STEREO Weekly Meeting Minutes for 2019-01-29 (Week 5) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. * 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 4 (Jan 21-27) * On day 021 (Monday Jan 21), during the DSS-63 support, turbo decoder lock was lost intermittently between 1248z and 1317z. This anomaly occurred while the spacecraft downlink was configured for one-way communication, and resulted in the loss of 13,118 frames of SSR data. Conscan was enabled and turbo decoder lock stabilized once the spacecraft downlink transitioned to two-way communication. SSR pointers were repositioned and all SSR data were recovered. See DR# M111142 for more information. * On day 024 (Thursday Jan. 24), the sixth acceptance test of the CCSDS SLE bluebook version 4 software update between the Ahead MOC with the DSN was successfully conducted. As this update is part of a new ground software release, the MOC will switch to version 4 after formal acceptance testing has been completed. They are hoping to do this by the end of February, but the date is not set yet. * On day 021, the G&C parameter release 1.3.6 was loaded to G&C EEPROM1 & 2 at 1342z. The release contained the wheel speed avoidance (CTL_WHLBADOFFSET) parameter for increasing the band about zero wheel speed to 36.5 (was 30.79) rads/second. This parameter change has been in use in G&C RAM since October 11, 2018 and is attempting to minimize the occurrence of fine pointing losses from wheel stiction when passing through zero speed. * The average daily science data return for Ahead was 5.6 Gbits during this week. Week 5 (Jan 28-Feb 3) * The 116th momentum dump on Ahead is scheduled for Wednesday, Jan 30, with ignition at 21:00 UT. This is the 35th dump without using the gyros. * Ahead has 9 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, two at 360 kbps, and one at 240 kbps. Week 6 (Feb 4-10) * Ahead has twelve passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, two at 360 kbps, one at 240 kbps, and one at 160 kbps. Week 7 (Feb 11-17) * The 46th SECCHI stepped calibration roll is scheduled for Monday, Feb 11, with ignition at 10:15 UT. This is the midpoint roll. System momentum is expected to be 7 N-m-s. * Ahead has nine passes during the week, all at 720 kbps, and overall coverage is nominal. Week 8 (Feb 18-24) * Feb 18th is Presidents Day, a federal holiday but a regular business day for APL. * Ahead has ten passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, and three at 360 kbps. Week 9 (Feb 25-Mar 3) * Ahead has nine passes during the week, all at 720 kbps, and overall coverage is nominal. Week 10 (Mar 4-Mar10) * Sunday March 10 at 07:00 UT Daylight Saving Time begins. * Ahead has eleven passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps and two at 360 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 14 (014) T Jan 15 (015) W Jan 16 (016) T Jan 17 (017) F Jan 18 (018) S Jan 19 (019) S Jan 20 (020) ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 21 (021) Martin Luther King day T Jan 22 (022) W Jan 23 (023) T Jan 24 (024) F Jan 25 (025) S Jan 26 (026) S Jan 27 (027) ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Jan 28 (028) T Jan 29 (029) W Jan 30 (030) Ahead: Momentum dump, 21:00 UT T Jan 31 (031) F Feb 01 (032) S Feb 02 (033) S Feb 03 (034) ------------------------------------------------------------------------------- Scheduled activities for Week 06: M Feb 04 (035) T Feb 05 (036) W Feb 06 (037) T Feb 07 (038) F Feb 08 (039) S Feb 09 (040) S Feb 10 (041) ------------------------------------------------------------------------------- Scheduled activities for Week 07: M Feb 11 (042) Ahead: SECCHI stepped calibration roll, 10:15 UT T Feb 12 (043) W Feb 13 (044) T Feb 14 (045) F Feb 15 (046) S Feb 16 (047) S Feb 17 (048) ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 18 (049) T Feb 19 (050) W Feb 20 (051) T Feb 21 (052) F Feb 22 (053) S Feb 23 (054) S Feb 24 (055) ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 25 (056) T Feb 26 (057) W Feb 27 (058) T Feb 28 (059) F Mar 1 (060) S Mar 2 (061) S Mar 3 (062) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 4 (063) T Mar 5 (064) W Mar 6 (065) T Mar 7 (066) F Mar 8 (067) S Mar 9 (068) S Mar 10 (069) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Mar 31-Apr 10 Parker Solar Probe perihelion pass * Apr Behind: Switch downlink rate to 240 kbps for 34 meter * Aug 28-Sep 7 Parker Solar Probe perihelion pass * Nov 4 Ahead: Close approach of Parker Solar Probe * Dec 26 Parker Solar Probe Venus flyby 2020: * Jan 24-Feb 4 Parker Solar Probe perihelion pass * 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