STEREO Weekly Meeting Minutes for 2018-08-14 (Week 33) ANNOUNCEMENTS ------------- * Approval for STEREO use of ESA stations has been received. There is no specific allocation, but ESA time will be requested as needed. The previously reported upcoming weekly shortages have been filled. 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 32 (Aug 6-12) * On day 219 (Aug 7), the DSS-14 support for Ahead scheduled on the next day, was replaced with a 6.4 hour support with DSS-55, downlinking at 240 kbps, to assist the Kepler mission with determining remaining propellant (nearly empty). All SSR data were received. * On day 221 (Aug 9), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 1244z. This anomaly resulted in the loss of 7 frames of SSR data. * On day 223 (Aug 11), due to PSP launch slip, the DSS-35 support for Ahead on day 224 was shortened by 4.2 hours and the DSS-55 support on day 224 was replaced with a DSS-65 support of nearly the same duration downlinking at the higher 240 kbps rate. All SSR data were received. * On day 224 (Aug 12), fine pointing on Ahead was lost intermittently beginning at 0233z through 226-0349z (early this morning, Aug 14). These occurrences were due to the reaction wheel #2 operating at low speeds at the limit of wheel speed avoidance range and no gyro operations during this time period. These transients can occur with no gyro operations and are not indicative of any problem with the spacecraft G&C. * The average daily science data return for Ahead was 6.2 Gbits during this week. Week 33 (Aug 13-19) * The 44th SECCHI stepped calibration roll was successfully executed early this morning (Aug 14). This occured after the problem with fine pointing loss was resolved. * 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). No carrier signal was detected during the pass this morning (Aug 14). Week 34 (Aug 20-26) * The project interface test originally scheduled for Thursday, Aug 19, has been cancelled. * 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. Week 35 (Aug 27-Sep 2) * The 112th momentum dump on Ahead is scheduled for Wednesday, Aug 29, with ignition at 14:30 UT. This will be the 31st dump without using the gyros. * Ahead has 12 tracks during the week, and overall coverage is now nominal. There are six tracks at 720 kbps, two at 360 kbps, one at 240 kbps, and three at 160 kbps. * There are no recovery passes for Behind during the week. Week 36 (Sep 3-9) * Monday, Sep 3, is Labor Day, which is an APL holiday. * The DSN network will be down for maintenance between 11-15 UT on Wednesday, Sep 5. This will have no effect on STEREO operations. * Ahead has 13 tracks during the week, and overall coverage is now nominal with the addition of two ESA Malargue passes on Thursday and Friday. There are six tracks at 720 kbps, one at 360 kbps, four at 240 kbps, and two at 160 kbps. * There are no recovery passes for Behind during the week. Week 37 (Sep 10-16) * There are ten tracks for Ahead during the week, and overall coverage is now nominal with the addition of ESA tracks on Wednesday and Thursday. There are three tracks at 720 kbps, two at 360 kbps, one at 240 kbps, and four at 160 kbps. * There are no recovery passes for Behind during the week. Week 38 (Sep 17-23) * There will be a telemetry assessment review on Wednesday, Sep 19, from 9-12 AM at APL. Webex invitations have been sent out. Please let APL know ahead of time if you plan to attend in person, so that security passes can be obtained. * Ahead has eight passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, two at 240 kbps, and one at 160 kbps. * Recovery passes for Behind using the 1 kHz frequency acquisition sequence are scheduled for Friday, Sep 21 (battery), and on Saturday and Sunday, Sep 22,23 (both carrier). Week 39 (Sep 24-30) * Ahead has seven passes during the week, and overall coverage is currently short 6 hours on Monday, Sep 24, and Thursday to Friday, Sep 27-28. ESA support has been requested to fill in the gaps. There are six passes at 720 kbps, and one pass at 360 kbps. * There are no recovery passes for Behind during the week. Other * The recent problems with getting sufficient DSN time are due to a combination of the launch of Parker Solar Probe, and the fact that only two 70 meter stations are currently operating. Station 63 is expected to come back online around the end of September. * There was a recent message about a DSN network security audit being carried out in the near future. The MOC will participate in the audit, but don't anticipate it causing any problems. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 13 (225) Behind: Recovery track, DSN 14 (search, battery) T Aug 14 (226) Ahead: SECCHI stepped calibration roll, 5:55 UT 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) ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 27 (239) T Aug 28 (240) W Aug 29 (241) Ahead: Momentum dump, 14:30 UT T Aug 30 (242) F Aug 31 (243) S Sep 01 (244) S Sep 02 (245) ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 03 (246) Labor Day T Sep 04 (247) W Sep 05 (248) T Sep 06 (249) F Sep 07 (250) S Sep 08 (251) S Sep 09 (252) ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 10 (253) T Sep 11 (254) W Sep 12 (255) T Sep 13 (256) F Sep 14 (257) S Sep 15 (258) S Sep 16 (259) ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 17 (260) T Sep 18 (261) W Sep 19 (262) T Sep 20 (263) F Sep 21 (264) Behind: Recovery track, DSN 14 (1 kHz, battery) S Sep 22 (265) Behind: Recovery track, DSN 14 (1 kHz, carrier) S Sep 23 (266) Behind: Recovery track, DSN 14 (1 kHz, carrier) ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 24 (267) T Sep 25 (268) W Sep 26 (269) T Sep 27 (270) F Sep 28 (271) S Sep 29 (272) S Sep 30 (273) ------------------------------------------------------------------------------- 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