STEREO Weekly Meeting Minutes for 2019-04-16 (Week 16) ANNOUNCEMENTS ------------- * The SSC reports that all ftp servers at NASA will have to be shut down by July 31. Instrument teams that get their data via ftp from the stereoftp server will have to change their scripts to get the data from https://stereo-ssc.nascom.nasa.gov. A new procedure for updating SolarSoft is still under development. The possibility of modifying the commonly used Perl mirror script to use ftps instead of ftp was found to be not feasible. The sftp protocol is still allowed by NASA, but this requires each user to have an account. It should also be possible to set up an ftps server, and the SSC would like to know whether anyone has a desire to use this protocol. * External connectivity to the STEREO MOC, for instrument commanding, real-time telemetry, and data products, will be interrupted for a 30 minute period, tomorrow, Wednesday, April 17th, between 5 PM through 8 PM ET (DOY 107 2100-0000z) due to an APL Internet maintenance. For those that stay connected to the MOC, they must reconnect afterwards. * External connectivity to the STEREO MOC, for instrument commanding, real-time telemetry, and data products, will be interrupted for 3 hours on Saturday, April 27th, between 7 AM through 10 AM ET (DOY 117 1100-1400z) due to an APL network switch upgrade. For those that stay connected to the MOC, they must reconnect afterwards. The actual down time is expected to be 15 minutes during the 3 hour window. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally. * Four years after the initial loss of communications anomaly with the Behind observatory, NASA has directed to cease periodic recovery operations with the last support on October 17, 2018. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 15 (Apr 8-14) * On day 103 (Apr 13), during the DSS-63 support for Ahead, turbo decoder lock was lost briefly at 1954z. This anomaly resulted in the loss of 10 frames of real-time telemetry and SSR data. * On day 103 (Apr 13), the MOC was informed that the DSS-14 station was red with an ETRO (Estimated Time of Return to Operation) of 105-2300z. As the day 104 support was with DSS-14, to avoid data being overwritten, the SSR playbacks for that support were deleted. However, just before BOT of the DSS-14 support the station anomaly was corrected and the SSR was played back. All SSR data were received, including the 10 frames lost during the previous DSS-63 support. * On day 101 (Apr 11), the 118th momentum dump on Ahead was executed successfully at 1400z, which imparted an estimated delta V of 0.083 m/sec. This was the 37th momentum dump that did not use the IMU. After thruster operations completed, there was a 1.36 degree of roll angle error. Fine pointing stabilized 2.5 minutes after completion of the momentum dump. * The average daily science data return for Ahead was 6.3 Gbits during this week. Week 16 (Apr 15-21) * The 52nd SECCHI watchdog reset occurred on Ahead at 00:32:10 UT this morning (Apr 16, or late Monday Apr 15 EDT). The instrument was commanded back into normal operations by 3:00 UT, and observations resumed at 4:00 UT. * The APL network will be down for maintenance for a short time tomorrow, Apr 16. See the announcement above for details. * There are several religious holidays during the week which may affect staffing schedules. Good Friday falls on Apr 19, and Passover runs from Apr 19-27. Sunday, April 21, is Easter. * Ahead has ten passes during the week, and overall coverage is nominal. There are nine passes at 720 kbps, and one at 240 kbps. Week 17 (Apr 22-28) * The APL network will be down for maintenance for a short time on Saturday, Apr 27. See the announcement above for details. * Ahead has eleven passes during the week, and overall coverage is nominal. There are ten passes at 720 kbps, and one at 240 kbps. Week 18 (Apr 29-May 5) * Ahead reaches perihelion on May 4. * The 48th SECCHI stepped calibration roll is scheduled for