STEREO Weekly Meeting Minutes for 2022-03-29 (Week 13) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. PLASTIC is in operational mode, but with a moderately higher than normal 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 12 (Mar 21-27) * On day 080 (Mar 21), the SECCHI instrument on Ahead reset at 20:29:23z. The SECCHI team reconfigured the instrument to operational mode by 081-0146z. This was the 69th reset of the SECCHI instrument on the Ahead observatory. * On day 081 (Mar 22), the 145th momentum dump was executed successfully on Ahead at 1945z, which imparted an estimated delta V of 0.065 m/sec. This was the 64th momentum dump conducted without gyro use. After thruster operations completed, there was a 0.47 degree of roll angle error. Fine pointing stabilized 3.2 minutes after completion of the momentum dump. * On day 082 (Mar 23), the star tracker on Ahead reset at 14:13:30z. Fault protection immediately promoted the star tracker back to AAD mode at 14:13:54z. The diagnostic data indicated that the reset cause was due to a Level 1 Software Reset (After EEPROM Loading Failure). This was the first occurrence for this type of Software Reset. This was the tenth star tracker reset on the Ahead observatory. This reset is still under investigation. * As of day 086 (Mar 27), all PLASTIC systems on Ahead are behaving well, except there is a moderate background count rate, which the team is continuing to monitor. * The average daily science data return for Ahead was 6.5 Gbits during this week. * The Ahead spacecraft experienced some brief toggling of fine pointing between days 79-81 (Mar 20-22). There were seven brief instances of loss of fine pointing for about two seconds during this period. No instances have been seen after the momentum dump on Mar 22. Week 13 (Mar 28-Apr 3) * Ahead has fourteen tracks during the week, all at 720 kbps, and overall coverage is nominal. * The signal strength has improved to the point where all DSN 34 meter station tracks can be held at 720 kbps for the next 2-3 years. The ESA stations are already operating at 720 kbps. For New Norcia, this requires that the elevation be above 15 degrees. * The MOC learned this morning that the DSN network will be down for firewall replacement starting tomorrow (Mar 30) at 22:45 until 02:45 the next day. This will end just before a track. The MOC will make sure the binds are okay after the maintenance period in time for the track. Week 14 (Apr 4-10) * Ahead has fourteen tracks during the week, all at 720 kbps, and overall coverage is nominal. Week 15 (Apr 11-17) * Ahead has eleven tracks during the week, all at 720 kbps, and overall coverage is nominal. Week 16 (Apr 18-24) * Ahead has eleven tracks during the week, all at 720 kbps, and overall coverage is nominal. Week 17 (Apr 25-May 1) * Ahead has eleven tracks during the week, all at 720 kbps, and overall coverage is nominal. * Comet PANSTARRS will pass through the COR2-A field-of-view on Apr 27-30, days 117-120. Week 18 (May 2-8) * Ahead has twelve tracks during the week, all at 720 kbps, and overall coverage is nominal. * The 146th momentum dump on Ahead is scheduled for Monday, May 2, with ignition at 18:30 UT. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 28 (087) T Mar 29 (088) W Mar 30 (089) T Mar 31 (090) F Apr 01 (091) S Apr 02 (092) S Apr 03 (093) Notes: * Solar Orbiter Remote Sensing Window 3, Mar 27-Apr 5 ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 04 (094) T Apr 05 (095) End of Solar Orbiter Remote Sensing Window 3 W Apr 06 (096) T Apr 07 (097) F Apr 08 (098) S Apr 09 (099) S Apr 10 (100) Notes: * Solar Orbiter Remote Sensing Window 3, Mar 27-Apr 5 ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 11 (101) T Apr 12 (102) W Apr 13 (103) T Apr 14 (104) F Apr 15 (105) S Apr 16 (106) S Apr 17 (107) ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 18 (108) T Apr 19 (109) W Apr 20 (110) T Apr 21 (111) F Apr 22 (112) S Apr 23 (113) S Apr 24 (114) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 25 (115) T Apr 26 (116) W Apr 27 (117) T Apr 28 (118) F Apr 29 (119) S Apr 30 (120) S May 01 (121) Notes: * Comet PANSTARRS in COR2-A field-of-view, Apr 27-30. ------------------------------------------------------------------------------- Scheduled activities for Week 18: M May 02 (122) Ahead: Momentum dump, 18:30 UT T May 03 (123) W May 04 (124) T May 05 (125) F May 06 (126) S May 07 (127) S May 08 (128) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2022: * 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: * Jan 3 Solar Orbiter Mercury transit * Mar 13-23 Parker Solar Probe perihelion pass * Apr 16 Solar Orbiter Venus occultation * May 5 Behind: Mercury transit * Jun 17-27 Parker Solar Probe perihelion pass * Jun 27 Solar Orbiter Mercury transit * 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