) F Jul 16 (197) S Jul 17 (198) S Jul 18 (199) ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 19 (200) T Jul 20 (201) W Jul 21 (202) T Jul 22 (203) F Jul 23 (204) S Jul 24 (205) S Jul 25 (206) ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 26 (207) T Jul 27 (208) Ahead: Momentum dump, 19:00 UT W Jul 28 (209) T Jul 29 (210) F Jul 30 (211) S Jul 31 (212) S Aug 01 (213) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2021: * May 13-Jul 15 Betelgeuse visible in SECCHI HI2 with 180 degree roll * Aug 5-15 Parker Solar Probe perihelion pass * Aug 9 Solar Orbiter Venus flyby * Aug 23 Solar Orbiter in quadrature with Earth * Aug 31 Solar Orbiter METIS roll * Sep 12-19 Solar Orbiter remote sensing window * Oct 16 Parker Solar Probe Venus flyby * Nov 5 Solar Orbiter along Sun-Earth line * Nov 17-26 Parker Solar Probe perihelion pass * Nov 27 Solar Orbiter Earth flyby * Dec 4 Solar eclipse in Antartica * Dec 17-21 Solar Orbiter METIS observations of Comet Leonard 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 * Sep 4 Solar Orbiter Venus flyby * 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: * Feb 18 Solar Orbiter Venus flyby * Mar 19-27 Parker Solar Probe perihelion pass * Apr 7 Ahead: Mercury transit * Jun 15-24 Parker Solar Probe perihelion pass 2026: * Dec 24 Solar Orbiter Venus flyby 2027: * Feb 1 Behind: Mercury transit 2028: * Mar 18 Solar Orbiter Venus flyby 2029: * Jun 10 Solar Orbiter Venus flyby * Jun 30 Ahead: Mercury transit 2030: * Sep 3 Solar Orbiter Venus flyby