STEREO Weekly Meeting Minutes for 2018-07-10 (Week 28) 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 27 (Jul 2-8) * Turbo decoder lock was lost briefly during the station 14 pass Jul 2 at 17:56 UT (day 183). SSR pointers were repositioned and all SSR data were received. * A return-to-service pass for station 25 with Ahead to verify KA-band and X-band Tracking, Telemetry and Command operations after the installation of a new HEMT receiver. A significant improvement in downlink signal strength, ~2.5 dB, as compared to previous tracks with DSS-25 was noted. Four commands were successfully received by the Ahead observatory and tracking was nominal Jul 3 (day 184). * The average daily science data return for Ahead was 6.1 Gbits during this week. * There were no recovery passes for Behind during the week. Week 28 (Jul 9-15) * There was a successful shadow track involving stations 14 and 25 with the STEREO Ahead spacecraft on Monday, Jul 9, to test a DSN antenna search pattern that may be needed for the launch of Parker Solar Probe. * Ahead has twelve tracks during the week, and overall coverage is nominal. There are three tracks at 720 kbps, three at 360 kbps, and six at 240 kbps. * Recovery tracks for Behind using the 1 kHz frequency acquisition sequence happened Monday, Jul 9 (battery), and are scheduled for Tuesday, Jul 10 and Wednesday, Jul 11 (both carrier). Week 29 (Jul 16-22) * Ahead has 16 tracks during the week, and overall coverage is nominal. There are four tracks at 720 kbps, three at 360 kbps, and nine at 240 kbps. * There are no recovery passes for Behind during the week. * Maintenance of the power systems in the building housing the STEREO Science Center is scheduled for Jul 19, between 20-22 UT. Actual interruption of power is expected to last 5 minutes, and it is believed that critical systems can be kept online during that period. However, it is possible that all systems will need to be powered down if the maintenance takes longer than expected. Week 30 (Jul 23-29) * The 111th momentum dump on Ahead is scheduled for Tuesday, Jul 24, with ignition at 20:30 UT. This will be the 30th dump without using the gyros. * Ahead has 12 tracks during the week, and overall coverage is nominal. There are three tracks at 720 kbps, six at 360 kbps, and three at 240 kbps. * There are no recovery passes for Behind during the week. Week 31 (Jul 30-Aug 5) * Ahead has 12 tracks during the week, and overall coverage is nominal. There are six tracks at 720 kbps, three at 360 kbps, and three at 240 kbps. * There are no recovery passes for Behind during the week. Week 32 (Aug 6-12) * Ahead has nine tracks during the week, and overall coverage is nominal. There are three tracks at 720 kbps, three at 360 kbps, two at 240 kbps, and one at 160 kbps. * There are no recovery passes for Behind during the week. Week 33 (Aug 13-19) * Ahead has ten tracks during the week, and overall coverage is nominal. There are five tracks at 720 kbps, two at 360 kbps, two at 240 kbps, and one at 160 kbps. * Recovery tracks for Behind using the double diamond search pattern are scheduled for Monday, Aug 13 (battery), Tuesday, Aug 14 and Wednesday, Aug 15 (both carrier). * 44th SECCHI stepped calibration roll is scheduled for Tuesday August 14th at 05:55 UT and taking 4.5 hours. This will be the midpoint roll. System momentum will be 1 N-m-s. Week 34 (Aug 20-26) * Ahead has 14 tracks during the week, and overall coverage is nominal. There are six tracks at 720 kbps, three at 360 kbps, four at 240 kbps, and one at 160 kbps. * There are no recovery passes for Behind during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jul 02 (183) T Jul 03 (184) Ahead: Return-to-service track with station 25 W Jul 04 (185) Independence Day T Jul 05 (186) F Jul 06 (187) S Jul 07 (188) S Jul 08 (189) ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 09 (190) Behind: Recovery track, DSN 14 (1 kHz, battery) T Jul 10 (191) Behind: Recovery track, DSN 43 (1 kHz, carrier) W Jul 11 (192) Behind: Recovery track, DSN 43 (1 kHz, carrier) T Jul 12 (193) F Jul 13 (194) S Jul 14 (195) S Jul 15 (196) Notes: * Power system maintenance work at SSC site, Jul 19, 20-22 UT. The SSC is expected to remain up on UPS. ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 16 (197) T Jul 17 (198) W Jul 18 (199) T Jul 19 (200) F Jul 20 (201) S Jul 21 (202) S Jul 22 (203) ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 23 (204) T Jul 24 (205) Ahead: Momentum dump, 20:30 UT W Jul 25 (206) T Jul 26 (207) F Jul 27 (208) S Jul 28 (209) S Jul 29 (210) ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Jul 30 (211) T Jul 31 (212) W Aug 01 (213) T Aug 02 (214) F Aug 03 (215) S Aug 04 (216) S Aug 05 (217) ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 06 (218) T Aug 07 (219) W Aug 08 (220) T Aug 09 (221) F Aug 10 (222) S Aug 11 (223) S Aug 12 (224) ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 13 (225) Behind: Recovery track, DSN 14 (search, battery) T Aug 14 (226) Behind: Recovery track, DSN 14 (search, carrier) W Aug 15 (227) Behind: Recovery track, DSN 14 (search, carrier) T Aug 16 (228) F Aug 17 (229) S Aug 18 (230) S Aug 19 (231) ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 20 (232) T Aug 21 (233) W Aug 22 (234) T Aug 23 (235) F Aug 24 (236) S Aug 25 (237) S Aug 26 (238) 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