STEREO Weekly Meeting Minutes for 2017-02-28 (Week 9) 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. 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 8 (Feb 20-26) * On day 054 (Feb 23), during the DSS-14 support for Ahead, turbo decoder lock was lost intermittently between 0151z through 0155z. This anomaly resulted in the loss of 168 frames of real-time and SSR data. * On day 054 (Feb 23), during the DSS-36 support for Ahead, the command uplink was lost at 0707z through 0711z due to the inadvertent disabling of the uplink drive at the station. Telemetry lock was subsequently lost beginning at 0738z and again at 0743z from re-establishing the uplink. This anomaly resulted in the loss of 926 frames of real-time telemetry and SSR data, corresponding to about 3-4 minutes for each instrument. See DR# C112566 for more information. * On day 051 (Feb 20), G&C parameter memory object release 1.3.5 was loaded and verified to G&C EEPROM on Ahead at 1630z. This release updated the following parameters: * Autonomous momentum dump (AUT_MOM_DMP) * Leap second (NAV_EPOCHOFFSET) * Maximum slew rate (Ctl_SLEWMAXRATE) * On day 054 (Feb 23), fine pointing on Ahead dropped out several times between 1933z through 2234z due to G&C zero wheel speed avoidance. * The average daily science data return for Ahead was 5.4 Gbits during this week. * A telemetry subsystem assessment review for the recovery operations for STEREO Behind was held Friday, Feb 24, at APL. * The next attempt to recover Behind will be March 17-19. Week 9 (Feb 27-Mar 5) * Ahead has 11 passes during the week, and overall coverage is nominal. There are ten passes at 720 kbps and one at 240 kbps. * There are no passes for Behind during the week. Week 10 (Mar 6-12) * Daylight Savings time in the US begins on March 12. * Ahead has 9 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, one at 240 kbps, and one at 160 kbps. * There are no passes for Behind during the week. Week 11 (Mar 13-19) * The 38th SECCHI stepped calibration roll is scheduled for Thursday, Mar 16, starting at 13:50 UT. The system momentum is expected to be 6 N-m-s. This is the midpoint roll, and will be the 7th roll without using the gyros. * Ahead has 10 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, one at 240 kbps, and one at 160 kbps. * Recovery attempts for Behind are scheduled for Friday, Saturday, and Sunday, Mar 17-19. The first two passes are for battery recovery, and will use the 80 kW transmitter on station 26. The radio science receiver will be used during the station 14 pass. Week 12 (Mar 20-26) * 97th momentum dump on Ahead is scheduled for 20:30 UTC on Wednesday, 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 Apr 8. The instrument teams will have to reconnect after the upgrade. * Ahead has 9 passes during the week, and overall coverage is nominal. There are seven 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. * 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. The other two tracks will use the 70 meter station 14, and will include the Radio Science Receiver. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 20 (051) T Feb 21 (052) W Feb 22 (053) T Feb 23 (054) F Feb 24 (055) Behind: Subsystem telemetry review S Feb 25 (056) S Feb 26 (057) ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 27 (058) T Feb 28 (059) W Mar 01 (060) T Mar 02 (061) F Mar 03 (062) S Mar 04 (063) S Mar 05 (064) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 06 (065) T Mar 07 (066) W Mar 08 (067) T Mar 09 (068) F Mar 10 (069) S Mar 11 (070) S Mar 12 (071) Daylight savings time begins ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 13 (072) T Mar 14 (073) W Mar 15 (074) T Mar 16 (075) Ahead: SECCHI calibration roll, 13:50 F Mar 17 (076) Behind: Battery recovery track with station 26 S Mar 18 (077) Behind: Battery recovery track with station 26 S Mar 19 (078) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- 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