STEREO Weekly Meeting Minutes for 2018-05-08 (Week 19) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Behind has transitioned to a monthly schedule to attempt to recover the spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 18 (Apr 30-May 6) * On day 120 (Apr 30), during the DSS-43 support for Ahead, turbo decoder lock was lost briefly at 0340z, 0443z, and 0720z. This anomaly resulted in the loss of 4 frames of SSR data. * On day 121 (May 1), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 1026z and 1248z. This anomaly resulted in the loss of 5 frames of real-time telemetry and SSR data. The SSR pointers were repositioned and all SSR data were recovered, except for 5 SECCHI packets. * On day 124 (May 4), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 1901z. This anomaly resulted in the loss of one frame of real-time telemetry. * On day 126 (May 6), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 1107z. This anomaly resulted in the loss of 5 frames of SSR data. * On day 126 (May 6), before BOT at 1845z for the DSS-14 support for Ahead, the transmitter was declared red due to a microwave interlock issue. This anomaly resulted in the loss of 90 minutes of commanding and two-way tracking data. All SSR data were received. See DRs #G119101 for more information. * On days 118 through 120 (Apr 28-30), the SECCHI instrument team conducted a COR2 Deep Exposure Campaign on Ahead. * The average daily science data return for Ahead was 6.8 Gbits during this week. Week 19 (May 7-13) * The 7th battery discharge maintenance event was successfully carried out yesterday (May 7). The battery charge state was reduced to 87% and then restored. * The 43rd SECCHI stepped calibration roll was carried out earlier today (May 8). * Ahead has 13 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, and six at 240 kbps, and one at 160 kbps. * The NASA InSight mission was successfully launched on time on Saturday, May 5. As a result, no contingency DSN plans needed to be carried out. * There are no recovery passes scheduled for Behind during the week. Week 20 (May 14-20) * The 109th momentum dump on Ahead is scheduled for Tuesday, May 15, starting at 20:00 UT. This will be the 28th momentum dump without using the gyros. * Ahead has 13 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, four at 240 kbps, and one at 160 kbps. * 1 kHz frequency acquisition recovery tracks for Behind are scheduled for Friday, May 18 (battery), and on Saturday, May 19, and Sunday, May 20 (both carrier). Week 21 (May 21-27) * Ahead reaches aphelion on Thursday, May 24. * The STEREO MOC will be on generator power between Saturday, 10:00 UT, and Sunday, 22:00 UT, May 26-27, for scheduled maintenance. This coincides with Memorial Day weekend. * Ahead has 12 passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps, two at 360 kbps, and one at 240 kbps. * There are no recovery passes for Behind scheduled during the week. Week 22 (May 28-Jun 3) * Monday, May 28, is Memorial Day, which is an APL holiday. * Ahead has 13 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, three at 360 kbps, two at 240 kbps, and two at 160 kbps. * There are no recovery passes for Behind scheduled during the week. Week 23 (Jun 4-10) * Ahead has 12 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, four at 360 kbps, one at 240 kbps, and one at 160 kbps. * There are no recovery passes for Behind scheduled during the week. Week 24 (Jun 11-17) * Sunday, Jun 17, marks the date when the Behind spacecraft should resume the capability of 633 bps on the LGA when 3-axis stabilized, with a 2 dB margin. * Ahead has nine tracks during the week, and overall coverage is nominal There are four tracks at 720 kbps, three at 360 kbps, and two at 240 kbps. * Search pattern tracks to attempt to recover Behind are scheduled for Tuesday, Jun 12 (battery), and on Thursday, Jun 14, and Friday, Jun 15 (both carrier). Week 25 (Jun 18-24) * Ahead has 11 tracks during the week, and overall coverage is nominal. There are six tracks at 720 kbps, three at 360 kbps, and two at 240 kbps. * The are no recovery passes for Behind during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 07 (127) Ahead: Battery maintenance, 12 UT T May 08 (128) Ahead: SECCHI stepped calibration roll, 10:30 UT W May 09 (129) T May 10 (130) F May 11 (131) S May 12 (132) S May 13 (133) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 14 (134) T May 15 (135) Ahead: Momentum dump, 20 UT W May 16 (136) T May 17 (137) F May 18 (138) Behind: Recovery track, DSN 14 (1 kHz, battery) S May 19 (139) Behind: Recovery track, DSN 14 (1 kHz, carrier) S May 20 (140) Behind: Recovery track, DSN 14 (1 kHz, carrier) ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 21 (141) T May 22 (142) W May 23 (143) T May 24 (144) Ahead: Aphelion F May 25 (145) S May 26 (146) S May 27 (147) ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 28 (148) Memorial Day T May 29 (149) W May 30 (150) T May 31 (151) F Jun 01 (152) S Jun 02 (153) S Jun 03 (154) ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 04 (155) T Jun 05 (156) W Jun 06 (157) T Jun 07 (158) F Jun 08 (159) S Jun 09 (160) S Jun 10 (161) ------------------------------------------------------------------------------- Scheduled activities for Week 24: M Jun 11 (162) T Jun 12 (163) Behind: Recovery track, DSN 14 (search, battery) W Jun 13 (164) T Jun 14 (165) Behind: Recovery track, DSN 14 (search, carrier) F Jun 15 (166) Behind: Recovery track, DSN 14 (search, carrier) S Jun 16 (167) S Jun 17 (168) ------------------------------------------------------------------------------- Scheduled activities for Week 25: M Jun 18 (169) T Jun 19 (170) W Jun 20 (171) T Jun 21 (172) F Jun 22 (173) S Jun 23 (174) S Jun 24 (175) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Apr Behind: Switch downlink rate to 240 kbps for 34 meter 2020: * 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 * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter 2021: * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter 2022: 2023: * May 5 Behind: Mercury transit * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth 2024: 2025: * Apr 7 Ahead: Mercury transit 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit