STEREO Weekly Meeting Minutes for 2017-07-12 (Week 28) ANNOUNCEMENTS ------------- * There will be a Behind recovery readiness review on Friday August 11, 9am at APL. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Attempts to recover Behind have transitioned from monthly schedule to a weekly schedule (every 3-days) on July 11. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 27 (Jul 3-9) * On day 185 (Jul 4) with Station DSS-63 support, the turbo decoder lock was lost briefly at 1045UT and again at 1115UT after the subreflector brakes on the antenna were momentarily set resulting in a 163 frames of real time & SSR data. * On day 186 (Jul 5) during Station DSS-15 support the turbo decoder lock was lost at 2317UT and at 2319UT resulting in a loss of 3 frames of real time and SSR data. * On day 188 (Jul 7) during Station DSS-63 support, telemetry lock was lost intermittently between 0836 UT through 0847UT due to heavy rain at the Madrid complex. During this anomaly, 52,269 frames of real-time and SSR data were lost during that track. However all SSR pointers were repositioned on the next support and all SSR data were recovered. * On day 190 (Jul 9) with Station DSS-63, turbo decoder lock was lost at 0755UT and again at 0804UT resulting in a loss of 1612 frames of real-time and SSR data. * Ahead operating normally with average daily science data return was 6.4 Gbits. * Ahead has 9 tracks during the week, and overall coverage is nominal. There are seven tracks at 720 kbps, one at 240 kbps, and one at 160 kbps. * There are no tracks for Behind during the week. * Recovery operations for Behind switch from a monthly to a weekly schedule (actually every three days). Three 4 hour tracks per week are scheduled, spaced so that if any commands do reach the spacecraft, the command loss timer won't have a chance to fire before the next track. Continue to test with the flatSAT simulator in preparations for recovery this fall and to evaluate the readiness of the project for recovery when the Behind observatory is next detected by DSN. * There will be a Behind recovery readiness review on Friday August 11 at 9am at APL (Building 200/E273). Week 28 (Jul 10-16) * On day 192 (Jul 11) PLASTIC did some real time commanding to set the MCP voltage to a higher value of 3060 v. * On day 193 (Jul 12) there will be a network switch software upgrade in the MOC which should not effect the mission (it's in between tracks) and will rebind telemetry with DSN afterwards. * There will be a network switch upgrade at the MOC on Wednesday, Jul 12, at 11:30 UT. This is outside any tracks, and is not expected to impact the instrument teams. * On day 192 (Jul 11) first Behind weekly recovery with Station DSS-63. 400 commands were sent, did lose command bind during that pass due to a network issue at Goddard which was quickly resolved. Lost two segments but continued to command afterwards. * Ahead has 11 tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, two at 240 kbps, and one at 160 kbps. * Behind recovery tracks are scheduled for Tuesday, Thursday, and Saturday, Jul 11, 13, and 15. The Radio Science Receiver will be operating during all tracks during each 70 m support. Week 29 (Jul 17-23) * Ahead has 11 tracks during the week, and overall coverage is nominal. There are six tracks at 720 kbps, two at 360 kbps, one at 240 kbps, and two at 160 kbps. * Recovery tracks for Behind are scheduled on Tuesday, Wednesday, and Saturday, Jul 18, 19, 22. All four-hour 70 m support with the Radio Science Receiver operating during all tracks. Week 30 (Jul 24-30) * A 2.6 hour project interface test has been scheduled with Ahead using station 24 on Saturday, Jul 29. There will be no instrument commanding or SSR playback during this track. The downlink rate will be 160 kbps. * Ahead has 9 tracks during the week, and overall coverage is nominal. There are seven tracks at 720 kbps, one at 360 kbps, and one at 240 kbps. * Recovery tracks (four hours each) for Behind are scheduled on Monday, Tuesday, Friday, and Saturday, July 24, 25, 28, 29. The Radio Science Receiver will be operating during all tracks. Week 31 (Jul 31-Aug 6) * The 101st momentum dump for Ahead is scheduled for Monday, Jul 31, with ignition at 17:30 UT. This will be the 20th dump without using the gyros. * TDRS 13 has daily 40 minute launch windows starting on Thursday, Aug 3 at 1302 UT. This is not expected to affect