Monday, Apr 29, starting at 19:55 UT. The system momentum is expected to be 1 N-m-s. This will be the 17th calibration roll without using the gyros. * The 8th battery discharge maintenance event is scheduled for Thursday, May 2, starting at 18:30 for about 2 hours during the station 54 pass. The battery state-of-charge will be lowered to about 85%, and then restored back to 100%. This operation will be backed up with autonomy rules to protect the battery. * Ahead has ten passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and two at 240 kbps. Week 19 (May 6-12) * Ahead has eleven passes during the week, and overall coverage is nominal. There are ten passes at 720 kbps, and one at 360 kbps. Week 20 (May 13-19) * Ahead has ten passes during the week, all at 720 kbps, and overall coverage is nominal. Week 21 (May 20-26) * The 119th momentum dump on Ahead is scheduled for Tuesday, May 21, with ignition at 19:30 UT. This will be the 38th dump without using the gyros. * Ahead has eleven passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, one at 360 kbps, and two at 240 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 15 (105) T Apr 16 (106) W Apr 17 (107) T Apr 18 (108) F Apr 19 (109) S Apr 20 (110) S Apr 21 (111) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 22 (112) T Apr 23 (113) W Apr 24 (114) T Apr 25 (115) F Apr 26 (116) S Apr 27 (117) S Apr 28 (118) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M Apr 29 (119) Ahead: SECCHI stepped calibration roll, 19:55 UT T Apr 30 (120) W May 01 (121) T May 02 (122) Ahead: Battery maintenance, 18:30 UT F May 03 (123) S May 04 (124) Ahead: Perihelion S May 05 (125) ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 06 (126) T May 07 (127) W May 08 (128) T May 09 (129) F May 10 (130) S May 11 (131) S May 12 (132) ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 13 (133) T May 14 (134) W May 15 (135) T May 16 (136) F May 17 (137) S May 18 (138) S May 19 (139) ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 20 (140) T May 21 (141) Ahead: Momentum dump, 19:30 UT W May 22 (142) T May 23 (143) F May 24 (144) S May 25 (145) S May 26 (146) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2019: * Aug 28-Sep 7 Parker Solar Probe perihelion pass * Nov 4 Ahead: Close approach of Parker Solar Probe * Dec 26 Parker Solar Probe Venus flyby 2020: * Jan 24-Feb 4 Parker Solar Probe perihelion pass * 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 * Jun 2-13 Parker Solar Probe perihelion pass * Jul 11 Parker Solar Probe Venus flyby, in HI2-A field-of-view * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter * Sep 22-Oct 2 Parker Solar Probe perihelion pass 2021: * Jan 13-23 Parker Solar Probe perihelion pass * Feb 20 Parker Solar Probe Venus flyby * Apr 25-May 4 Parker Solar Probe perihelion pass * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter * Aug 5-15 Parker Solar Probe perihelion pass * Oct 16 Parker Solar Probe Venus flyby * Nov 17-26 Parker Solar Probe perihelion pass 2022: * Feb 21-Mar 2 Parker Solar Probe perihelion pass * May 28-Jun 7 Parker Solar Probe perihelion pass * Sep 2-11 Parker Solar Probe perihelion pass * Dec 7-16 Parker Solar Probe perihelion pass 2023: * Mar 13-23 Parker Solar Probe perihelion pass * May 5 Behind: Mercury transit * Jun 17-27 Parker Solar Probe perihelion pass * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth * Aug 21 Parker Solar Probe Venus flyby * Sep 23-Oct 3 Parker Solar Probe perihelion pass * Dec 25-Jan 3 Parker Solar Probe perihelion pass 2024: * Mar 26-Apr 4 Parker Solar Probe perihelion pass * Jun 26-Jul 5 Parker Solar Probe perihelion pass * Sep 26-Oct 5 Parker Solar Probe perihelion pass * Nov 6 Parker Solar Probe Venus flyby, in HI2-A field-of-view * Dec 20-29 Parker Solar Probe perihelion pass 2025: * Mar 19-27 Parker Solar Probe perihelion pass * Apr 7 Ahead: Mercury transit * Jun 15-24 Parker Solar Probe perihelion pass 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit