STEREO Weekly Meeting Minutes for 2026-05-05 (Week 19) 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 18 (Apr 27 - May 3) * On day 120 (Apr 30), during the DSS-55 support, turbo decoder lock was lost briefly at 0558z. This anomaly resulted in the loss of two frames of SSR data. The MOPs team repositioned the SSR pointers during the support and recovered all the affected data. * Tracks were reconfigured due to station 55 being red. ESA support was added. * On day 123 (May 3), during the DSS-83 (ESA Cebreros) support, the beginning of track was delayed six minutes until 0356z, due to a DSN configuration problem. This anomaly resulted in the loss of six minutes of real-time telemetry, tracking, commanding and SSR data. The MOPs team repositioned the SSR pointers during the support and recovered all the affected data. * On day 122 (May 2), the battery pressure upper limit parameter in RAM was increased to 1055 psi at 1716z. The power subsystem engineer increased the limit to accommodate for the increased pressure, due to pressure sensor aging. * As of day 123 (May 3), all PLASTIC systems 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 6.9 Gbits during this week. Week 19 (May 4-10) * Ahead has thirteen passes during the week, three at 720 kbps and ten at 480 kbps, and overall coverage is nominal. * An ESA support was added due to station 55 being red. However, only 2 of the original 4 hours of track time could be obtained. * Station 55 is back up, and STEREO had a support from it this morning (May 5). * Because of the loss of track time on Monday, May 4, the SECCHI partition was 100% full for 3.9 hours. * The 2nd DSN Emergency Control Center (ECC) test track will be conducted on Tuesday, May 5th, from 19:15-21:15 UT using station 43. There will be no SSR playback or instrument commanding during this track. * The 185th momentum dump is scheduled for tomorrow, May 6th, at 13:30 UT. Week 20 (May 11-17) * Ahead has fifteen passes during the week, two at 720 kbps and thirteen at 480 kbps, and overall coverage is nominal. * There is a DSN network maintenance event scheduled for Monday, May 11th, from 15:00 to 19:00 UT. * The 20th battery discharge event will take place on Tuesday, May 12th at 17:40 UT. * On Thursday, May 14th, a MOC IONET secutiry scan is scheduled from 18:30 to 22:30 UT. Week 21 (May 18-24) * Ahead has thirteen passes during the week, one at 720 kbps and twelve at 480 kbps, and overall coverage is nominal. * The 79th SECCHI stepped calibration roll is scheduled for Tuesday, May 19th, at 22:10 UT. This is the perihelion roll. * Commercial power at APL will be down for maintenance between 06:00 UT on day 143, to 21:00 UT on day 144, i.e. between 2 AM Saturday to 5 PM Sunday local time. The MOC will be operating on generators during this time. Week 22 (May 25-31) * Ahead has thirteen passes during the week, three at 720 kbps and ten at 480 kbps, and overall coverage is nominal. * APL will be closed on Monday, May 25, for the Memorial Day holiday. * A NASCOM maintenance event is scheduled for Tuesday, May 26, between 17:30 to 20:30 UT. Week 23 (June 1-7) * Ahead has twelve passes during the week, one at 720 kbps and eleven at 480 kbps, and overall coverage is nominal. * There is a Parker Solar Probe perihelion pass scheduled June 4th through 12th. Week 24 (June 8-14) * Ahead has twelve passes during the week, four at 720 kbps, and eight at 480 kbps. * DSN maintenance is scheduled between 00:00-04:00 UT on day 160 (8-12 PM Monday night, June 8). Other * None COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 04 (124) T May 05 (125) W May 06 (126) Ahead: Momentum dump, 13:30 UT T May 07 (127) F May 08 (128) S May 09 (129) S May 10 (130) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 11 (131) T May 12 (132) W May 13 (133) T May 14 (134) F May 15 (135) S May 16 (136) S May 17 (137) ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 18 (138) T May 19 (139) Ahead: SECCHI stepped calibration roll, 22:10 UT W May 20 (140) T May 21 (141) F May 22 (142) S May 23 (143) S May 24 (144) ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 25 (145) Memorial Day holiday T May 26 (146) W May 27 (147) T May 28 (148) F May 29 (149) S May 30 (150) S May 31 (151) ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 01 (152) T Jun 02 (153) W Jun 03 (154) T Jun 04 (155) Start of PSP perihelion pass F Jun 05 (156) S Jun 06 (157) S Jun 07 (158) Notes: * Parker Solar Probe perihelion pass, Jun 4-12 ------------------------------------------------------------------------------- Scheduled activities for Week 24: M Jun 08 (159) T Jun 09 (160) W Jun 10 (161) T Jun 11 (162) F Jun 12 (163) End of PSP perihelion pass S Jun 13 (164) S Jun 14 (165) Notes: * Parker Solar Probe perihelion pass, Jun 4-12 ------------------------------------------------------------------------------- Upcoming events: 2026: * Aug 4-14 Solar Orbiter Remote Sensing Window 28 * Aug 15-25 Solar Orbiter Remote Sensing Window 29 * Sep 1-9 Parker Solar Probe perihelion pass * Sep 11-21 Solar Orbiter Remote Sensing Window 30 * Nov 28-Dec 6 Parker Solar Probe perihelion pass * Dec 24 Solar Orbiter Venus flyby 2027: * Feb 25-Mar 4 Parker Solar Probe perihelion pass * Feb 8 Solar Orbiter Perihelion * May 24-31 Parker Solar Probe perihelion pass * July 7 Solar Orbiter Perihelion * Aug 21-28 Parer Solar Probe perihelion pass * Nov 17-24 Parker Solar Probe perihelion pass * Dec 4 Solar Orbiter Perihelion 2028: * Feb 14-21 Parker Solar Probe perihelion pass * Mar 18 Solar Orbiter Venus flyby * May 8 Solar Orbiter Perihelion * May 12-19 Parker Solar Probe perihelion pass * Aug 8-15 Parker Solar Probe perihelion pass * Oct 5 Solar Orbiter Perihelion * Nov 5-12 Parker Solar Probe perihelion pass 2029: * Jun 10 Solar Orbiter Venus flyby * Jun 30 Ahead: Mercury transit 2030: * Sep 3 Solar Orbiter Venus flyby