STEREO Weekly Meeting Minutes for 2017-03-21 (Week 12) ANNOUNCEMENTS ------------- * A firewall upgrade at APL is scheduled between 15-17 UT on Apr 8. The instrument teams will have to reconnect after the upgrade. * The restricted IOnet will be upgraded on Thursday, Apr 13. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Attempts to recover Behind have transitioned back to a monthly schedule. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 11 (Mar 13-19) * On day 073 (Mar 14), during the DSS-43 support for Ahead, turbo decoder lock was lost intermittently between 0646z and 0702z due to heavy rain at the Canberra complex. This anomaly resulted in the loss of 26,385 frames of real-time and SSR data. As there was sufficient track time, SSR pointers were repositioned on the next support to recover the lost data. While all in-situ instrument data was recovered, unfortunately, due to the large volume of data recorded by SECCHI in between tracks, the SSR read pointer was repositioned behind the write pointer resulting in approximately 10.2 hour loss of SECCHI science data from 073-1336z through 2350z. See DR# C112588 for more information. The originally lost SECCHI data from Mar 13 was also not recovered. * On day 074 (Mar 15), during the DSS-63 support for Ahead, turbo decoder lock was lost at 1150z. This anomaly resulted in the loss of one frame of SSR data. * On day 077 (Mar 18), during the DSS-43 support for Ahead, turbo decoder lock was lost briefly while still one-way at 0513z, and then lost intermittently while two-way between 0641z and 0754z. This anomaly resulted in the loss of 58 frames of real-time telemetry and SSR data. See DR #C112592 for more information. * On day 075 (Mar 16), the 38th SECCHI stepped calibration was executed at 1350z for midpoint in the Ahead orbit. This was the 7th SECCHI stepped calibration roll to be conducted without gyro use. * On day 075 (Mar 16), IMPACT requested real-time commanding on Ahead to dump RAM and clear a checksum error and to enable burst data which has been disabled since before solar conjunction. * The average daily science data return for Ahead was 5.9 Gbits during this week. * On day 076 (Mar 17), during a 3.75 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, initial commanding was delayed 9 minutes until 1634z due to the transmitter tripping off-line. After the uplink was restored, 380 commands were transmitted during the support. No commands were lost because of the delay. No carrier was detected by the DSN station after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations for the remainder of the support which consists of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * On day 077 (Mar 18), during a 4.5 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, 480 commands were transmitted during the support. No carrier was detected by the DSN station after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations for the remainder of the support which consists of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * On day 078 (Mar 19), during a 6.5 hour support for Behind with DSS-14, 700 commands were transmitted during the support. No carrier was detected by either the DSN station or the radio science receiver team after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations for the remainder of the support which consists of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * The next recovery attempt for Behind is scheduled for April 14, 15, 16. Week 12 (Mar 20-26) * Turbo decoder lock was lost briefly during the station 63 pass for Ahead yesterday (Mar 20), resulting in the loss of 8 frames of data. * 97th momentum dump on Ahead is scheduled for 20:30 UTC tomorrow (Mar 22). This will be the 16th momentum dump without using the gyros * Ahead has 9 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps and one at 240 kbps. * There are no passes for Behind during the week. Week 13 (Mar 27-Apr 2) * Ahead has 11 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, four at 240 kbps, and one at 160 kbps. * There are no passes for Behind during the week. Week 14 (Apr 3-9) * A firewall upgrade at APL is scheduled between 15-17 UT on Saturday Apr 8. The instrument teams will have to reconnect after the upgrade. The next track starts around 00:25 UT. * The track schedule for Ahead has increased, due to additional time from Spitzer. Ahead has 10 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and two passes at 240 kbps. * There are no passes for Behind during the week. Week 15 (Apr 10-16) * Passover is between Apr 10-18. Good Friday is on Apr 14, and Easter is on Apr 16. * On Thursday April 13, there will be an upgrade for the restricted IO net, T1 link. Expect to lose IO net connectivity but will re-establish this in the MOC. The outage will be from 1600-2030z. * A return-to-service demo track for station 25 is scheduled for Thursday, Apr 13, after the IOnet upgrade. * Ahead has 8 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, and one at 160 kbps. * Recovery attempts for Behind are scheduled for Friday, Saturday, and Sunday, Apr 14-16. The battery recovery track on Friday will use the 80 kW transmitter on station 26 with no RSS recording. The other two tracks will use the 70 meter station 14, and will include the Radio Science Receiver. Week 16 (Apr 17-23) * Ahead has 9 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and one at 240 kbps. * There are no passes for Behind during the week. Week 17 (Apr 24-30) * The 98th momentum dump on Ahead is scheduled for Monday, Apr 24, with ignition at 16:00 UT. This will be the 17th momentum dump without gyros. * Ahead has 10 passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps, and on pass at 160 kbps. * There are no passes for Behind during the week. Week 18 (May 1-7) * Ahead has 8 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, and one at 160 kbps. * There are no passes for Behind during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 20 (079) T Mar 21 (080) W Mar 22 (081) Ahead: 97th momentum dump, 20:30 UT T Mar 23 (082) F Mar 24 (083) S Mar 25 (084) S Mar 26 (085) ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 27 (086) T Mar 28 (087) W Mar 29 (088) T Mar 30 (089) F Mar 31 (090) S Apr 01 (091) S Apr 02 (092) ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 03 (093) T Apr 04 (094) W Apr 05 (095) T Apr 06 (096) F Apr 07 (097) S Apr 08 (098) S Apr 09 (099) ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 10 (100) T Apr 11 (101) W Apr 12 (102) T Apr 13 (103) F Apr 14 (104) Behind: Battery recovery track with station 26 S Apr 15 (105) Behind: Battery recovery track with station 14 S Apr 16 (106) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 17 (107) T Apr 18 (108) W Apr 19 (109) T Apr 20 (110) F Apr 21 (111) S Apr 22 (112) S Apr 23 (113) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 24 (114) Ahead: Momentum dump, 16:00 UT T Apr 25 (115) W Apr 26 (116) T Apr 27 (117) F Apr 28 (118) S Apr 29 (119) S Apr 30 (120) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M May 01 (121) T May 02 (122) W May 03 (123) T May 04 (124) F May 05 (125) S May 06 (126) S May 07 (127) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2017: 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