STEREO Weekly Meeting Minutes for 2020-04-07 (Week 15) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. PLASTIC is back to operational mode, but with a higher background rate. Modifications are still needed to allow PLASTIC data to appear in the SSC beacon plots. * 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 14 (Mar 30-Apr 5) * On day 090 (Mar 30), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently from 1932z through 1952z. This anomaly resulted in the loss of 551 frames of SSR data. See DR #M112160 for more information. * On day 091 (Mar 31), during the DSS-63 support for Ahead, turbo decoder lock was lost briefly at 1717z. This anomaly resulted in the loss of 14 frames of SSR data. * On day 095 (Apr 4), during the DSS-63 support for Ahead, turbo decoder lock was lost briefly at 1727z. This anomaly resulted in the loss of two frames of SSR data. * On day 096 (Apr 5), during the DSS-34 support for Ahead, turbo decoder lock was lost briefly at 0616z, 0748z, and 0909z. This anomaly resulted in the loss of eight frames of SSR data. * As of day 096 (Apr 5), 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 7.5 Gbits during this week. * The problem with Turbo decoder lock started with a software update in February, and is seen at all the stations. Next availablity for correcting the problem is the regular software update in July, though the specific part of the software could be updated after that if necessary. Falling back to the previous software version won't happen unless there's a major loss of data. The performance might differ based on the specific Turbo encoding scheme being used. Loss of decoder lock at station 34 may have started before the software update. The MOC has not heard yet about station 34 performance. All the stations are currently down to the bare minimum of staffing. The MOC thanked the DSN for repairing the station 63 transmitter 20 hours earlier than predicted. Week 15 (Apr 6-12) * Ahead has eleven passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps, and two at 360 kbps. * The 127th momentum dump on Ahead is scheduled for Wednesday, Apr 8, at 21:45 UT. Week 16 (Apr 13-19) * Ahead has fifteen passes during the week, and overall coverage is nominal. There are ten passes at 720 kbps, and five at 360 kbps. * The battery maintenance activity originally scheduled for Monday, Apr 13, has been postponed until the current coronavirus situation is resolved, since it requires staffing on-site. Week 17 (Apr 20-26) * Ahead has fifteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, one at 480 kbps, and three at 360 kbps. Because there were back-to-back station 63 passes at the end of the week, a station 26 pass was added out of caution, to make sure that the command loss timer would not trigger. * The 53rd SECCHI stepped calibration roll is scheduled for Wednesday, Apr 22, starting at 13:50 UT. This is the aphelion roll. There is no need to postpone this activity because of the coronavirus. Week 18 (Apr 27-May 3) * Ahead has thirteen passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and five at 360 kbps. To assist another mission, the 480 kbps station 54 pass on Friday, May 1, was changed to a 360 kbps support with station 65. * Solar Orbiter will be along the Sun-Earth line between Apr 27 to May 3. The SECCHI team has requested that spacecraft operations be avoided during this period. Solar Orbiter resumed commissioning activities on Monday, Mar 30. There may have been enough slack in the original schedule to absorb most of the 10 day delay caused by the coronavirus situation. Week 19 (May 4-10) * Ahead has sixteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and five at 360 kbps. Week 20 (May 11-17) * Ahead has thirteen passes during the week, and overall coverage is nominal. There are eleven passes at 720 kbps, and two at 360 kbps. Other * A question was raised about how the instrument teams are able to do their commanding. All the teams except PLASTIC are able to command from home. PLASTIC personnel are on the allowed list to go into UNH to do their commanding, and so far have had no trouble getting in. * The beacon partner station in France had to shut down because of the coronavirus situation. However, two stations in Germany cover most of that same time period. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 06 (097) T Apr 07 (098) W Apr 08 (099) Ahead: Momentum dump, 21:45 UT T Apr 09 (100) F Apr 10 (101) S Apr 11 (102) S Apr 12 (103) ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 13 (104) T Apr 14 (105) W Apr 15 (106) T Apr 16 (107) F Apr 17 (108) S Apr 18 (109) S Apr 19 (110) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 20 (111) T Apr 21 (112) W Apr 22 (113) Ahead: SECCHI stepped calibration roll, 13:50 UT T Apr 23 (114) F Apr 24 (115) S Apr 25 (116) S Apr 26 (117) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M Apr 27 (118) T Apr 28 (119) W Apr 29 (120) T Apr 30 (121) F May 01 (122) S May 02 (123) S May 03 (124) Notes: * Apr 27-May 3 Solar Orbiter along Sun-Earth line ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 04 (125) T May 05 (126) W May 06 (127) T May 07 (128) F May 08 (129) S May 09 (130) S May 10 (131) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 11 (132) T May 12 (133) W May 13 (134) T May 14 (135) F May 15 (136) S May 16 (137) S May 17 (138) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 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 * 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