STEREO operations. * Ahead has 11 tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, one at 240 kbps, and two at 160 kbps. * Recovery tracks for Behind are scheduled for Tuesday, Friday, and Sunday, Aug 1, 4, 6, all using station 63 (all four hours 70 m support). The Radio Science Receiver will be operating during all tracks. Week 32 (Aug 7-13) * Ahead has 9 tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, and one at 160 kbps. * Recovery tracks for Behind are scheduled for Monday, Wednesday, and Saturday, Aug 7, 9, 12. The Radio Science Receiver will be operating during all tracks. Week 33 (Aug 14-20) * On Day 130 (Aug 18) there will be a return to service support demonstration track with Station DSS-24 for 2.6 hours. No SSR playback and no instrument commanding and downlinking at 160 kbits/sec. * Ahead has 7 tracks during the week, and overall coverage is nominal. There are six tracks at 720 kbps, and one at 240 kbps. * Recovery tracks for Behind are scheduled for Monday, Wednesday, and Friday, Aug 14, 16, 18 (about 3.5 hours each). The Radio Science Receiver will be operating during all tracks. Week 34 (Aug 21-27) * Ahead has 9 tracks during the week, and overall coverage is nominal. There are eight tracks at 720 kbps, and one at 240 kbps. * Recovery tracks switch to a daily cadence (~4-hours 70-m time each day). During the first two days, will use a different frequency acquisition sequence (using 1 kHz steps and going down 18 steps and then back up) in case the transponder has drifted out of the currently used 4kHz range. Anticipate using this faster frequency the first two days of each week. Recovery tracks for Behind are scheduled (each about 3.5-4 hours of 70-m support) for Monday, Wednesday, and Friday, Aug 21, 23, 25. The Radio Science Receiver will be operating during all tracks. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jul 03 (184) T Jul 04 (185) Independence Day W Jul 05 (186) T Jul 06 (187) F Jul 07 (188) S Jul 08 (189) S Jul 09 (190) ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 10 (191) T Jul 11 (192) Behind: Recovery track with station 63 W Jul 12 (193) T Jul 13 (194) Behind: Recovery track with station 43 F Jul 14 (195) S Jul 15 (196) Behind: Recovery track with station 43 S Jul 16 (197) Notes: * Start of weekly recovery attempts to recovery Behind spacecraft. ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 17 (198) T Jul 18 (199) Behind: Recovery track with station 63 W Jul 19 (200) Behind: Recovery track with station 43 T Jul 20 (201) F Jul 21 (202) S Jul 22 (203) Behind: Recovery track with station 63 S Jul 23 (204) ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 24 (205) Behind: Recovery track with station 63 T Jul 25 (206) Behind: Recovery track with station 63 W Jul 26 (207) T Jul 27 (208) F Jul 28 (209) Behind: Recovery track with station 63 S Jul 29 (210) Ahead: Project interface test with station 24 Behind: Recovery track with station 63 S Jul 30 (211) ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Jul 31 (212) Ahead: Momentum dump, 17:30 UT T Aug 01 (213) Behind: Recovery track with station 63 W Aug 02 (214) T Aug 03 (215) F Aug 04 (216) Behind: Recovery track with station 63 S Aug 05 (217) S Aug 06 (218) Behind: Recovery track with station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 07 (219) Behind: Recovery track with station 63 T Aug 08 (220) W Aug 09 (221) Behind: Recovery track with station 43 T Aug 10 (222) F Aug 11 (223) Behind recovery readiness review, 9am at APL (Building 200/E273). S Aug 12 (224) Behind: Recovery track with station 14 S Aug 13 (225) ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 14 (226) Behind: Recovery track with station 14 T Aug 15 (227) W Aug 16 (228) Behind: Recovery track with station 43 T Aug 17 (229) F Aug 18 (230) Behind: Recovery track with station 43 S Aug 19 (231) S Aug 20 (232) ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 21 (233) Behind: Recovery track with station 14 T Aug 22 (234) W Aug 23 (235) Behind: Recovery track with station 43 T Aug 24 (236) F Aug 25 (237) Behind: Recovery track with station 43 S Aug 26 (238) S Aug 27 (239) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2017: * Aug 11 Behind recovery readiness review at 9am at APL (Building 200/E273). * Aug 21 Behind: Switch to daily recovery attempts 2018: * Mar 5 Ahead: Mercury transit 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